Help needed figuring out D FA 28-105

nomadkng · 07-26-2016, 02:55 PM

Originally posted by Adam

My new theory is that some K-1 shutter units are defective and are in need of repair. It might not be a widespread issue, however.

Roll montage of 10,000 K1 owners shooting at 1/90 of a second and pixel peeping..... in 3-2-1.....

I'm not sure if I even want to test my K1, I don't use SR very often so maybe I can get away with sustained ignorance.

Ole · 07-26-2016, 03:07 PM - **1 Like**

Originally posted by nomadkng

Roll montage of 10,000 K1 owners shooting at 1/90 of a second and pixel peeping..... in 3-2-1.....

I'm not sure if I even want to test my K1, I don't use SR very often so maybe I can get away with sustained ignorance.

It isn't SR related so not using SR won't necessarily help you maintain your ignorance I'm afraid!

Nickrs · 07-26-2016, 03:16 PM

Originally posted by Ole

I ran several tests today. Tripod, hand held, SR on, SR off, view finder view, live view, D FA 28-105 and D FA 24-70, you name it I did it.

Even with my perhaps too flimsy tripod the images are blurred at 1/90s and 1/125s. They are fine at 1/180s and higher.

Live view is worse than viewfinder view.

With a heavy lens like the D FA 24-70 the blur is a tad less pronounced but it is still there.

So my conclusion is that the issue is not with the lens. And it is not a bokeh issue. It is shutter induced blur at 1/90s and 1/125s.

Attached are first three samples with the camera tripod mounted thus eliminating the human "shake" factor. Focusing was done once (using live view) prior to capturing the images so there is no variation in focus between the images. The last three samples were shot handheld, SR on. The lens was set to 35mm and F8 throughout.

Actually that is quite bad! :-(

N

photoptimist · 07-26-2016, 03:29 PM - **1 Like**

If you look at the tiny little bokeh through the leaves of the trees in the 100% crop, they are are little crescents.

Something is moving in the system. If you had this problem with all lenses, I'd blame SR. But given that it only happens with this one lenses, I'd suspect a loose element or part of the zoom mechanism that is shifting slightly during the vibration created by the mirror, shutter, or aperture stop-down motions.

Adam · 07-26-2016, 03:36 PM

Originally posted by photoptimist

Something is moving in the system. If you had this problem with all lenses, I'd blame SR. But given that it only happens with this one lenses, I'd suspect a loose element or part of the zoom mechanism that is shifting slightly during the vibration created by the mirror, shutter, or aperture stop-down motions.

An interesting theory. I think this warrants some more test shots @Ole .

Nickrs · 07-26-2016, 03:48 PM

Originally posted by photoptimist

If you look at the tiny little bokeh through the leaves of the trees in the 100% crop, they are are little crescents.

Something is moving in the system. If you had this problem with all lenses, I'd blame SR. But given that it only happens with this one lenses, I'd suspect a loose element or part of the zoom mechanism that is shifting slightly during the vibration created by the mirror, shutter, or aperture stop-down motions.

I'm sorry to say this problem seems to be lens independent, we now have a number of instances with a number of lenses so "the fickle finger of fate" appears to be pointing at vibration in the K1 camera(s). Of course it could be stray neutrinos travelling at supra light speed interfering with the polarity of the flux capacity distorting space-time, then again possibly not.

Would it be really inappropriate of me to say I'm really glad it doesn't appear to be the 28-105 lens because I've got one?

Actually it might make me very careful when/if I buy a K1.

rawr · 07-26-2016, 03:49 PM

Originally posted by photoptimist

If you had this problem with all lenses, I'd blame SR. But given that it only happens with this one lenses, I'd suspect a loose element or part of the zoom mechanism that is shifting slightly during the vibration created by the mirror, shutter, or aperture stop-down motions.

Sounds logical. It may not happen with all 28-105's either (ie mine seems OK at 1/125) due to manufacturing variation, or depend on some other aspect of 28-105 usage (eg aperture setting or lens support).

Nickrs · 07-26-2016, 03:57 PM

Originally posted by Adam

An interesting theory. I think this warrants some more test shots @Ole .

I think @Ole said he is getting his problem with multiple lenses. Are we talking about multiple different faults rather than multiple single faults creating a similar symptom?

N

**monochrome** · 07-26-2016, 04:06 PM

Do I have a slight tickle of a memory that there was a post on a Chinese blog last year about K-1 shutter shock, or is that a false memory?

scopedude · 07-26-2016, 04:20 PM

I've used the 28-105 maybe around 90% of the time, and among 3000 shots I did find several 'weird' images that were shot at 28mm and have some 'doubling blurriness'. No it is not motion blur, SR was on, 28mm (only), mostly f8~9, and the blurriness occurs only off center. The problems is easier to detect if I do some sharpening by adjusting the 'Detail' slider in LR CC and use 0.5 Radius. I will have to dig the files again but I remember how confused I was because it didn't make any sense at all to have motion blurs on those shots.

Adam · 07-26-2016, 04:32 PM

Originally posted by scopedude

I've used the 28-105 maybe around 90% of the time, and among 3000 shots I did find several 'weird' images that were shot at 28mm and have some 'doubling blurriness'. No it is not motion blur, SR was on, 28mm (only), mostly f8~9, and the blurriness occurs only off center. The problems is easier to detect if I do some sharpening by adjusting the 'Detail' slider in LR CC and use 0.5 Radius. I will have to dig the files again but I remember how confused I was because it didn't make any sense at all to have motion blurs on those shots.

This could simply be the SR system not being properly armed. In Ole's test shots, there were two photos both taken at 1/90s with SR. One looked better but still a bit blurry due to motion, and the other one was terrible with that doubling effect.

cali92rs · 07-26-2016, 04:42 PM

Originally posted by Adam

My body isn't getting any issues, whereas Ole's is consistently introducing blur at 1/90s and to a lesser extent, 1/125s. Slower and faster shutter speeds are fine. Without SR, camera shake can exacerbate the issue, but there seems to be a degree of blur being introduced by the shutter regardless.

My new theory is that some K-1 shutter units are defective and are in need of repair. It might not be a widespread issue, however.

The D810 is known to have this issue with these shutter speeds too.
However, to alleviate this issue, Nikon has EFCS, where Pentax requires (for some unknown reason) pixel shift to use EFCS.
This blog discusses this:
http://blog.kasson.com/?p=6638

GEKarcz · 07-26-2016, 06:14 PM

This may be an issue of shutter shock, given the OP's following statements: "Even with my perhaps too flimsy tripod the images are blurred at 1/90s and 1/125s. They are fine at 1/180s and higher." and the following:

"The exact amount of average blur ... has its maximum for shutter speeds of about 1/100s to 1/80s. It is less than 5 µm for 1/25s and slower. Or 1/250s and faster." From: LumoLabs: Shutter-induced blur with an SLR camera

ChristianRock · 07-26-2016, 06:37 PM

I have this issue (shutter vibration) with the K-r and K-S1. In both cases it goes away with the use of a heavier lens or a heavy flash like my AF280T. Since the K1 shutter is over twice the size it will probably take a combination of things to make it go away...

krazykat · 07-26-2016, 08:19 PM

It would be interesting if someone could test with a different wide and light lens, e.g. FA 20-35.

07-26-2016, 03:36 PM	#65
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,593	Originally posted by photoptimist Something is moving in the system. If you had this problem with all lenses, I'd blame SR. But given that it only happens with this one lenses, I'd suspect a loose element or part of the zoom mechanism that is shifting slightly during the vibration created by the mirror, shutter, or aperture stop-down motions. An interesting theory. I think this warrants some more test shots @Ole . 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:

07-26-2016, 04:32 PM	#71
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,593	Originally posted by scopedude I've used the 28-105 maybe around 90% of the time, and among 3000 shots I did find several 'weird' images that were shot at 28mm and have some 'doubling blurriness'. No it is not motion blur, SR was on, 28mm (only), mostly f8~9, and the blurriness occurs only off center. The problems is easier to detect if I do some sharpening by adjusting the 'Detail' slider in LR CC and use 0.5 Radius. I will have to dig the files again but I remember how confused I was because it didn't make any sense at all to have motion blurs on those shots. This could simply be the SR system not being properly armed. In Ole's test shots, there were two photos both taken at 1/90s with SR. One looked better but still a bit blurry due to motion, and the other one was terrible with that doubling effect. 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:

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
D FA 28-105 better IQ than D FA 24-70	PhilRich	Pentax SLR Lens Discussion	26	07-28-2016 06:30 AM
Problem with K-1 and D FA 28-105?	StevenLS	Pentax K-1 & K-1 II	3	06-25-2016 10:38 AM
Pentax D FA 28-105 on K-1 - any experience?	6x7	Pentax SLR Lens Discussion	9	06-25-2016 07:40 AM
HD D-FA 28-105 leaked online	banep	Pentax News and Rumors	189	03-10-2016 10:02 AM
Dropped my lens. Need help figuring out the problem.	geomez	Troubleshooting and Beginner Help	3	05-21-2013 05:02 PM

07-26-2016, 02:55 PM	#61
nomadkng Veteran Member Join Date: Sep 2008 Location: Phoenix, AZ Posts: 1,448	Originally posted by Adam My new theory is that some K-1 shutter units are defective and are in need of repair. It might not be a widespread issue, however. Roll montage of 10,000 K1 owners shooting at 1/90 of a second and pixel peeping..... in 3-2-1..... I'm not sure if I even want to test my K1, I don't use SR very often so maybe I can get away with sustained ignorance.

07-26-2016, 03:07 PM - 1 Like	#62
Ole Administrator Join Date: Sep 2006 Location: Copenhagen, Denmark Photos: Gallery \| Albums Posts: 4,408	Originally posted by nomadkng Roll montage of 10,000 K1 owners shooting at 1/90 of a second and pixel peeping..... in 3-2-1..... I'm not sure if I even want to test my K1, I don't use SR very often so maybe I can get away with sustained ignorance. It isn't SR related so not using SR won't necessarily help you maintain your ignorance I'm afraid!

07-26-2016, 03:16 PM	#63
Nickrs Senior Member Join Date: Oct 2013 Location: "The Green Desert" Photos: Albums Posts: 175	Originally posted by Ole I ran several tests today. Tripod, hand held, SR on, SR off, view finder view, live view, D FA 28-105 and D FA 24-70, you name it I did it. Even with my perhaps too flimsy tripod the images are blurred at 1/90s and 1/125s. They are fine at 1/180s and higher. Live view is worse than viewfinder view. With a heavy lens like the D FA 24-70 the blur is a tad less pronounced but it is still there. So my conclusion is that the issue is not with the lens. And it is not a bokeh issue. It is shutter induced blur at 1/90s and 1/125s. Attached are first three samples with the camera tripod mounted thus eliminating the human "shake" factor. Focusing was done once (using live view) prior to capturing the images so there is no variation in focus between the images. The last three samples were shot handheld, SR on. The lens was set to 35mm and F8 throughout. Actually that is quite bad! :-( N

07-26-2016, 03:29 PM - 1 Like	#64
photoptimist Pentaxian Join Date: Jul 2016 Photos: Albums Posts: 5,121	If you look at the tiny little bokeh through the leaves of the trees in the 100% crop, they are are little crescents. Something is moving in the system. If you had this problem with all lenses, I'd blame SR. But given that it only happens with this one lenses, I'd suspect a loose element or part of the zoom mechanism that is shifting slightly during the vibration created by the mirror, shutter, or aperture stop-down motions.

07-26-2016, 03:48 PM	#66
Nickrs Senior Member Join Date: Oct 2013 Location: "The Green Desert" Photos: Albums Posts: 175	Originally posted by photoptimist If you look at the tiny little bokeh through the leaves of the trees in the 100% crop, they are are little crescents. Something is moving in the system. If you had this problem with all lenses, I'd blame SR. But given that it only happens with this one lenses, I'd suspect a loose element or part of the zoom mechanism that is shifting slightly during the vibration created by the mirror, shutter, or aperture stop-down motions. I'm sorry to say this problem seems to be lens independent, we now have a number of instances with a number of lenses so "the fickle finger of fate" appears to be pointing at vibration in the K1 camera(s). Of course it could be stray neutrinos travelling at supra light speed interfering with the polarity of the flux capacity distorting space-time, then again possibly not. Would it be really inappropriate of me to say I'm really glad it doesn't appear to be the 28-105 lens because I've got one? Actually it might make me very careful when/if I buy a K1.

07-26-2016, 03:49 PM	#67
rawr Veteran Member Join Date: Jun 2009 Posts: 11,913	Originally posted by photoptimist If you had this problem with all lenses, I'd blame SR. But given that it only happens with this one lenses, I'd suspect a loose element or part of the zoom mechanism that is shifting slightly during the vibration created by the mirror, shutter, or aperture stop-down motions. Sounds logical. It may not happen with all 28-105's either (ie mine seems OK at 1/125) due to manufacturing variation, or depend on some other aspect of 28-105 usage (eg aperture setting or lens support).

07-26-2016, 03:57 PM	#68
Nickrs Senior Member Join Date: Oct 2013 Location: "The Green Desert" Photos: Albums Posts: 175	Originally posted by Adam An interesting theory. I think this warrants some more test shots @Ole . I think @Ole said he is getting his problem with multiple lenses. Are we talking about multiple different faults rather than multiple single faults creating a similar symptom? N

07-26-2016, 04:06 PM	#69
monochrome Loyal Site Supporter Join Date: Mar 2008 Location: Working From Home Photos: Gallery \| Albums Posts: 26,276	Do I have a slight tickle of a memory that there was a post on a Chinese blog last year about K-1 shutter shock, or is that a false memory?

07-26-2016, 04:20 PM	#70
scopedude Junior Member Join Date: Apr 2013 Posts: 43	I've used the 28-105 maybe around 90% of the time, and among 3000 shots I did find several 'weird' images that were shot at 28mm and have some 'doubling blurriness'. No it is not motion blur, SR was on, 28mm (only), mostly f8~9, and the blurriness occurs only off center. The problems is easier to detect if I do some sharpening by adjusting the 'Detail' slider in LR CC and use 0.5 Radius. I will have to dig the files again but I remember how confused I was because it didn't make any sense at all to have motion blurs on those shots.

07-26-2016, 04:42 PM	#72
cali92rs Veteran Member Join Date: May 2011 Location: Long Beach, CA Posts: 3,354	Originally posted by Adam My body isn't getting any issues, whereas Ole's is consistently introducing blur at 1/90s and to a lesser extent, 1/125s. Slower and faster shutter speeds are fine. Without SR, camera shake can exacerbate the issue, but there seems to be a degree of blur being introduced by the shutter regardless. My new theory is that some K-1 shutter units are defective and are in need of repair. It might not be a widespread issue, however. The D810 is known to have this issue with these shutter speeds too. However, to alleviate this issue, Nikon has EFCS, where Pentax requires (for some unknown reason) pixel shift to use EFCS. This blog discusses this: http://blog.kasson.com/?p=6638

Thread Tools	Search this Thread
	Search this Thread: Advanced Search

07-26-2016, 06:14 PM	#73
GEKarcz New Member Join Date: May 2016 Posts: 4	This may be an issue of shutter shock, given the OP's following statements: "Even with my perhaps too flimsy tripod the images are blurred at 1/90s and 1/125s. They are fine at 1/180s and higher." and the following: "The exact amount of average blur ... has its maximum for shutter speeds of about 1/100s to 1/80s. It is less than 5 µm for 1/25s and slower. Or 1/250s and faster." From: LumoLabs: Shutter-induced blur with an SLR camera

07-26-2016, 06:37 PM	#74
ChristianRock Pentaxian Join Date: Jul 2013 Location: People's Republic of America Photos: Gallery \| Albums Posts: 9,910	I have this issue (shutter vibration) with the K-r and K-S1. In both cases it goes away with the use of a heavier lens or a heavy flash like my AF280T. Since the K1 shutter is over twice the size it will probably take a combination of things to make it go away...

07-26-2016, 08:19 PM	#75
krazykat Veteran Member Join Date: Aug 2010 Posts: 546	It would be interesting if someone could test with a different wide and light lens, e.g. FA 20-35.