Question about HDR & Toning with Canon 40D using auto exposure bracketing 5 exposures

[snowshine]

Hi,
There are few programs allow 5 exposures to be unified in HDR processing.

I find in Canon 40D Auto Exposure Bracketing [AEB] allows one to automatically take three different exposures automatically by pressing the shutter button only once [by setting the shutter button on timer].

Is there a way it could be set for 5 different exposures under Auto Exposure Bracketing?

Regards

[NoCard]

Hi Arun,
I don't know the Canon 40D but I think it could be done this way...
eg. If bracketing is +/- 1EV
1. Set EV compensation to -1EV
2. Take a AEB shot - gives actual EV's of -2, -1, 0 (due to EV compensation of -1 EV)
3. Rest EV Comp to +1EV
4. Retake AEB shot - this time it should give 0, +1, +2
5. From these 6 shots you can select -2, -1, -0 , +1 and +2 to make your 5 exposure set.

Hope this helps!

[snowshine]

Hi NoCard,
That is one way but I felt to get maximum compatibility for tone mapping, I preferred not to touch the camera while I take my scene with multiple exposures.
In your proposed way though one could in theory avoid the camera position change while doing, in practice I felt it is bound to have some change in it's position while changing the AEB [Auto Exposure Bracketing].

Regards

[FrankMi]

Hi Arun, you are fortunate that your camera has Auto-Bracketing. My Nikon D3100 does not, but then I've never felt that this was a drawback as I can shoot any number of bracketed exposures by just flicking the Exposure Compensation anywhere from +5EV to -5EV in as small as 1/3rd EV stops. By the same token, I shoot night photography and my camera will only shoot down to 30 seconds before I need to shoot in bulb mode and time it manually. Without the Auto-Bracketing feature, I use the same procedure regardless of the number or range of exposures. I think the most number of exposures I've taken of a single image for HDR was 9 and Photomatix had no problem processing them.

[dje]

Hi NoCard,
That is one way but I felt to get maximum compatibility for tone mapping, I preferred not to touch the camera while I take my scene with multiple exposures.
In your proposed way though one could in theory avoid the camera position change while doing, in practice I felt it is bound to have some change in it's position while changing the AEB [Auto Exposure Bracketing].

Regards

Hi Arun

If you're using a tripod and are careful when changing the settings, you shouldn't have too many problems with change of camera postion. HDR software usually allows for alignment of images anyway and this should compensate for small changes in camera position.

I wonder however whether there's any real need for more than 3 exposures ?

Cheers Dave

[Colin Southern]

I wonder however whether there's any real need for more than 3 exposures ?

Hi Dave,

A lot of people have "mantras" about how many shots to take, and how far apart to make them, but the short anwser is that "it really depends on the dynamic range of the scene that one wishes to capture" - sometimes I'll only need two (perhaps the interior of a room and the view outside the window) (usually about 3 stops apart), whereas at other times I might shoot up to 7 (in situations where I'm shooting into the setting light, but want to retain foreground shadow detail).

There really isn't "one size fits all".

Having just said that, many folks take their bracket at only 1 shot EV intervals, which is really a waste of time - 2 stops (minimum) for HDR is fine.

[FrankMi]

Having just said that, many folks take their bracket at only 1 shot EV intervals, which is really a waste of time - 2 stops (minimum) for HDR is fine.

I may be incorrect as my camera doesn't have the Auto-Bracketing feature, but I've been told that this feature on some cameras only allow you to shoot in 1EV increments? If so, then they need to take 5 shots to get the -2EV to +2EV range. Can anyone confirm?

[Colin Southern]

I may be incorrect as my camera doesn't have the Auto-Bracketing feature, but I've been told that this feature on some cameras only allow you to shoot in 1EV increments? If so, then they need to take 5 shots to get the -2EV to +2EV range. Can anyone confirm?

No idea I'm afraid

Personally I wouldn't be too worried though -- just as easy to have the camera in manual mode and adjust the shutterspeed between shots. If one were capturing 1EV steps then personally, I just wouldn't use every 2nd one -- all it's going to do is slow everything down for no visible benefit.

[stevewe88]

Going back to Arun's original question.

The answer on any Canon camera is unfortunately no. Canon only ever build in a 3 shot auto bracket. I think it depends on the model as to whether this can be done in 1/3rd, 1/2 or full stop increments.

Being a Canon user, it is something that you learn to live with and do as Rob said, use EV comp to take a second, third etc set of bracketed shots without having a '0' exposure frame in every set of three bracketed shots.

I know Nikon allow you to take at least 5 bracketed shots on a lot of their bodies and more too on some.

As long as you have a sturdy tripod then changing settings shouldn't cause too much of an issue but even if it does, the auto align feature on most HDR software should sort that out no problem at all.
Cheers
Steve

[Colin Southern]

Canon only ever build in a 3 shot auto bracket.

Not quite,

The 1D3 / 1Ds3 / (presumably) 1D4 have firmware selectable 2 - 3 - 5 - 7 shots

[stevewe88]

Not quite,

The 1D3 / 1Ds3 / (presumably) 1D4 have firmware selectable 2 - 3 - 5 - 7 shots

Apologies I was listening to something on a podcast last week where they were talking about the rumours for the new 1D and it sounded like the 3 shot restriction went all the way through the range.

[Colin Southern]

Apologies I was listening to something on a podcast last week where they were talking about the rumours for the new 1D and it sounded like the 3 shot restriction went all the way through the range.

Probably the reviewers couldn't afford one

[snowshine]

I think it could be done this way...
eg. If bracketing is +/- 1EV
1. Set EV compensation to -1EV
2. Take a AEB shot - gives actual EV's of -2, -1, 0 (due to EV compensation of -1 EV)
3. Rest EV Comp to +1EV
4. Retake AEB shot - this time it should give 0, +1, +2
5. From these 6 shots you can select -2, -1, -0 , +1 and +2 to make your 5 exposure set.

Hope this helps!

Where there is a will there is a way, Thank you.

It is also very helpful to know that minute camera position change would not make a difference.

Thank you all.
Regards

[victor]

On my 7D I use the custom settings c1,c2 and c3 for HDR Work.

AV set to F13 ISO to 100.

For example using 1 stop of Ev for each:

C1 has the Darkest Exposures (-4,-3,-2)
C2 has the Zero Included in its range (-1,0,+1)
C3 has the Lightest Exposures (+2,+2, +4)

Set the AEB sequence to be -,0,+ in the menu AEB Sequence.

All photos are then taken on a tripod starting at C1, then C2, Then C3. All appear in Lightroom and Bridge in the correct order for processing as well.

Regards

[Dave Humphries]

I may be incorrect as my camera doesn't have the Auto-Bracketing feature, but I've been told that this feature on some cameras only allow you to shoot in 1EV increments? If so, then they need to take 5 shots to get the -2EV to +2EV range. Can anyone confirm?

Hi Frank,

The manual on my Nikon D5000 says the AEB increments can be varied in 0.3 stop steps, between 0.3 and 2.
That is achieved in 3 exposures (no option for more).

All,

If I were doing AEB for HDR (as opposed to just lazily getting an exposure spot-on), I would set 2 stops, as (agreeing with Colin again) I can't see a point in having less - if you have a camera with say 12 stops Dynamic Range (DR), why make an AEB shot set that only extends that by about one more stop? The scene could be more!

Using such tiny increments for HDR is a bit like trying to drive fast, but economically, in a car with 6 gears and only using the lowest 5

The aim of AEB for HDR is to extend the top and bottom ends of total DR of the set, doing that by tiny steps and more exposures isn't going to make that much difference.
More shots might give a little versatility if one were compromised in some way, but using 3 shots at -2, 0 and +2, giving 16 stops DR, sounds like a better way to go to me, speaking as someone who has never felt the need to 'go there'

Cheers,

[arith]

I don't know, I tthink I worked it out all myself and worked out you need perfect exposure on the base shot. then two more 2 ev apart as quickly as possible. I used to do better HDR but with superfluous images and effort, now I don't bother because people are not even interested.

[FrankMi]

Hi Dave,

I agree. In testing to determine what works well and what doesn't for HDR I've found that most scenes that need it, -2EV, 0EV, and +2EV is sufficient unless you are shooting directly into the sun for something like a sunrise/sunset or certain combinations of city and sky lighting for night photography in which case I may go as high as -4EV to +4EV with 5 images. Although it seems that Photomatix is quite happy with as many images as I care to throw at it, provided they are spaced at least 1EV apart, I've not seen any noticeable benefit using images less than 2EV apart. However, If my camera forced me to take 5 images to get from -2EV to +2EV (or more), I can just throw the 5 or 9 image set into the mix rather than mess with sorting out the odd numbered images.

My point to Arun is that it's no big deal to shoot multiple EV's even if you don't have Auto-Bracketing. In that situation I am always on a tripod with a cable release, in aperture priority, I let the camera set the shutter speed by varying the EV with the thumbwheel, always go from underexposed to overexposed for consistency, and reset the EV back to zero at the end of the series. I also check the histograms before I move the camera in case my exposures need tweeking. In short, I'm having fun!

By the way, I might run the series more than once, particularly for night photography so that I have the option of cloning out glairing headlights, getting traffic lights to match, etc. More fun!

[Dave Humphries]

Hi Frank,

My mistake; the only bit of my post that was actually aimed at you was the Nikon answer about AEB.

I should have (and have now) opened the rest up to general discussion, but as usual, what you say makes perfect sense. If there's a quick, easy way, go with that, but otherwise, especially if doing it manually, the less times you have to touch the camera to adjust the EC/EV the better, so going wider makes sense.

Have you ever tried -4, 0, +4 compared to -4, -2, 0, +2, +4?
I ask because, hey, you never know, I might try one day
(mind you, I'd have to do it by your method to get the steps that wide)

Cheers,

[FrankMi]

Have you ever tried -4, 0, +4 compared to -4, -2, 0, +2, +4?

Hi Dave,

I have not tried running the tonemapping range that wide. Usually I'm dealing with the sky at night when I need a wide EV range and that can get really noisy. I haven't done any specific testing to verify that it helps, but I prefer to use more, rather than less images when the exposure range gets really wide, thinking that it may help to reduce the noise. I suppose I really need test to see if it actually helps or not and if so, by how much!

[Dave Humphries]

~ but I prefer to use more, rather than less images when the exposure range gets really wide, thinking that it may help to reduce the noise. I suppose I really need test to see if it actually helps or not and if so, by how much!

Yes, I was guessing it didn't help (because of different exposures?) mainly due to the fact that a lot of ultra-tone mapped images are often also noisy! I could be wrong of course.

I'd be interested to hear the result if you do test one day.

Cheers,