K3 Shake reduction artifact?

**gaweidert** · 07-31-2017, 03:36 PM

Below are two images. They were taken in May while I was out in Yellowstone. Temperatures were about 0 - 2 degrees centigrade This is one of a series of six images showing with the same artifact.. They were taken with my K3, a D FA 450-150 lens, hand held with shake reduction on. All shot at 1/2000 sec. What is interesting is that I also see this artifact at 1/100 of a second when using my D FA 28-105 lens. I seem to remember reading somewhere that there were whispers of this happening but cannot find the thread that mentions it.

It has me stumped a bit as 1/2000 sec should just about freeze any camera movement so it is not me being too shaky. Other images taken at slower shutter speeds are fine. I noticed this when looking at the shots and seeing an overall "softness: When zooming in I saw what is shown here. At 1/100 sec, the "shadow" area seems to be the same size, but not as pronounced as at 1/2000 sec. I did push contrast to emphasize the artifact. The two shots are to show how much I cropped the original image.

Are these shutter speeds just something to avoid when using SR? Any other thoughts appreciated.

Attached Images

View Picture EXIF

View Picture EXIF

Last edited by gaweidert; 08-02-2017 at 06:40 AM.

amoringello · 07-31-2017, 03:42 PM

It shouldn't be. I leave SR on all the time, whether I'm shooting zoom or wide angle, fast or slow shutter, on or off tripod.
I have yet to see a confirmed issue... I don't believe anyone has scientifically proven this to be an issue with Pentax SR, either.

Only thought is perhaps the cold had some effect? Only time I shot that Cold, the lenses ceases to work before the body got cold enough to be an issue. :-)

Proactive comment: As one troll is likely to look up (again), I did mention seeing similar behavior of blurred images with SR some number of years ago (circa K-7, I think). I never had the issue again and never confirmed it was anything but user error at that time, either. Of course, both I and the camera's technology has improved a lot since then.

**shardulm** · 07-31-2017, 03:45 PM

PF for sure. SR artifacts.. not sure. It seems to me that the subject moved or you did or you both in such a way that the blur was additive. Did you try taking one with SR turned off? Its worth checking for the lens de-centering at that FL.

Adam · 07-31-2017, 03:47 PM - **1 Like**

The shutter can cause visible vibrations between about 1/90s and 1/180s, and this looks like it might be an example of that. There was a long thread on this topic earlier this year.

Adam
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awscreo · 07-31-2017, 03:53 PM

I've ran into mirror shock myself with my 28-105, since then I only use LV mode with ES option on to eliminate any possibility of this effect. Kind of a pain when I'm hand holding some of my lenses, but I guess nothing is perfect.

stevebrot · 07-31-2017, 04:23 PM

Originally posted by shardulm

PF for sure. SR artifacts.. not sure.

I don't know about purple fringing, but I agree that SR artifact would be sort of iffy and about as likely as simple camera motion. That being said, I would be interested in seeing the rest of the frame at higher magnification. My "spider senses" say something optical.

Steve

fehknt · 07-31-2017, 04:23 PM

Very interesting; I've seen similar but only occasionally on my 150-450 but haven't been able to determine why and when. I always thought I was just getting unlucky with some weird fringing or such seeing as it didn't happen the most of the time.

**gaweidert** · 07-31-2017, 04:58 PM

Hey mods! Could you move this to the K3 section. Looking at multiple images and got my wires crossed. Seems to be happening more and more lately.

Unregistered User 8 · 07-31-2017, 11:12 PM

Originally posted by gaweidert

Hey mods! Could you move this to the K3 section.

**JimJohnson** · 08-02-2017, 05:04 AM

Originally posted by gaweidert

1/2000 sec should just about freeze and camera movement

yes and no.... SLR cameras with a mirror for the optical viewfinder, with few exceptions, use a focal plane shutter. A focal plane shutter has two curtains, leading and trailing. Exposure to any part of the sensor or film is based on the amount of time a gap between the two curtains takes to pass over that part of the sensor or film - - however, it is a misconception that the entire exposure takes that amount of time. In actuality, at shutter speeds higher than X-sync, the entire exposure always takes the same amount of time and is equal to the shutter's X-sync speed. With the K-3, that is 1/180th of a second.

At 1/2,000 the gap between curtains is very small indeed. Individual pixels in general are frozen. However, an object moving perpendicular to the direction the curtains travel still has up to 1/180th second of motion across the entire exposure. This is why panning is often still necessary at higher shutter speeds to minimize subject distortion. And Shake Reduction can add its own funkiness to an image shot at high shutter speeds depending on how it interprets the camera movement.

richandfleur · 08-08-2017, 04:40 PM

Originally posted by Adam

The shutter can cause visible vibrations between about 1/90s and 1/180s.

If this is the case, you'd hope Pentax would have addressed this in the firmware, and disabled the SR system at those shutter speeds?

stevebrot · 08-08-2017, 05:31 PM

Originally posted by richandfleur

If this is the case, you'd hope Pentax would have addressed this in the firmware, and disabled the SR system at those shutter speeds?

I will have to find the thread, but I don't believe the behavior was completely characterized or is universal. I will report back if I find it.

Steve

awscreo · 08-08-2017, 05:42 PM

Originally posted by stevebrot

I will have to find the thread, but I don't believe the behavior was completely characterized or is universal. I will report back if I find it.

Steve

My dfa 28-105 has shutter shock from 1/30 to 1/200, pretty broad range. I meant to call them, see if it's maybe fixable somehow under warranty, so far I haven't seen anyone on pf with such issues with this combo.

stevebrot · 08-08-2017, 05:53 PM

Originally posted by awscreo

My dfa 28-105 has shutter shock from 1/30 to 1/200, pretty broad range. I meant to call them, see if it's maybe fixable somehow under warranty, so far I haven't seen anyone on pf with such issues with this combo.

With the K-1, right?

Steve

Adam · 08-08-2017, 06:04 PM

Originally posted by richandfleur

If this is the case, you'd hope Pentax would have addressed this in the firmware, and disabled the SR system at those shutter speeds?

They did, they added the electronic shutter option. SR is not to blame, it's the shutter. But yes, SR gets disabled when ES is on in the K-1.

There was another lengthy thread on the topic, which ultimately resulted in identification of the problem (note that this was before they added the ES solution):

https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/326500-hel...-28-105-a.html

08-08-2017, 06:04 PM	#15
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	Originally posted by richandfleur If this is the case, you'd hope Pentax would have addressed this in the firmware, and disabled the SR system at those shutter speeds? They did, they added the electronic shutter option. SR is not to blame, it's the shutter. But yes, SR gets disabled when ES is on in the K-1. There was another lengthy thread on the topic, which ultimately resulted in identification of the problem (note that this was before they added the ES solution): https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/326500-hel...-28-105-a.html Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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07-31-2017, 03:42 PM	#2
amoringello Veteran Member Join Date: May 2008 Location: Virginia, USA Photos: Gallery Posts: 1,562	It shouldn't be. I leave SR on all the time, whether I'm shooting zoom or wide angle, fast or slow shutter, on or off tripod. I have yet to see a confirmed issue... I don't believe anyone has scientifically proven this to be an issue with Pentax SR, either. Only thought is perhaps the cold had some effect? Only time I shot that Cold, the lenses ceases to work before the body got cold enough to be an issue. :-) Proactive comment: As one troll is likely to look up (again), I did mention seeing similar behavior of blurred images with SR some number of years ago (circa K-7, I think). I never had the issue again and never confirmed it was anything but user error at that time, either. Of course, both I and the camera's technology has improved a lot since then.

07-31-2017, 03:45 PM	#3
shardulm Loyal Site Supporter Join Date: Jul 2013 Location: Cumming, GA Posts: 793	PF for sure. SR artifacts.. not sure. It seems to me that the subject moved or you did or you both in such a way that the blur was additive. Did you try taking one with SR turned off? Its worth checking for the lens de-centering at that FL.

07-31-2017, 03:47 PM - 1 Like	#4
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	The shutter can cause visible vibrations between about 1/90s and 1/180s, and this looks like it might be an example of that. There was a long thread on this topic earlier this year. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

07-31-2017, 03:53 PM	#5
awscreo Veteran Member Join Date: May 2016 Photos: Gallery \| Albums Posts: 2,722	I've ran into mirror shock myself with my 28-105, since then I only use LV mode with ES option on to eliminate any possibility of this effect. Kind of a pain when I'm hand holding some of my lenses, but I guess nothing is perfect.

07-31-2017, 04:23 PM	#6
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by shardulm PF for sure. SR artifacts.. not sure. I don't know about purple fringing, but I agree that SR artifact would be sort of iffy and about as likely as simple camera motion. That being said, I would be interested in seeing the rest of the frame at higher magnification. My "spider senses" say something optical. Steve

07-31-2017, 04:23 PM	#7
fehknt Senior Member Join Date: Oct 2015 Posts: 142	Very interesting; I've seen similar but only occasionally on my 150-450 but haven't been able to determine why and when. I always thought I was just getting unlucky with some weird fringing or such seeing as it didn't happen the most of the time.

07-31-2017, 04:58 PM	#8
gaweidert Loyal Site Supporter Join Date: Mar 2012 Location: Rochester, NY Photos: Gallery Posts: 5,325 Original Poster	Hey mods! Could you move this to the K3 section. Looking at multiple images and got my wires crossed. Seems to be happening more and more lately.

07-31-2017, 11:12 PM	#9
Unregistered User 8 Closed Account Join Date: Mar 2015 Photos: Gallery Posts: 8,694	Originally posted by gaweidert Hey mods! Could you move this to the K3 section.

08-02-2017, 05:04 AM	#10
JimJohnson Loyal Site Supporter Join Date: Jan 2012 Location: Summer:Lake Superior - Michigan Winter:Texas Hill Country Photos: Gallery Posts: 2,772	Originally posted by gaweidert 1/2000 sec should just about freeze and camera movement yes and no.... SLR cameras with a mirror for the optical viewfinder, with few exceptions, use a focal plane shutter. A focal plane shutter has two curtains, leading and trailing. Exposure to any part of the sensor or film is based on the amount of time a gap between the two curtains takes to pass over that part of the sensor or film - - however, it is a misconception that the entire exposure takes that amount of time. In actuality, at shutter speeds higher than X-sync, the entire exposure always takes the same amount of time and is equal to the shutter's X-sync speed. With the K-3, that is 1/180th of a second. At 1/2,000 the gap between curtains is very small indeed. Individual pixels in general are frozen. However, an object moving perpendicular to the direction the curtains travel still has up to 1/180th second of motion across the entire exposure. This is why panning is often still necessary at higher shutter speeds to minimize subject distortion. And Shake Reduction can add its own funkiness to an image shot at high shutter speeds depending on how it interprets the camera movement.

08-08-2017, 04:40 PM	#11
richandfleur Pentaxian Join Date: Mar 2014 Location: Palmerston North, New Zealand Photos: Albums Posts: 1,788	Originally posted by Adam The shutter can cause visible vibrations between about 1/90s and 1/180s. If this is the case, you'd hope Pentax would have addressed this in the firmware, and disabled the SR system at those shutter speeds?

08-08-2017, 05:31 PM	#12
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by richandfleur If this is the case, you'd hope Pentax would have addressed this in the firmware, and disabled the SR system at those shutter speeds? I will have to find the thread, but I don't believe the behavior was completely characterized or is universal. I will report back if I find it. Steve

08-08-2017, 05:42 PM	#13
awscreo Veteran Member Join Date: May 2016 Photos: Gallery \| Albums Posts: 2,722	Originally posted by stevebrot I will have to find the thread, but I don't believe the behavior was completely characterized or is universal. I will report back if I find it. Steve My dfa 28-105 has shutter shock from 1/30 to 1/200, pretty broad range. I meant to call them, see if it's maybe fixable somehow under warranty, so far I haven't seen anyone on pf with such issues with this combo.

08-08-2017, 05:53 PM	#14
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by awscreo My dfa 28-105 has shutter shock from 1/30 to 1/200, pretty broad range. I meant to call them, see if it's maybe fixable somehow under warranty, so far I haven't seen anyone on pf with such issues with this combo. With the K-1, right? Steve