HDR exercise (Candle)

[Doug Nelson]

It seems to me a lot could be learned about HDR from a shared simple exercise. How about your camera on a tripod, and a candle on a table? Put a book or something else interesting with fine detail next to the candle. Light the candle, turn off all room lights (needless to day, do this at night), then take your 3-5 exposures, 1-2 EV apart. Assemble into HDR using your preferred technique, then post what you get here along with how you did it.

[ChinaMark]

Sounds like a good exercise Doug and I haven't tried really extreme HDR imaging with nighttime shots....shot in near darkness!....should be interesting

[0lBaldy]

Thought I would try a comparison (Granny says I go overboard!)


Shot with Canon S1Is (3mp)
from about 4 feet
200ASA
Custom White Balance using sheet of paper
2 stops up and down
Auto 3 exposure burst
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1
Middle/Normal Exposure

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2
HDR Photomatix
Default Tone mapping
Photoshop CS2
Levels
Gradient layer to even things out
NoiseWare
Lab sharpen

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3
Photoshop CS2
Shadow/Highlight
Levels, Curves
NoiseWare
Hue/Saturation
Lab Sharpen

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4
Photoshop CS2
History Brush Set to Screen
Levels, Curves
NoiseWare
Hue/Saturation
Lab Sharpen

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My conclusion...

The candle flame looks better in HDR.. BUT.. this is maybe the third time I used Photomatix.. (could probably be much better in more capable hands)


Just using the History brush don't look bad to me!

[Doug Nelson]

Good test. I can't see much exposure difference between 3 and 4, but 4 definitely looks smoother. 2 has so much color noise I can't get much beyond that.

With such a harsh specular highlight (the candle) there's not a lot of reason to underexpose. I was hoping the shadows being available in the midtone area might mitigate some of the noise, but perhaps this was a bit of a drastic test.

I'll be posting a test of my own, but I have to go tripod shopping first

[skydog]

what did you do in 4 to get significantly less noise? You used noise ware in each case?

[ChinaMark]

Here's my attempt with my Nikon D80 / 18-200mm VR. I took these 3 images using manual focus:

Candle Test normal exp.jpg
normal exposure - f4.5 - ISO 100 - 1 second 31mm

Candle Test under exp.jpg
under-exposed - f4.5 - ISO 100 - 4/10 second 31mm

Candle Test over exp.jpg
over-exposed - f4.5 - ISO 100 - 6 seconds 31mm

Candle Test HDR Final.jpg
Final HDR image

I shot RAW images...don't know if that made much difference!...and then processed them in Photomatix using the default method. Finished off with some contrast tweaks in Photoshop and I cropped it a little.

Conclusion: I can only bracket for 3 exposures at +/- 2ev....maybe it would be more successful with cameras that can bracket more.....mind you, I used a tripod so I could have taken 5 bracketed images but I didn't think of it at the time. I really think though for successful HDR images you need a more equal amount of extreme highlights and shadows to get a better range.

Maybe tomorrow I'll try with 5 exposures and see if that covers the whole range.

[Markzebra]

olbaldy - Would have thought you could get a lot smoother tone mapping than that with three exposures. I dont know Photomatrix. Why dont you just use Merge to HDR? even CS2 its good enough, you can output different layers into a 16 bit file using different mapping techniques one for localised detail and another for overall tone avoiding all the shadow noise. If you are using CS3 you can then read the file into camera RAW for nice high bit depth tonal work

[Doug Nelson]

ChinaMark:

ISO 100 is more daring than I've been in my prelim tests
Good final result, though I'm still debating over whether I just like the 6 second exposure better by itself.

I do think a wider range with even EV steps might be helpful.

[lkroll]

...ChinaMark. I took your brightest version and copied the Darkest version on Top layer and ran a Dynamic Range Extender Script-fu on it. I then ran a Tonemap Script-fu to further enhance the piece. Finally, I took a copy of the original bright version and copied it to Top layer and set to Saturation and blended it down to taste.

[Doug Nelson]

Sounds like we might need a separate thread explaining Script-fu, or even a blog

[ChinaMark]

Ikroll's method sounds a hell of a lot easier than all this HDR palava

[lkroll]

LOL

I'm sure; in fact I know there are CS2 actions that can do this too on Action Central. Believe it was Chip that created an action that does this (CSpringer). Always a lot easier to use scripts and plugins, especially if you are lazy like me.

[palms1]

This Is a great idea and enjoyed "having a go " problem is camera limitations and i think i have exceeded them on my camera, when using the aeb in low light i am getting banding more noticeably down the left side (or top) .
I probably would not knowingly post a image with this problem but as i made the effort i will.

I got out the little tripod attached it then decided i wanted a portrait shot so stood the camera on end on top of some books to get the height wanted (tripod sticking out ) took 3 shots -2,0,+2 and then used the trial version of hdri

Palms

[0lBaldy]

Originally Posted by skydog

what did you do in 4 to get significantly less noise? You used noise ware in each case?

In 3 I used Layer>Adjustments> Shadow/highlight and it seemed to show a lot more colored and neutral noise..
In 4 I did not make any different adjustments to the picture except for using the history brush around the perimeter. On second thought I probably did change a few settings in NoiseWare
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Originally Posted by Markzebra

olbaldy - Why dont you just use Merge to HDR? even CS2 its good enough, you can output different layers into a 16 bit file using different mapping techniques one for localised detail and another for overall tone avoiding all the shadow noise. If you are using CS3 you can then read the file into camera RAW for nice high bit depth tonal work

Answer: I looked again at the HDR thingy in CS2 and finally figured out how to merge to HDR.. I did not have enough tonal range before when I tried it.. It worked well on these images though..

As for the rest of your post... HUH? Way over my head...
HINT.. there is a tutorial section here at RetouchPro.. I would love to learn what the heck you just said.. BTW, I use PS7 mostly and CS2 just recently... my camera is a point and shoot... no RAW, but it has satisfied my needs thus far.
I would like to see a sample from you of what you are talking about in this thread using this "simple exercise" in HDR..
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ChinaMark

I think your HDR looks very good.. lots of detail in both the near and far objects
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palms1

Your composition, like your art work, is superb I think it came out pretty well except for the banding.. How does your longest exposure compare to the Tonemap?


I Re-Shot my previous scene using manual, ISO 50, F8 using a bracket of 7 shots from 1/25 thru 3Sec... (maybe longer exposures, maybe up to a minuet or more, may have helped some)It's a pretty big area (4ft X 5ft) to capture with one little candle..

These have not had anything done to them except being saved for web to be posted here.. The last photo on the right is a HDR tonemap from just the one 3 second exposure(I used an older version of Photomatix for this, The newer versions need 2 or more photos to make a HDR)

3 sec exposure, ToneMap, EnhansedToneMap, 1PhotoToneMap

[palms1]

Thank you for your kind comments OlBaldy unfortunately i cant look anything up on the images taken, because i had a "Hissy fit" when i saw the banding on the final image and deleted everything

Palms