Sunday, 21 February 2016

More lens experiments.

Having seen a bit of chat on a Sony E-mount forum about problems with "shutter shock" on the A7r, I thought I would do a few test shots with different lenses, shutter speeds and apertures. There are 8 images and I have taken a central crop from each one at 3000x2000 pixels for a closer inspection. All lenses are close to their minimum focus distance.

The first lens is a Makinon 135mm

f2.8. 1/3200s


f2.8, 1/3200s

f8, 1/125s

f8, 1/125s

Next is a Pentax 50mm
f1.4, 1/800s

f1.4, 1/800s

f8, 1/60s

f8, 1/60s


Next is the Sony FE 28-70mm using deliberately long shutter speeds on a tripod (gorillapod resting on carpet)

f5.6, 1/20s

f5.6, 1/20s

f5.6, 1/10s

f5.6, 1/10s

 Finally, a Cosina 200mm - again with long exposures on the gorillapod

f4, 1/25s

f4, 1/25s

f6.3, 1/8s

f6.3, 1/8s

There is no doubt that the shutter does clunk a bit, but there is little evidence of camera movement in these images, maybe a little in the 200mm 1/8s shot mounted on an imperfect tripod. The image is slightly worse than the f4, 1/25s photo.

In theory the worst shutter speed range is 1/30 to 1/100s - but here, the 1/60s image at f8 on the Pentax 50mm is spectacularly the best image.

My general impression is that you have to be very picky to find a much fault with shutter shock and even then you have to try fairly hard to make it significant.







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