D70 Exposure question

Hi All,

Just got back from a quick trip to my local inland site here in the UK with My now 4 week old D70.

My system is

D70 - Sea & Sea Dx70 - 15mmFE - compact Dome - SB-105 x2

The conditions were totally terrible viz was about 1-1.5m and extremely cruddy...

I'm still not convinced about Digital, Or am / was i expecting too much coming off trannies after the 7 years.

I got a bag a very mixed results.

I'm going to try and post some pictures below but not 100% sure how too do it, so if no pictures are present can someone inform me on how too.

Ok the basic problem seems to be what i'd discribe as Exposure latitude or the lack of it.

I just can't seem to capture a typical wide angle exposure slightly pointed towards the surface.

the problems are listed

Blowing out the surface pixels to WHITE (far right spikes on the histogram),

you'll notice on the portrait shot of my wife, she's exposed ok. the lower section of the image is underexposed, it transitions to the top into a COMPLETE WHITE BLOW OUT.

i'm struggling to get my head around why. surely if i had metered the water somewhere near the surface the lower section of the image would have been extremely underexposed, this shot was taken in 5meters of water on a cloudy dull day iso 200.

i've tryed using the D70 in manual and using the shutter speed to control the background exposure, but i can't seem to capture the WHOLE image.

Is it just the conditions that i'm shooting in, i await a trip to the blues for a proper test.

the other images as you can see the diver shot through a window is a nice exposure however the other one is terrible, the surface water again just blew out.

I do understand that i can't have all my cake and eat it, as there must come a point where the exposure between the two areas is more than the camera can handle.

Please Any information you guys might have to restore my confidence in the D70 would be more than welcome along with any tips for sorting out the problems in photoshop however i dont think much can be done for WHITE SPIKES

Thanks

Craig

I've had acceptable results in clear water shooting with higher shutter speeds and higher f stops....I've found that time of day, depth and water condition contribute to the equation

I'm going to guess that the dark water in which you are shooting is requiring that you open up the lens in order to expose your subject....clearer water allows us to close down a bit and still properly expose the subject...IMHO

1/200 at f10

1/160 at f8

Karl

I think the key points to understand are that in manual mode, shutter speed controls the background lighting and the aperture and strobe control the foreground lighting. That said, you should be able to use a fast shutter speed e.g. 1/250 sec. and still be able to properly expose the subject.

More on my thoughts on exposure here.

http://www.splashdowndivers.com/photo_gall...gs_exposure.htm

Blowing out the surface pixels to WHITE (far right spikes on the histogram),

<{POST_SNAPBACK}>

Craig, I think you've figured out what the problem is yourself. You've got some superb pictures on your website that demonstrate you have mastered the concepts necessary to get great shots. Seems like you just need to learn to work with your new toys strengths and manage its weaknesses.

Firstly, I don't think it is necessarily your fault here. You are right that you have chosen some very difficult conditions in which to test your new camera. The difference in brightness in your shots is far greater than that found in normal tropical conditions in which Karl (and you) are lucky enough to shoot. I'm sure even trannies would have struggled to contain the dynamic range you've got here (unless you routinely shoot Astia or Scala).

My experience has been that with digital, the shadows and highlights behave very differently in comparison to trannies. Unlike with trannies (particularly velvia which I normally shoot), there is a lot of detail contained in the digital shadows. You probably won't see much detail in the shadows on the LCD screen on the camera, but it is easily recoverable in Capture or PS when you get home (provided you have shot RAW). You can easily fill in your diver subject with the strobe (as you have done very nicely already), but you will need to let the lower water go darker than you might expect in order to hold highlight detail up top.

You may find that you need to rely a bit more on the histogram UW, or even just the "flashing highlights" mode, so that you can see where you are loosing detail. You are going the right way about it shooting in manual mode, but it looks to me like you need to expose more for the highlights. Unlike with shadows, there is virtually no way to acceptably recover lost highlight detail as you have discovered.

Trannies tend to have a more gradual "fall off" into extreme highlight, but once you have lost detail, there is no way to recover it. So the expose for the highlights mantra remains. It probably doesn't matter too much if you loose some highlight detail in a small area, but when it covers a larger part of the photo (as it does in two of your examples), you might need to modify your technique. The third shot with your wife and the port hole doesn't seem to be "looking up" as much as the others and therefore doesn't have the same dynamic range to deal with.

As has been discussed extensively in the digital sunburst thread (and in Alex's excellent article in the new UWP mag), digital cameras handle highlights differently and you need to be aware of this different behaviour when shooting (and selecting exposure).

Don't be disheartened, life will be easier in the blue-water tropics... And if you can nail exposures in the green soup, you'll be a gun when it comes to the tropics (although you'll have to remember to dial down your SB105s ) Remember, PS is your friend.

Hi Guys

Thanks for the information so far, Peter the sigma 15mmFE you recommended is wonderful, thanks for your help.

Anthony,

Thanks for your information so next time around i'll start exposing for the highlights and try and train my brain to set aside what looks to be very dark shadows.

I'm slowly getting to grips with the histogram after reading lots on this forum, the highlights settings as you mentioned is also excellent.

I'll try this method on my next outing,

I did'nt learn to shoot film overnight , that took lots of hard work , so i must not expect to learn this art overnight. I think in this day and age we expect the term DIGITAL to be better and easier than our older methods, as i'm finding out this is not so true.

I shot a 5060wz before my D70 and got some excellent results using that camera, the benefit i now found was that i could see the exposure on the screen before i hit the shutter button, which is not the case with the D70.

Learning will take place..

has anyone got anymore tips on settings to use on the D70, i did find that SHADE and Cloudy WB settings gave a pleasant results in my Green Water.

I've been juggling around with custom curves on the D70 using a number of software items availble on the net or would it just be better to shoot with NORMAL settings entered into the D70 contrast/curve area.

Keep your advice coming

thanks

craig :-)

has anyone got anymore tips on settings to use on the D70, i did find that SHADE and Cloudy WB settings gave a pleasant results in my Green Water.

 

I've been juggling around with custom curves on the D70 using a number of software items availble on the net or would it just be better to shoot with NORMAL settings entered into the D70 contrast/curve area.

<{POST_SNAPBACK}>

Hi Craig, glad my advice was vaguely useful. You certainly have the right idea.

In terms of WB, custom curves etc., I wouldn't even bother worrying about any of that. My suggestion would be to shoot RAW in any WB setting you feel looks ok and then adjust it later on. The level of green in the water is always going to vary and provided you have shot RAW, it will be very easy to adjust later on. Remeber that anything you do on on the camera in terms of WB, can easily be re-done with no ill effects later on in Capture or PS.

For custom curves, I would suggest just leaving that for the moment and shooting in RAW and then doing the curves yourself in PS and then maybe applying that adjustment to a batch if it looks to be working.

Remember RAW gives you the control, you don't really need to worry about anything except exposure in the water then - much easier (well comparitively) Good luck and look fwd to seeing your future results.

I'll join to Anthony with the RAW advice.

Its will give also the option to change the expose also later on the computer.

Also there is an option to create 2 images from the same RAW file one under where the highlights are ok and one over where the dark part are expose ok and merge them to one final image. There is an action of Fred Miranda that do the merge or it can be done manually with layers and masks.

Ok can you expand a little on this method pls.

i understand where your coming from and to deal with a difficult exposure situtaion this method might well be useful.

are you able to get the 2 images "in camera" as a pre setting to shoot 2 images 1 over / 1 under

i haven't seen any settings for that option. or are you just simply using exposure bracketing or even just doing the same shot twice with different settings,

however this latter method would be a little tricky to get the shot composed exactly as the first one.

thanks

craig

HI again everyone

to expand on this thread a little,

find below one of the half not too bad images from my days shoot (read above)

i'm getting quite critical here now.

I've found on a lot of the results that i'm getting a kind of Gradient colour banding on the background water ( is it my monitor / computer settings or is it the D70)

all are RAW and converted using PS. no matter what file type i save to the image still has this colour seperation banding..... weird...

can anyone explain why or how this is happening

regards

craig

Ok can you expand a little on this method pls.

 

i understand where your coming from and to deal with a difficult exposure situtaion this method might well be useful.

 

are you able to get the 2 images "in camera" as a pre setting to shoot 2 images  1 over / 1 under

 

i haven't seen any settings for that option. or are you just simply using exposure bracketing or even just doing the same shot twice with different settings,

 

however this latter method would be a little tricky to get the shot composed exactly as the first one.

 

thanks

 

craig

<{POST_SNAPBACK}>

You don't need to shoot twice, if you use RAW, when open it there is a slide of 'exposure comp' (or something close) so you can create an images (jpg, gif...) with different exposures then you originally used u/w.

Now you can create 2 images totally the same but the exposure, in the first one the exposure is set ok for highlights and in the seconds for the darks.

Then you merge this 2 shots.

The action that do it called: DRI from fredmiranda you can see there some explanations of the process.

Thanks Arnon

i'm with you now

regards

craig

I've found on a lot of the results that i'm getting a kind of Gradient colour banding on the background water ( is it my monitor / computer settings or is it the D70)

<{POST_SNAPBACK}>

Umm, all I can see is a diver and a tank track. No banding whatsover. You aren't using an LCD or 256 colour display or something are you?

Seriously, I see perfect skin tones and lovely gradual tonality betwen the greens in the background. Perhaps there is something funny going on with your display.

Hi Anthony

I Guess then its my LAPTOP screen ... LCD however the color depth is set to the highest setting (millions of colors)

thanks

regards

craig