Basic HDR (Photomatix) Question

[Arthur Morris]

I created five image of a barn and the Tetons bracketing +/- 2/3 stops around what I thought was the correct exposure. The three lightest images had the highlights blown. When I ran HDR in Photomatix, tone-mapped--with no tweaking at all, and processed the image, there were over-exposed highlights.

My understanding is that the program is supposed to take detail from the dark areas from the too bright frames.... Apparently it took some over-exposed pixels from the lightest images.....

What to do? Do I take all images with any over-exposed pixels from the mix before I start? (In this case that would leave me with only two....)

Any and all help would be appreciated.

[Arthur Morris]

Furthermore, after you generate HDR and go into Tone Mapping, is it proper to go to the histogram for each color and move the various sliders to eliminate all clipping (especially at the highlight end)? And again, the rephrase my original question, I thought that the HDR program was supposed to do that for us....

[Joel Eade]

Artie,

I don't know if I'm understanding you correctly and my experience with Photomatix is limited but....On my shots it seemed that I had to "tweak" the tonemapping sliders to get a good result...the initial HDR combined image out of Photomatix did not look good without "tweaking".

If I recall correctly, the reason is that a computer monitor cannot display the entire dynamic range held within the data of the combined image so you must correct for that by adjusting the sliders.

Joel

[Arthur Morris]

An even more basic question: do I bring RAW files into Photomatix or converted TIFFs?????????????????????????

[Joel Eade]

Artie,

I don't recall having to adjust each color slider...you probably have looked at this but if not, maybe it will answer the question

http://www.hdrsoft.com/videos/videos.php?vid=W1

[Joel Eade]

Artie,

I think Photomatix pro will allow raw CR2 files to be imported

[Arthur Morris]

Thanks Joel. I am making progress. I am getting much better results bringing RAWs into HDR as opposed to converted TIFFs. Will be back in a bit.

[Steve Martin]

I would use the following 3 adjustments in Photomatix to overcome the highlights. 1) Luminosity 2) White Point 3) Gamma. I import all of my files from Lightroom as 16-bit Tiff files. Keep in mind, the final product you see in Photomatix is not always an accurate representation of the processed file. Once I import the file back into Lightroom, I make the final adjustments and output. I normally shoot 7 or 9 frames for safety and this gives me the ability to eliminate over/under exposed frames before processing. You can view my processed images here http://wild-captures-photography.smu...amic-Range-HDR

[Arthur Morris]

Thanks Steve. When I began with TIFFs I had big time problems with overexposed highlights. When I started with the RAW files. let Photomatix do the conversions, and adjusted some of the sliders, the results were much better. I will try your slider suggestions.

More questions:

1- When Tone Mapping, do you routinely examine the R, G, and B histograms and eliminate any clipping by adjusting the sliders?

2- When you bring an image into Lightroom do you check to see that there are no over-exposed highlights?

[Steve Martin]

1 - I do check the histograms but rarely find a need for adjusting. May not be the best way, but I do a lot of processing by "eye".

2 - yes, and I make the final tweaks there if needed.

One other tip that I have found very helpful is to make some minor adjustments in Lightroom prior to exporting to Photomatix. I will adjust anything/everything except "Exposure" before exporting. Any adjustment to exposure can cause an error in reading the EV in Photomatix.

[John Chardine]

Thanks Joel. I am making progress. I am getting much better results bringing RAWs into HDR as opposed to converted TIFFs. Will be back in a bit.

This makes sense Artie. In the HDR module of CS5, Adobe warns that better results (more dynamic range) will be obtained if RAW images are processed up front. BTW I have so far found that the CS5 HDR is inferior to Photomatix but I must admit to not playing around much with the settings.

[Nick Palmieri]

Hey Artie, I will give you my work flow, it seems to work, but not everyone agrees that it's the best way to do it. When I shoot the images I just make sure the histogram is pinned on each end (0, 255) and everything in between, if it takes 2, 3 or 7 images the entire tonal range must be available for Photomatix. I let PM process the RAW. I will then start with one of the presets (grunge, painterly, natural etc), and go to work using mainly the highlights, luminoscity, and strength sliders. If I'm not happy with the result I will sometimes use the others. I then import to PS for additional processing (usually requires a contrast boost). I would be willing to bet that rarely, if ever, are highlights blown or blacks have lost all detail...it was my impression that is what the tone mapping process does and since the most information is in the RAW files let PM process from RAW. I also do most of it by eye.

[Arthur Morris]

Thanks all for your help. I am pretty much on track as Nick suggested. But, I have one major concern. Here it is: I am using Photomatix. I am bringing in at least one dark image that has no highlight clipping. And I am bringing in at least one image that has no shadow clipping. It would seem that when I open the HDR processed image in Tone Mapping that there should never be any blown highlights (that even before I touch any sliders....) If my darkest image has no blown highlights, why are blown highlights showing up in the image that is ready to be tone-mapped????? It would seem that the program is not doing what it is supposed to do....

I would suggest that folks start checking the three histograms while Tone Mapping and also that they hold down the ALT key while hitting the Highlight triangle in Levels with each image that they import from Photomatix of whatever they are using for the HDR processing.....

In the meantime, I still cannot understand why the program is not doing what it is supposed to be doing....

[Nick Palmieri]

Hey Artie, I don't have access to the program right now but... are there preferences that you have set-up in PM that may be causing this? I have used the program a lot and have not had that problem. I recently had a discussion with someone regarding why I would clip both sides in the camera, and my theory was to make sure I got everything, as PM would dump the rest (over and underexposed). When I pull my images into PP, the histogram is usually pretty good. Usually needs a contrast boost...

[Diane Miller]

There have been a series of versions of Photomatix Pro. I recommend the latest one, 4.0.2, free upgrade. I don't know what has changed under the hood, but the user interface is now more straightforward. PM is a very powerful program and it gives you a lot of control, which means a lot of sliders to tweak for the final appearance. But there are presets along the bottom of the screen to get you started. There are also several tone mapping methods in those presets (also available as choices earlier in the workflow): enhancer, compressor and fusion.

I always bring in straight Raw files, no tweaking, although tweaks some things such as color temp. will be honored. I *think* PM will ignore exposure and tonal adjustments but I'm not certain. (Easy to test but I don't have time just now.)

I choose the files from Lightroom (File > Export to Preset). When the first PM dialog opens the choices there shouldn't be critical to image quality -- just chose as appropriate to your situation. When the images open in PM I usually prefer to start with Process: Tone Mapping, and Method: Detail Enhancer.

Then the dialog box with the sliders comes up, your last settings should be the ones you see. There is a Default button at the bottom for resetting. Or cruise through the filmstrip of preset choices at the bottom of the screen.

When you find a good starting point, play with the sliders. They are powerful and flexible. The filmstrip presets just give you various starting points for the sliders. There are infinite settings in between.

It is usually desirable to do some final tweaks in Photoshop.

Here is my recent article on Photomatix, but it was before this new version:
http://www.adorama.com/alc/article/T...matix#comments

I write about 10 articles a year for Adorama.com on digital darkroom topics and you can find an index of them on my web site:
www.DianeDMiller.com

[Diane Miller]

Several days ago I left a long reply with some hopefully useful information, but it didn't get posted. Now I'm in a rush and not sure what I said.

I write digital darkroom tutorials for Adorama.com, and here is a recent one on Photomatix, but not the latest version:
http://www.adorama.com/alc/article/T...matix#comments

The latest version has a streamlined user interface that makes choosing presets easier. I've never had problems with blown out highlights or blocked-up blacks. When you come in to the interface you start with your last settings -- look at the presets to find a decent starting point and then you can fine-tune with the sliders. I think the tutorial covers the basics to get you started.

Let me know if I can add anything more.

[Diane Miller]

Thanks all for your help. I am pretty much on track as Nick suggested. But, I have one major concern. Here it is: I am using Photomatix. I am bringing in at least one dark image that has no highlight clipping. And I am bringing in at least one image that has no shadow clipping. It would seem that when I open the HDR processed image in Tone Mapping that there should never be any blown highlights (that even before I touch any sliders....) If my darkest image has no blown highlights, why are blown highlights showing up in the image that is ready to be tone-mapped????? It would seem that the program is not doing what it is supposed to do....

I would suggest that folks start checking the three histograms while Tone Mapping and also that they hold down the ALT key while hitting the Highlight triangle in Levels with each image that they import from Photomatix of whatever they are using for the HDR processing.....

In the meantime, I still cannot understand why the program is not doing what it is supposed to be doing....

I tried to reply here twice but neither post has showed up. I used the reply box at the bottom of the page -- I'll try again with the reply button below your post.

Its a busy season and the topic is old now, but here is my 2 cents. I've never seen a problem with blown out highlights or blocked-up shadows with Photomatix. It is a somewhat complex program, but very powerful and flexible. The newest version (free upgrade) has improvements to the interface that make it a little easier to look at the possibilities, and then once you get a look close to your liking, fine-tune the sliders.

I wrote a review of the program recently, which may be helpful, but it was before the newest version was out:

http://www.adorama.com/alc/article/T...ith-Photomatix