Re: canon 20D flash sync at 1/320?
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Re: canon 20D flash sync at 1/320?
| Colin_D | 23 May 2007 00:27 |
>>> Another resounding reason (among dozens) of why I went with advanced P&S cameras >>> instead of DSLRs when I switched from film to digital. On my Sony I can shoot [quoted text clipped - 9 lines] > > Jealous? You should be. Of what? There are only four Sony cameras with better than the 8.2 MP of the 20D; the DSLR-A100, which is a dslr, not a P&S, so that's out; the DSC-R1 which is properly a zlr, not a p&s; and two point&shoots, the DSC-W200 at 12 MP on a small 1/1.7" sensor; and the DSC-N2, a 10MP P&S with another 1/1.7" sensor.
Neither of the latter two have external flash capability, so raving about shooting flash at 1/2000 sec with the miniscule herring-gutted internal flash is a joke, not to mention the fixed lens maximum length of only about 110 or 120 mm. The implied comparison with Canon lenses is farcical.
Noise from those sensors at higher ISO speeds seriously limits the practicability of using those speeds whereas the 20D and similar dslrs have good noise characteristics up to at least 1600 ISO, just no contest there.
As for IR shots in the dark, how many shots like that do you take? Is that a cogent reason for rejecting a camera that is otherwise light-years ahead in capability?
Of course, it could be that you do have a DSC-R1 zlr, in which case it would appear that you don't know what is a P&S and what isn't. But even if that is the case you are still stuck with a 24-120 mm zoom, and 3 frames max at a time (then wait for 4 seconds or more) for sports shooting. And at 10 MP versus Canon's 8.2 MP, the practical difference is barely discernible, and then only at big enlargements.
You sound like an inexperienced youngster with no practical experience, and all your 'knowledge' is learned from websites and brochures. Come back later when you've learned a bit more.
This is not to say that Sony cameras are no good; it's to say that 'Nobody' doesn't know what he is talking about.
Colin D.
PS: The above references to Canon apply also to Nikon and other genuine dslrs; Canon is mentioned only because 'Nobody' was boasting about his P&S as against Annika's Canon 20D.
 Signature Posted via a free Usenet account from http://www.teranews.com
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| nobody@noplace.org | 21 May 2007 03:09 |
>> Another resounding reason (among dozens) of why I went with advanced P&S cameras >> instead of DSLRs when I switched from film to digital. On my Sony I can shoot >> with flash (IN SYNC) up to 1/2000th of a second. > >How about posting some of those Mavica shots so we can have a laugh >(oops, I meant a "look"). Who said it was a Mavica? Fool.
My Sony P&S has more megapixels and higher resolution than your DSLR and can take photos in the pitch-black using only IR. Surpassing your ancient DSLR in every respect.
Jealous? You should be.
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| Annika1980 | 21 May 2007 02:29 |
> Another resounding reason (among dozens) of why I went with advanced P&S cameras > instead of DSLRs when I switched from film to digital. On my Sony I can shoot > with flash (IN SYNC) up to 1/2000th of a second. How about posting some of those Mavica shots so we can have a laugh (oops, I meant a "look").
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| nobody@noplace.org | 21 May 2007 02:18 |
Another resounding reason (among dozens) of why I went with advanced P&S cameras instead of DSLRs when I switched from film to digital. On my Sony I can shoot with flash (IN SYNC) up to 1/2000th of a second. Using shutter speeds above 1/500th of a second to even alter the strength of flash I'm exposing for. On my Canon S3 I can shoot (IN SYNC) up to 1/500th of a second, even in 1st and 2nd curtain modes. There's just no getting around last century's SLR mechanical shutter & mirror-slap technology when you go the DSLR route. It's a shame that so many are still hoping that DSLRs will be able to incorporate digital imaging technology to its fullest. They keep giving manufacturers excuses and a fool's financial-incentive to put R&D into DSLRs instead of surpassing them with more advanced P&S cameras, from which we will all benefit.
>$Don't know why canon won't allow it even in manual mode. Why is it called >$manual mode if the shutter speed is changed automatically for me?? [quoted text clipped - 43 lines] >know it's there and therefore will not impose the maximum X-sync >limit) and hope for the best. |
| Stephen M. Dunn | 20 May 2007 01:01 |
$Don't know why canon won't allow it even in manual mode. Why is it called $manual mode if the shutter speed is changed automatically for me??
Remember that the output of a flash is controlled not by adjusting its intensity but by adjusting its duration. The more power you want, the longer the flash is on. The camera's maximum X-sync speed has to be designed such that it will not cause problems with the longest possible flash burst, which will depend on the flash unit but is usually more than 1 ms and perhaps as much as 2 ms. With the flash taking that long, that means that in order to achieve a maximum X-sync speed of 1/250, the shutter curtains must be able to make their full motion in 2 ms (during the first 2 ms, the first curtain opens; for the next 2 ms, the shutter is fully open; during the next 2 ms, the second curtain closes). 2 ms isn't a lot of time to take a physical device, accelerate it from rest to full speed and have it traverse the opening.
Chances are that if you fire a full-power flash burst with the shutter speed set to 1/320, the second curtain is going to start closing before the flash has completed firing. Now, since flash output rises rapidly and falls slowly, the part of the flash burst that you're blocking as the second curtain starts to close is quite dim and likely will be very hard to spot in the results - but it's nevertheless not syncing correctly.
On the other hand, if you fire a partial-power burst, it will take quite a bit less time, perhaps much less than 1 ms, and in this case there *is* enough time for the flash to complete before the second curtain starts to close, even at a shutter speed above maximum X-sync.
As for why the camera doesn't allow you to pick a higher sync speed at least some of the time, well, the camera doesn't know how long the flash burst will be. That's controlled by the flash. And the flash may not know, either; among other things, it depends on whether you let the capacitor charge fully before firing the flash. The camera and the flash don't even know at what strength to fire the flash until flash metering is done, which (unless you use flash exposure lock) doesn't happen until after the ambient exposure value has already been set.
Anyway, the bottom line is that the camera's specs clearly indicate that 1/250 is the maximum X-sync speed. If you expected something else, you were mistaken. If you absolutely need to use a flash along with a shutter speed that's only a third of a stop above what the specs say, go ahead and use a non-dedicated flash (the camera doesn't know it's there and therefore will not impose the maximum X-sync limit) and hope for the best.
 Signature Stephen M. Dunn <stephen@stevedunn.ca>
>>>----------------> http://www.stevedunn.ca/ <----------------<<< ------------------------------------------------------------------ Say hi to my cat -- http://www.stevedunn.ca/photos/toby/
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| peter | 19 May 2007 20:19 |
>> When I attach a canon speedlite 550ex (high speed sync off) on a 20D, the >> shutter speed automatically reduced to 1/250s if I had it faster. [quoted text clipped - 11 lines] > > Turn high speed sync on. That's why they call it high speed sync. I don't want to, that why I turn it off. High speed sync is less powerful than low speed sync. Cheating the sync speed is equivalent to boosting the flash's output power when used as a fill flash.
Don't know why canon won't allow it even in manual mode. Why is it called manual mode if the shutter speed is changed automatically for me??
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| Annika1980 | 19 May 2007 06:51 |
> When I attach a canon speedlite 550ex (high speed sync off) on a 20D, the > shutter speed automatically reduced to 1/250s if I had it faster. [quoted text clipped - 7 lines] > Any ideas? I checked all the custom functions and none of them look like it > would help. Turn high speed sync on. That's why they call it high speed sync.
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| peter | 19 May 2007 05:14 |
When I attach a canon speedlite 550ex (high speed sync off) on a 20D, the shutter speed automatically reduced to 1/250s if I had it faster.
Is there a way to override this?
I found by experiment, I can flash sync at 1/320s (the experiment is done with a 3rd party flash that does not change the shutter speed). So I would like to use this speed with the canon speedlite, but it won't let me.
Any ideas? I checked all the custom functions and none of them look like it would help.
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