Alignment of multiple HDR bracketed shots in recent OM-D cameras

[vmlinuz]

Hello,

Let's imagine we're taking a HDR bracket of 3 or 5 images. (I mean HDR bracketing that produces a sequence of ORF files, not the HDR1 and HDR2 modes that produce JPEGs.) Quite often the total time to take the sequence will be a fraction of a second - a shutter speed that the camera's stabilization (especially Sync IS) can handle easily in most cases.

Are there any OM-D cameras where the stabilization is active during the whole sequence (as if it was a single shot), such that no alignment is necessary in post processing?

On my E-M5 III this is not the case. Moreover, HDR mode insists on using the mechanical shutter, which does not seem to make much sense for typical use. So I use AE bracketing with electronic shutter (5 shots separated by 1 EV) which works OK, but it would be great if the camera already did its best to align the shots by itself.

I understand that the stabilization can work better if it is free to readjust in-between shots. But when HDR bracketing, the total duration of the sequence is dominated by the longest single exposure time anyway, so I don't expect that one would loose much by having the stabilization work as if a single long exposure was taken.

 

[sciencenerd]

If you set up exposure bracketing (not HDR), you can select electronic shutter. Then use "fps priority" in IS settings. In this case, the sensor will not be reset during a burst.

"[Fps Priority]: Shooting speed gets priority over image stabilization. The sensor will not be reset to the center during sequential shooting."

With the E-M5 iii 30 fps maximum burst rate, you should be able to get a bracket f five shots in the range of 1/5 s, or a little bit more, depending on the individual shutter speed of each shot.

 

[Regor250]

Hello,

Let's imagine we're taking a HDR bracket of 3 or 5 images. (I mean HDR bracketing that produces a sequence of ORF files, not the HDR1 and HDR2 modes that produce JPEGs.) Quite often the total time to take the sequence will be a fraction of a second - a shutter speed that the camera's stabilization (especially Sync IS) can handle easily in most cases.

Are there any OM-D cameras where the stabilization is active during the whole sequence (as if it was a single shot), such that no alignment is necessary in post processing?

Stabilization should still be active during bracketing for the entire duration as long as you keep the shutter button pressed, but this doesn't guarantee alignment to the degree that is needed for multiple shots stacking. Use a tripod or align images in post.

On my E-M5 III this is not the case. Moreover, HDR mode insists on using the mechanical shutter, which does not seem to make much sense for typical use. So I use AE bracketing with electronic shutter (5 shots separated by 1 EV) which works OK, but it would be great if the camera already did its best to align the shots by itself.

I understand that the stabilization can work better if it is free to readjust in-between shots. But when HDR bracketing, the total duration of the sequence is dominated by the longest single exposure time anyway, so I don't expect that one would loose much by having the stabilization work as if a single long exposure was taken.

 

[vmlinuz]

If you set up exposure bracketing (not HDR), you can select electronic shutter. Then use "fps priority" in IS settings. In this case, the sensor will not be reset during a burst.

That's amazing, you are my hero of the day! For me this is like getting a new camera, thanks! (I believed that I knew all OM-D settings very well, but always thought about this particular one as something that I don't need, because I mostly don't care about exact FPS.)

I did a few test shots. All came out perfectly. The slowest one consists of 5 images with exposure times between 1/80 s and 1/5 s taken with the 12-40 f/2.8 at f=13 mm (so without Sync-IS). All images are aligned absolutely perfectly. I did not even lean against anything, just applied proper technique.

Since the longest exposure of a burst comes last, the whole process is quite robust: if there is shake, it will only affect the brightest image in most cases. This won't ruin the shot, only increase noise by 1 EV.

I use Darktable under LInux for raw development, and all tools for aligning stacks that I tried have their quirks and are cumbersome: hugin is complicated and not very robust in my experience, hdrmerge works but has fundamental limitations (it cannot rotate and can only shift by whole pixels). Integration of these tools with Darktable is inconvenient.

Now I can simply use Darktable's built-in stacking which is meant for tripod-shot series. Who knows, perhaps this can be used for reducing noise of non-HDR shots, which could also serve as homemade computational ND.

I've put this, together with other appropriate settings (aperture priority at f/5.6, -1/3 EV, ISO 200, 30 fps electronic shutter, AE bracketing) onto the C mode. My previous use of the custom mode was not nearly as useful.

 

[vmlinuz]

Are there any OM-D cameras where the stabilization is active during the whole sequence (as if it was a single shot), such that no alignment is necessary in post processing?

Stabilization should still be active during bracketing for the entire duration as long as you keep the shutter button pressed, but this doesn't guarantee alignment to the degree that is needed for multiple shots stacking. Use a tripod or align images in post.

Well, it's not unless fps priority is enabled as thankfully explained by sciencenerd!

Also, if OM-D stabilization is capable of rock-solid single exposures of, say, 0.5 s (which it is), why would a tripod be needed for bursts of shorter duration?

 

[sciencenerd]

Happy to hear. I've been using these settings with my E-M5 ii for exposure bracketing for a long time. But, just like you, it took me a while to stumble across the fps priority setting.

As to Darktable, I love the program. Very powerful, but also a very steep learning curve.

 

[Regor250]

Are there any OM-D cameras where the stabilization is active during the whole sequence (as if it was a single shot), such that no alignment is necessary in post processing?

Stabilization should still be active during bracketing for the entire duration as long as you keep the shutter button pressed, but this doesn't guarantee alignment to the degree that is needed for multiple shots stacking. Use a tripod or align images in post.

Well, it's not unless fps priority is enabled as thankfully explained by sciencenerd!

Also, if OM-D stabilization is capable of rock-solid single exposures of, say, 0.5 s (which it is), why would a tripod be needed for bursts of shorter duration?

Not quite "rock solid". Good enough for useful result with slow shutter speed, but when stacking multiple images it has to match pixel for pixel. The slightest drift, othewise un-noticed on long exposure if absolute sharpness isn't critical, will create motion artifacts (double edges etc.) when stacking.

--
Roger

 

[TorsteinH]

If you set up exposure bracketing (not HDR), you can select electronic shutter. Then use "fps priority" in IS settings. In this case, the sensor will not be reset during a burst.

"[Fps Priority]: Shooting speed gets priority over image stabilization. The sensor will not be reset to the center during sequential shooting."

With the E-M5 iii 30 fps maximum burst rate, you should be able to get a bracket f five shots in the range of 1/5 s, or a little bit more, depending on the individual shutter speed of each shot.

Strange, I have taken several pretty long exposures with exposure bracketing without setting my camera to FPS Priority.

A sample I'm happy with, HDR from 5 exposures (-4, -2, 0, +2, +4,) at ISO 12800 - 1/10s - f/2.8 :





I'm using Affinity Photo to do the HDR merge. It has an option to remove "ghosts," maybe that's the reason I feel it's sharp enough?

--
Torstein
Some of my latest Photos