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03-28-2017, 06:55 AM   #31
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QuoteOriginally posted by monochrome Quote
Are you testing a studio scene on a tripod with controlled lighting (x lumens @ y K)?
If mounted on a tripod, is SR disabled?
Are you shooting with remote?
Are you testing MUP and not MUP?
The tests were actually made to test the SR, so they were all hand held (that's why I took multiple shots for each shutter speed, to increase accuracy of the outcome).
I am planning to do the same test but with SR disabled - with the same lens, and a 50mm. I can try to repeat on the tripod, but to be honest I'm using ES with a remote (or timer) on a tripod
all the time so I never get any shake, I'm mostly concerned with hand-held shooting for the tests.

03-28-2017, 07:36 AM   #32
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QuoteOriginally posted by awscreo Quote
I'm also
seeing blurred shots all the way down to 1/30 in some cases, with very low shutter speeds (1/5-1/25) and higher ones (1/250 onwards) showing the sharpest results.
This does not seem to me to be a 'shutter-shock' issue, just plain old camera motion blur at slow shutter speeds. The sort any camera would produce. The K-1's SR may be very capable, but SR can't completely fix that problem.
03-28-2017, 07:41 AM   #33
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QuoteOriginally posted by awscreo Quote
huh, so I went out and shot a sequence - DFA 28-15, 28mm at f6.3, starting at 1/5 all the way to 1/250, with 3 exposures for each stop.

Weird things happened. from 1/5 to 1/25 image is razor sharp. from 1/30 to 1/80 it's softens up. 1/100 to 1/160 is very soft. At 1/200 image starts to become sharp again, and at 1/250 image is razor sharp again.

So what the hell lol. SR works for very slow shutter speeds, but doesn't for ones that should be sharp logically? Is shutter shock affecting images from 1/30 to 1/200??? that's just crazy! Is my unit faulty? I'm paranoid now.
Just to be sure I'll probably do a set with another lens, probably my 50 1.8 because i don't remember getting results like that with that lens in the past.

I'm thinking maybe to send it in to tune up to Pentax if this is outside of the spec..

Full res jpegs from sequence are below (still being uploaded as of now):
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Although it seems weird, what you are seeing makes complete sense if you think about what's happening inside the camera.

When the exposure begins, the first set of curtain blades fly open and hit their end of travel with a tiny bang that is just a bit too fast for the SR system to compensate. The image shakes for just a tiny fraction of a second.

For a slow shutter speed, the shutter shock is still there in the image but the fraction of the image's light that was collected during the shock period is small compared to the amount of light collected during the rest of the shutter's opening time. The longer the shutter is open, the less the relative contribution of the perturbed image in the final result.

If the shutter speed is near or faster than flash sync speed, the shock created by the start of the closing second curtain actually acts in the opposite direction of the shock created when the first curtain hits the end of travel. Thus, the total shock in the camera is lower.
03-28-2017, 07:54 AM   #34
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QuoteOriginally posted by awscreo Quote
The tests were actually made to test the SR, so they were all hand held (that's why I took multiple shots for each shutter speed, to increase accuracy of the outcome).
I am planning to do the same test but with SR disabled - with the same lens, and a 50mm. I can try to repeat on the tripod, but to be honest I'm using ES with a remote (or timer) on a tripod
all the time so I never get any shake, I'm mostly concerned with hand-held shooting for the tests.
Personally, using a lens 100mm or shorter I can hand hold K-1 to 1/30 but no slower. At 200mm 1/60 is my limit if I am deliberate with each shot, using a squeeze rather than a punch on the shutter button; 1/125 is better. Above 200mm (I have manual lenses of 300mm & 400mm that I have attempted hand shooting with) I don't even try to hand hold if <1/250 is required.

400mm and up I can get motion blur even on a tripod.

03-28-2017, 07:57 AM   #35
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QuoteOriginally posted by rawr Quote
This does not seem to me to be a 'shutter-shock' issue, just plain old camera motion blur at slow shutter speeds. The sort any camera would produce. The K-1's SR may be very capable, but SR can't completely fix that problem.
I would agree.
03-28-2017, 08:03 AM   #36
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QuoteOriginally posted by rawr Quote
This does not seem to me to be a 'shutter-shock' issue, just plain old camera motion blur at slow shutter speeds. The sort any camera would produce. The K-1's SR may be very capable, but SR can't completely fix that problem.
mm, you can see the shots I've uploaded - I get razor sharp images at 1/5 up to 1/25, but then from there to 1/250 I see clearly worse results, with 1/250 being as sharp as 1/5. I shot 3 exposures for each shutter speed, to improve accuracy of the test. I have a fairly steady hand, and I was trying my best to hold the camera steady for each exposure. If it was just motion blur I'd surely see more of it at slower shutter speeds, but I don't.
03-28-2017, 08:05 AM   #37
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QuoteOriginally posted by photoptimist Quote
Although it seems weird, what you are seeing makes complete sense if you think about what's happening inside the camera.

When the exposure begins, the first set of curtain blades fly open and hit their end of travel with a tiny bang that is just a bit too fast for the SR system to compensate. The image shakes for just a tiny fraction of a second.

For a slow shutter speed, the shutter shock is still there in the image but the fraction of the image's light that was collected during the shock period is small compared to the amount of light collected during the rest of the shutter's opening time. The longer the shutter is open, the less the relative contribution of the perturbed image in the final result.

If the shutter speed is near or faster than flash sync speed, the shock created by the start of the closing second curtain actually acts in the opposite direction of the shock created when the first curtain hits the end of travel. Thus, the total shock in the camera is lower.
So K-1 has shutter shock from 1/30 to 1/200? I've never heard of another camera with such crazy broad range of affected shutter speeds...

03-28-2017, 08:25 AM   #38
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QuoteOriginally posted by rawr Quote
This does not seem to me to be a 'shutter-shock' issue, just plain old camera motion blur at slow shutter speeds. The sort any camera would produce. The K-1's SR may be very capable, but SR can't completely fix that problem.
QuoteOriginally posted by C_Jones Quote
I would agree.
I think you are missing the detail from the other thread. 1/125th sec shots are blurry, 1/25th are not. The behavior is not SR related either as he did some shots with SR disabled using 2 sec self-timer and the problem persists.
03-28-2017, 08:33 AM   #39
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QuoteOriginally posted by awscreo Quote
So K-1 has shutter shock from 1/30 to 1/200? I've never heard of another camera with such crazy broad range of affected shutter speeds...
I think it's pretty normal for the mechanical shutter's vibrations to cause the most damage in the 1/100s range, and the impact on your photo decreases as your shutter speed heads off in both directions. It will depend on body, lens, support, and probably a bunch of other things. See Falk Lumo: LumoLabs: Shutter-induced blur with an SLR camera for an in depth study of the K-7.

As mentioned earlier, the K-1 has an electronic shutter option in Liveview mode. You might want to throw that into your testing mix.
03-28-2017, 08:40 AM   #40
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QuoteOriginally posted by UncleVanya Quote
I think you are missing the detail from the other thread.
True. I didn't look there.

All I can offer then is my own anecdotal experience - no shutter shock noticed so far. I certainly noticed it with an old NEX-5 I had, but it's not something I've felt with the K-1 (so far?).
03-28-2017, 08:41 AM   #41
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I am curious if the shots being taken are in Spot AF mode or not. Really, testing SR on a brushy area of woods is not as effective as testing on a more isolated object such as a flower or a well lit lone object that has distinct characteristics. Just a suggestion.
03-28-2017, 08:51 AM   #42
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QuoteOriginally posted by rawr Quote
This does not seem to me to be a 'shutter-shock' issue, just plain old camera motion blur at slow shutter speeds. The sort any camera would produce. The K-1's SR may be very capable, but SR can't completely fix that problem.
QuoteOriginally posted by C_Jones Quote
I would agree.
What they said. This "issue" was discussed in exquisite detail on other threads and while some remain unconvinced, consensus was that the problem reflects inadequate camera support with SR off. As for hand-held with SR on...as noted above, there are limits.

That being said, I do understand your angst. You are free to seek a replacement body from your vendor or make a warranty claim if you seriously feel your camera has a defect. After all, it is your investment and you are the one who is dealing with the symptoms.


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03-28-2017, 08:56 AM   #43
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That hook behavior is very specific and it seems hard to imagine at 1/125 on a 28-105...
03-28-2017, 09:00 AM   #44
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QuoteOriginally posted by UncleVanya Quote
That hook behavior is very specific and it seems hard to imagine at 1/125 on a 28-105...
What is amazing is that he actually got sharp shots at 1/10s @ 28mm in his example photos. I am impressed.


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03-28-2017, 09:08 AM   #45
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QuoteOriginally posted by awscreo Quote
So K-1 has shutter shock from 1/30 to 1/200? I've never heard of another camera with such crazy broad range of affected shutter speeds...
If you search the internets you'll find some cameras are even worse. One test found the Canon 5DS had issues from 1/2 to 1/125 sec.

High resolution sensors and extremely fast mechanical motions simply don't mix that well. The blades of the shutter curtain are moving about 20-30 miles per hour when they hit the end of travel.
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