Topic: HDR - suggestions and advice (Read 5812 times)

pco98 · « **on:** June 03, 2008, 02:31:11 am »

I've been experimenting with HDR images using CS3. When converting to 16 bit I always use local adaptation and the tonal curve. I think this is the most powerful option. But so far I'm not entirely satisfied with the results. I use the tonal curve much like I do regular curves. First setting the black and white points and then using the curve to bring out some nice contrast. But I'm less sure about the radius and threshold controls which can produce some really bizarre results (abstract painting) What are good ball park settings and what do these controls do? I don't really understand other than the visual effect I see.

So far I'm not really satisfied with with my end images. I often feel that the entire HDR has been captured successfully in HDR. Most of my shots are early light with the foreground more in the shadow. I want to bring this shadow out more. often I end up with good highlight capture but the shadow end is still darker and I'm having to use shadow controls or regular curves to try to bring it out more but then it ends up flat or washed out.

By the way, the white balance preview setting - my understanding is that this is just so you view the entire dynamic range but is the point at which you leave it set at critical when you subsequently convert it?

Thanks

Ross

Ken Bennett · « **Reply #1 on:** June 03, 2008, 07:44:55 am »

Hi, Ross,

I've had better luck with the Photomatix HDR software, which you can download on a trial basis.

That said, from your description of your own work, you might be better off shooting two or three frames and blending them together by hand, using layers in Photoshop. A lot depends on what the transitions look like between the brightest and darkest areas, of course. You might also try the Adjustment Layer blending technique on single 16-bit files. This technique is described well in the Real World Photoshop books.

When I have images with a strong horizon line transition between shadow and highlight, I often find that HDR damages the contrast in both the shadows and the highlights. It makes the transition look okay, so maybe it's a way to make yet another layer? Haven't tried that yet.

--Ken

rdonson · « **Reply #2 on:** June 03, 2008, 07:50:58 am »

With Photomatix 3.x you have a choice of HDR or blended exposure processing. HDR isn't for everything. In any case, Photomatix is much, much easier to use than CS3 and the results are far more satisfying.

mcbroomf · « **Reply #3 on:** June 03, 2008, 12:09:08 pm »

Consider trying Enfuse.

Adam L · « **Reply #4 on:** June 03, 2008, 12:46:08 pm »

I'm interested in better understanding how to optimize the bracketing process.

Is the selection of the number of images and the number of stops a creative decision or is there an optimum number/+-?

Does the dynamic range in the scene play a role in how you bracket the image?

I am just starting to research and learn how to create these HDR images so I would appreciate recommendations on books or tutorials that can get me started.

Geoff Wittig · « **Reply #5 on:** June 03, 2008, 06:35:20 pm »

1) Bloch's HDRI Handbook (from RockyNook) is a bit intense, but it'll tell you anything you want to know on the subject, delving into all sorts of arcane software if you're curious. It provides examples of tone-mapping results from different programs working on the same image.

2) Photomatix is far more intuitive and usable than Photoshop CS3's relatively crude and clumsy HDR tools.

3) At least in my limited experience so far, three equally spaced exposures tuned to catch detail from shadows to highlights work well enough for most subjects. Any more than that, and my 4 gig system starts to bog down juggling all those raw files at 32 bits.

gmitchel · « **Reply #6 on:** June 04, 2008, 12:00:45 am »

Quote

1) Bloch's HDRI Handbook (from RockyNook) is a bit intense, but it'll tell you anything you want to know on the subject, delving into all sorts of arcane software if you're curious. It provides examples of tone-mapping results from different programs working on the same image.

2) Photomatix is far more intuitive and usable than Photoshop CS3's relatively crude and clumsy HDR tools.

3) At least in my limited experience so far, three equally spaced exposures tuned to catch detail from shadows to highlights work well enough for most subjects. Any more than that, and my 4 gig system starts to bog down juggling all those raw files at 32 bits.
[a href=\"index.php?act=findpost&pid=199621\"][{POST_SNAPBACK}][/a]

I agree that Photomatrix does an excellent job.

Another tool that does a good job and also with making panoramas is PTGui Pro. It'll do HDR, LDR, and Exposure Fusion as well as a superb job of automatically stitching panoramas.

Cheers,

Mitch

hassiman · « **Reply #7 on:** June 04, 2008, 02:44:19 pm »

I have found the the GUI front end for ENFUSE called Bracketeer is superb. Does a much more natural job than Fotomatrix which I also own... and it's only $30!

Colorwave · « **Reply #8 on:** June 04, 2008, 04:35:59 pm »

Quote

I agree that Photomatrix does an excellent job.

Most people here seem to be discussing Photomatix, but you mention Photomatrix. Both programs seem to be similar, but Photomatix seems like more polished software. Typo, or alternate suggestion?

Regarding Photomatix, I downloaded the demo to try it out. I selected three 38mb IIQ-L files of three exposures of the same scene from my P30 back to import for HDR. For some reason, when these import, the image size is only about the size of a postage stamp. I know that I'm selecting the RAW files and not some sort of preview, so might this be a problem with the demo mode or with the fact that I'm running 10.5.3?

-Ron H.

rdonson · « **Reply #9 on:** June 04, 2008, 04:58:02 pm »

Quote

I'm interested in better understanding how to optimize the bracketing process.

Is the selection of the number of images and the number of stops a creative decision or is there an optimum number/+-?

Does the dynamic range in the scene play a role in how you bracket the image?

I am just starting to research and learn how to create these HDR images so I would appreciate recommendations on books or tutorials that can get me started.
[a href=\"index.php?act=findpost&pid=199567\"][{POST_SNAPBACK}][/a]

I started out taking 5-7 images with one stop between each. Since then I've refined my approach based on what Uwe Steinmueller recommended and now generally take 3 images at -1.5, 0, +1.5 EV. It probably is scene dependent but this is good for most of the times I'm shooting for HDR.

Geoff Wittig · « **Reply #10 on:** June 04, 2008, 06:15:31 pm »

Quote

Most people here seem to be discussing Photomatix, but you mention Photomatrix. Both programs seem to be similar, but Photomatix seems like more polished software. Typo, or alternate suggestion?

Regarding Photomatix, I downloaded the demo to try it out. I selected three 38mb IIQ-L files of three exposures of the same scene from my P30 back to import for HDR. For some reason, when these import, the image size is only about the size of a postage stamp. I know that I'm selecting the RAW files and not some sort of preview, so might this be a problem with the demo mode or with the fact that I'm running 10.5.3?

-Ron H.
[a href=\"index.php?act=findpost&pid=199737\"][{POST_SNAPBACK}][/a]

Photomatix is the only program I know of in this category going by that approximate name.
The program does have a limitation (or a bug if you like). The Photoshop plug-in version cannot handle files above a certain size due to internal memory limits. It could work with files from my Eos-1Ds II sometimes, but it gagged on the 1ds III. The freestanding version of Photomatix works fine with the 1Ds III files. The files from your P30 back are undoubtedly bigger yet, so it's possible that the plug in version just can't handle that much data.

Colorwave · « **Reply #11 on:** June 04, 2008, 07:10:43 pm »

I Googled Photomatrix and found a number of references, including a reasonably thorough review and a number of forum postings about it, but it looks as if all of these people are just typing the name wrong. No wonder they have a disclaimer on the Photomatix website saying that their name is NOT Photomatrix. Oops.

Regarding my issue with tiny imports, it isn't caused by using the Photoshop plugin, as I'm using the standalone program. I tried dragging and dropping, as they suggest in their tutorial, as well as importing the images, and had the same results. I also got frequent crashes, though, which lead me to believe that it may not be ready for 10.5.3 Leopard yet.

-Ron H.

mcbroomf · « **Reply #12 on:** June 04, 2008, 08:24:33 pm »

I would contact them. It sounds like it's ignoring the raw file and just working on the thumbnail file which I assume is embedded. I can't remember..do they have a list of all the raw files supported? If the Phase One included?

Plekto · « **Reply #13 on:** June 04, 2008, 08:28:33 pm »

The most realistic exposures come, IMO, from it being fairly tightly bracketed in the direction that you want to improve.

ie - a 0, -1/2, -1 setup rather than a +1/0/-1 shotgun approach.

Good blending software is a must, of course.

http://luminous-landscape.com/forum/index....showtopic=17775
I like this program the best for this. It produces very clean results as well as good HDR blending.

In fact, anything that is a still subject I tend to do a tight bracketing of and then blend just to get rid of noise and artifacts.

Obviously, you can do a +4/0/-4 approach with this software as well if you want to really pull things out of the shadows.

Author Topic: HDR - suggestions and advice (Read 5812 times)