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Photo Forum / Digital Photography / DSLR Cameras / September 2006High ISO noise CCD's vs CMOS
Ok, I'm in the market for my first DSLR (upgrade from 35 mm SLR and Nikon 5700). I've been looking at reviews on the Sony A100, Nikon D80/D200 and Canon 30D. These are both 1600 ISO (see reviews for more detailed information about conditions etc). http://www.steves-digicams.com/2006_reviews/30d/samples/IMG_8337.JPG http://www.steves-digicams.com/2006_reviews/d200/samples/DSC_3490.JPG What a HUGE difference !!! I see so many people say only if you shoot high ISO is it a concern. Unless your shooting with lights in a studio can't any one use high ISO at times? If you can get 2 (or so) stops lower on every lens and get the same picture, why not take it? You'll pay a small fortune for 2 stops on a lens. Are there other compromises in going higher ISO (even in the low range) besides noise. Do you lose color accuracy etc. I really favor Nikon for feel and operation. But this ISO noise has me leaning towards canon CMOS. I also see numerous comments that Canon IS is better than Nikon VR. So that to me is worth probably another stop. So the canon seems to have like a 3 stop advantage over Nikon. I have no investment in lens (my 35mm was a Pentax and I'd never use those boat anchor manual focus lens again). > Ok, I'm in the market for my first DSLR (upgrade from 35 mm SLR and > Nikon 5700). [quoted text clipped - 30 lines] > I have no investment in lens (my 35mm was a Pentax and I'd never use > those boat anchor manual focus lens again). There is little dispute that Canon's CMOS produces the cleanest ISO images. I wouldn't dispute, however, that the D200 has a build that I wish Canon would emulate.  SignatureImages (Plus Snaps & Grabs) by Mark² at: www.pbase.com/markuson > So the canon seems to have like a 3 stop advantage over Nikon. Problem solved - buy Canon. > Ok, I'm in the market for my first DSLR (upgrade from 35 mm SLR and > Nikon 5700). [quoted text clipped - 30 lines] > I have no investment in lens (my 35mm was a Pentax and I'd never use > those boat anchor manual focus lens again). You'll get used to the feel of the 30D; you'll never be happy with the crap images from the Nikon. No contest. Canon. Colin D. SignaturePosted via a free Usenet account from http://www.teranews.com > > Ok, I'm in the market for my first DSLR (upgrade from 35 mm SLR and > > Nikon 5700). [quoted text clipped - 37 lines] > > Colin D. Looking at those two images, the little $599 Nikon kicked the $1200 Canon's a--. >>> Ok, I'm in the market for my first DSLR (upgrade from 35 mm SLR and >>> Nikon 5700). [quoted text clipped - 40 lines] > Looking at those two images, the little $599 Nikon kicked the $1200 > Canon's a--. You're talking out of yours ... Colin D. SignaturePosted via a free Usenet account from http://www.teranews.com > Ok, I'm in the market for my first DSLR (upgrade from 35 mm SLR and > Nikon 5700). [quoted text clipped - 10 lines] > > What a HUGE difference !!! Did you look at the exif? The Canon photo is at 1/250s f/2.8 while the Nikon at 1/100s f/7.1. (There is no ISO in the Nikon's exif data). Also the sharpness in the Nikon is set to "hard", which seems a less than intelligent thing to do when shooting at ISO 1600. There is a difference between the two cameras in terms of noise (I spent some time trying the 20D and the D200 when I was deciding), but it's by no means as much as you'd think from these two samples. Thanks for catching this. The summary info in the review was a little short on info. The photos were not a fair comparison. By the way the site where those photo's come from (Steves Digicam) highly favors the Nikon D200. But I think it is true that the Canon is at least 1 stop better, and I keep reading excuses. One is (only if you shoot high ISO). But if you can shoot one stop better which often happens for what ever reason, that seems huge. Other folks have said the Nikon is more conservative on in camera noise reduction, but I've seen reviews do everything raw and still have higher noise. Build no question, the D200 is more solid. How it operates is purely a matter of taste. But I just can't get paste this ISO thing and I have not typically shot high ISO because it was so bad on my 5700. That's why I asked is there other reasons to keep your ISO low. > > Ok, I'm in the market for my first DSLR (upgrade from 35 mm SLR and > > Nikon 5700). [quoted text clipped - 19 lines] > spent some time trying the 20D and the D200 when I was deciding), but > it's by no means as much as you'd think from these two samples. As far as build quality goes the 20D and 30D are more than adequate unless you are demanding weather sealing. EOS 5D owners jump in here? As for higher ISO the alternative is spending more on lenses with a larger maximum aperture. That usually means brighter viewfinder and better low light focusing. I know the eos 20D can make use of F2.8 or wider lenses. An extra set of autofocus sensors come into play. 2 vertical ones. My one gripe with canon equipment is the tendency of flash system to underexpose. Nikon is said to be superior in this regard. > As far as build quality goes the 20D and 30D are more than adequate > unless you are demanding weather sealing. EOS 5D owners jump in here? True. Although in spite of my whining, I have yet to even experience my first sensor-dust speck on my 5D, much less any trouble with other seals. Would I prefer 1D type sealing? Absolutely. Is it life or death? No. Should Canon provide it anyway...on a $3K DSLR? No question. -Gaskets are super-cheap. Nikon proves that. > As for higher ISO the alternative is spending more on lenses with a > larger maximum aperture. That usually means brighter viewfinder and [quoted text clipped - 3 lines] > flash system to underexpose. Nikon is said to be superior in this > regard. I've had excellent flash performance with my 5D and the 580EX. Improvement over my 10D w/ 550EX is significant. Still not perfect, but it's an improvement. With full frame, I've had to get back in the habit of flipping down the built-in wide screen on the flash...but it works well. SignatureImages (Plus Snaps & Grabs) by Mark² at: www.pbase.com/markuson > But I just can't get paste this ISO thing and I have not typically shot > high ISO because it was so bad on my 5700. You've answered your own question then: Get the Canon. Cheers. Gosh - you sounded just like me when you said that. > But I think it is true that the Canon is at least 1 stop better, and I > keep reading excuses. There isn't enough noise with any of these cameras that it should even be a factor in your decision. I could make a picture with the Canon that has far more noise than that Nikon "example"; does that mean it's a noisy camera? No, of course not. If you don't expose properly you get noise. If you do expose properly, it's just not a factor. I shoot with low light and high ISO with a Nikon D2x quite a lot, and noise just doesn't enter into it. I haven't seen enough noise to even tempt me into getting any noise reduction software. But, naturally, if you underexpose, then there's noise. So don't do that. Most "noise comparison" shots you see are total nonsense. Comparing noise from one camera to another is very nearly impossible to do in a way that means anything at all. > But I just can't get paste this ISO thing Get past it. It's not worth worrying about. SignatureJeremy | jeremy@exit109.com > If you don't expose properly you get noise. If you do expose properly, > it's just not a factor. I shoot with low light and high ISO with a Nikon > D2x quite a lot, and noise just doesn't enter into it. I haven't seen > enough noise to even tempt me into getting any noise reduction software. > But, naturally, if you underexpose, then there's noise. So don't do that. The point, however, is that the D200 at high ISO reacts badly to underexposure (ie worse than the 20D). If it gets enough light, there is no visible noise. But of course a photograph with a wide dynamic range will include shadows. Still, with postprocessing, I found that the difference can be minimised, so it's a non-issue in reality (for me). Of course, someone else's definition of reality might be different from mine. >> But I think it is true that the Canon is at least 1 stop better, and I >> keep reading excuses. [quoted text clipped - 17 lines] > > Get past it. It's not worth worrying about. Of course it's not worth worrying about, and any thinking photographer understands that. That is anyone who actually USES THE EQUIPMENT IN QUESTION!!! Think about it though -- if we didn't have these esoteric "noise" threads periodically, it would get dull around here and all the "pixel peepers" wouldn't have anything to discuss, let alone getting out to actually photograph anything. Bob >> If you don't expose properly you get noise. If you do expose properly, >> it's just not a factor. But ... sometimes there is not enough light to expose "properly". Sometimes even with the f/2.8 super lens, wide open, there is not enough light at a shutter speed short enough to get rid of subject movement. Then sensor noise matters. You get a seriously underexsposed picture, but you can of course post-process it to get the shading "right" ... and you get noise. Effectively, this is like setting the camera at ASA 30000 or more. Both CCD and CMOS are linear at low light levels, so it actually works well ... noise excepted, of course. Doug McDonald >>> If you don't expose properly you get noise. If you do expose properly, >>> it's just not a factor. > But ... sometimes there is not enough light to expose > "properly". Sometimes even with the f/2.8 super lens, wide > open, there is not enough light at a shutter speed short > enough to get rid of subject movement. That's what the 24mm f/1.4L 28mm f/1.8 35mm f/1.4L or f/2 50mm f/1.2L[1] or f/1.4 or f/1.8 (or f/1.0, if you find it, have the budget and want to go crazy) 85mm f/1.2L of f/1.8 100mm f/2 135mm f/2 are for ... I imagine Nikon has a similar product palette. -Wolfgang [1] Yep, it's a new one, but you'll have to wait a few more months. http://www.usa.canon.com/consumer/controller?act=ModelDetailAct&fcategoryid=153& modelid=14259 (and the 70-200mm f/4 IS is to be found there too.) >> But ... sometimes there is not enough light to expose >> "properly". Sometimes even with the f/2.8 super lens, wide [quoted text clipped - 12 lines] > 135mm f/2 > are for ... True, but: a) not everyone has the resources to own these lenses b) the DOF at apertures below 2 is so shallow that this might not yield acceptable pictures of some scenes Not that you were claiming otherwise, and I've lost track of exactly what the point was suppsoe to be here, but since in another context, there was argument over the value of high ISO settings compared to faster lens, I thought this is worth mentioning. I can understand some poeople not caring about high ISO for themselves. But to argue that others should have reason to care, well, that's just foolish. --------------- Marc Sabatella marc@outsideshore.com Music, art, & educational materials Featuring "A Jazz Improvisation Primer" http://www.outsideshore.com/ > >> But ... sometimes there is not enough light to expose > >> "properly". Sometimes even with the f/2.8 super lens, wide [quoted text clipped - 18 lines] > b) the DOF at apertures below 2 is so shallow that this might not yield > acceptable pictures of some scenes He did mention 35/2, 50/1.8, and 85/1.8, which are very affordable, very good quality, adequate DoF, and still 1 stop faster than much more expensive f/2.8 zooms. > Not that you were claiming otherwise, and I've lost track of exactly > what the point was suppsoe to be here, but since in another context, > there was argument over the value of high ISO settings compared to > faster lens, I thought this is worth mentioning. I can understand some > poeople not caring about high ISO for themselves. But to argue that > others should have reason to care, well, that's just foolish. Both ISO 1600 and f/2 primes are very useful. http://digitcamera.tripod.com/#slr > He did mention 35/2, 50/1.8, and 85/1.8, which are very affordable, > very good quality, adequate DoF, and still 1 stop faster than much > more > expensive f/2.8 zooms. True, but still, I don't see the existence of these as a substitute for good high ISO performance. That's a limited range of focal lengths. Once again, I'm not sure that Wolfgang *intended* to suggest the existence of these lenses made high ISO performance irrelevant, but taken somewhat out of the context of the rest of thread, it appeared that way. > Both ISO 1600 and f/2 primes are very useful. Absolutely! --------------- Marc Sabatella marc@outsideshore.com Music, art, & educational materials Featuring "A Jazz Improvisation Primer" http://www.outsideshore.com/ >>> But ... sometimes there is not enough light to expose >>> "properly". Sometimes even with the f/2.8 super lens, wide >>> open, there is not enough light at a shutter speed short >>> enough to get rid of subject movement. >> That's what the >> 24mm f/1.4L [quoted text clipped - 7 lines] >> 135mm f/2 >> are for ... > True, but: > a) not everyone has the resources to own these lenses $90 for the 50mm f/1.8 is certainly not to high for multi-hundred $ DSLR owners. And you _can_ rent lenses (and bodies and flashes), too. > b) the DOF at apertures below 2 is so shallow that this might not yield > acceptable pictures of some scenes True, but it WILL help focussing (manually and AF) even in the dark. And "What did you expect? Sshooting in available darkness usually means a shallow DOF and low contrast and sharpness wide open!" And if high ISO and fast lens won't be acceptable, pushing doesn't help and flash or more light is impossible, tripods not being an option due to moving objects ... well, then you are out of luck; you'll have to re-create the setting in a studio or where more light is available. -Wolfgang "Wolfgang Weisselberg" <ozcvgtt02@sneakemail.com> wrote : > $90 for the 50mm f/1.8 is certainly not to high for > multi-hundred $ DSLR owners. Probably not. But a whole collection of them at different focal lengths may well be. > And if high ISO and fast lens won't be acceptable I never said high ISO wouldn't be acceptable; on the contrary, I'm trying to argue it is necesary and indeed often preferable. As I said, I kind of lost track of the various points being made in this thread, but it *appeared* your lens listing was trying to demonstrate that high ISO wasn't necessary - just spend a few thousand dollars and carry around huge bag of lenses. That's probably not what your point really was, but it kind of came off that way to me. --------------- Marc Sabatella marc@outsideshore.com Music, art, & educational materials Featuring "A Jazz Improvisation Primer" http://www.outsideshore.com/ > "Wolfgang Weisselberg" <ozcvgtt02@sneakemail.com> wrote : >> $90 for the 50mm f/1.8 is certainly not to high for >> multi-hundred $ DSLR owners. > Probably not. But a whole collection of them at different focal lengths > may well be. True, but start with a cheap, optically good lens and see what you need and if it appeals to you. >> And if high ISO and fast lens won't be acceptable > I never said high ISO wouldn't be acceptable; on the contrary, I'm > trying to argue it is necesary and indeed often preferable. High ISO is always preferrable to digital pushing (unless the camera does aught than digital pushing itself and you don't need any off-the-camera JPEG). > but it *appeared* your lens listing was trying to demonstrate that high > ISO wasn't necessary - just spend a few thousand dollars and carry > around huge bag of lenses. I was responding to Doug McDonald: "Sometimes even with the f/2.8 super lens, wide open, there is not enough light at a shutter speed short enough to get rid of subject movement." (Message ID: <ecdam3$m9e$1@news.ks.uiuc.edu>) I was trying to show that f/2.8 was _not_ the lower end at all. And by extension: if you find yourself often in places where a f/2.8 is too slow, consider a faster lens of matching focal length! (there are many that are cheap compared to your average zoom lens.) -Wolfgang > I was responding to Doug McDonald: "Sometimes even with the f/2.8 > super lens, wide open, there is not enough light at a shutter > speed short enough to get rid of subject movement." > (Message ID: <ecdam3$m9e$1@news.ks.uiuc.edu>) > > I was trying to show that f/2.8 was _not_ the lower end at all. True enough, at least for moderate focal lengths - it's tough to come by anything below f/2.8 at 200mm. And I'd still observe that even with 2.0, 1.7, or even 1.4, there are many shooting situations where there isn't enough light to get rid of subject movement, unless you start looking at ISO of 1600 and above. --------------- Marc Sabatella marc@outsideshore.com Music, art, & educational materials Featuring "A Jazz Improvisation Primer" http://www.outsideshore.com/ >> I was trying to show that f/2.8 was _not_ the lower end at all. > True enough, at least for moderate focal lengths - it's tough to come by > anything below f/2.8 at 200mm. You can always try for a 200mm f/1.8. :-) > And I'd still observe that even with > 2.0, 1.7, or even 1.4, there are many shooting situations where there > isn't enough light to get rid of subject movement, unless you start > looking at ISO of 1600 and above. Yep. -Wolfgang > >>> But ... sometimes there is not enough light to expose > >>> "properly". Sometimes even with the f/2.8 super lens, wide [quoted text clipped - 26 lines] > True, but it WILL help focussing (manually and AF) even in the > dark. I have a lot of AF error with 50/1.4, while 50/1.8 AF much better. Under good conditions, the 50/1.4 AF fine, so the lens is not defective. I think it is because AF is done at wide open, and 50/1.4 wide open at f/1.4 is softer than 50/1.8 at f/1.8. The softer image makes it more difficult for AF sensors to work correctly. http://digitcamera.tripod.com/#slr >> > b) the DOF at apertures below 2 is so shallow that this might not yield >> > acceptable pictures of some scenes >> True, but it WILL help focussing (manually and AF) even in the >> dark. > I have a lot of AF error with 50/1.4, while 50/1.8 AF much better. I have no AF problems with the f/1.4, even in very low light. > Under good conditions, the 50/1.4 AF fine, so the lens is not > defective. Good conditions != wide open? Maybe you are experiencing a shift in focus with closing the aperture (and that helps you) or a smaller aperture increases the depth of field, hiding inaccuracies. Or maybe yours is a lemom. > I think it is because AF is done at wide open, and 50/1.4 > wide open at f/1.4 is softer than 50/1.8 at f/1.8. Then you'd also find the problems with many of the other f/1.4 and f/1.2 lenses. > The softer image > makes it more difficult for AF sensors to work correctly. Since the sensors work from the de-focussed lens image and even work with tele lenses (where they have much less 'sharp' images to work from if the focus is way off), I don't really buy that theory. -Wolfgang > >> > b) the DOF at apertures below 2 is so shallow that this might not yield > >> > acceptable pictures of some scenes [quoted text clipped - 10 lines] > > Good conditions != wide open? No. Sometimes the AF errors are huge that even stopped down shots are out of focus. Examples of bad condition: backlit, high flare, low contrast, etc. But I use the 50/1.4 and 50/1.8 under the same conditions. With 50/1.8, I have very few AF errors. While with 50/1.4, about half of the shots have AF errors. But the other half look good, so I think it is not a defective lens, but a design problem. > > I think it is because AF is done at wide open, and 50/1.4 > > wide open at f/1.4 is softer than 50/1.8 at f/1.8. > > Then you'd also find the problems with many of the other > f/1.4 and f/1.2 lenses. I don't have any other f/1.4 or larger lens. I'd think that 85/1.2 has the same problem. I read that some other people have this problem with 85/1.2, 50/1.4, and 50/1.0. > > The softer image > > makes it more difficult for AF sensors to work correctly. > > Since the sensors work from the de-focussed lens image and even > work with tele lenses (where they have much less 'sharp' images to > work from if the focus is way off), I don't really buy that theory. Maybe the small lenses in front of the AF sensors focus it for them? Like the split images in manual focus are sharp themselves even though the lens is out of focus. If they really work from defocussed images, I can not believe that it can focus accurately from vastly out of focus images. They have to get more accurate reading when it gets close. So the lens sharpness when wide open will affect AF accuracy when it gets close. http://digitcamera.tripod.com/#slr >> >> > b) the DOF at apertures below 2 is so shallow that this might not yield >> >> > acceptable pictures of some scenes >> >> True, but it WILL help focussing (manually and AF) even in the >> >> dark. >> > I have a lot of AF error with 50/1.4, while 50/1.8 AF much better. >> I have no AF problems with the f/1.4, even in very low light. >> > Under good conditions, the 50/1.4 AF fine, so the lens is not >> > defective. >> Good conditions != wide open? > No. Sometimes the AF errors are huge that even stopped down shots are > out of focus. > Examples of bad condition: backlit, high flare, low contrast, etc. Ok, that is hard for the AF. > But > I use the 50/1.4 and 50/1.8 under the same conditions. With 50/1.8, I > have very few AF errors. While with 50/1.4, about half of the shots > have AF errors. But the other half look good, so I think it is not a > defective lens, but a design problem. Ok, so you are saying, with the 50/1.4 you have 50% chance of AF error and <5% with the 1.8, right? And you say that it misfocusses even enough to see it well stopped down. Now, if that was a design problem, I'd see the very same with my 50/1.4, at least when shooting in the dark w/o focus assist, so we can probably rule out a design problem. It could be that on your camera the AF sensors are not exactly mounted where the focus points are. If that was the case, you'd probably focus on the background instead of the subject. >> > I think it is because AF is done at wide open, and 50/1.4 >> > wide open at f/1.4 is softer than 50/1.8 at f/1.8. >> Then you'd also find the problems with many of the other >> f/1.4 and f/1.2 lenses. > I don't have any other f/1.4 or larger lens. I'd think that 85/1.2 has > the same problem. I read that some other people have this problem with > 85/1.2, 50/1.4, and 50/1.0. With the minimal DOF of these lenses, it's very easy to focus on the center of the eye --- or an eyelash --- and have the iris be out of focus (at least on the computer screen). Tiny movements of the photographer or the object are getting very important there. Focus and recompose _will_ show up, as the DOF plane is slanted and might well move completely behind the focussed-on area. >> > The softer image >> > makes it more difficult for AF sensors to work correctly. >> Since the sensors work from the de-focussed lens image and even >> work with tele lenses (where they have much less 'sharp' images to >> work from if the focus is way off), I don't really buy that theory. > Maybe the small lenses in front of the AF sensors focus it for them? Nope. Unless the lens has another AF (with a lens that is focussed by yet another AF? And wouldn't that need yet another lens that focusses?), it cannot focus in the AF sense of the word. At best it could stop down a lot, but that would not help the AF (if it's sharp, it's sharp, what else can the AF say?). And would not ever confer better focus abilities for fast lenses, yet at least for it's top of the line models Canon claims exactly that. > Like the split images in manual focus are sharp themselves even though > the lens is out of focus. That's because your eye _can_ compensate with it's AF. The eye cannot compensate to a ground glass, as the glass itself is forming the image; what's OOF there cannot be corrected with any AF. > If they really work from defocussed images, I can not believe that it > can focus accurately from vastly out of focus images. You may observe focus hunting when you use a long fast lens and have the focus completely off. > They have to get > more accurate reading when it gets close. So the lens sharpness when > wide open will affect AF accuracy when it gets close. In digital P&S cameras, it's easy: move the lens and see if the AF areas get more or less hard borders. Continue in the right direction until you are better than some pre-set limit. The very short lenses (e.g. 6-18mm) necessitated by the small sensors help thanks to their deep DOF. In SLRs (and DSLRs), this is ... different. You cannot read the sensor. And you want to be _much_ faster. So what they use is conceptionally a split image, backed by a small, 1x200 or so sensor on each side. These can, even when the image is defocussed, usually still detect patterns (vertical or horizontal, or both, depending on the camera and which of it's sensors it is). Then they can see how much said pattern is shifted on the other sensor. That difference tells them exactly in which direction and how much to move the lens; the lens is ordered into that position and it is made sure that the position is, indeed, reached. However, there is no second read from the sensor. (At least that is how I undertand Canon works.) If no pattern can be detected (too dark, too low contrast, long tele very defocussed, ...), the lens may be moved through the whole focus range in the hope of picking up something in the sensors. Fast lenses obviously help the sensors (more light, for one). If the lens was 'too fast' for the sensor, the AF may be off a bit, but I still don't see how the lens would misfocus more than a slower lens (when stopped down to be identical, at least). A softer lens would produce more, well, softened patterns on the sensor, still, the sensor is _used_ to softened patterns (after all, we call that bukeh ... and usually train the AF on unfocussed parts). Worst case: it starts hunting. OK, the passive AF sensor is bad with repeating and weak patterns. -Wolfgang > >> >> > b) the DOF at apertures below 2 is so shallow that this might not yield > >> >> > acceptable pictures of some scenes [quoted text clipped - 17 lines] > > Ok, that is hard for the AF. But I get much better AF with 50/1.8 under the same situations. > > But > > I use the 50/1.4 and 50/1.8 under the same conditions. With 50/1.8, I [quoted text clipped - 9 lines] > my 50/1.4, at least when shooting in the dark w/o focus assist, > so we can probably rule out a design problem. I get about 50% good AF with 50/1.4. I don't think I can get that many accidentally good AF with a defective lens. And I don't doubt you can get a lot of good AF shots with your lens. And maybe your camera is better. > It could be that on your camera the AF sensors are not exactly > mounted where the focus points are. If that was the case, you'd > probably focus on the background instead of the subject. Many of the shots don't have anything in focus in the whole frame. It is possible that the AF points are not accurate, e.g., when I point AF to one eye it may actually measuring a spot next to the eye that has low contrast. But the AF confirmation light shows AF lock. And again, 50/1.8 AF much better than 50/1.4 on the same camera, in the same situations. > >> > I think it is because AF is done at wide open, and 50/1.4 > >> > wide open at f/1.4 is softer than 50/1.8 at f/1.8. [quoted text clipped - 12 lines] > Focus and recompose _will_ show up, as the DOF plane is slanted > and might well move completely behind the focussed-on area. The AF errors are much larger than DoF, even when stopped down. > >> > The softer image > >> > makes it more difficult for AF sensors to work correctly. [quoted text clipped - 15 lines] > yet at least for it's top of the line models Canon claims > exactly that. They have AF sensors spread further apart for f/2.8 lenses, in addition to the closer f/5.6 AF sensors. So if each side has its own lens, then the small AF sensor lenses won't affect the wider sensors being activated by f/2.8 lenses. http://digitcamera.tripod.com/#slr > But I just can't get paste this ISO thing Then buy the canon. For me things like color saturation and overall image quality is what matters but most gearheads seem OBCESSED with shooting at ISO 1600. Go join their club! SignatureStacey >> Ok, I'm in the market for my first DSLR (upgrade from 35 mm SLR and >> Nikon 5700). [quoted text clipped - 19 lines] > spent some time trying the 20D and the D200 when I was deciding), but > it's by no means as much as you'd think from these two samples. I'm reading ISO 3200 with Panda exif reader on the Nikon file, this on top of the photo being underexposed, so it is not a fair comparison. Patrick > Ok, I'm in the market for my first DSLR (upgrade from 35 mm SLR and > Nikon 5700). [quoted text clipped - 30 lines] > I have no investment in lens (my 35mm was a Pentax and I'd never use > those boat anchor manual focus lens again). The point about the exposure times and f/stop being different has nothing to do with noise, because the light levels between the two different scenes are probably different. It is all a matter of the total amount of photons received in each exposure. (A laboratory with fixed lighting would make for better tests.) Noise in DSLR camera images is greatly affected by raw converter software, so the only true way to understand the noise is a proper noise analysis on raw data that has not gone through a raw converter. Examples: Procedures for Evaluating Digital Camera Sensor Noise, Dynamic Range, and Full Well Capacities; Canon 1D Mark II Analysis http://www.clarkvision.com/imagedetail/evaluation-1d2 The Nikon D50 Digital Camera: Sensor Noise, Dynamic Range, and Full Well Analysis http://www.clarkvision.com/imagedetail/evaluation-nikon-d50 The factors that will influence the noise between different cameras is directly related to quantum efficiency, fill factor, pixel size, and at the low intensity end, read noise (and for long exposures, thermal noise). CCD quantum efficiencies tend to be slightly higher than CMOS sensors, so the advantage there is the Nikon (by perhaps 10%). Fill factors are essentially 100% by the use of micro-lenses over the detectors (CCD or CMOS), so no advantage to either. Read noise: Canon's CMOS has <4 electrons on good cameras like the 20D (and by extension 30D; same sensor). CCDs are typically 7 to 15 electrons (the D50 above is ~ 7.5 electrons. So the CMOS has an advantage of ~2x at the very lowest signals, not the main things you see in the steves-digicams.com images which are much brighter. That leaves the major factor in noise: the pixel size. The important factor is delivering photons, and to do that, you need aperture. See: The f/ratio Myth and Digital Cameras http://www.clarkvision.com/photoinfo/f-ratio_myth The D200 has 6.1 micron pixels versus the 30D at 6.4 micron pixels, so a small difference (actually area is the important factor: 37.2 versus 40.1 square microns, again not much difference). There should be a slight advantage to the 30D but it should be small. (I would choose the camera based on other factors.) I will be evaluating a 200 in the next couple of months. Other sensor data are located in Tables 1-3 at: The Signal-to-Noise of Digital Camera images and Comparison to Film http://www.clarkvision.com/imagedetail/digital.signal.to.noise Roger Roger > The point about the exposure times and f/stop being different > has nothing to do with noise, because the light levels between > the two different scenes are probably different. It is all > a matter of the total amount of photons received in each > exposure. (A laboratory with fixed lighting would make > for better tests.) Hello, I don't disagree with your points below (and indeed the photos were not even taken on the same day, so the light levels must have been different), however, the noise in the D200 image is much worse than I see in my photos, therefore I suspect it was underexposed. Hence my remark about the different exposures. The point here being that these samples aren't representative of the difference between the two cameras, at least in my experience with both of them (and various raw converters which I used to test them). My conclusion in the end was that the difference is in high ISOs and in shadows. Probably, from a brief look at your analysis of the D50 (lack of time, drowning in work), due to higher read noise. By the way, do you have any idea which factors affect the read noise (ie why would the D50 have higher read noise than the 1D)? The amplifiers (seems unlikely to me)? Presumably, this is random (eg thermal), otherwise they'd just model it and remove it. I've though of taking photographs of printed targets with various kinds of noise on them just to see what kinds of noise reduction are done on the raw data. [The Nikons certainly do this, see http://astrosurf.com/buil/d70v10d/eval.htm and I can't see how the Canons get their noise so low, but haven't confirmed anything.] Do you have any idea if anybody has done this? I could not find anything on the web. Cheers. > Noise in DSLR camera images is greatly affected by raw converter > software, so the only true way to understand the noise is a proper [quoted text clipped - 55 lines] > > Roger > My conclusion in the end was that the difference is in high ISOs and in > shadows. Probably, from a brief look at your analysis of the D50 (lack [quoted text clipped - 3 lines] > to me)? Presumably, this is random (eg thermal), otherwise they'd just > model it and remove it. Yes, read noise is random. CCDs commonly have the 7-15 electron read noise, even in professional cooled CCDs used in astronomy. It was amazing to see Canon improve CMOS so much, which 5+ years ago many said CMOS would never match CCD performance. I do not know the specifics of how they achieved that. > I've though of taking photographs of printed targets with various kinds > of noise on them just to see what kinds of noise reduction are done on [quoted text clipped - 5 lines] > Do you have any idea if anybody has done this? I could not find > anything on the web. No, I have not seen that either. It could be an interesting experiment. Roger SNIP >> I've though of taking photographs of printed targets with various >> kinds of noise on them just to see what kinds of noise reduction >> are done on the raw data. SNIP All it would take is a white noise (all frequencies equally represented) target (could be made with Photoshop). Outputting it as an inkjet image or on an LCD might introduce it's own noise spike, but printing it on photopaper could come a long way. One could also buy such a target: <http://www.appliedimagegroup.biz/aig%2Dimaging/targets_QA.html#QA-80> > It could be an interesting experiment. Some of he math required for quantification could be derived from: <http://www.sinepatterns.com/docs/Random%20Target%20MTF%20Engineering.pdf> One would have to compare the actual result to that of theoretically perfect area sampling with a given fill-factor and sampling density, or to that of another camera for a relative (instead of an absolute) difference. A program like Imatest also allows an analysis of the noise spectrum, e.g. by using a shot of a grayscale steptablet; <http://www.imatest.com/docs/tour_q13.html> , or as part of an SFR/MTF determination. And for some more background info: <http://www.imatest.com/docs/noise.html> SignatureBart > All it would take is a white noise (all frequencies equally > represented) target (could be made with Photoshop). Outputting it as > an inkjet image or on an LCD might introduce it's own noise spike, but > printing it on photopaper could come a long way. One could also buy > such a target: > <http://www.appliedimagegroup.biz/aig%2Dimaging/targets_QA.html#QA-80> Thanks for the links. White noise would be sufficient to evaluate what happens assuming the processing is "dumb" (ie doesn't react differently to the signal). But what if it's not? If I had means of producing reliably targets and analyzing the results (well, I suppose Mathematica will be ok for the analysis) I'd give it a try (with both white noise and noise with various spectra, to see how it behaves, and from what I find, think about what to do next). Do you have any suggestions for how I can reliably produce a target? I can produce it easily in the computer, my question refers to getting it to print or displaying it. Sources of extraneous noise? I have zero experience in practical matters here, but I'm on vacation for two weeks and this sounds an interesting thing to try. > One would have to compare the actual result to that of theoretically > perfect area sampling with a given fill-factor and sampling density, > or to that of another camera for a relative (instead of an absolute) > difference. How does the fill factor come into it? Are you referring to the effect of the sampling density/fill factor combination on the sampled signal, or something else? I supose also that the actual camera noise will have to be taken into account. Maybe at low ISOs it can be ignored. And how about the CFA? This is starting to sound like a serious project... > Ok, I'm in the market for my first DSLR (upgrade from 35 mm SLR and > Nikon 5700). [quoted text clipped - 10 lines] > > What a HUGE difference !!! Be aware that differences in in-camera sharpening, and in noise reduction algorithms may account for a large part of the difference you are seeing. By the way: I recently had the chance to compare my Nikon 8400 with a top-of-the-range Canon 5D. The viewfinder on the Canon was awfully dark, even though the image quality was (obviously) better. People tell me that was one of the better cameras, as well! It would seem to me that buying these cheap lenses with a maximum aperture of f/5.6 may be a mistake, and you should factor in the price of better (brighter) lenses, David >> Ok, I'm in the market for my first DSLR (upgrade from 35 mm SLR and >> Nikon 5700). [quoted text clipped - 17 lines] > top-of-the-range Canon 5D. The viewfinder on the Canon was awfully > dark, even though the image quality was (obviously) better. Ah...but that is entirely dependant upon what lens you had attached to the 5D. Your words below seem to indicate some awareness of this, but I wonder if you realize how dramatic a difference it is... A 2.8 lens lets in FOUR TIMES as much light at a 5.6 lens, so if you had an f5.6 lens attached (for example), it would show you a viewfinder image that exhibits only 1/4th the light of another lens. Heck...if you had the 50mm 1.4 lens atached, that would be a whopping 16x brighter than a 5.6! Every stop doubles or halves the difference in light collected by lenses one stop different. A 2.8 is 2 stops faster than a 5.6, meaning it doubles the light (f4) and then doubles THAT at 2.8, for four times the light. A 1.4 lens doubles at f4 (2x the light), doubles that at 2.8 (now 4x), doubles again at f2 (now 8x) and again at f1.4 (16x!!). All that to say... You can't judge any viewfinder on a DSLR until you know what lens is on it. -Mark > People > tell me that was one of the better cameras, as well! It would seem > to me that buying these cheap lenses with a maximum aperture of f/5.6 > may be a mistake, and you should factor in the price of better > (brighter) lenses, Yes... So...which lens was on the 5D? :) SignatureImages (Plus Snaps & Grabs) by Mark² at: www.pbase.com/markuson [] > Ah...but that is entirely dependant upon what lens you had attached > to the 5D. Your words below seem to indicate some awareness of this, > but I wonder if you realize how dramatic a difference it is... Yes, I used to own a Nikon F3 with some f/1,4 and f/2.8 lenses. > A 2.8 lens lets in FOUR TIMES as much light at a 5.6 lens, so if you > had an f5.6 lens attached (for example), it would show you a [quoted text clipped - 20 lines] > Yes... So...which lens was on the 5D? > :) One of the f/5.6-ish zooms. The owner had both wide-angle and telephoto zooms. I only handled the camera for a new moments, but as I have been using my Nikon 8400 just before, the brightness difference was shattering. If the 5D is supposed to be a "bright" camera, I hate to think what the others are like. Certainly nothing as pleasant as my SLR experiences of 10-15 years ago. And, of course, no split-image focussing, micro-prism etc.! Just goes to affirm what I always suggest - try the equipment for yourself before purchase. David > >> People > >> tell me that was one of the better cameras, as well! It would seem [quoted text clipped - 18 lines] > > David The Nikon 8400 has a video based view finder, so the brightness of the viewfinder is based on the video gain, not the lens. So it is apples and oranges. One of the problems with having auto focus and variable ISO in digital cameras, and that the higher ISO results are so good, is the slow lens (f3.5 - f5.6) is making its come back. With film SLRs we were sold 50 f2 as the entry level lens, now we have a f3.5- f5.6 zoom. With this we get a dim viewfinder. The less expensive Nikon and Canon cameras also have mirror based viefinders dimming the view even more. It is actually a good thing that the D70 and D50 Nikon can't take manual focus lenses as it would be difficult to focus with these lenses with the dim view finders. When I bought my D200, the first DSLR I owned, I bought a 24 f2 mf Nikon lens for it, mainly because I was used to 35 f2s on my film SLRs. Not a big brightness difference between my D200 and my Canon F1n with a 35 f2 lens on it. There is a visible frame size difference, but the brightness is about equal. The D200 screen though makes it tough to accurately focus a wide angle, may get a Katz screen for it. Back to high ISO, the D200 is only about a stop different from a Canon D30 IF you nail the exposure, under exposure is a killer with that camera in high ISO. Unfortunatly working in high ISO necessary environs often is where you are shooting quickly rather than figuring out each shot, if you are shooting in that evironment alot get a Canon. Other wise which ever body is ergonomicly good for you. Tom mswlogo skrev: > Ok, I'm in the market for my first DSLR (upgrade from 35 mm SLR and > Nikon 5700). [quoted text clipped - 10 lines] > > What a HUGE difference !!! This comparison is ridiculous - the second is underexposed at leat one step - more likely two steps. In Denmark we could call such a comparison fraud without any riscs. SignatureMed venlig hilsen, Ole Larsen. New Images And Design, aug. 2006 http://Olelarsen.eu/ http://home.tiscali.dk/muggler Here is a different ISO 1600 comparison from Imaging Resource of the Canon 30D and the Nikon D50. While the Canon has a little less noise it is at the cost of substantial smearing of the detail. I much prefer the D50 image. Nikon D50 http://www.imaging-resource.com/PRODS/D50/FULLRES/D50INI1600.HTM Canon 30D http://www.imaging-resource.com/PRODS/E30D/FULLRES/E30DINI1600.HTM > Ok, I'm in the market for my first DSLR (upgrade from 35 mm SLR and > Nikon 5700). [quoted text clipped - 30 lines] > I have no investment in lens (my 35mm was a Pentax and I'd never use > those boat anchor manual focus lens again). >> I've been looking at reviews on the Sony A100, Nikon D80/D200 and Canon >> 30D. [quoted text clipped - 3 lines] >it is at the cost of substantial smearing of the detail. I much prefer >the D50 image. That's great, but the problem is that the discussion was relating to the performance of the 10mp sensors from Nikon and Sony, such as the D200 and A100 where high ISO performance is not as good as the D50. In fact, the D50 has some of the best noise levels of any current DSLR. > Are there other compromises in going higher ISO (even in the low range) > besides noise. Do you lose color accuracy etc. > > I really favor Nikon for feel and operation. But this ISO noise has me > leaning towards canon CMOS. I also see numerous comments that Canon IS > is better than Nikon VR. So that to me is worth probably another stop. I used to also be a big believer in Nikon until I saw similar results. True, the Nikon has 2 more megapixels, but this is a textbook example of how, at 8 megapixels and above, the resolution alone isn't everything. I would easily conclude that despite having a lower pixel count, I'm getting *more* usable image data from the 30D than I would be from the D200. SignatureE-mail fudged to thwart spammers. Transpose the c's and a's in my e-mail address to reply. Here is a comparison at ISO 1600 between the Canon 30D and the Nikon D200. I think the Nikon wins this one. Canon 30D http://www.imaging-resource.com/PRODS/E30D/FULLRES/E30DINI1600.HTM Nikon D200 http://www.imaging-resource.com/PRODS/D200/FULLRES/D200INI1600.HTM > Ok, I'm in the market for my first DSLR (upgrade from 35 mm SLR and > Nikon 5700). [quoted text clipped - 30 lines] > I have no investment in lens (my 35mm was a Pentax and I'd never use > those boat anchor manual focus lens again). >Here is a comparison at ISO 1600 between the Canon 30D and the Nikon >D200. I think the Nikon wins this one. > >Canon 30D >http://www.imaging-resource.com/PRODS/E30D/FULLRES/E30DINI1600.HTM This image looks out of focus. Noise level is much lower than d200,though. >Nikon D200 >http://www.imaging-resource.com/PRODS/D200/FULLRES/D200INI1600.HTM Here is an in focus 3200 ISO 30D shot from Steves Digicam. Compare it to the 1600 ISO D200 image http://www.steves-digicams.com/2006_reviews/30d/samples/IMG_0623.JPG |
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