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Photo Forum / Digital Photography / DSLR Cameras / August 2006About the Sony Alpha100 RAW converter.
I finally got around to installing the Sony RAW converter - it's pretty good, it has all the bells and whistles you'd expect, ( like Adobe Lightroom I suppose but since Adobe can't run a simple web site I couldn't get their software so screw them but I digress...) It has full control over all of the parameters, EG: WB = presets, camera settings, color temp, hue, gray point sample selector, color sliders, and that's just one window! ( there's more there but I forget...) didn't play too much with it... but I did fix a shot I accidentally set to tungsten outside... I picked SHADE and then added 10 to the hue towards the magenta. (I think) There are over a dozen "palettes" in the main selector. You click the list and a window opens. Close the window if you want. There is a tone curve window that gives you 4 possible settings and views of the curves, LIGHT, R, G, B. You grab the curve with your mouse and it sets a point you can move. I guess you can have multiple points (like Micrografx) on each curve and different points on all 4 curves... There are batch processing commands and SAVE SETTINGS commands - sounds interesting! It had a choice of 8 or 16 bit but I'm not sure about that... You can 'save as' - it picked TIFF - a jpeg and a few other, not a lot. It wanted to know if I wanted to save to the RAW but I said no - until I find out about non-destructive saves. One other thing - the noise at ISO 800 is disgusting! I thought it was set to 1600 it was so bad! (I should have bought the Canon...) Tomorrow I'll try to do some raw shots of farmland if it's sunny like today so I can compare to my Nikon which I already took this morning... Bob I must live in a different world: 1.Why would someone buy into the Sonalta if one already owns Nikon/Nikon glass? I honestly don't get it. I would think the money better spent on a Nikon D200/80 or more/better glass. If one is a first time dSLR buyer I think the Sonalta may be the best deal out there right now. 2. Why is noise at ISO greater than 800 a surprise? What do users expect? Haven't any writers to this newsgroup ever shot high speed film? Why would noise at such high ISOs be a deal breaker? I have used Nikon and Canon dSLRs and while I think these are great cameras, personally I think the noise is horrible at anything much above ISO 400. 3. Why would anyone depend on the camera manufacturer raw converter? Why does anyone depend on any stand-alone raw converter, all of which lack the ability to make regional adjustments to the image? Imagine what Ansel Adams could do with Photoshop instead of dancing around an enlarger. > I must live in a different world: > 1.Why would someone buy into the Sonalta if one already owns Nikon/Nikon [quoted text clipped - 10 lines] > ability to make regional adjustments to the image? Imagine what Ansel Adams > could do with Photoshop instead of dancing around an enlarger. You don't have to depend on the raw converter, but you can't do anything with the raw file in Photoshop until it is converted. So it's a vital first step. Like processing your neg. Photoshop is like printing your neg, and dancing round the enlarger. The raw noise which honest Sony A100 users - like me! - are discussing is something like you've never seen before. If you think a Nikon D100 at 6400 ISO has noise, you've not seen a Sony raw file at 1600 without NR. It is so extreme that unless you have used the camera you have no idea. The JPEGs produced by the camera, in contrast, manage to control this extreme noise quite well and even ISO 1600 is just usable. I love the A100's ability to capture extremely fine detail at ISO 100 and handle highlights which blow out all too easily on a KM 7D or a Nikon D70 - it's high quality instrument at this setting. But high ISO noise is going to affect the reputation of the A100. I have a vested interest in the success of this system both as an owner and organiser of the UK's owner club for what used to be Minolta. But I am not blind to shortcomings and I use many other camera systems regularly. In the words of a Marks & Spencer ad voiceover, this isn't just noise, this is... David >I must live in a different world: >1.Why would someone buy into the Sonalta if one already owns Nikon/Nikon >glass? I honestly don't get it. I bought the Sony when my Nik was in the shop (twice) for 6 weeks... I wanted to try something new... and needed a camera. >I would think the money better spent on a >Nikon D200/80 no, I'm going to wait for something better than the 200. The 80 wasn't out yet when I bought the Sony - Nikon kept the 80 a big mysterious mystery so since I didn't know what it was going to be - I didn't buy it. Score another one for dumb-as-sh.t marketing monkeys! > or more/better glass. If one is a first time dSLR buyer I >think the Sonalta may be the best deal out there right now. >2. Why is noise at ISO greater than 800 a surprise? Believe me - this is NOISE!!! Like a cheapo P&S!! > What do users expect? A dslr... not a p&s... >Haven't any writers to this newsgroup ever shot high speed film? Apples and oranges... sensors should (and can) be quieter. > Why would >noise at such high ISOs be a deal breaker? I have used Nikon and Canon dSLRs >and while I think these are great cameras, personally I think the noise is >horrible at anything much above ISO 400. Then DON'T BUY the A100!! >3. Why would anyone depend on the camera manufacturer raw converter? Because the people who designed the camera know it best. > Why >does anyone depend on any stand-alone raw converter, all of which lack the >ability to make regional adjustments to the image? HUH?? What's that mean?? > Imagine what Ansel Adams >could do with Photoshop instead of dancing around an enlarger. Photoshop sucks sh.t! You can get carpel tunnel from it with all the stupid required mouse moves. You should try some real graphics software before spouting off about Adobe crap. > You should try some real graphics > software before spouting off about Adobe crap. I'm interested. Which software? -Mike >> You should try some real graphics >> software before spouting off about Adobe crap. > >I'm interested. Which software? > >-Mike I prefer to use Micrografx 10. In doing the things I do with photos, I use about 1/10 the mouse movements required by Adobe. EG To cut out a 1280x1024 piece of a photo to put as wallpaper, I drop in a photo I like from my camera, 3008x2000, and select crop, set by size, and type in 1280x1024. Now when I click the image a box of that size appears, and I move it around till I like the composition, drop the mouse button, and it's done. Or if I don't like the composition, and have to change the size of the image, I select set by aspect, set the aspect to 1280x1024, and click about where I want the upper left corner - but here is where it gets better, since the box I make is never where I want it, I just hold the right button, and now I can move the box. So I move AND resize the box in real time and pick the exact composition I want - drop the mouse buttons and it's cropped, click the resize icon and set the size - 10 seconds, and no mousing all over the place and clicking and dragging and clicking and dragging and mousing and selecting yes and all the other crap you have to do in Adobe. BTW I tried to do this in Adobe and failed - couldn't find a way to crop out exactly 1280x1024 from a 3008x1000 picture to make wallpaper. Another thing is you can select icons for tools, and put ONLY the icons around the screen that you want - you don't lose half of your screen to stupid window boxes. Plus it has all of the tone curve tools you could want. It also supports objects, and I use it to create electrical drawings, since I can create "capacitors" and "resistors" and move them around on the base image of the chassis until everything is like I want it, and then "stamp" all the objects. I of course save a version with the objects so I can change the design in the future. Since I can use actual photos of parts, I can make photo-realistic blueprints! In some drawings I have over 100 parts - imagine working with 100 layers in adobe? It's too bad it didn't catch on like adobe, but with computers, the rule is only the bad survive... >>> You should try some real graphics >>> software before spouting off about Adobe crap. [quoted text clipped - 3 lines] > I prefer to use Micrografx 10. In doing the things I do with photos, > I use about 1/10 the mouse movements required by Adobe. Ok. I see your requirements are different than mine. I use CS2 for photo editing, Easy-PC for PCB design and AutoCAD for mechanical design. Thanks for the info. -Mike >>>> You should try some real graphics >>>> software before spouting off about Adobe crap. [quoted text clipped - 12 lines] > >-Mike I can't justify the expense for all of that software... I don't do PC cards, and my designs don't really require CAD - especially at the horrendous price! > EG To cut out a 1280x1024 piece of a photo to put as wallpaper, I drop in a > photo I like from my camera, 3008x2000, and select crop, set by size, and type [quoted text clipped - 11 lines] > couldn't find a way to crop out exactly 1280x1024 from a 3008x1000 picture to > make wallpaper. You can do all of this in PS 7 onwards, any current version. Just select the crop tool, type the dimensions (you can type px for pixels, mm, in etc and it automatically knows what you mean) click on your image and a crop box appears. This can be moved freely round the image until placed as you wish using either the mouse or arrow keys, and then cropped in a single press of the enter or return key. You dont' have to use the mouse at all if you set some function key shortcuts. > Another thing is you can select icons for tools, and put ONLY the icons around > the screen that you want - you don't lose half of your screen to stupid window > boxes. Plus it has all of the tone curve tools you could want. Same. PS uses 'workspace' defaults, but you can assemble your own workspace and create minimal tool bars or palettes. You can dock any of the floating palettes in the default space just by dragging them to the top menu bar, where they remain instantly accessible by a click, or can be detached and returned to floating or side-magnetic-click-to located space. > It also supports objects, and I use it to create electrical drawings, since I > can create "capacitors" and "resistors" and move them around on the base image [quoted text clipped - 3 lines] > photo-realistic blueprints! In some drawings I have over 100 parts - imagine > working with 100 layers in adobe? The creation of new layers with every paste action is annoying, but if your objects remain moveable in Micrografx, it is doing just the same thing but not telling you. 100 layers containing small objects - easily stored, and even saveable as PSD with massive files, but pretty difficult to navigate around. For work like this I use the whole Adobe CS2, creating objects and then placing (normally) on InDesign pages. These have optional layers, not obligatory layers like PS, and it's fairly easy to arrange graphic or image clip elements (which can also be kept in a convenient library). Finally a PDF is written. I like the idea of electrical drawings with real photo objects. David >> EG To cut out a 1280x1024 piece of a photo to put as wallpaper, I drop in a >> photo I like from my camera, 3008x2000, and select crop, set by size, and type [quoted text clipped - 19 lines] >single press of the enter or return key. You dont' have to use the mouse >at all if you set some function key shortcuts. I bought Elements 2 and then got Elements 4 - and you can't even work in pixels in #2!! #4 doesn't do anything like that. I haven't yet figured out how to cut a specific size... In Micrografx I can also just place a mask boundry around the area I want - press CTRL-C and hit 'paste as new photo' and zip! it's done!! >> Another thing is you can select icons for tools, and put ONLY the icons around >> the screen that you want - you don't lose half of your screen to stupid window [quoted text clipped - 30 lines] > >David Micrografx does just about everything I need - and cost $120 VS $900 for CS2!! The only thing it doesn't do is RAW conversion or 12bit files, but it's based on old software and is out of date for that, but I can use other things. > >> EG To cut out a 1280x1024 piece of a photo to put as wallpaper, I drop in a > >> photo I like from my camera, 3008x2000, and select crop, set by size, and type > >> in 1280x1024. Sounds like you're not composing your shots very well. The rest of us are fine resizing from 3008x2000 or whatever down to 1280x1024. Photoshop downsamples fairly well. Are the downsampling algorithms of Micrografx not good or something? Greg >> >> EG To cut out a 1280x1024 piece of a photo to put as wallpaper, I >drop in a [quoted text clipped - 3 lines] > >Sounds like you're not composing your shots very well. I suppose that's true! But the edges of photos are not always the best, specially when the camera viewfinder isn't accurate. Both of my cameras are around 95% accurate, so I always take bigger and crop later. > The rest of us are fine You asked EVERYBODY? WOW! That's about a billion people! > resizing from 3008x2000 or whatever down to 1280x1024. It doesn't fit - the aspect is different, you have to crop something... > Photoshop >downsamples fairly well. Are the downsampling algorithms of Micrografx not >good or something? Probably not up to pro standards of today... I've always preferred to crop and resize by integers such as 50% or whatever. Any re-sizing produces some distortion, in any program. Maybe I should compare, and do my re-sizing in Elements if it's better. >Greg >>>>>EG To cut out a 1280x1024 piece of a photo to put as wallpaper, I >> [quoted text clipped - 11 lines] > specially when the camera viewfinder isn't accurate. Both of my cameras are > around 95% accurate, so I always take bigger and crop later. But you're talking about chopping a 1280x1024 image out of 3008x2000. That's just a small section, accomodating waaaaaaaaaaaaay more than any edge distortion or viewfinder display accounts for. >>The rest of us are fine > [quoted text clipped - 3 lines] > > It doesn't fit - the aspect is different, you have to crop something... Set the aspect ratio in PS to 1280x1024, size and then position the crop area if needed, then resize to 1280x1024. I really can't understand taking such a small chunk out of a 3000x2000 image. Greg  Signature"All my time I spent in heaven Revelries of dance and wine Waking to the sound of laughter Up I'd rise and kiss the sky" - The Mekons >>>>>>EG To cut out a 1280x1024 piece of a photo to put as wallpaper, I >>> [quoted text clipped - 15 lines] >That's just a small section, accomodating waaaaaaaaaaaaay more than any >edge distortion or viewfinder display accounts for. This is true... but that isn't ALL I do to EVERY photo! I was merely talking about making wallpaper for the computer, using a simple method I haven't found out how to do in Elements... The photos I use for wallpaper are usually wide angle shots of farms and clouds, or down at the lake, where there is water, boats, and mountains in the distance. There are lots of possible walls there. It actually started as a game of finding pictures within pictures... >>>The rest of us are fine >> [quoted text clipped - 9 lines] > >Greg > I suppose that's true! But the edges of photos are not always the best, > specially when the camera viewfinder isn't accurate. Both of my cameras are > around 95% accurate, so I always take bigger and crop later. Funny how people differ - with a 95 per cent coverage finder, I know there are extra pixels all round, and compose so the subject touches the very edges of the viewfinder frame! With point and shoots, often having 85 per cent coverage and about 2 per cent 'accuracy' (the finder is aiming one place, the lens another!) it's true that really tight composition, especially for close-ups, is not sensible. But they have nice 100 per cent accurate LCD finders for doing that stuff. David <BobF@nospam.com> > Probably not up to pro standards of today... I've always preferred to crop > and > resize by integers such as 50% or whatever. Any re-sizing produces some > distortion, in any program. I'm curious now. Since I'm a software engineer and I used to make image processing algorithms, what standards and what distortions downsampling produce? Cheers Padu ><BobF@nospam.com> >> Probably not up to pro standards of today... I've always preferred to crop [quoted text clipped - 9 lines] > >Padu I'm not a software engineer - I have a useful profession - but anyway, one thing I do know is that you can't resize a 3x1 image to a 2x1 image and expect to retain 3 colors... there is also the matter of aliasing distortion - some pixels have to go away no matter what you do, and that can create banding patterns. The other thing I know is that after re-sizing I have to apply an un-sharp mask to the image else it's a blurred mess. Unless it acquired a pattern, in which case I have to apply a pattern removal tool. > I bought Elements 2 and then got Elements 4 - and you can't even work in pixels > in #2!! #4 doesn't do anything like that. I haven't yet figured out how to cut > a specific size... In Micrografx I can also just place a mask boundry around > the area I want - press CTRL-C and hit 'paste as new photo' and zip! it's done!! I have no idea about Elements 2 now, but in 3 you just click on the crop tool and a dialog appears on the top menu bar called Presets. You type the pixel dimensions. This tool resamples when you crop. If you use the Marquee tool, you can set fixed dimensions, and it does not resample - the rectangle is always pixel for pixel. Unless you do some messing with function keys, you have to use the mouse to select a menu item with no keystroke for crop. This is annoying, and Photoshop full version has a few similar 'no shortcut' items in its menus, but you can modify this. One of the neat aspects of PS is that if you crop an area and copy it, then ask for a new document, the program will automatically create a new doc exactly the right size to paste the copied info into, with the same bit depth and colour mode as the copied data. Of course the main reason for buying Elements 4 is that it converts Sony ARW files from raw extremely rapidly and easily, for only £69 (UK), and Bridge allows full DAM functions such as copyright embedding and keywording. On a laptop it can be a full image capture/edit/manage prog. Does Micrografx convert Sony A100 raw files? Or KM 5D/7D raw .MRW files? David >> I bought Elements 2 and then got Elements 4 - and you can't even work in pixels >> in #2!! #4 doesn't do anything like that. I haven't yet figured out how to cut [quoted text clipped - 4 lines] >tool and a dialog appears on the top menu bar called Presets. You type >the pixel dimensions. NOPE! I'm running Elements 4 right now - tried to type in the pixel size and it says "WRONG! Must enter value in inches!" Funny, as it says pixels/inches right there, (with no other choices). piece of sh.t - my computer runs in pixels, not inches. >This tool resamples when you crop. If you use the >Marquee tool, you can set fixed dimensions, and it does not resample - [quoted text clipped - 9 lines] >doc exactly the right size to paste the copied info into, with the same >bit depth and colour mode as the copied data. I don't have to go to all that trouble - after selecting an area with the mask tool and pressing CTRL-C, I merely click the "paste as new image" button... >Of course the main reason for buying Elements 4 is that it converts Sony >ARW files from raw extremely rapidly and easily, NOPE!!! Just tried it - "Incorrect image file" or some such bullshit - can't read em'. > for only £69 (UK), and >Bridge allows full DAM functions such as copyright embedding and >keywording. On a laptop it can be a full image capture/edit/manage prog. Are you kidding!?!? On a small laptop screen there are too many tool windows and wasted space menu bars to even see the photo! Micrografx can work in full screen - no visable tools! >Does Micrografx convert Sony A100 raw files? nope - and neither does the sh.t you are pushing. Do you work for Adobe or are you just a Brand Nazi? >David > NOPE! I'm running Elements 4 right now - tried to type in the pixel size and it > says "WRONG! Must enter value in inches!" Funny, as it says pixels/inches > right there, (with no other choices). All I have to do is type 280 px and it works. It even works if I don't leave a space and type 280px - Elements puts the space in for me. Same with mm, cm, in. If I type 'pc' it changes it to a % sign, and I can type that too. Maybe Elements 4 for PC has some bugs? I'm using Mac. David >> NOPE! I'm running Elements 4 right now - tried to type in the pixel size and it >> says "WRONG! Must enter value in inches!" Funny, as it says pixels/inches [quoted text clipped - 8 lines] > >David Maybe I should get a Mac... Another thing about Adobe that pisses me off - when you re-save a jpeg it throws away the camera EXIF data and puts it's own bullshit advertising! What a f.cking nerve! f.ck Adobe, I don't need it. >>> NOPE! I'm running Elements 4 right now - tried to type in the >>> pixel size and it says "WRONG! Must enter value in inches!" [quoted text clipped - 15 lines] > jpeg it throws away the camera EXIF data and puts it's own bullshit > advertising! If you Save For Web? > I finally got around to installing the Sony RAW converter - it's pretty good, it > has all the bells and whistles you'd expect, ( like Adobe Lightroom I suppose [quoted text clipped - 26 lines] > Tomorrow I'll try to do some raw shots of farmland if it's sunny like today so I > can compare to my Nikon which I already took this morning... All my tests have shown that the raw file is impossible to use at 1600 and not much cop at 800. Not one of the converters I've used so far can handle it. The in-camera noise reduction is far, far more effective than the best raw conversion - including Sony's own converter. This is the 'wrong way round' but really, if shooting 800 or 1600, you are best forgetting raw and just shooting JPEGs. The 1600 is so bad that anyone saying it resembles Canon at 3200, or even Konica Minolta or Nikon at 3200, is either judging solely by the JPEG or has severe vision problems. The Sony converter is very fast indeed on the Mac, building the thumbnail browser even faster than Bridge, and making Silkypix look as if it has a bug (constant rebuilding of browser previews). Lightroom does a modestly good job on the Sony high ISO noise. The worst situation with the noise is deep shadow on the bright day at 1600. The bright areas, even from raw, appear relatively free from noise at 1600. You would even say the sky of a shot was acceptable. But the moment you go below values around 180/180/180 RGB, a massive snowstorm of noise hits the dark midtones and shadows. It has a sudden break effect, between this and clean lighter midtones and highlights with loads of detail. It's one of the most peculiar things I've seen in years of studying raw files and processing images. The 800 setting is getting ignored a bit; in fact it's not too bad, the real problem is 1600. They would have been better leaving if off the camera entirely, or devising a way to limit RAW shooting to 100-400. David SNIP > All my tests have shown that the raw file is impossible to use at > 1600 and not much cop at 800. Not one of the converters I've used > so far can handle it. The in-camera noise reduction is far, far more > effective than the best raw conversion - including Sony's own > converter. It would be interesting to compare it to NeatImage's (or NoiseNinja) noise reduction capabilities. I'm quite optimistic it can beat the in-camera noise reduction. I could do a NeatImage job on a file, but for the best results I'd need to make a noise-profile from a test target <http://www.neatimage.com/testtarget.html>, shot at the same ISO setting and Raw processed just like the other arbitrary image that need salvaging. SignatureBart Bart: if you can email me at iconmags3@btconnect.com I'll send you a URL for an unprocessed clip of 1600 exported by ACR to download and have a look at David >> I finally got around to installing the Sony RAW converter - it's pretty good, it >> has all the bells and whistles you'd expect, ( like Adobe Lightroom I suppose [quoted text clipped - 37 lines] >Nikon at 3200, is either judging solely by the JPEG or has severe vision >problems. Thats good to know, I'll limit my RAW to daytime snapshots! >The Sony converter is very fast indeed on the Mac, building the >thumbnail browser even faster than Bridge, and making Silkypix look as [quoted text clipped - 15 lines] > >David >>All my tests have shown that the raw file is impossible to use at 1600 >>and not much cop at 800. Not one of the converters I've used so far can [quoted text clipped - 6 lines] >>Nikon at 3200, is either judging solely by the JPEG or has severe vision >>problems. That's a problem with RAW conversion outside the camera. It's my guess the A100 is softening the images in-camera when converting to JPG so the noise is less grating and obvious, perhaps similar to what Noise Ninja and other noise reduction programs do. >Thats good to know, I'll limit my RAW to daytime snapshots! What you should do is limit ISO in daytime shots, not the format. With good lighting there is no need to crank up the ISO, so noise won't be an issue whether you shoot RAW or JPG. In low light without a tripod where you might need to turn up the ISO, shoot in JPG to help reduce obvious noise. >>The 800 setting is getting ignored a bit; in fact it's not too bad, the >>real problem is 1600. I found the same with Nikon - shooting at 800 or lower is usually quite good. > With good lighting there is no need to crank up the ISO, so noise won't > be an issue whether you shoot RAW or JPG. But it's not really setting a higher ISO that causes noise. Try shooting something at the same exposure at ISO 200 and 800 (use an exposure that doesn't blow out things irreparably at 800) and add 2 stops in raw conversion to the ISO 200 shot. Compare the two shots (I suppose it also depends on the camera). The point is that how much light reaches the sensor is what mainly determines the noise level (of course depending on the dynamic range of your photograph, "underexposure" of some parts might be inevitable). >> With good lighting there is no need to crank up the ISO, so noise won't >> be an issue whether you shoot RAW or JPG. > >But it's not really setting a higher ISO that causes noise. Yes it does - well it doesn't 'cause' noise, but the higher gain stage amplifies it more so we can see it. Check your EXIF file for "low gain up". >Try >shooting something at the same exposure at ISO 200 and 800 (use an >exposure that doesn't blow out things irreparably at 800) and add 2 >stops in raw conversion to the ISO 200 shot. That's the same thing (almost) but the gain increase is done by your computer. You won't see increased camera amplifier input stage noise this way. > Compare the two shots (I >suppose it also depends on the camera). The point is that how much >light reaches the sensor is what mainly determines the noise level (of >course depending on the dynamic range of your photograph, >"underexposure" of some parts might be inevitable). There are 2 sources of noise in a digital camera ( or any other system ). One is sensor noise, and it exists at a fixed level. It could change according to stimulation by photons as well. The other is amplifier noise, and it increases with gain. Well actually to be correct, the higher gain amplifies more of the noise from the input stages. And it also amplifies the sensor noise more. Normally in electronic systems, we worry about the input noise of an amplifier, merely because that gets amplified, the output stages also have noise but it is far below the level of the signal we amplified. Note that once converted to digital, no more noise can be added. So the noise is always there - the question is can we see it? In an audio system the same thing occurs - you can hear the noise plainly when the music breaks, but not when they're really rockin'! A scratchy vinyl record would be analogous to a noisy and poor sensor, a dollar store amp would be analogous to a cheap camera with poor electronics. A recording of Beethoven's Moonlight Sonata (the beginning) would be like shooting at night, and Led Zeppelin would be like a daytime shoot at noon! There's enough data for you to ponder! > >> With good lighting there is no need to crank up the ISO, so noise won't > >> be an issue whether you shoot RAW or JPG. [quoted text clipped - 3 lines] > Yes it does - well it doesn't 'cause' noise, but the higher gain stage amplifies > it more so we can see it. Check your EXIF file for "low gain up". But what did I say? OK, see below; maybe I can explain myself better. > >Try > >shooting something at the same exposure at ISO 200 and 800 (use an [quoted text clipped - 3 lines] > That's the same thing (almost) but the gain increase is done by your computer. > You won't see increased camera amplifier input stage noise this way. But according to this argument, shooting something at ISO 800 and "correctly" exposed would have more noise than if you shoot the same thing, with the same aperture and shutter speed (ie let the same amount of light hit the sensor) at ISO 200 and then amplify in raw conversion. Try it and you will see (look at the shadows). > > Compare the two shots (I > >suppose it also depends on the camera). The point is that how much [quoted text clipped - 13 lines] > the output stages also have noise but it is far below the level of the signal we > amplified. You also have shot noise, which is caused by the fact that the sensor pixels are actually counting photons, and these are discrete particles. This increases as the sqrt of the signal (the arrival of photons being a Poisson process), so its ratio to the signal behaves as 1/sqrt(signal). It therefore increases as the light arriving decreases, or as the physical size of the pixels decreases (higher resolution for the same sensors area, same resolution for smaller area etc; this is because the number of photons per pixel decreases as t). At any rate, try what I suggested. Maybe it's different on your camera (perhaps it depends on the amplifier). You can also see the limitations of the ADC's bit depth (why do we get better shadows at ISO 800 with a given exposure than at ISO 100 at the same exposure, assuming correct exposure for 800?) > Note that once converted to digital, no more noise can be added. > > So the noise is always there - the question is can we see it? In an audio system > the same thing occurs - you can hear the noise plainly when the music breaks, > but not when they're really rockin'! No disagreement! > A scratchy vinyl record would be analogous to a noisy and poor sensor, a dollar > store amp would be analogous to a cheap camera with poor electronics. A > recording of Beethoven's Moonlight Sonata (the beginning) would be like shooting > at night, and Led Zeppelin would be like a daytime shoot at noon! Switch to Bach. Purely for the uniform sound level, you see :) > There's enough data for you to ponder! >> >> With good lighting there is no need to crank up the ISO, so noise won't >> >> be an issue whether you shoot RAW or JPG. [quoted text clipped - 19 lines] >of light hit the sensor) at ISO 200 and then amplify in raw conversion. >Try it and you will see (look at the shadows). Well, if you shoot at ISO 800 you are going to get noise from the amplifier being turned up. I don't know 'exactly' how they do that since I haven't seen a schemagic of a camera, but I imagine they have an op-amp of some kind with switched gain resistors. So if you shoot at 200 the amp will be turned down, now when you turn it up in the computer, you are doing a slightly different operation. As far as I know, going from ISO 200 to 800 in a computer simply shifts the bits over by two times... that guaranties that the lower bits are both zero? Wouldn't an analog amp possibly fill those bits and that would be more noise? >> > Compare the two shots (I >> >suppose it also depends on the camera). The point is that how much [quoted text clipped - 22 lines] >the same sensors area, same resolution for smaller area etc; this is >because the number of photons per pixel decreases as t). Yes, but that's sensor noise, and I did say that amplifying the signal or not won't change it, it merely brings it up where we can see it. >At any rate, try what I suggested. Maybe it's different on your camera >(perhaps it depends on the amplifier). You can also see the limitations >of the ADC's bit depth (why do we get better shadows at ISO 800 with a >given exposure than at ISO 100 at the same exposure, assuming correct >exposure for 800?) Do we? Does that have to do with some non-linearity in the sensor range? I find the noise too high at 800 to test shadows... especially on the Sony! I know that dynamic range of cameras is lacking, I'd prefer 16 bit depth!! >> Note that once converted to digital, no more noise can be added. >> [quoted text clipped - 12 lines] > >> There's enough data for you to ponder! |
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