I am going to try HDR (photomatix 3) but with film scans (I still use film) and wonder if anyone out there has any experience of this. I understand that allignment or registration is the big issue, and I am awaiting some film back with bracketed exposures to give it a try. (I am of course using a tripod.)
any advise or experience to share would be very helpfull

Are you using one exposure of film or multiple exposures of film?

Scanned film will never be perfectly in register, so the software will have to work a lot harder to bring everything into alignment. If you're shooting medium format film and scanning at high resolution, you'd better have a lot of RAM and have plenty of time on your hands. Even with 35 mm film, a high resolution (5400 dpi) scan yields a ~120 megabyte file, so you're asking a lot of the software.

For what it's worth, the Photomatix Photoshop plugin cannot accept files from the Eos-1Ds III because they're too big at 100 meg plus; you have to use the stand-alone version. I presume high resolution scans will have the same issue, but I haven't tried it personally.

It's been a while since I've scanned film, and I may not be up to date on the latest techniques, but to get a true HDR image, you will likely need more than one exposure. Combining film exposures is difficult, since film is non-linear. Paul Debevec discusses one method. True HDR uses special encodings, which are discussed here. Sixteen bit aRGB is not sufficient for HDR.

Finally, you will want to use scanner software that allows HDR capture without tone mapping into a 24 bit space. SilverfastHDR is one such program.

Bill

I can’t provide information comparable to the in depth information of the prior posters, but I can relay my personal amateur experience. I hope it is of some help.

I’ve used multiple film exposures with limited success with my Minolta 5400 (original version). I did the blending manually in Photoshop. I did not use HDR, so I can’t comment on the HDR aspects. I always used bracketed exposures shot with a tripod.

I’ve never been able to get an acceptable alignment over the entire film frames, so I never used multiple film exposures except in limited circumstances. If, for example, I had a scene where the top portion was very bright, with a fairly well defined border between the bright top and lower darker area, I have successfully used two film exposures. In that case, I just needed to make sure that the border area between the top and bottom portions was aligned. It was not necessary that other portions of the film frames aligned.

In Photoshop I put the two scanned frames in separate layers with a layer mask and blended the mask accordingly to reveal the darker exposure of the top bright portion and the lighter exposure of the darker lower portion. If the situation is good, the technique works very well. Most of the time, however, I had alignment problems.

I’ve also used the same film frame but scanned with different scan exposures. If I did so with one scan immediately followed by the second scan, I obtained perfect (or near perfect) alignment. I then blend the two scans as described above. In this case, however, I could blend the two exposures throughout the entire film frame if necessary. In practice, however, I usually ended up with very little use of one of the two scans. I’m not sure that after all is said and done that I really accomplished much by using two scan exposures. I certainly wouldn’t guarantee that using multiple scan exposure is going to deliver results that you couldn’t obtain otherwise by normal Photoshop editing of a single well exposed film frame.

Geoff,
I have been using the plug-in without problems on my 1Ds Mk3 files. There is indeed a limit on the size the plug-in can work on, but it is related to Megapixels (width x height in pixels), not Megabytes. The current limit is between 30-40 Megapixels, so your 1DS Mk3 with 21 Megapixels should be fine.

Cheers,

Andrew

As I said I am bracketing exposures on the film (I have done 3 shot bkt. with 1, 1.5 & 2 stop gaps as tests)

Yes I have tried all these techniques and had varying success. I think it really depends on what your photograph is as to how successful the results will be.

I have got the film back and given the process a try, so far allignment has been OK on one scene but not so good on another, so I suspect that this will be hit and miss.
The bigest problem so far has been getting anything nice as a result, but I think I need to play more with all the adjustments. The best result so far was with the Photomatix 'Blending' mode, which is not a HDR process it just blends the 3 exposures, you can tweek it a bit but not much. Its a bit like the photoshop blending layers method but automated.

I will continue to try it out.

I've done this before. Perfect registration is impossible, so HDR software won't work well. What works best is to scan the exposures correctly (e.g., do not compensate for their exposure values) and use layer masks to hide & reveal the elements of the scene to your liking.

Thanks for that, yes that seems to be the conclusion I am getting to.
Thanks for the information.

If image alignment is such a big problem when scanning film, I could have a solution to this: I wrote a program to blend RAW files with different exposures focusing on:
1. Maximum noise reduction: each individual pixel is taken from the less noisy RAW file
2. Avoid any progressive blending: final pixels are taken from one single source image so any loss of sharpness due to misalignment is not possible

To avoid artifacts in the border areas taken from one or other shot, some configurable progressive blending can be set for those areas. It usually does not represent more than 3% of the total image surface.

For instance this HDR scene (12 f-stops of real DR):



was built noise free from 3 RAW files 2EV apart. Each pixel was taken from one of them according to this blending map (black colour represents the highest exposure RAW file, gray is medium and white is the least exposed RAW file):




A tutorial with an approach to do the manual tone mapping of the resulting image is also included. Sorry for the crappy English online translations.

ZERO NOISE TUTORIAL

HDR TONE MAPPING


Peter, if you provide me with 2 or more RAW files shot over the same film at different exposure values, I would be glad to blend them and show you the result.

BR

Thanks for that, I have sent you an email (address from your website), so we can progress from there.

Hi Guillermo,

how do you make raws out of scanned film??

- But your images look very good, I look forward to use your programs on raws from my Nikon D200.

Good light! - Hening.

I won't do that, will use the TIFF files instead. My worry is how linear or pre-processed they will be, let's see...

I am happy to learn that your programs work on TIFFs as well, so I will be able to use them on my scanned film, too!