20 replies to this topic

[Julian D]

Hi.  I’m just learning. Where I live the visibility is currently bad (3 ft) but I am going out anyway to develop my skills. 

In my earlier attempts I wasn’t really getting any colour and couldn’t get sharp photos and I figured that it might be to do with ambient light (shooting in 3 ft of water).  So this week I took both strobes (DS125’s) and put them on 1/2 power. I am still getting washed out looking photos but after tweaking in lightroom I’m much happier with them.

 

Have read in the underwater photographer that it is better to take the shot overexposed and darken in lightroom in order to get more detail so was kind of trying to do that. To me the actual photo looks way overexposed, but the histogram doesn’t?, and the photo doesn’t seem to have any blown out detail.  My questions:

Am I doing this right? 

Should I be aiming for a better exposure out of the camera?

Is this possibly anything to do with strobe positioning?

Any comments general on how to improve this shot?

I’ve attached the photo as shot, histogram and the photo with exposure/contrast and clarity tweaked but nothing else.  D7000, 105mm lens, 2 x DS125’s.  ISO 200, f16, 1/320^th.

Thanks,

 

Julian

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Edited by Julian D, 21 February 2013 - 01:52 AM.

[johnjvv]

In my experience you get that milky look when your strobes are pointing directly to the subject, if you angle slightly away to hit the subject with the sides of the strobe light then it should look a bit clearer. You may find in doing that the pics become underexposed, however you still have half your power to dial up....

[Balrog]

Any detail that is blown away by over exposure can't be recovered so it is generally safer to underexpose by 1/2 stop.  LR will do a much better job of recovering dark areas. 

A good starting point is to process in LR to maximise the spread of the histogram (exposure & black sliders) then if necessary adjust fill light or recovery to taste. Failing that start playing with the tone curves or region sliders. A touch of the clarity slider seldom hurts. All post processing works much better with raw files.

[maxman2402]

it's better to underexpose like said above

[Steve Williams]

Hey folks,

Please don’t intentionally underexpose your images.  It made sense with film to get those nice rich blues but it makes no sense with digital.  Our camera’s response to light is not linear.  The highlights or top fifth of the histogram represents about half the available tonal values.  On a 12 bit image that’s 4096 discrete total values from pure white to pure black.  If you aim for the middle of the histogram you can be throwing half of the available image data away.  It can get worse; remember that the histogram displayed on the back of the camera is the display of the jpeg data not the raw file.  What looks like over exposure on the histogram can be perfectly good imagery and most definitely can be recovered depending on how you have the camera setup.

Julian, what camera are you using and how do you have the “Picture Styles” setup if Canon, “Picture Controls” for Nikon setup?

 

Cheers,

Steve   

[E_viking]

Don't underexpose, since you loose tonal information and increase noise.

 

The Picture is overexposed, but the highlights are not blown out. Therefore, you can still correct it  in Lightroom.

I would be aiming for a better exposure with perhaps a slight overexposure ( atleast no  underexposure)

 

When the visibility is really bad. Set the Strobe Power as low as possible and think about how to aim the Strobes, to avoid  Backscatter.

[Julian D]

Thanks for the comments everyone.  This forum is great - living in New Zealand I can hardly whip down to the local underwater photography store for advice!

 

Johnjvv - I think you might be right about the direction of my strobes.  Previously I have tried to light with the edge of my strobe -  This was my first time with both strobes on and I guess I forgot. In fact I can see the flash reflected in his eye which I haven't really seen previously.  Next time I'll try full flash and light with the edges.

 

Regarding overexposing and Steves comments I read about this in the book by Martin Edge and here on wetpixel.  For a more detailed explanation you can find one here: http://wwwimages.ado...inear_gamma.pdf

 

Steve I checked my camera (D7000) and it is set on "Standard".  I should have mentioned that I shot in raw - so does this setting matter?  I have also attached a photo of the camera's histogram - could I have actually given this more exposure? 

 

Thanks again everyone,

 

Julian

 

Edited by Julian D, 21 February 2013 - 12:04 PM.

[johnjvv]

Why are you using rear curtain on your flash setting?

[Julian D]

Good question.  I've just checked my camera and the manual setting has rear curtain but the U1 (my underwater settings) is set for normal flash. When I took this photo I was in a few feet of water with a surge and was finding it impossible to stay still.  The only way I could get photos was to hold onto a big rock with my legs and look for something to photograph (it's the rocks at the side of a boat ramp).  There was a lot of wrestling with current/gear going on and I bumped my controls and strobes a number of times so it looks like I've changed settings in the middle of the dive. 

 

Would that make a difference?

[E_viking]

Judging the Camera settings and the Histogram. I would say that your Strobe Setting is a too high ( f16, 1/320s & ISO200 should make it pretty dark without Strobes).

 

I would personally reduce the flash Power stepwise until you get a result that you are happy with ( perfect exposure or a wee bit of overexposure, but no blown out highlights).

Well, I start with a minimum Flash power setting and increase it until I like it. A small amount of Flash helps also against Backscatter.

 

Rear Curtain does not really make a difference in this Pic, since it has no movement. The Strobes are syncing anyway. So, it should be no problem.

 

Above all have fun!

 

/Erik

[Damo]

Hey Julian

 

I still think it's a lovely image tho'- well done! :-)

You'll only get better!

 

ps. do you use a focus light on your rig?  If not, do consider getting one- it will help your camera with focussing, particularly shooting macro subjects in low vis.

[Steve Williams]

Good question.  I've just checked my camera and the manual setting has rear curtain but the U1 (my underwater settings) is set for normal flash. When I took this photo I was in a few feet of water with a surge and was finding it impossible to stay still.  The only way I could get photos was to hold onto a big rock with my legs and look for something to photograph (it's the rocks at the side of a boat ramp).  There was a lot of wrestling with current/gear going on and I bumped my controls and strobes a number of times so it looks like I've changed settings in the middle of the dive. 

 

Don't worry Julian, that was just Neptune messing with you to see if you were serious.  You know of course that it's perfectly all right to try this stuff on land.  You don't have to jump in the ocean and grab a rock between your legs to test your strobe settings.  That's what land photography is for.  

 

Have fun,

Steve

[Julian D]

Thanks all for the encouragement & advice. I clearly need to take my time more and experient with exposures/strobe positioning & power levels etc.  I'm really busy so haven't been able to get to any of the great spots that NZ has to offer so I figure I'm better to get some underwater practice so I make the most of it when I get to a good spot. 

 

Take you point about above water practice Steve - although there only so much a guy with a new camera/housing can take!  Despite the viz etc I still really enjoyed going out and I'm happy with the photo - looking back they are actually getting better each time.

 

I'm travelling to California tomorrow and as I have a weekend off I am heading out on a photo dive trip to Anacapa island with Bluewater photo.  So I'm hopefully going to be out on my first trip out into real photo territory (ironically not in NZ).

 

Damo - I do have a focus light but I felt it was scaring them (no red LEDs) so left it at home this time and it seemed to help.  I seem to be getting a much higher percentage in focus than when I first started (virtually none!). 

 

Thanks again everyone,

 

Julian

[DamonA]

Hi Julian,

I am the same as you setup wise with the d7000(I love it) and new to this passion. I started by spending a whole year doing ambient light shots, I have bought a YS-D1 and use the TTL II function via an optical fiber cable. This allows me to concentrate on strobe position and camera settings- without having to play with the strobe as much as manual setting. I have a friend using a ikelite strobe and he uses the E-ttl cable setup which control brightness to suit the shot via the cameras light metering.

I am concentrating on getting my shots right without editing- can play with them later when I have improved as a UW photog.

 

 

Also in crap viz look for subject under ledges or crevasses/caves where the water is more settled, this shot was in shocking green water viz conditions- however they didn't penatrate too far into the cave in which I shot this Pineapple fish(@cod hole, Julian rocks). http://flic.kr/p/cRuDKo

 

Using a 60mm macro lens would be easier also in that situation as it cuts down on distance to the subject, also back scatter in between the subject and the lens.

Edited by DamonA, 25 February 2013 - 03:38 AM.

[Julian D]

Hey thanks for the tips Damon and I really like your turtle photo!  Unfortunately I'm manual flash only as my housing isn't ikelite so doesn't have the converter. It also only has optical bulkheads -  I really like the optical connections they seem to work well and the whole thing feels like a lot less to go wrong.  Later on I'll probably get some strobes that can handle optical TTL. 

 

Good tip re caves/ledges in poor vis - I'll try that next time.

 

I'll get a 60mm too.  I read that they were better to learn with and for poor viz but when I look at a lot of peoples photos I tend to like the shots taken with 105 better, so decided (maybe foolishly!) to take the pain and learn with a 105.  Also hoped to get out in good vis more often.

 

Speaking of which I'm in the US now and heading out on a day trip to some islands off LA on Saturday.  I'm going to try and focus getting exposures right if I can resist zooming round trying to photograph everything and having a ball.  If I get some shots I'm not embarrased about I'll post a few.

 

Cheers

[Julian D]

Well, I got out to Santa Cruz Island on atrip with bluewater photo and with the help of you guys and a few pointers from some people on the boat I got some images I'm really happy with.  In addition to having a high power setting I think I also had my strobes too far forward. Here's one of my favourites - as shot.

 

Thanks again for the advice.

 

Julian

 

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[Damo]

Super Julian!!

 

The only little thing I would add is that in this case I would have gone for a vertical composition so as to get all the nudibranch in shot.

Dont be afraid to move your camera around to improve on the image!!

 

Otherwise...well done!! Lovely focus and colours!

[SwiftFF5]

Very nice - it looks like you've really applied everyone's advice.  Good job.

[Steve Williams]

Congrats Julian!  Santa Cruz can be a magical place.  Glad you had the folks from Blue Water to help too, good people.

 

Cheers,

Steve 

[johnjvv]

Nice going!