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01-09-2011, 10:24 AM   #16
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QuoteOriginally posted by mikknu Quote
So in your opinion the SR effect is negligible for macro photography?.....

....
When I have the Sigma EM 140 DG attached along with my Sigma EX 105 macro lens on my K-x, the SR symbol stays on.

Mikael
That's not exactly what I am saying. More precisely I am saying the SR effect is likely to be very small for FLASH assisted macro photography because the flash is so fast compared to camera motion speeds.

As pointed out by another poster SR with flash may decrease background blur if lighting conditions are just right.

However, SR for hand-held, non-flash close-up work may be a benefit, especially if you can tell the camera what focal length to use (ie. f(1+m)). Lacking that capability*, I'm sure that at least in theory, half SR is likely better than no SR at all.

Say you put on a 100mm lens and use SR with a magnification of 1:1; if the camera moves during the exposure the SR will try to correct for half the actual motion due to the (1+M)=2 factor. But that's certainly better than no correction at all!

SR for macro work (even with the appropriate focal length info) isn't totally effective because it only corrects for side-side and up-down shake and not in-out shake which is important for macro photos but not for normal photos.

Dave

*It turns out that you can fool the camera into asking the focal length by putting a piece of thin paper, plastic, or foil over the bottom data pin on the lens mount when you mount the lens on the camera. This will not harm the camera.

01-09-2011, 11:03 AM   #17
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QuoteOriginally posted by ChrisJ Quote
If you use a fast shutter speed, the 'X' speed of 1/180th of a second and a small aperture to get DOF, then you have virtually 'killed' the ambient, if you take a picture at those settings without flash it would be just a black frame.

Then your effective shutter speed is the duration of the flash which will be at least 1/1000th of a second, much faster than that if the flash power is turned down, around the 1/5000th of a second mark at half power.

This means that obviously hand holding becomes possible. As the flash to subject distance doesn't alter much as it's set by the focus manual everything becomes possible. My 'bug hunting kit' consists of my K10D a set of bellows, an old Takumar 135mm and an off camera manual flash set on 1/16th power. Focusing is by moving the whole camera/bellows/lens/flash contraption backwards and forwards.

As the only things to think about is the framing and focus it's very quick to use, the 135mm lens puts me further away from the subject, out of the insects 'radar' range.

Beetle _1024X768px | Flickr - Photo Sharing!

Any shake reduction is obviously not necessary.

Chris
Sounds a bit technical. English is not my native language, so I'm having a bit of trouble imagining what you are telling me. I am a bit thrown off by the bellows, can't quite figure out what it is in camera terms.
Nice picture you got with your contraption though

Mikael
01-09-2011, 11:49 AM   #18
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QuoteOriginally posted by newarts Quote
That's not exactly what I am saying. More precisely I am saying the SR effect is likely to be very small for FLASH assisted macro photography because the flash is so fast compared to camera motion speeds.

As pointed out by another poster SR with flash may decrease background blur if lighting conditions are just right.

However, SR for hand-held, non-flash close-up work may be a benefit, especially if you can tell the camera what focal length to use (ie. f(1+m)). Lacking that capability*, I'm sure that at least in theory, half SR is likely better than no SR at all.

Say you put on a 100mm lens and use SR with a magnification of 1:1; if the camera moves during the exposure the SR will try to correct for half the actual motion due to the (1+M)=2 factor. But that's certainly better than no correction at all!

SR for macro work (even with the appropriate focal length info) isn't totally effective because it only corrects for side-side and up-down shake and not in-out shake which is important for macro photos but not for normal photos.

Dave

*It turns out that you can fool the camera into asking the focal length by putting a piece of thin paper, plastic, or foil over the bottom data pin on the lens mount when you mount the lens on the camera. This will not harm the camera.
Thank you for the extra details Dave, think I understand now.
I read about the sensor being able to counter side to side and up/down movement, but the document didn't mention the lack of forward/backward counter movement.

However until I try putting on an older lens or do the thin plastic trick you mentioned, I wont entirely understand the (1+M)=2 factor... I will have to look into it when I get a chance. Thanks for the tip.

Mikael
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