Shake Reduction, both useful and not.

pathdoc · 08-11-2015, 06:13 AM

So the other day I tried SR for the first time with my Takumars, primarily because I understand that the focal length I manually input will be fed through to the EXIF data and enable me to sort out afterwards which pictures I took with which lens. However, looking at the pictures I took with SR on, I am not completely satisfied with some of them and would like to turn it off (bizarre of me, I know). However, I would also like to retain the focal length information.

If I mount the lens with SR turned on, switch the camera on and tell it the focal length, then switch SR off, does the FL data still get fed through?

**UncleVanya** · 08-11-2015, 06:18 AM

Easy to test... I can try later today. What was the downside you saw?

pathdoc · 08-11-2015, 06:22 AM

If anything, the pics didn't seem quite as sharp with it turned on. I said it was bizarre, didn't I? Also I'm getting back into film, and while I'm quite happy to meter the Taks in Av mode, I like to keep everything else except focus confirmation turned off to keep the experience as close to shooting my P30T as possible. (The P30T has an aperture priority mode, so using it on the K-5 isn't cheating as far as I'm concerned, while "focus confirmation" is taken care of by the split prism - as the K5 doesn't have one, I figure this is also a fair deal.)

**realitarian** · 08-11-2015, 06:50 AM

This past Saturday I took a 1000+ pictures at a roller derby bout with my K3. A significant number of them turned out blurry towards the bottom of the frames. This was with a Sigma 50-150mm lens at f2.8. I thought it was due to a thin DoF but other pictures turned out fine. Also fine with my K50 last month and same lens, same aperture. All the time at 1/250 sec (indoors).

And then I found out the you need to turn SR off when mounted on a tripod. The K3 was on a tripod for most of the shots, the K50 was either monopod or handheld.

Maybe that was the case with you as well? Was your camera stabilized in some fashion with SR turned on?

Gimbal · 08-11-2015, 06:56 AM

SR and panning is a bad combination, but that is about it. Apart from that I always leave SR on.

Giklab · 08-11-2015, 06:57 AM

Did you by any chance input the "effective" focal length? That will mean the SR overcompensates and usually blurs the image.

vonBaloney · 08-11-2015, 06:59 AM

You also have to make sure it is ready (little green hand icon) -- if you fire instantly it can cause a blur. It definitely helps hand-held shots at low/medium shutter speeds...

wombat2go · 08-11-2015, 07:01 AM

The K-01 exif does contain the manually entered focal length for photos with SR Off.
Regards

pathdoc · 08-11-2015, 07:05 AM

Originally posted by realitarian

Maybe that was the case with you as well? Was your camera stabilized in some fashion with SR turned on?

For some of the unsatisfying shots, yes, it was - my bad, as I realised afterwards. Some of the shots were on the tripod. Once I realised that in no way were my shutter speeds coming anywhere near blur-inducing (even at ISO 80 and stopped way down, they were faster than 1/180 and my longest lens was a 135), I took the tripod back to the car. Some of the other shots were taken with my elbows/forearms resting on a convenient structure, but I don't know just how "stabilised" that is.

LensBeginner · 08-11-2015, 07:09 AM

Originally posted by Giklab

Did you by any chance input the "effective" focal length? That will mean the SR overcompensates and usually blurs the image.

Don't ever input higher. If forced, use lower (eg. zooms or when exact FL isn't available).
I use 75mm for my 80-200mm, for instance (and note down the FL and correct the exif data afterwards).

audiobomber · 08-11-2015, 07:18 AM

Originally posted by pathdoc

For some of the unsatisfying shots, yes, it was - my bad, as I realised afterwards. Some of the shots were on the tripod. Once I realised that in no way were my shutter speeds coming anywhere near blur-inducing (even at ISO 80 and stopped way down, they were faster than 1/180 and my longest lens was a 135), I took the tripod back to the car. Some of the other shots were taken with my elbows/forearms resting on a convenient structure, but I don't know just how "stabilised" that is.

SR doesn't need to be active. With a manual lens, the exif will show the focal length that was last entered.

I've done extensive testing over the years with SR on vs. off. My conclusions:

Do not use SR for action or panning where you are deliberately moving the camera
Don't use SR on a tripod
Use SR with a monopod and when hand-held with elbows resting on a solid surface
SR has no effect, positive or negative, at high shutter speeds, i.e. higher shutter speed than 1/(effective focal length)

These results follow Pentax recommended practice.

pathdoc · 08-11-2015, 07:18 AM

Originally posted by Giklab

Did you by any chance input the "effective" focal length? That will mean the SR overcompensates and usually blurs the image.

If you mean, did I translate 135mm to 200mm and input that, the answer is no. What went in was what's written on the lenses. Like I said, I was in part using it to include the focal length in the EXIF data.

pathdoc · 08-11-2015, 07:28 AM

I think I'll take a "dummy" shot with each lens to anchor the focal length in the EXIF for the start of a session with that lens, and then switch it off until I change lenses. I can sort things out later based on the changeover point when I'm looking at the pics at leisure.

**Rondec** · 08-11-2015, 07:53 AM

Some folks have suggested that if you push the shutter before the SR is ready, you may not have as good results. I have not found this to be the case. If the SR isn't ready, the sensor is locked down as if you had it turned off.

I think audiobomber has a nice list. When I am on a tripod, I usually use mirror lockup or 2 second timer which turn off the SR. I certainly wouldn't use it if I was panning. Otherwise, it stays on all of the time.

audiobomber · 08-11-2015, 09:18 AM

Originally posted by Rondec

Some folks have suggested that if you push the shutter before the SR is ready, you may not have as good results. I have not found this to be the case. If the SR isn't ready, the sensor is locked down as if you had it turned off.

I believe the shot will be spoiled if it is taken during the fraction of a second that the SR is spooling up.

---------- Post added 2015-08-11 at 12:20 ----------

Originally posted by pathdoc

I think I'll take a "dummy" shot with each lens to anchor the focal length in the EXIF for the start of a session with that lens, and then switch it off until I change lenses.

I don't have IBIS in my Sony a6000, and I sorely miss it in low light.

08-11-2015, 06:13 AM	#1
pathdoc Pentaxian Join Date: Mar 2015 Photos: Gallery \| Albums Posts: 6,381	Shake Reduction, both useful and not. So the other day I tried SR for the first time with my Takumars, primarily because I understand that the focal length I manually input will be fed through to the EXIF data and enable me to sort out afterwards which pictures I took with which lens. However, looking at the pictures I took with SR on, I am not completely satisfied with some of them and would like to turn it off (bizarre of me, I know). However, I would also like to retain the focal length information. If I mount the lens with SR turned on, switch the camera on and tell it the focal length, then switch SR off, does the FL data still get fed through?

08-11-2015, 07:18 AM	#11
audiobomber Veteran Member Join Date: May 2008 Location: Sudbury, Ontario Photos: Albums Posts: 6,806	Originally posted by pathdoc For some of the unsatisfying shots, yes, it was - my bad, as I realised afterwards. Some of the shots were on the tripod. Once I realised that in no way were my shutter speeds coming anywhere near blur-inducing (even at ISO 80 and stopped way down, they were faster than 1/180 and my longest lens was a 135), I took the tripod back to the car. Some of the other shots were taken with my elbows/forearms resting on a convenient structure, but I don't know just how "stabilised" that is. SR doesn't need to be active. With a manual lens, the exif will show the focal length that was last entered. I've done extensive testing over the years with SR on vs. off. My conclusions: Do not use SR for action or panning where you are deliberately moving the camera Don't use SR on a tripod Use SR with a monopod and when hand-held with elbows resting on a solid surface SR has no effect, positive or negative, at high shutter speeds, i.e. higher shutter speed than 1/(effective focal length) These results follow Pentax recommended practice. Last edited by audiobomber; 08-11-2015 at 10:54 AM.

08-11-2015, 09:18 AM	#15
audiobomber Veteran Member Join Date: May 2008 Location: Sudbury, Ontario Photos: Albums Posts: 6,806	Originally posted by Rondec Some folks have suggested that if you push the shutter before the SR is ready, you may not have as good results. I have not found this to be the case. If the SR isn't ready, the sensor is locked down as if you had it turned off. I believe the shot will be spoiled if it is taken during the fraction of a second that the SR is spooling up. ---------- Post added 2015-08-11 at 12:20 ---------- Originally posted by pathdoc I think I'll take a "dummy" shot with each lens to anchor the focal length in the EXIF for the start of a session with that lens, and then switch it off until I change lenses. I don't have IBIS in my Sony a6000, and I sorely miss it in low light. Last edited by audiobomber; 08-11-2015 at 09:23 AM.

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08-11-2015, 06:18 AM	#2
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,401	Easy to test... I can try later today. What was the downside you saw?

08-11-2015, 06:22 AM	#3
pathdoc Pentaxian Join Date: Mar 2015 Photos: Gallery \| Albums Posts: 6,381 Original Poster	If anything, the pics didn't seem quite as sharp with it turned on. I said it was bizarre, didn't I? Also I'm getting back into film, and while I'm quite happy to meter the Taks in Av mode, I like to keep everything else except focus confirmation turned off to keep the experience as close to shooting my P30T as possible. (The P30T has an aperture priority mode, so using it on the K-5 isn't cheating as far as I'm concerned, while "focus confirmation" is taken care of by the split prism - as the K5 doesn't have one, I figure this is also a fair deal.)

08-11-2015, 06:50 AM	#4
realitarian Site Supporter Join Date: Jun 2014 Location: Los Angeles, CA Photos: Albums Posts: 221	This past Saturday I took a 1000+ pictures at a roller derby bout with my K3. A significant number of them turned out blurry towards the bottom of the frames. This was with a Sigma 50-150mm lens at f2.8. I thought it was due to a thin DoF but other pictures turned out fine. Also fine with my K50 last month and same lens, same aperture. All the time at 1/250 sec (indoors). And then I found out the you need to turn SR off when mounted on a tripod. The K3 was on a tripod for most of the shots, the K50 was either monopod or handheld. Maybe that was the case with you as well? Was your camera stabilized in some fashion with SR turned on?

08-11-2015, 06:56 AM	#5
Gimbal Pentaxian Join Date: Apr 2007 Location: Sweden Posts: 2,106	SR and panning is a bad combination, but that is about it. Apart from that I always leave SR on.

08-11-2015, 06:57 AM	#6
Giklab Veteran Member Join Date: Jan 2012 Location: Slovenia Photos: Gallery Posts: 2,182	Did you by any chance input the "effective" focal length? That will mean the SR overcompensates and usually blurs the image.

08-11-2015, 06:59 AM	#7
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	You also have to make sure it is ready (little green hand icon) -- if you fire instantly it can cause a blur. It definitely helps hand-held shots at low/medium shutter speeds...

08-11-2015, 07:01 AM	#8
wombat2go Veteran Member Join Date: Jan 2010 Location: Michigan Photos: Gallery Posts: 2,207	The K-01 exif does contain the manually entered focal length for photos with SR Off. Regards

08-11-2015, 07:05 AM	#9
pathdoc Pentaxian Join Date: Mar 2015 Photos: Gallery \| Albums Posts: 6,381 Original Poster	Originally posted by realitarian Maybe that was the case with you as well? Was your camera stabilized in some fashion with SR turned on? For some of the unsatisfying shots, yes, it was - my bad, as I realised afterwards. Some of the shots were on the tripod. Once I realised that in no way were my shutter speeds coming anywhere near blur-inducing (even at ISO 80 and stopped way down, they were faster than 1/180 and my longest lens was a 135), I took the tripod back to the car. Some of the other shots were taken with my elbows/forearms resting on a convenient structure, but I don't know just how "stabilised" that is.

08-11-2015, 07:09 AM	#10
LensBeginner Veteran Member Join Date: Sep 2014 Photos: Albums Posts: 4,696	Originally posted by Giklab Did you by any chance input the "effective" focal length? That will mean the SR overcompensates and usually blurs the image. Don't ever input higher. If forced, use lower (eg. zooms or when exact FL isn't available). I use 75mm for my 80-200mm, for instance (and note down the FL and correct the exif data afterwards).

08-11-2015, 07:18 AM	#12
pathdoc Pentaxian Join Date: Mar 2015 Photos: Gallery \| Albums Posts: 6,381 Original Poster	Originally posted by Giklab Did you by any chance input the "effective" focal length? That will mean the SR overcompensates and usually blurs the image. If you mean, did I translate 135mm to 200mm and input that, the answer is no. What went in was what's written on the lenses. Like I said, I was in part using it to include the focal length in the EXIF data.

08-11-2015, 07:28 AM	#13
pathdoc Pentaxian Join Date: Mar 2015 Photos: Gallery \| Albums Posts: 6,381 Original Poster	I think I'll take a "dummy" shot with each lens to anchor the focal length in the EXIF for the start of a session with that lens, and then switch it off until I change lenses. I can sort things out later based on the changeover point when I'm looking at the pics at leisure.

08-11-2015, 07:53 AM	#14
Rondec Loyal Site Supporter Join Date: Mar 2009 Location: Gladys, Virginia Photos: Gallery Posts: 27,653	Some folks have suggested that if you push the shutter before the SR is ready, you may not have as good results. I have not found this to be the case. If the SR isn't ready, the sensor is locked down as if you had it turned off. I think audiobomber has a nice list. When I am on a tripod, I usually use mirror lockup or 2 second timer which turn off the SR. I certainly wouldn't use it if I was panning. Otherwise, it stays on all of the time.