Available light shots

Hi everyone...

just a quick note to tell, everyone that Lars tried to summarize this thread in an

article at digideep.com which should raise some additional interest to this thread.

It's also pinned on our homepage B) So it should get abround 200.00 PI's within

one month...

Thanks, Andi!

Wetpixel is working on a "summary" as well. The only reason it hasn't been posted is that I am a out travelling. sorry, guys!

Thanks, Andi!

 

Wetpixel is working on a "summary" as well.  The only reason it hasn't been posted is that I am a out travelling.  sorry, guys!

When are you going again Eric? Is it already preparation for that trip you won?

Be sure to make a nice gallery for your audience at wetpixel & digideep.com !

Cannot wait to see what's down in the sea there...

So, here's what I just ordered, on the advice of Craig (thanks, Craig!):

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Kodak Wratten Gelatin Filter 75mm/3x3 Color Compensating CC 30 Magenta 1 14.95

Kodak Wratten Gelatin Filter 75mm/3x3 Color Compensating CC 30 Magenta 1 14.95

Kodak Wratten Gelatin Filter 75mm/3x3 Yellow Series Color Conversion #81EF 1 14.95

Kodak Wratten Gelatin Filter 75mm/3x3 Amber Series Color Conversion #85 1 14.95

Adorama Step-Up Adapter Ring 67mm lens to 77mm filter Size 1 7.95

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The idea is that you mix Magenta and Yellow filters to get something approximating an FL-D filter.

Since both of my wide-angle lenses (the Sigma 15mm full-frame fish-eye and Canon 16-35) have rear filter holders, this will work out quite nicely.

I also happen to have a glass Tiffen 77mm FLD filter, which I can use on the front of the 16-35, should I decide that I want to do so. The 67-77mm step-up filter is for use with my PT-015 housing, which is 67mm threaded in the front.

I suppose I should go around looking for a grey and white cards now. But what I might do instead is spray-paint the top of one fin grey, and the top of the other one white.

We'll see. If I do that, I'll start to become paranoid when I am around sharks. Well, unless I'm with Douglas Seifert or Anna Abernethy, who both wear yum-yum yellow wetsuits.

That sound like a good plan. Keep a careful eye on flare when you use the Tiffen. It has a film sandwich construction that introduces 6 light boundries instead of 2. I suspect that to be the cause of occasional flare issues I've seen with video (but with glass UR Pro's). Otherwise I like the Tiffen FL "recipes". Don't want to be alarmist since I've never had a problem with a Tiffen.

If we had a source for someone who could cut and mount filters into rings, the Lee FL-B's are great. I've just heard (somewhere else!) that the Singh-Ray's were cancelled. Formatt makes FL-B's as well but I've never bought any.

Keep a careful eye on flare when you use the Tiffen. It has a film sandwich construction that introduces 6 light boundries instead of 2. I suspect that to be the cause of occasional flare issues I've seen with video (but with glass UR Pro's). Otherwise I like the Tiffen FL "recipes". Don't want to be alarmist since I've never had a problem with a Tiffen.

Interesting. I doubt the construction is the same, but I swapped out my Tiffen UV filters for B+W MRC filters because the Tiffens were giving me problems. Granted, it took me years before I noticed -- or cared.

Screw-on will be last-resort, anyway. Only if my big setup fails will I be using the Oly wide-angle.

Craig Jones has written up a summary as a wetpixel feature:

http://wetpixel.com/features/200307_available_light/

Photos courtesy of Alex Mustard.

Wow. Looks much better with pretty pictures!.

You guys wrock.

Cheers

James

I have also written an article for UWP magazine on available light. My approach differs from Craig's article here, basically because I don't understand the theory as well as he does! My article focuses a bit more on the in water side of things - how to use and control available light in our pictures. So hopefully the two should complement each other well.

The pictures in that article may give you a sense of deja-vu! I really must do some more available light pictures when I am in Cayman next week. Anyway it will be out at the end of the month.

Alex

I'm going to be doing some experimentation with my Oly setup in the Galapagos next month, too. We'll have a huge influx of ambient-light images!

Hey -- can you talk a bit about red/magenta filter usage in only a few feet of water? A little bit probably helps, right? But will it color the whiteness of the "sunball" (or whatever we digital folk get when we point a camera at the sun.

I think that full sunbursts should be avoided with currently houseable digital cameras - just because they don't come out as well as on slide.

When shooting available light I tend to use a slightly downward camera angle because this ensures the sunlight (that is coming from above) illuminates the scene evenly.

When shooting with filters with a slightly upward camera angle it is easy to get red sunbeams or red tinted water because the light path of whatever is at the top of your frame is shorter than the lightpath of the main subject.

I have just drawn (with my mouse) the example below in Photoshop. Sorry 4 the quality! Anyway if you have the filtering correct for the dolphin then any surface (or sunlight) in the top of the frame will be over filtered (because the light path is shorter) and therefore too red.

So in shallow water use a weak red or magenta filter and shoot downwards to get even illumination and to avoid red water or sunlight at the top of the frame.

Alex

hope this is clear

I'd add a general comment about filters tinting some colors pink. It's true that may happen, but the same is true for the effect of water itself. White light gets tinted green or cyan by the water but we're used to that and think it's OK. White balance compensates for the effect, so just think of white balance working with filters the same way but possibly in the opposite direction.

Ambient light underwater is a continuous mixture of light with spectral qualities that vary with distance. The way to get the most uniform color is to control the various distances and make them as similar as possible. When you introduce unfiltered strobes you alter that balance in the wrong direction. In Alex's diagram he's explaining how to avoid a source of light that's too short. Remember that it's not the various distances that matter but rather their ratios.

Once in the camera, you ideally want a color balance that requires the least amount of color correction. Whether that turns out to be too pink or too green isn't as important as how much correction is required. If you shoot RAW, you should pay close attention to the color balance settings in the converter even if you are using Alex's manual white balance technique. This is the best way to tell how much filtering is best for the depths you are diving.

Wetpixel is working on a "summary" as well. The only reason it hasn't been posted is that I am a out travelling. sorry, guys!

We look like dwarfs, compared to Craig's article! It's awesome.. great work!

Good to have a videographer in this digital think tank...

One basic question about technique:

How far away do you hold the white/grey card? Seems like even a little change in the distance of the card from the camera will make a big difference...?

If we had a source for someone who could cut and mount filters into rings, the Lee FL-B's are great.  I've just heard (somewhere else!) that the Singh-Ray's were cancelled.  Formatt makes FL-B's as well but I've never bought any.

Hi Craig,

it took me some time... But I found this page:

http://www.leefilters.com/CPTF.asp?PageID=106

However I will try to order some Lee Filters from Great Britain.

I want to use the rear gel holder of our SIGMA 15-30mm lense B)

I'll keep in touch as soon as we have UW-piccies

However I have one question Craig: When I use the gel filters

what happens to the flourescent filters? Would you recommend

these in addition? And do you know any source which offers

flourescent filters which I can insert into the rear gel holder?

You have been a great help so far! Thanxx... :-)

However I have one question Craig: When I use the gel filters

what happens to the flourescent filters? Would you recommend

these in addition? And do you know any source which offers

flourescent filters which I can insert into the rear gel holder?

Oh gosh... I overlooked something here is the source

http://www.leefilters.com/CPTF.asp?PageID=109

I should take of my sunglasses B) => avoids quoting yourself!

Thanks, Andi.

Ideally the gray card should be at the subject distance. Assuming you are 20 feet deep and the difference between the card and the subject distances is 1 foot the error will be 5% so the setting really won't be that sensitive. As long as the card is at least as close as the subject (or you move a little deeper) your subject won't turn pink.

With video I don't necessarily recalibrate on every shot. When I'm close to the surface I do or when I change depths more than 5-10 feet. I know I have to correct the video anyway to match the other clips so there I'm looking for a 90% solution.

However I have one question Craig: When I use the gel filters

what happens to the flourescent filters? Would you recommend

these in addition? And do you know any source which offers

flourescent filters which I can insert into the rear gel holder?

Oh gosh... I overlooked something here is the source

http://www.leefilters.com/CPTF.asp?PageID=109

 

I should take of my sunglasses B) => avoids quoting yourself!

Yes, these are the Lee filters I'm referring to and the ones listed on the wetpixel page. The three FL-B filters produce a nice shallow-medium-deep combination and one of the FL-D's is suitable as well.

Unfortunately the Lee's are cast acrylic and won't fit in the gel slot on the wide angle lenses and I'm not aware of any flourescent gels that will.

For the Sigma 15-30 and other wides likes the Sigma 15mm fisheye, you will need to combine two gels, a warming gel and a magenta gel. Doing this produces the same effect as a flourescent. If you uncomfortable with using two gels then omit the warming one. The wetpixel page has some advice on which combination of gels to use.

I just spoke with Lee Peterson at Marine Camera Distributors. They do have the ability to cut down rectangular filters and mount them into rings. The process requires some setup time so it's really only justifiable when doing multiple filters (of the same size). It still could be an option but would not be inexpensive. He said the Lee filters are brittle and require special care.

The wetpixel page has some advice on which combination of gels to use.

I read that one, but found it very hard to match the right filter on the Lee Page.

:angryfire: Why don't these guys have a shopping basket and article numbers?!

It makes it very hard for me as a non-native speaker to work through their

technical English. Maybe someone could post the link of the correct Lee Filter

Page, where I can find the magenta Filters.

Thanks