Low Viz is hard....

[robindotadams]

Hey guys/gals, This weekend has been rather a disappointing one for me, and I'm looking for some general guidance as I used my Tokina 10-17 for the first time in UK inland waters. Vobster wasn't great for Viz and my expectations were "high" after getting the hang of the port and flash while over in the Red Sea... I guess I was getting over confident, but as ever, came back to earth with a resounding crash.

As background, I've never been a person who really understood the "basics", and only in the last 6 months have begun to understood things many of you probably take for granted (depth of field, focal length, ISO) and so am "baby stepping" my way into the big boys arena! So when something doesn't work out, my lack of basics hinders me - hence my appeal to you guys/gals for guidance.

Anyways - I did 4 dives over the weekend. All with my set up of dome port, Tokina 10-17 and 2 strobes. I was hoping for cracking viz, but an ROV from the week kicked up day 1 and the heavy rain didn't help day 2.
Dive 1 - I used autofocus and spent most of the dive getting very grumpy as the low viz meant it was consistently hunting (I think) and I couldn't get it to fire...
Dive 2 - Learning from my problems on dive 1 I moved to MF, but stupidly didn't change the focus ring to infinity and end up with loads of very blurry images.... not great.
Dive 3 - Put the focus ring correct (at least I thought!) and proceeded to shoot like there was no tomorrow - but was still getting very poor performance...
Dive 4 - Decided to start playing with ISO (something new) which was OK-ish On getting home I reviewed the pix from Dive's 3 & 4 and was quite disappointed with the quality.

I couldn't decide if it was because the focus was screwy again (as an AF person, I could have got it wrong), My shutter speed was too long (and I have wobbly hands), I'd set the ISO too high, or that I was just expecting too much and getting decent UW pix in low viz/light with a wide angle is really quite hard!!!

The weekend wasn't a total waste - I learnt an awful lot about strobe placement, trying to work with Natural light, and I even moved off TTL for a while... But it's all about the final image and I was a bit disappointed. Please see the output below - they are not very good, but guidance on how I can improve them would be great... (or am I just expecting too much?).

[Cussy]

Robin,
Before commenting, it would help if you could post the EXIF of those pictures. This would help to identify what might be amiss.
Rob

[TimIngmire]

OK, few comments from me before we see the details:

1. There is nothing wrong with your composition
2. Sometimes the viz is so bad that you cna be on a hiding to nothing trying to get any kind of results
3. Diving in clear blue water can easily make you feel that you've really cracked it and coming back to UK waters can bring you down with a real thump - I know, it happens to me everytime I go away.
4. WA photography (and especially really wide angle) in crap viz is much more difficult than you think
5. Practise makes perfect - you will get de-motivated as you learn but keep at it and suddenly you will make a real improvement and bingo!

And, one question, were these ambient shots? I see no sign of strobe use at all in these (Backscatter / glare etc).

[Chris R]

Hi Robin,
Yep, I'm right with you on this one! Bizzarely, Vobster can be very challenging. The combination of contending with the freezing cold water and crap vis here often makes me feel like giving it all up!
Your pictures don't seem bad , composition is good and as you say, the focusing is the main issue. I can't quite bring myself to post some of the numerous rubbish photos I have taken in Vobster but they would make you feel much better!
I am definitely no expert but in really bad vis, strobes are off and I do generally push the ISO quite high there on my Nikon 200. Other than that, I experiment with strobe placement, as you seem to have been trying and I do use the auto focus.... Isn't there a focus light on your DS125 strobe? Not that there seems much use of a strobe in the pictures? Backscatter is generally my worst enemy ......
I often have my camera there so if you see anyone struggling with big housing and a rebreather...it's me! Say hi!

[KenByrne]

They seem very dark and out of focus. A shame because as others have said the composition is good.

It's difficult to identify the problem without information on your settings. I wouldn't say it was camera shake. I always use autofocus and in these pics I would have tried using different focus points are focussing and recomposing. The autofocus would probably have locked onto the torch in the first shot at the white cylinder in the second shot. and probably on some of the lighter gear in the third shot. Obviously I can't be sure abot this as I wasn't there. Focus lights on strobes aren't a great help in this sort of situation as to use them they need to point at the subject which means your strobe is pointing at your subject which is not what you need to avoid backscatter.

As Tim says there are sometimes when conditions are so bad you're not going to get anything worthwhile.

[Cussy]

This is what I do in bad/low vis:

1. If I arrive at a site and I know the vis is shocking or patchty I'll either head for somewhere where it's acceptable, or just stay very shallow and hope that you get plenty of light in the shallows to take photos in. Just look at the thread on Guildenburgh - most divers wont have ever seen it that clear. It's no different from normal, but if you steer clear of the "popular" bits you can usually find better vis.

2. Close-focus wide-angle. This is your best bet. Find a subject. Let's say it's a car as I bet there was one in there. Get really close and I mean within a feet of it and pick out a feature - maybe a head light or a badge of some sort. Set the camera to full fisheye and aim to illuminate the foreground only. The shot then has great clarity in the foreground and as long as there isn't major back-scatter the back ground becomes less important.

I use CFWA all the time and I'd say it's the one technique you should aim to nail. If it's in the sea I'm searching for Urchin or something to get a nice bit of foreground, or the bow of a wreck. In your shots it's difficult to do that as you appear much further back.

The secret is basically knowing when to give up. Not necessarily give up on a dive, but knowing that you are at a location on that dive where there is just nothing to work with. Move on and find a better spot.

I've got to add that I've not had problems with focus on my Tokina, other than when it's virtually zero vis. What I do then is find something it will focus on that is getting on for infinity, knocking the camera into manual, and then shooting that way. I've recently added a small focus light to my setup as the lights within a DS-125 are useless, but have only ever had to resort to using it in macro. When I first had the setup it kept focusing on an internal reflection, so I used masking tape to cover the springs on the Ikelite attachment to the zoom and used black pen on the shiny gold ring on the lens.

Every now and then we all have dives like that. It's why Tim setup Digigreen as post something on Wetpixel and most clearly have no idea what bad vis is!

Hope that helps,
Rob

[robindotadams]

Gents,

really appreciate the comments... it's nice to know it may not just be my lack of skills!!!

With reference to some of the points made:

- I took over 200 shots while in the water...

- As I said, I'd guess "composition" is my strong point - it's the technical back up I'm lacking!!! (mind you it's not hard to find 3 pix composed nicely out of 200!!!)

- If nothing else, I'm happy with strobe placement now. But all 3 shots I've picked above were done with Strobe's either off or at their lowest setting.

- All pictures were taken on Manual focus.

- I'll get the EXIF info up tonight when I get home

- I think my key question is best described in picture 3 - it just doesn't seem sharp (and this was the sharpest!!!), is it shutter speed (I think I was at about 1/30) or a poor focus.. I need to go back and reread "the edge" on dome port theory I think

Ultimately, thanks for the feedback, it's nice to know that it may not just be my lack of skills affecting the pictures

R

[TimIngmire]

Hi Robin,

looking at Pic 3 I'd say i that instance that the focus wasn't right. A slow shutter speed would show a movement blur rather than an overall blur.

Was that clear?

[robindotadams]

yes Tim... thanks... I'm beginning to realise what my mistakes are... hence the next header I'm putting on the front page....

[DDT uk]

Robin

One other point to remember is that when you are shooting very wide (and I assume that you were at the 10mm end) the depth of field is significant even at a fairly wide aperature. Bearing in mind that the aim is always to get as close as possible, it should mean that you can autofocus on something like your fin, put the AF lock on, and then the subject should still in focus. The other thing is to ensure that you point the focus point at the area of highest contrast (such as the edge of the diver) and then AF lock and recompose.

If you happen to be having a long Christmas break, Rob and I are venturing over to Wraybury on the 2nd for a dive. You're welcome to join us (as are all).