White balance and strobes

Oops - I didn't mean to imply that the Strobist article is a substitute for Alex's piece in UWP! Basically everyone should sign up and download (and read lol) the UWP article first.

The strobist article is a topsides article which gives the rudimentary information about how to "gel" your strobes and why. It will require some interpretation to make it relevant for underwater photographers.

Cheers

James

Folks - this has been very interesting so far, and with all 'interesting' topics has only served to confuse me more - not too difficult really! I'm still a total novice at u/w DSLR work, and only upgraded (?) to a DSLR fairly recently from my trusty 35mm. - So, a slight tangential query:

I run a Nikon D70s in a Fantasea housing mated to a Nikon SB800 flash in its own dedicated Fantasea housing, with the two connected by a Nikonos 5-pin cable, which allows iTTL between the two. I also shoot RAW, simply because JPG converters will always improve (Moore's law) and if I have the original bit-stream I'm happy. And then there's PhotoShop

My question is, what should I be doing with this kind of set up? Leave it all to the electronics, or go manual with a medium aperture and a max shutter speed of 1/250? I tried that in the red sea, and had very mixed results, even going so far as to add the diffuser to the front of the flash, which seemed to help, and then powering-down the flash output, which helped in some instances - I think I left a totally blinded blue-spotted ray looking for a white stick . I know everything is trial and error to some degree, and, as Alex says, if it looks good to you, it is good! But I think I could do with some help!! I'm going back to the Red Sea on another liveaboard in September , so would like the opportunity to 'practice' locally (Scotland ) I know the results won't be the same, but it is a practice set of dives, anyway!

So - any advice gratefully received!

Thanks, folks - your knowledge and time is appreciated

Alex, I would be very interested in seeing the difference (if you have an example) between when using the warming gels behind your 0.5 diifusors and when not.

I managed to do a quick test shot while I was in the Canaries. It is far from perfect but it gives you the idea. On this particular dive I was not using the Lee 444, but a similar filter. Anyway, I think it shows the affect on the white balance and hence the blue-ness water caused by warming your strobes.

The image on the left was taken with the standard INON Z240 + the 0.5 diffuser. The image on the right was taken with the same camera at the same time with an INON Z240 + the 0.5 diffuser + a warming filter gel on the strobe. Both foreground have "correct" neutral colours (just about) while the warmer light from the filtered INON has required a lower Kelvin value of white balance that also acts to cool the blue background rendering a richer blue.

Alex

I managed to do a quick test shot while I was in the Canaries. It is far from perfect but it gives you the idea. On this particular dive I was not using the Lee 444, but a similar filter. Anyway, I think it shows the affect on the white balance and hence the blue-ness water caused by warming your strobes.

 

The image on the left was taken with the standard INON Z240 + the 0.5 diffuser. The image on the right was taken with the same camera at the same time with an INON Z240 + the 0.5 diffuser + a warming filter gel on the strobe. Both foreground have "correct" neutral colours (just about) while the warmer light from the filtered INON has required a lower Kelvin value of white balance that also acts to cool the blue background rendering a richer blue.

 

 

Alex

Wow! Alex, that is quite impressive, thank's for posting. I'm going to try this. Such a simple idea, yet one of the best I have seen in a very long time for extending the creative opportunties - easily beats the the Nikon FF inmo

cheers

Such a simple idea, yet one of the best I have seen in a very long time for extending the creative opportunties - easily beats the the Nikon FF inmo

Cool. Send me the 5000 Euros!

Alex

"I love it when a plan comes together."

- Col. John "Hannibal" Smith

Amazing how the perception of water quality changes with color. Strobe filtering is great.

Funnily enough I was deleting my Wetpixel PMs this morning and I spotted some messages we (Craig and I) exchanged about warm filtering INONs over a year ago.

At the time I had been trying too strong filters and was not getting good results. My sage advice at the time was:

It might be worth experimenting with a very weak warm up filter on the Inons - but I am unconvinced it would be a lasting solution. In general, if you want warm strobes - i'd say buy warm strobes!

Something I'd refute now! The best thing about forums is that posts last for ever - so you can read how wrong IO used to be! It is a dynamic time in underwater photography.

Alex

p.s. Craig, I think that the A Team quote would make a good signature. Either that or the old Obiwan Kenobi one.

Something I'd refute now! The best thing about forums is that posts last for ever - so you can read how wrong IO used to be! It is a dynamic time in underwater photography.

 

Alex

Great thread and great article Alex. I have to go back and figure out what to put on my strobes. DS-125s 4800 Degrees and YS-90DX 5100 w/Diffuser. Definate worth warming them up more as your photos show.

p.s. Craig, I think that the A Team quote would make a good signature. Either that or the old Obiwan Kenobi one.

That'll work! Many of us dive with a Death Star now.

I think it's a credit to digital that we can easily experiment with techniques like this and Alex can so readily demonstrate their effects.

This is fascinating stuff. I experimented with green (strobe) and magenta (lens) filters with my D100 and Inon 220 strobes four years ago after Craig made a series of postings on using filters to improve the water background color. I liked the results with those filters when shooting WA with the D100, but I also had recently converted from DS125 strobes to the Inons, and wanted the warmer light back for my macro shots. So I bought warming filters for the strobes (81B), but started using a warming filter on my macro lens instead, which I still use with my D2X (and even when shooting film with the Inons). I'm no longer using the green/magenta filters with the D2X for WA, but still not quite happy with the blues, and Alex's article has illuminated exactly why.

Now I'm excited about trying warming filters on the strobes again, but it sounds like the 81Bs I have are much too strong (and I found it too strong for macro as well, on my lenses). I'll check out the Lee 444. It'll go in my little filter kit, full of Cokin filters, strobe filter holders, lens gels and magic filters!

Thanks for writing the article, Alex, and for clarifying things here.

Linda

By the way, just for reference, I found this mired shift calculator (you input the original and desired kelvin values and it displays a list of (Lee) filters:

http://www.leefilters.com/architectural/pr...I46CB01BDDD6E0/

Alex has probably already seen this or can do the calculations in his head , but I found it helpful.

Linda

Sorry for all the posts, guys, but I'm back with a question...

It looks like the mired difference between the Inons (5500 kelvin) and Alex's Subtronics (4300 kelvin) is about 50 mireds. The Lee 444 is 20 mireds. I'm curious why a stronger filter would be too much? Wouldn't a stronger filter (e.g. equiv to 50 mireds) just be similar to using the Subtronics? Is something else at work here?

I found Craig's old article : http://wetpixel.com/i.php/full/filters-and...ht-photography/

where he lists the mired values for various CC and warming filters, and I see exactly why I settled on the 81B filters at the time to make my Inons have similar color temp to the DS125s.

I'm just wondering what the effects are of using a filter that is too strong. Is it just a matter of getting the right blue?

[Edit: I have partially answered my own question and all it took was a more careful reading of Alex's article. He was going for a correction to make the strobes similar to DS200/DS125 and not his Subtronics. That makes the numbers work out. And it may be that the 81B filter could be sufficient for me, so I'll give them a try when I'm next in blue water...]

thanks,

Linda

PART 3

Magic fliters seem to be designed for ambient light and Auto WB. Can you use them with a set WB and a strobe.

Not sure if anyone chimed in on this part ...

I wondered the same thing after I got my Canon G9. The G9 shoots GREAT video and I wanted to be able to shoot "color corrected" video and strobe-light stills on the same dive. I did not have a way to put a wet filter on my housing, so I used the Magic Filter. I got some of the "original" Magic Filters - which require a manual WB, but don't filter out quite as much ambient light as the "auto". I found that if I set the manual WB with the Magic Filter on and my strobes firing, I got good results.

It looks like the mired difference between the Inons (5500 kelvin) and Alex's Subtronics (4300 kelvin) is about 50 mireds. The Lee 444 is 20 mireds. I'm curious why a stronger filter would be too much? Wouldn't a stronger filter (e.g. equiv to 50 mireds) just be similar to using the Subtronics? Is something else at work here?

 

where he lists the mired values for various CC and warming filters, and I see exactly why I settled on the 81B filters at the time to make my Inons have similar color temp to the DS125s.

 

[Edit: I have partially answered my own question and all it took was a more careful reading of Alex's article. He was going for a correction to make the strobes similar to DS200/DS125 and not his Subtronics. That makes the numbers work out. And it may be that the 81B filter could be sufficient for me, so I'll give them a try when I'm next in blue water...]

 

thanks,

Linda

Hi Linda,

My Subtronics are rather unusual, and I think it is better to aim for 4800K to 5000K (modern Subtronics, Harteberger, Ikelite DS125/200 etc). In terms of Mired shift from an INON this would be a range of +18 to +26.

The Lee 444 is +20 Mireds and the Lee 223 is + 26 Mireds.

I think that the Lee 444 is a good compromise - within the range. The Lee 223 would have a stronger effect, but would costs a bit more light. For most people after a subtle improvement that is not going to cause other issues in some situations (I have found that very warm strobes confuse the camera's Auto WB in greeny waters leading the the WB adding unsightly amounts of magenta). I don't want people trying strobe filters getting weird results and then giving me a hard time, therefore I recommend the Lee 444 is the best choice.

An 81B would be slightly stronger than the 223, but should be fine. The downside is that it would cost a lot more money - being an optical quality lens filter, rather than a lighting gel. Lee lighting gels are made of the same material as their lens filters (although different colour recipes) but the lens filters are made to much much higher optical tolerances (which is why they cost about 200x more per unit area). Plus you would have to buy two packs for two strobes and would not have a spare. But if you have them already, then go-ahead (most of these comments are for others following the conversation).

Alex

Alex (and everyone) - I've really enjoyed and learned a lot from this discussion. Thanks so much! As I've said before, this community has saved me literally years of trial and error.

With respect to the difference between Lens Gels and Lighting Gels ... for someone like me that has neither laying around who want to try this out, sounds like you would recommend buying the less expensive lighting gels, right?

Also - how much light does a lighting gel "steal" from you?

I have a YS-27dx (5500 w/diffuser) and a YS-110 (5100 w/diffuser) ... and I'm thinking about putting a gel on the YS-110. Seems like I may have an opportunity to both warm up my YS-110 and possibly balance the power between the two.

S&S claims the YS-110 is GN=22 and the YS-27dx is GN-20 - I assume on a relative basis that is probably accuarte.

Am I right in thinking a Lee 444 warming gel on my YS-110 might do the trick?