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 High Dynamic Range Images  |
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Chriso
Scuba Imports / Dive-Oz Supporter
Perth
Australia
3654 Posts |
 Posted - 05 January 2009 : 7:03:08 PM
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Hi All
I am wondering if anyone has toyed with HDR on underwater images ?
Thinking it might be fun to take the Tripod out and play with t on some wrecks.
For those that would like to know more about HDR
http://www.stuckincustoms.com/hdr-tutorial/
Cheers
Chriso |
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Melbourne_diver
300+ Posts
melbourne
Australia
568 Posts |
Posted - 06 January 2009 : 02:05:45 AM
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Yo,
An equally important question is to why you would want to do HDR underwater? Wide angle underwater shots look best with large changes in lighting. Think of moody wreck shots, sun bursts through kelp forests etc. With HDR underwater you would potentially be taking away from the impact of the image.
On a more practical note, HDR underwater is very difficult because of the dynamic nature of the underwater world; everything is constantly moving and changing.
Also, there are such large differences in lighting underwater that you would need a practically difficult number of shots to adequately cover the dynamic range.
Cal |
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Mick T
600+ Posts
Port Kennedy (Perth)
Australia
733 Posts |
Posted - 06 January 2009 : 10:30:21 AM
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Chriso,
Get a better camera, like a Canon 20D 40D 50D  |
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Chriso
Scuba Imports / Dive-Oz Supporter
Perth
Australia
3654 Posts |
Posted - 06 January 2009 : 10:38:30 AM
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quote:
Originally posted by Mick T
Chriso,
Get a better camera, like a Canon 20D 40D 50D
No thanks Mick
I used Canons 19 years ago at college, its like the first spirit you get drunk on. I could never go back gives me a sickly feeling just thinking about it.
Anyway thinking I might try some HDR stuff on some reef and see what the results are.
Cheers
Chriso
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Panda
1200+ Posts
Geelong
Australia
1331 Posts |
Posted - 06 January 2009 : 11:21:33 AM
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Might work well with wrecks and tripod in black and white.
The wreck is unlikely to move and you could end up adding detail in the dark areas of the wreck without blowing out the background.
Do it and show us the results. |
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Melbourne_diver
300+ Posts
melbourne
Australia
568 Posts |
Posted - 07 January 2009 : 5:19:28 PM
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Hey
Wrecks on tripods could be good. As Andrew said, you could capture the detail in the shadows which would be cool. Your likely to get a lot of noise in the shadow areas unless you really capture the light there. A raw file is only so good in post processing.
I'd start by taking a light reading of the shadow area and shooting that first before moving onto the well lit areas.
Maybe take a few lead weights down to stablize the tripod? otherwise its likely to move marginally if your holding it still for more then 3 shots.
I'm keen to see how it goes!!!!!
Cal
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Chriso
Scuba Imports / Dive-Oz Supporter
Perth
Australia
3654 Posts |
Posted - 07 January 2009 : 7:47:37 PM
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Thanks Guys
Next time we dive the swan I will pour lead into the legs of my old Gizo Tripod, that should keep it from moving around.
Results to follow.
Cheers
Chriso
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betti154
600+ Posts
Sydney
Australia
708 Posts |
Posted - 05 March 2010 : 2:44:47 PM
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I've done a reasonable amount of HDR above water and like you Chriso I've considered it for underwater use. I thought it would come in handy with longer exposures that result in a blown our top half.
My tripod usage has been limited at best. Though I've also had some success with HDR on land without one use burst and braketing. ie. set exposure braketing at 1.5 stop intervals, and in burst mode you can rattle off 3 shots within 0.5s. You can then compose a hdr with 3 raw images. Granted you don't have as much play as say 5-6 images, but you don't need the tripod.
I thought that the aforementioned technique might be good for a cave. In practice though I think it's easier to take more lights down instead.
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telephema
300+ Posts
Leopold
Australia
527 Posts |
Posted - 05 March 2010 : 5:00:59 PM
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I haven't done any "real" HDR yet, but when my strobe went caput, i messed around with ambient lighting shots using my fisheye lens. I only took one shot (in raw), and then created three shots from the original image, and then merged them.(purists scream now).
Since i didn't have a strobe, i wanted to expose the subject, while maintaining definition in solar bursts and light beams.
Here's a couple of shots using this process. I want to try real HDR now i have my OW certificate.
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betti154
600+ Posts
Sydney
Australia
708 Posts |
Posted - 05 March 2010 : 5:22:59 PM
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| With only one raw shot, are you actually doing anything with that method that can't be done in a single raw edit? I guess you might be limited to what your raw editor can do but since you're not extending the data within the raw file itself I expect this could be done i a single edit. Merging jpegs might visually make sense but doesn't to me from a data range perspective at least. |
Edited by - betti154 on 05 March 2010 5:48:37 PM |
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telephema
300+ Posts
Leopold
Australia
527 Posts |
Posted - 05 March 2010 : 5:33:56 PM
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| yeah..your absolutely right. I actually only shoot in JPG, (i have 1 TB just of JPG's!) so i'm not overly familiar with the RAW workflow. But as you said, all the image data is obviously in the RAW file, and with the correct editting you must be able to achieve the same results with less noise artificats and loss of quality. Unfortunately its beyond me, so i stuck with what was familiar. Its not real HDR...and is only capturing the dynamic range of one exposure, not multiple. |
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betti154
600+ Posts
Sydney
Australia
708 Posts |
Posted - 05 March 2010 : 5:50:13 PM
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| Well if you shot Jpegs then it makes sense, but hard work compared to raw. |
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Dave
Dive-Oz Supporter 2008
Melbourne
Australia
4085 Posts |
Posted - 05 March 2010 : 6:27:12 PM
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| Love that jellyfish shot!! |
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Dave S
Dive-Oz Supporter
Warm, sunny Melbourne
Australia
2646 Posts |
Posted - 05 March 2010 : 8:34:11 PM
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quote:
Originally posted by betti154
With only one raw shot, are you actually doing anything with that method that can't be done in a single raw edit?
Yes, tone mapping. Tone mapping is what most people actually mean when they say "HDR", and it can be done from a single image (but may produce more noise than a tone-mapped combination of images). |
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betti154
600+ Posts
Sydney
Australia
708 Posts |
Posted - 05 March 2010 : 9:19:12 PM
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Honestly tone mapping is something I'd not heard of until just now, though reading the wikipedia wisdom is does make sense. Ultimately you're only ever snapshoting a visual segment from a true HDR anyway, which is the tone mapped images or (LDR) if I've understood it correct.
To be honest though, I'm still not sure that the RAW -> JPEGs --> HDR merge will give you anything more than you could have achieved with a RAW file to begin with. As mentioned if you're shooting jpeg that's another matter, but one raw to jpegs and merge only suggests to me that you'd loose data.
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High Dynamic Range Images |
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