U/W HDR

I finally got around to trying an underwater HDR. I took a 7 3/4 EV series and combined and tonemapped it using Photomatix.

I also spent a week with a gentleman who works with Adobe on the Lightroom product and am told that a 2.1 update should be out shortly. Everything on my bitch list is "known" and should be included in the fix. Hopefully.

Interesting; I think with underwater (even topside with water) some degree of artifact probably has to be expected as shimmering at the surface or subtle movement of any kind is likely to degrade the image. Can you post the original normal exposure for comparison? My thoughts are that fewer exposures say 1 or 2EV each way may be better to keep the image as sharp as possible.

Interesting; I think with underwater (even topside with water) some degree of artifact probably has to be expected as shimmering at the surface or subtle movement of any kind is likely to degrade the image. Can you post the original normal exposure for comparison? My thoughts are that fewer exposures say 1 or 2EV each way may be better to keep the image as sharp as possible.

Yeah .. I agree ... I've made the point before that I think fewer exposures spread out across the same dynamic range results in a sharper final image, with fewer artifacts and the same expanded tonal and dynamic range capture.

My "standard" topside HDR is a -2EV/Meter/+2 EV three-shot bracket. Unfortunately, Nikon only allows 1EV increments, so I have to shoot 5 frames to get those three.

Here is the original 0 EV shot.

Here is the original 0 EV shot.

Yes I prefer the color rendering in the HDR shot, and it does have a more 3D appearance both in the kelp and the surface texture I think.

Did you hand hold those? Were you in channel islands? If so how was the viz as I'm going this weekend

Did you hand hold those? Were you in channel islands? If so how was the viz as I'm going this weekend

Yes, hand held, but one edge of the housing was resting on a rock. The vis at Catalina was about 50 ft which is fairly good. At te other islands it was not quite as good, ranging from 30ft at Santa Barbara to 10 - 20 feet at San Miguel. Of course, the vis around here changes drastically from day to day. Water temps were still warm in the southern islands.

Happy travels.

Thanks. I'll be three days up north, in my dry suit

i think your image has great visual impact!

if thats the first shot, there seems plenty of scope for some real pearlers

cheers

Leander

I've been looking more at your shot, and showed it to my wife as well (she liked it a lot), I think there is a lot of potential with HDR to add more visual depth to underwater images, particularly ambient light images. Hmmmmm...Warren you have given me ideas.

That was my impression after looking at the shot compared with the 0 EV exposure.

I've dusted off my $40 aluminum tripod and will be bringing that with me to Turks in two weeks to try some more shots of this nature. I have my trusty machinist working on a mounting bracket for my housing as I type.

One thing of interest to me is that some HDR shooters here on Wetpixel advocate less shots with greater EV spreads. I have found that shooting smaller series takes some of the finesse away from the tonemapped images, making for more "startling" lighting.

However, it would make such shots potentially suffer less ghosting. As Jeremy pointed out, the Nikon only goes up to 1 EV steps, and depending on the scene, 3 - 1 EV shots may not cover the dynamic range required (certainly not the shot I took in the kelp).

i think your image has great visual impact!

 

if thats the first shot, there seems plenty of scope for some real pearlers

 

cheers

Leander

Thanks! I'm going to take this type of shooting a bit more seriously now that I know it can be done underwater. I'll keep posting my results & thoughts.

Really interesting results. I don't like them (yet), but I do think that you are treading a path to some completely new types of undewater images. Bravo!

I'll be following the progress with real interest.

Alex

That was my impression after looking at the shot compared with the 0 EV exposure.

I've dusted off my $40 aluminum tripod and will be bringing that with me to Turks in two weeks to try some more shots of this nature. I have my trusty machinist working on a mounting bracket for my housing as I type.

One thing of interest to me is that some HDR shooters here on Wetpixel advocate less shots with greater EV spreads. I have found that shooting smaller series takes some of the finesse away from the tonemapped images, making for more "startling" lighting.

However, it would make such shots potentially suffer less ghosting. As Jeremy pointed out, the Nikon only goes up to 1 EV steps, and depending on the scene, 3 - 1 EV shots may not cover the dynamic range required (certainly not the shot I took in the kelp).

I think there are a huge number of variables with HDR, starting with 'What you are trying to achieve?' Is one trying to create more realism, or trying to create an effect.

As you know all the HDR software options have different tone mapping options etc, so there's an infinite number of results one can achieve.

At the present time I personally am simply trying to extend the realism of my photographs, trying to take them as far as possible to being there, yet still being believable.

I don't think there is any right or wrong on the number of images, but I think one simply has to keep in mind that more images may generate more artifacts in underwater images. The two topside images I have posted on this forum both contained surface water in the images, and on close inspection of both of my images, it is in the water surface that one can see artifacts generated in the software interpretation even with the appropriate alignment settings checked. Motion is the killer of HDR, and underwater nothing is ever static, including light shimmering down through the water, subtle current related movement of plants etc. One of the reasons I wanted to see the original of your image is to see this, and I think you can see some softening of the kelp for example in terms of sharpness and detail, although in this case the dreamy effect of the image is actually very nice. So I think it's a matter of trying to get the highest dynamic range while trying to generate the least amount of artifact. With topside HDR, the most common starting recommendations I have seen are 3 images, with +2,0 and -2EV, keeping aperture constant so there are no DOF / Focus changes. Underwater we may want to keep a constant higher shutter speed to keep the time of the exposure sequence to a minimum. (With the Nikon at present this means at least 5 frames.) Unfortunately this is at least 1 second say with the D700 and a little quicker with your D3. Underwater 1 second is a long time in terms of keeping ambient light static. This is one of the reasons I think future RAW video capture possibilities will really take underwater HDR to the next level.

One suggestion I would make for all of us as we post these HDR images for learning purposes, is to provide as much specifics about how we generate the image - which software, what type of tone mapping algorithm, exposure values etc.

Cool stuff!

First off that is a great shot Matthew - and my missus loved it!, having messed a bit with HDR on land you have made me want to give it a go in the water.

I personally like the slightly surreal feel of the shot but not what the tone mapping has done to the blues.

Looking forward to the tripod shots.

Paul C

I've shot a few UW hdr in very similar circumstances

I have had no pleasing results has of yet due to the dynamic nature of the environment ie to much movement between shots.

it'll be an interesting next couple of years with this technique.

Cal

I think there are a huge number of variables with HDR, starting with 'What you are trying to achieve?' Is one trying to create more realism, or trying to create an effect.

As you know all the HDR software options have different tone mapping options etc, so there's an infinite number of results one can achieve.

Absolutely right! If anyone would be interested, I could download the original 7 images to a photo sharing site so other wetpixel members could play with them and post results. I would be very interested in seeing what could be done. Any suggestions to a sharing site? I tried Kodak, but it seems you can only order prints & mugs??? Not helpful in this instance.

Yes,

It would be great to play with the images. I'm no sure of the best way to transfer large images though.

This was too easy! You can download the 7 images from my .mac account (who knew!).

http://idisk.mac.com/matthewaddison1-Public?view=web

Hopefully this will work.

It worked for me.