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Nathan Potter
26-Jun-2012, 08:31
Over the years I have occasionally taken multiple images using 4X5 film. Usually that consists of three exposure brackets, one centered and one each under and over at 1 to 2 stops. This for mostly scenes I thought were particularly unique at the time. Since these are principally chromes with rather crappy dynamic range I've recently had the thought of combining these using some kind of HDR technique to increase dynamic range. I've not fiddled with HDR software at all so have no experience with the technique.

My thought is to make three scans on an Epson 750 then move them to an HDR package such as Photomatix to combine and tweak, then move to PS for final tweaking. Would Photomatix be suitable for this?

I've not seen any references for doing this in large format so I wonder about a couple of issues. First can multiple LF images that have been scanned be adequately registered using a software package? Has anyone tried this? Second, I'd like to preserve decent resolution for say a 16 X 20 print, so what are the prospects for doing this?

Essentially I'm not after gaudy effects but would like to preserve the natural rendering found in mostly Fuji Astia chromes. I suppose the same technique could be used for B&W LF.

Any input would be very useful.

Nate Potter, Austin TX.

rdenney
26-Jun-2012, 09:13
This falls into the category of "any input" rather than "expert input".

The Photomerge software in Photoshop is accurate enough to align images in translation, but has more problems in rotation, in my experience. Given your overlap will be 100%, it might work better than in my case, where I was scanning and merging two 6x9 ends of a 6x12 image.

Read about stitching in the various threads on using stitching from DSLRs for scanning--that should provide more clues.

As to managing the tones during the merge into an HDR--I'll step aside and let others comment. My ideas on the topic are all theoretical.

Rick "curious" Denney

Andrew O'Neill
26-Jun-2012, 10:15
Could you not increase the dynamic range by pre-exposing in the field? I did this back in the 90's. You'd save money on film, too.

drm
26-Jun-2012, 10:16
You might consider doing a manual exposure blend in PS, instead of the usual hdr approach. You have complete control of the process and the result can be much more natural looking. Along with the traditional exposure blending through layer masks there is a more precise technique, exposure blending through a luminance mask (http://goodlight.us/writing/paintinghdr/paintinghdr-1.html) which is a little more complex at first, but in reality it is much less work and produces better results.

Peter De Smidt
26-Jun-2012, 11:15
You are going to want to use Adobe's PhotoMerge to align the images. You can then save them as separate files. After that, you can use any HDR software that you like. You might as well give Photoshop a try, since you have it. Photomatix would certainly work too, and it should have a demo mode. If you do use it, try the exposure fusion method instead of true HDR, as it gives a much more realistic result.

I took a series of of 4x5 chromes with this in mind, but I haven't gotten around to actually doing it. The main issue will be if there is any subject movement between the frames.

I agree with Dean. If you go the manual route, luminosity masks in Photoshop would be the way to go.

adam satushek
26-Jun-2012, 13:48
I have blended scans from multiple negatives in PS to increase dynamic range. I used to do it more when I scanned on an Imacon, but with my current scanner it has not yet been necessary.

I prefer the manual method; open 2 (or 3) scans in photoshop, layer manually, add layer masks, and simply paint in the areas that are needed. I find this an easy method to open shadows and add detail to highlights. I have tried HDR in photoshop but I prefer the control this offers. I have not played with luminiosity masks....so cannot comment there.

Ken Lee
26-Jun-2012, 14:39
I tried Photomatix and thought most of it was gimmicky. Perhaps the "effects" are less appealing if we're looking for a classic Large Format look.

Photoshop lets us merge in a number of ways, as others have pointed out.

Did I miss something with Photomatix?

Kirk Gittings
26-Jun-2012, 14:40
I've been using Tony's luminosity masks for many years. They are quite effective for small adjustments, but for a boost say beyond about 2/3-1 stop in shadow areas, I think he will find it lacking. I know I do. It is worse for recovering highlights. HDR programs, as a means of exposure blending (rather than creating cartoonish effects), are getting much better-at least the ones I mentioned.

Henry Ambrose
26-Jun-2012, 15:33
If its about gaining some details in particular areas, blend it by hand. IE: If you're working to save a blown out or featureless sky you can simply transfer over the well exposed sky and a bit more of the edges, then erase, adjust opacity, curves, etc. until you get what you want. Its tedious but works well. I do it regularly with DSLR files. You can also scan the same piece of film with different scan settings to get "better" sections of the film to blend with the good overall exposure that's lacking something.

Peter De Smidt
26-Jun-2012, 15:59
I tried Photomatix and thought most of it was gimmicky. Perhaps the "effects" are less appealing if we're looking for a classic Large Format look.

Photoshop lets us merge in a number of ways, as others have pointed out.

Did I miss something with Photomatix?

Try Photomatix's Exposure Fusion.

Another tip is to get as good a non-hdr image as you can. Then use that to blend with your hdr image, using masks if needed.

Peter De Smidt
26-Jun-2012, 19:42
I've been using Tony's luminosity masks for many years. They are quite effective for small adjustments, but for a boost say beyond about 2/3-1 stop in shadow areas, I think he will find it lacking. I know I do. It is worse for recovering highlights. HDR programs, as a means of exposure blending (rather than creating cartoonish effects), are getting much better-at least the ones I mentioned.

This sounds like using a layer mask and something like a curve to make a tonal adjustment on an image. Like Kirk says, there's only so far you can push this, but that's not the suggestion here. In this case we're talking about using luminosity masks to blend files from differently exposed negatives. Once the files are aligned and in a layer stack you would apply an appropriate luminosity mask to each layer. For instance, with the layer with the most exposure you'd use something like an extended dark mask. (Using the darks from that file would give the most shadow separation.) For the middle exposure you'd use something like an extended mid-tone map, and for the the least exposed image you'd use the extended highlight luminosity mask. You'd then adjust the opacities of the layers to generally get the look you're after, kinda like finding the right contrast setting for your VC silver print. You'd then flatten the layers (or ctrl+alt+shift+E). It's on that layer that you'd apply any needed curves or local tonal adjustments.

This (or hdr) bracketing could be useful with an extreme range of tonal values, or where you already have negatives that were bracketed. For new BW exposures, though, divided Pyrocat would likely capture the whole range of luminosities in the scene in one go.

alexn
26-Jun-2012, 20:39
I have done Velvia 50 HDR's and the results are always very very noisy... I think if I tried doing smaller steps (1 stop is a big step on slide film as we all know) bracketing -1/3, 0 & +1/3 or even half stops... In my opinion, the results I've seen have made me a more proficient meter user, as I dont think HDR with slides is worth the effort.. Just work hard to nail the exposure, and worst case scenario, in really tricky spots, bracket at 1/3 or 1/2 stops then pick the best when they are developed... Single exposures always look better than merged/fused/hdr blends... (In my opinion)

Brian Ellis
27-Jun-2012, 07:09
There are many ways to do what you're talking about. Photomatix is one (the image can often look as "natural" as you want, there's nothing about Photomatix that automatically produces the kind of images that scream "HDR"). The merge tools in Photoshop are another. I sometimes use Photomatix, other times I put the three images as layers in a single file (Tools > Photoshop > Load Files Into Photoshop Layers is one way) and then mask, blend, paint and erase as desired.

MIke Sherck
27-Jun-2012, 07:15
Could you not increase the dynamic range by pre-exposing in the field? I did this back in the 90's. You'd save money on film, too.

Could you possibly point me to a reference? I'd like to know more about it.

Mike

Preston
27-Jun-2012, 08:28
Mike,

St. Ansel explains pre-exposure in detail in his book The Negative for B&W films.

I have done it in the field. I photographed a grey card with the exposure of the card placed on Zone II, on Tri-X. I don't recall if I adjusted my development time, though.

--P

Kirk Gittings
27-Jun-2012, 10:16
There are many ways to do what you're talking about. Photomatix is one (the image can often look as "natural" as you want, there's nothing about Photomatix that automatically produces the kind of images that scream "HDR"). The merge tools in Photoshop are another. I sometimes use Photomatix, other times I put the three images as layers in a single file (Tools > Photoshop > Load Files Into Photoshop Layers is one way) and then mask, blend, paint and erase as desired.

If the desired effect is a natural looking exposure blend, I think most people will find Photomatix a pretty blunt tool compared to LR/Enfuse (for about a two stop compression) or S-N-S HDR Pro (for up to about a 4 stop compression). None of these programs are perfect but the two I mentioned give you a file pretty close that can be further tweaked or combined in areas with a "straight" image for very satisfying results. I personally can't come close to these results with Photomatix.

FWIW, even at the very top of the Architectural Photography profession, pretty much all practitioners that I know are using some HDR exposure blending technique to one extent or another.

Henry Ambrose
27-Jun-2012, 10:40
I agree with Kirk about Photomatix. A very blunt tool, like a baseball bat.
Its really not hard and costs nothing to blend by hand.
After a little practice it gets easier and you get faster.

cjbroadbent
27-Jun-2012, 12:35
.... A very blunt tool....
Not so blunt if you get rid of the awful presets, keep it low strength and learn to use the sliders.
To answer the original question; Photomatix matches-up perfectly two 4x5 negatives scanned in the Epson holder. You just have to be careful sliding the crop frame across and make sure to exclude the border. My egg-cup on the still-life thread is from two negatives. With one negative, I always do three scans when there are whites and reflections. It's a weakness, but I trust my negative but I don't trust the scanner.

Andrew O'Neill
27-Jun-2012, 13:15
Mike,

The easiest way in my opinion, is to metre the scene through a piece of milky plexi glass (as noted in AA's book, The Negative), transfer your reading (minus 4 stops or so. you'll have to experiment) to the lens, and then place the same plexi over your lens when you make the pre-exposure.

andrew

Ivan J. Eberle
27-Jun-2012, 14:30
If talking about new exposures for goodness sake use color neg to gain 4 stops or more dynamic range over Astia and 6 or more versus Velvia. It's fairly uncommon that you'll need more than what neg film will provide in one exposure and unlikely that you'll ever need 3.

Henry Ambrose
27-Jun-2012, 16:10
Not so blunt if you get rid of the awful presets, keep it low strength and learn to use the sliders.
To answer the original question; Photomatix matches-up perfectly two 4x5 negatives scanned in the Epson holder. You just have to be careful sliding the crop frame across and make sure to exclude the border. My egg-cup on the still-life thread is from two negatives. With one negative, I always do three scans when there are whites and reflections. It's a weakness, but I trust my negative but I don't trust the scanner.

If you're gonna use it turned all the way down to "1" why not do it manually.
Its just not that hard.
And you learned something rather than just bought something.

MIke Sherck
27-Jun-2012, 16:51
Thanks, Preston and Andrew! I have that book somewhere but haven't read it in years. I'll look it up and see how it might help.

Mike

Nathan Potter
27-Jun-2012, 19:42
Folks, thanks for the discussion. I procured Photomatix as a first try since it was recommended by Steimueller
and Gulbins and they describe a bit about its use.

As Kirk points out there seems to be high regard for the S-N-S HDR Pro and I assume that is often used in architectural work which I would guess is fairly demanding for capturing reality.

cjbroadbent, the registration of scanned 4X5s was one of my concerns since I could find nothing about HDR operations on scanned images; so your comment is encouraging. Turning down the Photomatix sliders makes sense.

ivan Eberle, for me I'll work with some old exposures for now (4X5 and 35mm) but start using Ektar 4X5 soon.

I'm limited in using Photoshop - have only CS on a Mac G5 with 8Gb. Also not thoroughly adept at PS intricacies. I'm really an analogue person since 1942 when my first postcard format image was taken.

Never used a digital camera until a month ago when a D800E arrived. My god! 34 external buttons and switches almost exceed the cockpit controls on my old VP-23 US Navy Neptune plane!

Nate Potter, Austin TX.

timparkin
28-Jun-2012, 00:46
I've done this a few times.. I would recommend a manual exposure blend after getting the images aligned in photoshop (or I have used PT-GUI in the past). If you are exposing neg film you shouldn't really need to bracket unless you are dodging the skies (or other areas) quite dramatic amounts; if that is the case then make a second exposure 4 stops underexposed and, again, manually blend.

The nice thing about manually blending using masks is that you can go back and tweak when you notice a f-up. I also then use the 'warp' tool occasionally when I find out a layer isn't quite matching in an area.

Tim

Brian Ellis
28-Jun-2012, 13:22
If the desired effect is a natural looking exposure blend, I think most people will find Photomatix a pretty blunt tool compared to LR/Enfuse (for about a two stop compression) or S-N-S HDR Pro (for up to about a 4 stop compression). None of these programs are perfect but the two I mentioned give you a file pretty close that can be further tweaked or combined in areas with a "straight" image for very satisfying results. I personally can't come close to these results with Photomatix.

FWIW, even at the very top of the Architectural Photography profession, pretty much all practitioners that I know are using some HDR exposure blending technique to one extent or another.

I perhaps should have been more clear - when I use Photomatix I don't just click and print. I use the result as a starting point for further adjustments in Photoshop. I think it's a blunt tool if it's used as a blunt tool but there's plenty of room for fine adjustments elsewhere.

Kirk Gittings
28-Jun-2012, 13:42
FWIW I don't use HDR on film-only digital files. On film I use divided Pyrocat which usually solves my problems. I first bought Photomatix after reading about if from Steinmueller (though I always thought his usage of HDR was not very realistic-I thought I could do better). I read many tutorials and really worked at it. I've never used the presets in Photomatix-only the sliders (the presets total suck). After having used it for a few years I gave up-never liking the results even as a starting point for further work. I got back into HDR after reading some glowing reports from APs about LR/Enfuse I could not get even close with Photomatix to the results of even the basic defaults in LR/Enfuse or later the presets in S-N-S HDR Pro. I've tried pretty much all the programs out therewith some rep including Oleneo-which some people swear by-didn't measure up to the two I mentioned.

Peter De Smidt
28-Jun-2012, 14:24
Kirk, did you try Photomatix's Exposure Blending mode? That's what I mainly use with Photomatix. It's much more realistic than the Detail Enhancer. I'll have to give S-N-S HDR a try. Which version do you use, home or professional?

On my system, Enfuse is unfortunately extremely buggy.

Kirk Gittings
28-Jun-2012, 15:10
I only ever used Exposure Blending mode as I am only interested in a natural looking exposure blend as mentioned in one of my posts above. I'm not at home and can't look to see which version.

What is your system? I use LR/Enfuse on both a Mac (10.74) and a PC (W7) and it works fine on both. Have you updated it? There was a new release a couple of weeks back.

Peter De Smidt
28-Jun-2012, 17:30
Thanks, Kirk. I haven't tried Enfuse for about 6 months. I'll try the update. I use a W764 machine.

Jan Pedersen
28-Jun-2012, 20:11
Never used a digital camera until a month ago when a D800E arrived. My god! 34 external buttons and switches almost exceed the cockpit controls on my old VP-23 US Navy Neptune plane!

Nate Potter, Austin TX.

Good to have you onboard Captain Potter.
Mine's not an E but trying to learn from these "Pro's" here makes me appreciate the simplicity of an 8x10 :)

architorture
4-Jul-2012, 20:06
I would second the recommendation for trying Enfuse - in fact I would suggest you try the whole process in Hugin, which incorporates Enfuse. Hugin is free, open-source software available on most platforms. It gives much more control in aligning and transforming images than Photoshop's Photomerge function (which is not an option for you anyway I don't think in the original Creative Suite).

The algorithms in Enfuse are very good at avoiding any halos, which are easy to create when manually masking between layers with a brush in PS.

As far as special considerations doing this with scanned LF film: I think it depends on how you mount the film - I've found with my Epson V700 that if I scan a 6x7 negative multiple times, each scan will look slightly distorted compared to the others, when using the OEM Epson holder. I believe the heat from the lamp makes the negative move a little over time. If you were dry-mounting or wet-mounting onto a piece of glass, I think this would be much less of an issue.

I have read comments about the motor that drives the ccd in Epson scanners not having perfect registration or identical movement speed from scan-to-scan, but I can't comment on this from personal experience. I would point out, however, that Lasersoft must believe it is accurate enough since they offer a feature in Silverfast that combines multiple scans of one negative...

Walter Jakubowski
6-Jul-2012, 07:32
I have had success with my Imacon scans. So far I've only used two images. Photomatix software has had no problem aligning the images to my delight (involved translating and rotating the images). Download a trial version and give it a try.

thrice
14-Jul-2012, 22:13
As mentioned above, get the Enfuse plugin for Lightroom. It is the only high-dynamic-range software of any kind that gives natural looking results in my experience.

Kirk Gittings
14-Jul-2012, 22:24
I have read comments about the motor that drives the ccd in Epson scanners not having perfect registration or identical movement speed from scan-to-scan, but I can't comment on this from personal experience. I would point out, however, that Lasersoft must believe it is accurate enough since they offer a feature in Silverfast that combines multiple scans of one negative...

Which, the last time I tried it, couldn't properly align the multiple passes because of the cheap step motors in Epson scanners that give a varying length to the multiple passes. It may have been fixed in later versions. I gave up on it.

Valdecus
15-Jul-2012, 00:27
As mentioned above, get the Enfuse plugin for Lightroom. It is the only high-dynamic-range software of any kind that gives natural looking results in my experience.

The "Fusion" method (previously named Exposure Blending) contained in Photomatix is based on the same algorithm and gives you very natural results. As mentioned before, Photomatix also has much better methods to align the images than Enfuse.

Cheers,
Andreas

Nathan Potter
15-Jul-2012, 09:18
Hey Kirk, thanks; that was one of the comments I was looking for about registration of multiple scans. I have recently tried Photomatix using two 4X5 images and found that the registration is OK from V750 scans. My V750 is about 1.5 years old so is somewhat recent and has only seen perhaps 500 scans total. Maybe age of the scanner makes some difference.

Nate Potter, Austin TX.

Kirk Gittings
15-Jul-2012, 10:07
FWIW again. As I have said a couple of times above. IME exposure Fusion in Photomatix does not give as natural results as LR/Enfuse. If it did I wouldn't have given up on it after a couple of years of effort-switched to LR/Enfuse and never looked back. Exposure fusion in general is critical to how I make my living and I try to test every new program that comes out-always looking for a better tool. It is essential to me. Right now that is IMO LR/Enfuse and SNS HDR Pro. Neither of which has any problems aligning my images.


The "Fusion" method (previously named Exposure Blending) contained in Photomatix is based on the same algorithm and gives you very natural results. As mentioned before, Photomatix also has much better methods to align the images than Enfuse.

Cheers,
Andreas

Peter De Smidt
16-Jul-2012, 14:34
You can always align images in Photoshop and then output the layers as files which can then be HDR'd by whatever you like.

Kirk Gittings
16-Jul-2012, 15:53
Interesting approach. Align, crop, save then to HDR? Works for me.

Peter De Smidt
16-Jul-2012, 18:43
For a script to help out with this, see: http://www.outbackphoto.com/CONTENT_2007_01/section_hdr_and_tonemapping_2009/20100917_HDR_OptimizedAlignment/index.html

cjbroadbent
23-Aug-2012, 22:56
For a script to help out with this, see: http://www.outbackphoto.com/CONTENT_2007_01/section_hdr_and_tonemapping_2009/20100917_HDR_OptimizedAlignment/index.html
Thanks for the link, Peter.

Simon Liddiard
9-Nov-2012, 08:55
Could you not increase the dynamic range by pre-exposing in the field? I did this back in the 90's. You'd save money on film, too.

Hi Andrew - please could you explain what you mean by 'pre-exposing in the field'?

A very interesting topic this - thanks for the information everyone!

S