Exposure Bracketing: Why not faster?

tempelorg · 03-14-2012, 08:06 AM

I have a K20D and a K-5, and I keep wondering about this non-feature:

When I shoot with exposure bracketing, i.e. take a series of shots at different EVs of the same scene, why does the camera move the mirror between each of the pictures instead of taking ONE measurement and then just lock the mirror up, shoot the 3 or 5 images, and only then lower the mirror again? Wouldn't that be much faster? Or are the electronics (sensor) so "slow" that they can't handle the gained speed?

To clarify: I am aware that there are more moving parts involved, e.g. focussing and aperture. But my point is: The camera could offer a special "fast bracketing" mode, in which it assumes a fixed aperture and fixed focus for the entire bracketed sequence, and only varies ISO and/or exposure time. I'm pretty sure the camera mechanics can handle that, since it's already partly possible with the mirror-lock feature (i.e shutter independent from mirror, focus and aperture). Meaning, it's all just a question of software.

(Man, as a software developer, it really bugs me that camera firmwares aren't open sourced, and that the makers are so closed up about their software dev process)

Last edited by tempelorg; 03-14-2012 at 08:56 AM.

parsons · 03-14-2012, 08:45 AM

it only takes a send to flick off five images, what difference will it make?
it is just the way the camera works is my guess

tempelorg · 03-14-2012, 08:49 AM

But in that ~1 second for the 3 or 5 shots the object might have slightly moved, and that annoys me.

The other day I tried to take such imgs for HDR composition, in a darkened room with a video projector. I tried to get the speaker (dark) with the projected img (bright) on the same picture, so I needed the exposure bracketing. But the fact that the speaker moved slightly during this process makes creating the HDRs quite difficult. Had the camera taken the imgs in faster succession, this would be a much smaller issue.

JinDesu · 03-14-2012, 08:59 AM

I believe that having to drop the mirror down each time when doing bracketing is stupid, yes. It should just flip the mirror up, and take all the bracket shots, then drop the mirror.

I imagine continuous drive should ALSO do this, except I believe continuous drive also drops the mirror after each shot.

Macario · 03-14-2012, 09:15 AM

Well, if you tried to take a shot of the dark speaker and the brigh projector in a darkened room, having the mirror up doesn't matter at all> The shutterspeed would be so low, that having the mirror up would not have made any significant difference in speed.

And Jin, you cannot track a moving subject with the mirror up, as you cannot keep on composing. So the mirror needs to come back down.

**DAZ** · 03-14-2012, 09:27 AM

Just a little more info, if you are in live view the mirror doesn’t come down. It can take the photos at the max speed that the shutter speed and the speed of the shutter can go. There is also no mirror vibration if you use live view.

DAZ

tempelorg · 03-14-2012, 09:52 AM

Originally posted by Macario

Well, if you tried to take a shot of the dark speaker and the brigh projector in a darkened room, having the mirror up doesn't matter at all> The shutterspeed would be so low, that having the mirror up would not have made any significant difference in speed.

I wonder how you can come to that conclusion. This is a K-5 after all, and I used a f/2 lens, ISO 6400, even handheld, and all the shots were 1/30 at most. So, in that regard, I am pretty sure that avoiding the extra mirror and other mechanics would indeed shorten the overall time.

tempelorg · 03-14-2012, 09:57 AM

Originally posted by DAZ

Just a little more info, if you are in live view the mirror doesn’t come down. It can take the photos at the max speed that the shutter speed and the speed of the shutter can go.

Ah, good point! I forgot about trying that.

I tried now, and I find it just as fast as with the non-live view mode. If I take 5 shots per bracketing, it takes about the same time, i.e. a bit more than a second. Maybe it's the shutter reset that takes so much time.

Adam · 03-14-2012, 10:09 AM

The mirror should be just as fast as the shutter, so the main issue here is noise and vibration. I guess some might like the fact that the image flickers in the vf, though. As far as I recall the Nikon D3x behaves the same way

Macario · 03-14-2012, 10:14 AM

Originally posted by tempelorg

I wonder how you can come to that conclusion. This is a K-5 after all, and I used a f/2 lens, ISO 6400, even handheld, and all the shots were 1/30 at most. So, in that regard, I am pretty sure that avoiding the extra mirror and other mechanics would indeed shorten the overall time.

What are all your shutterspeeds thenin this bracketing series. Then we can easily calculate the extra time the mirror takes

tempelorg · 03-14-2012, 10:23 AM

Originally posted by Adam

The mirror should be just as fast as the shutter

What makes you believe that? I've taken apart SLRs 30 years ago and have some understanding of the shutter mechanism. The "opening" process of the shutter is about what the flash sync time on it is, and then there's the time it takes to reset it. Both together should not take a 1/5 second, it should be much less.

Or look at it this way: The new Sony a77 is so fast with its 10 shots/s BECAUSE it doesn't have a moving mirror, or so they say. Read the reviews.

All this supports my assumption that the mirror slows down the bracketing time. What is your argument against it?

Clarification: Maybe you confuse cause and effect in this relationship: If the mirror is the slowest part (as I claim), then there's no use in making extra efforts to make the shutter faster, since _usually_ one won't gain any overall speed from it. The question I pose in this thread is: Could it be that the shutter is faster anyway, and if so, couldn't this special application (shooting with fixed Aperture and fixed Focus) speed up the bracketing shots thus?

Macario · 03-14-2012, 10:34 AM

Originally posted by tempelorg

What makes you believe that? I've taken apart SLRs 30 years ago and have some understanding of the shutter mechanism. The "opening" process of the shutter is about what the flash sync time on it is, and then there's the time it takes to reset it. Both together should not take a 1/5 second, it should be much less.

Or look at it this way: The new Sony a77 is so fast with its 10 shots/s BECAUSE it doesn't have a moving mirror, or so they say. Read the reviews.

All this supports my assumption that the mirror slows down the bracketing time. What is your argument against it?

Clarification: Maybe you confuse cause and effect in this relationship: If the mirror is the slowest part (as I claim), then there's no use in making extra efforts to make the shutter faster, since _usually_ one won't gain any overall speed from it. The question I pose in this thread is: Could it be that the shutter is faster anyway, and if so, couldn't this special application (shooting with fixed Aperture and fixed Focus) speed up the bracketing shots thus?

Did you know that the new Canon 1D-X can take 14fps, with mirror going down after everyshot? So it not the mirror that is the biggest issue, it is the shutter

Jodokast96 · 03-14-2012, 02:08 PM

Originally posted by tempelorg

The new Sony a77 is so fast with its 10 shots/s BECAUSE it doesn't have a moving mirror, or so they say.

I can't recall any that have said that. What they have said is that it allows the AF to function so fast because there is no moving mirror.

Wheatfield · 03-14-2012, 02:41 PM

Originally posted by Macario

Did you know that the new Canon 1D-X can take 14fps, with mirror going down after everyshot? So it not the mirror that is the biggest issue, it is the shutter

More to the point, it's a decision made by the manufacturer. In the case of Pentax, they decided to go with a shutter that would hit some 7 fps, so there isn't much point in putting in a mirror mechanism that would go faster.

falconeye · 03-14-2012, 04:11 PM

@templeorg, please read my studies about possible shutter-induced vibration in the K-5 and you'll know everything you'll ever need, and then some. The mirror is NOT slowing down exposure bracketing shots. It is not the slowest part as you claim. Or loudest. Or the one causing most vibration.

03-14-2012, 08:06 AM	#1
tempelorg Senior Member Join Date: Apr 2011 Location: Munich Photos: Gallery Posts: 203	Exposure Bracketing: Why not faster? I have a K20D and a K-5, and I keep wondering about this non-feature: When I shoot with exposure bracketing, i.e. take a series of shots at different EVs of the same scene, why does the camera move the mirror between each of the pictures instead of taking ONE measurement and then just lock the mirror up, shoot the 3 or 5 images, and only then lower the mirror again? Wouldn't that be much faster? Or are the electronics (sensor) so "slow" that they can't handle the gained speed? To clarify: I am aware that there are more moving parts involved, e.g. focussing and aperture. But my point is: The camera could offer a special "fast bracketing" mode, in which it assumes a fixed aperture and fixed focus for the entire bracketed sequence, and only varies ISO and/or exposure time. I'm pretty sure the camera mechanics can handle that, since it's already partly possible with the mirror-lock feature (i.e shutter independent from mirror, focus and aperture). Meaning, it's all just a question of software. (Man, as a software developer, it really bugs me that camera firmwares aren't open sourced, and that the makers are so closed up about their software dev process) Last edited by tempelorg; 03-14-2012 at 08:56 AM.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Exposure Bracketing	txborn	Pentax K-5 & K-5 II	11	01-16-2012 10:23 PM
HDR/Multi-exposure/Exposure Bracketing	sany	Troubleshooting and Beginner Help	4	04-24-2011 08:52 PM
Exposure bracketing with the K-x	ptx101	Troubleshooting and Beginner Help	6	04-05-2011 08:17 PM
Anyone with a k7 please help (exposure bracketing)	pixelhunter	Troubleshooting and Beginner Help	11	02-04-2011 11:06 AM
Exposure Bracketing	iman1981	Troubleshooting and Beginner Help	8	05-24-2010 01:21 AM

03-14-2012, 08:45 AM	#2
parsons Inactive Account Join Date: Apr 2010 Location: ENGLAND Posts: 389	it only takes a send to flick off five images, what difference will it make? it is just the way the camera works is my guess

03-14-2012, 08:49 AM	#3
tempelorg Senior Member Join Date: Apr 2011 Location: Munich Photos: Gallery Posts: 203 Original Poster	But in that ~1 second for the 3 or 5 shots the object might have slightly moved, and that annoys me. The other day I tried to take such imgs for HDR composition, in a darkened room with a video projector. I tried to get the speaker (dark) with the projected img (bright) on the same picture, so I needed the exposure bracketing. But the fact that the speaker moved slightly during this process makes creating the HDRs quite difficult. Had the camera taken the imgs in faster succession, this would be a much smaller issue.

03-14-2012, 08:59 AM	#4
JinDesu Veteran Member Join Date: Jun 2011 Location: New York City Photos: Gallery Posts: 5,638	I believe that having to drop the mirror down each time when doing bracketing is stupid, yes. It should just flip the mirror up, and take all the bracket shots, then drop the mirror. I imagine continuous drive should ALSO do this, except I believe continuous drive also drops the mirror after each shot.

03-14-2012, 09:15 AM	#5
Macario Pentaxian Join Date: Feb 2011 Location: Hoek van Holland Photos: Gallery \| Albums Posts: 1,393	Well, if you tried to take a shot of the dark speaker and the brigh projector in a darkened room, having the mirror up doesn't matter at all> The shutterspeed would be so low, that having the mirror up would not have made any significant difference in speed. And Jin, you cannot track a moving subject with the mirror up, as you cannot keep on composing. So the mirror needs to come back down.

03-14-2012, 09:27 AM	#6
DAZ Loyal Site Supporter Join Date: Sep 2006 Location: Everett, WA USA Photos: Gallery Posts: 744	Just a little more info, if you are in live view the mirror doesn’t come down. It can take the photos at the max speed that the shutter speed and the speed of the shutter can go. There is also no mirror vibration if you use live view. DAZ

03-14-2012, 09:52 AM	#7
tempelorg Senior Member Join Date: Apr 2011 Location: Munich Photos: Gallery Posts: 203 Original Poster	Originally posted by Macario Well, if you tried to take a shot of the dark speaker and the brigh projector in a darkened room, having the mirror up doesn't matter at all> The shutterspeed would be so low, that having the mirror up would not have made any significant difference in speed. I wonder how you can come to that conclusion. This is a K-5 after all, and I used a f/2 lens, ISO 6400, even handheld, and all the shots were 1/30 at most. So, in that regard, I am pretty sure that avoiding the extra mirror and other mechanics would indeed shorten the overall time.

03-14-2012, 09:57 AM	#8
tempelorg Senior Member Join Date: Apr 2011 Location: Munich Photos: Gallery Posts: 203 Original Poster	Originally posted by DAZ Just a little more info, if you are in live view the mirror doesn’t come down. It can take the photos at the max speed that the shutter speed and the speed of the shutter can go. Ah, good point! I forgot about trying that. I tried now, and I find it just as fast as with the non-live view mode. If I take 5 shots per bracketing, it takes about the same time, i.e. a bit more than a second. Maybe it's the shutter reset that takes so much time.

03-14-2012, 10:09 AM	#9
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	The mirror should be just as fast as the shutter, so the main issue here is noise and vibration. I guess some might like the fact that the image flickers in the vf, though. As far as I recall the Nikon D3x behaves the same way

03-14-2012, 10:14 AM	#10
Macario Pentaxian Join Date: Feb 2011 Location: Hoek van Holland Photos: Gallery \| Albums Posts: 1,393	Originally posted by tempelorg I wonder how you can come to that conclusion. This is a K-5 after all, and I used a f/2 lens, ISO 6400, even handheld, and all the shots were 1/30 at most. So, in that regard, I am pretty sure that avoiding the extra mirror and other mechanics would indeed shorten the overall time. What are all your shutterspeeds thenin this bracketing series. Then we can easily calculate the extra time the mirror takes

03-14-2012, 10:23 AM	#11
tempelorg Senior Member Join Date: Apr 2011 Location: Munich Photos: Gallery Posts: 203 Original Poster	Originally posted by Adam The mirror should be just as fast as the shutter What makes you believe that? I've taken apart SLRs 30 years ago and have some understanding of the shutter mechanism. The "opening" process of the shutter is about what the flash sync time on it is, and then there's the time it takes to reset it. Both together should not take a 1/5 second, it should be much less. Or look at it this way: The new Sony a77 is so fast with its 10 shots/s BECAUSE it doesn't have a moving mirror, or so they say. Read the reviews. All this supports my assumption that the mirror slows down the bracketing time. What is your argument against it? Clarification: Maybe you confuse cause and effect in this relationship: If the mirror is the slowest part (as I claim), then there's no use in making extra efforts to make the shutter faster, since _usually_ one won't gain any overall speed from it. The question I pose in this thread is: Could it be that the shutter is faster anyway, and if so, couldn't this special application (shooting with fixed Aperture and fixed Focus) speed up the bracketing shots thus?

03-14-2012, 10:34 AM	#12
Macario Pentaxian Join Date: Feb 2011 Location: Hoek van Holland Photos: Gallery \| Albums Posts: 1,393	Originally posted by tempelorg What makes you believe that? I've taken apart SLRs 30 years ago and have some understanding of the shutter mechanism. The "opening" process of the shutter is about what the flash sync time on it is, and then there's the time it takes to reset it. Both together should not take a 1/5 second, it should be much less. Or look at it this way: The new Sony a77 is so fast with its 10 shots/s BECAUSE it doesn't have a moving mirror, or so they say. Read the reviews. All this supports my assumption that the mirror slows down the bracketing time. What is your argument against it? Clarification: Maybe you confuse cause and effect in this relationship: If the mirror is the slowest part (as I claim), then there's no use in making extra efforts to make the shutter faster, since _usually_ one won't gain any overall speed from it. The question I pose in this thread is: Could it be that the shutter is faster anyway, and if so, couldn't this special application (shooting with fixed Aperture and fixed Focus) speed up the bracketing shots thus? Did you know that the new Canon 1D-X can take 14fps, with mirror going down after everyshot? So it not the mirror that is the biggest issue, it is the shutter

03-14-2012, 02:08 PM	#13
Jodokast96 Veteran Member Join Date: Oct 2007 Location: Erial, NJ USA Photos: Gallery \| Albums Posts: 2,134	Originally posted by tempelorg The new Sony a77 is so fast with its 10 shots/s BECAUSE it doesn't have a moving mirror, or so they say. I can't recall any that have said that. What they have said is that it allows the AF to function so fast because there is no moving mirror.

03-14-2012, 02:41 PM	#14
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,981	Originally posted by Macario Did you know that the new Canon 1D-X can take 14fps, with mirror going down after everyshot? So it not the mirror that is the biggest issue, it is the shutter More to the point, it's a decision made by the manufacturer. In the case of Pentax, they decided to go with a shutter that would hit some 7 fps, so there isn't much point in putting in a mirror mechanism that would go faster.

03-14-2012, 04:11 PM	#15
falconeye Veteran Member Join Date: Jan 2008 Location: Munich, Alps, Germany Photos: Gallery Posts: 6,871	@templeorg, please read my studies about possible shutter-induced vibration in the K-5 and you'll know everything you'll ever need, and then some. The mirror is NOT slowing down exposure bracketing shots. It is not the slowest part as you claim. Or loudest. Or the one causing most vibration.