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04-30-2008, 08:04 AM   #31
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For me SR is very useful for a number of reasons. The first is that it allows me to use a smaller aperture. say f10 as opposed tof4 to achieve greater depth of field.

Second it allows me to shoot handheld in extremely low light where a tripod is impractical or not allowed.

Finally it allows me to work very quickly in times of changing light (sunrise/sunset) I cna change angles quiclky without fooling with a tripod. At very slow shutter speeds SR doesn't guarantee sharpness but it increases the odds, so a higher percentage of images are sharp.

23mm (35 mm w/ crop) 1/6 second, which is 2.5 stops.


04-30-2008, 08:37 AM   #32
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QuoteOriginally posted by Mike Cash Quote
Here is an entirely unscientific comparison with my K100D. Both photos are handheld, using a 135mm prime lens and a shutter speed of 1/6th second:






Ignoring actual shutter speeds and just doing simple doublings:

1/6 (actual shutter speed)
1/12
1/25
1/50
1/100
1/135
1/200


Mike, sorry for my ignorance, but can you explain the methodology behind your "4 stops calcs" ?


Whats intriguing me is that you took the focal length and treated as shutter speed. I do vaguely know some rules of thumb if you are using ISO 100 and blah blah blah for daylight pictures... but I am not sure if you are using this rule for your calcs.
04-30-2008, 09:08 AM   #33
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QuoteOriginally posted by BBear Quote
Mike, sorry for my ignorance, but can you explain the methodology behind your "4 stops calcs" ?


Whats intriguing me is that you took the focal length and treated as shutter speed. I do vaguely know some rules of thumb if you are using ISO 100 and blah blah blah for daylight pictures... but I am not sure if you are using this rule for your calcs.
Yes, that's what he seems to be doing. He's starting with the idea that, with the focal length at 135mm, he "should" be shooting at 1/135th sec or faster. Since he was able to take a reasonably sharp photo at 1/6th sec, he just did the math backwards starting with 1/6 to get up to 1/135:

2 x 1/6 = 1/12
2 x 1/12 = 1/24
2 x 1/24 = 1/50 (rounding)
2 x 1/50 = 1/100

which is THREE stops faster than 1/6, and since 1/135th sec is faster than 1/100th sec, he adds in a fourth stop. I might have said "three and a half stops" but that's a quibble.

__________


My complaint (well, it's not a complaint really) - my observation is simply that this kind of test, while interesting and everybody ought to do it for himself just to make sure SR is working, nevertheless, doesn't really demonstrate the benefits of shake reduction in real life. If you found yourself frequently wanting to see how slowly you could shoot the photo before the image blurred, then this test would really prove something.

But I don't shoot ANYTHING at 1/6th sec, ever. OK, I'm sure I have once or twice and perhaps it wasn't even by accident, but shots at less than about 1/30th sec are statistically negligible in my own collection and I bet in nearly everybody else's. You don't buy a camera with SR so you can do SR tests!!

I'd note also that the advantage can only honestly be calculated against the best you can do without shake reduction. In my test photos, I think I demonstrated that a reasonably steady hand can take a picture of a still object at around 1/30th sec - even with a focal length above 1/200th sec. If you noted only that it's also possible to take a sharp picture WITH SR enabled at 1/30th sec, and ignored the "without" result, and if you used Mike's method of calculating the advantage of SR which compares SR on not to SR off, but to some hypothetical rule, you'd come up with a five or six stop advantage, which is of course ridiculous.

The rule of thumb about the recommended relationship between focal length and shutter speed is a rule of thumb, not a law of physics. If you want to be safe, you pay some attention to that rule, whether you've got SR or not.

To what I've already said about SR's benefits (remember, I'm in favor of in-body SR!) I would add two things.

First, like the camera's performance at higher ISOs, the camera's performance using SR seems to vary from one circumstance to another in ways that I can't really make good sense of. I've taken shots at ISO 1600 with my K10D/K20D that were remarkably noise free, and others that were quite noisy, and all I can say is that the quality of the light and the content of the picture makes a difference to the level of noise that shows up in the photo. And in the same way, I've felt occasionally that SR really made a difference, but even more often I felt that it didn't. I've occasionally taken the camera off the tripod and forgotten to turn SR back on, and I'm happy to report that my next 50 shots were NOT ruined. My wild-ass guess is that, on average, I can count on SR to give me a solid one-stop advantage in the shutter speed, assuming that the subject isn't moving.

The other point about SR is that it does help, and it never hurts. Well, I've read that it can hurt to have SR on if the camera's on the tripod. Perhaps, although I've put the camera on the tripod occasionally and forgotten to turn SR off and I didn't see the difference. (And I have a pretty solid tripod.) For me, the SR feature is considerably more important than, say, the K10D/K20D's weather-sealing. That matters to me, too, but only occasionally.

Bottom line: We all seem to agree that SR is worth having. We seem to have some small disagreement about how often it matters and to what extent it matters, but that's a disagreement on details, not on general principles.

Will
04-30-2008, 09:16 AM   #34
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Good post WMBP. So much depends on shooting style, steadiness, subject matter etc. A tripod will almost always be better but a tripod can be inconvenient at times.

I also find SR effectiveness varies from lens to lens as well. It seems to work better on my 16-45 than my old 18-55 and really well on my M50 1.7.

For me SR has been a godsend as I do tend to shoot at 1/6 more often than I should (low ISO for detail+low f stop to maximize DOF) and I can cut the weight of a tripod off my long backpacking trips.

04-30-2008, 09:21 AM   #35
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Hi arbutusq

The points you make regarding the benefits of Shake Reduction are very valid ones, particularly when you said:

QuoteQuote:
It allows me to shoot hand-held in extremely low light where a tripod is impractical or not permitted.
We recently returned from an enjoyable few weeks vacation in Rome & Sicily and I pretty much lost count of the number of historic locations where photography was either entirely prohibited or flash and/or tripods were forbidden. Back in days that I used to shoot relatively costly 35mm transparencies, the best one could hope for in such difficult situations was to use 400ASA Fujifilm and simply cross my fingers, steadying myself against any solid surface that might alleviate the inevitable effects of hand movement !!! I don't believe ANY manufacturer is presently claiming that their Shake Reduction technology is a guaranteed panacea for producing pin-sharp images (it isn't !) and reckon that most of their claims about gaining 4-stops are overly optimistic (I'll concede 2/2 stops), but I simply cannot understand those who seem to regard SR with slight contempt ? If you don't wish to use it, just turn the feature OFF on your camera !! All I know for certain is that many of the photographs which I took on holiday in problematic lighting conditions would simply have been impossible using my old 35mm SLR's.....

Best regards
Richard

Last edited by Confused; 04-30-2008 at 11:10 AM.
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