Color correcting lens question

[koozemani]

I use a Nikon point and shoot in an ikelite housing with an AF-35 strobe. Not great, but I still end up will a few pics that I'm proud of. My biggest pet peeve is taking pics that are beyond the range of my strobe and the pervasive green or blue hue washing out all the colors.

My question is, is it worth buying color correcting lenses?

I usually dive in the Sea of Cortez, but usually get out to somewhere tropical once or twice a year.

So, will color correcting lenses make a significant difference?

 

[herman]

Not unless you want to turn the strobe Off. If you don't, all your near field (strobe lit) objects will be excessively red. You can have one or the other, both is not an option once you get more than a few feet deep.

 

[koozemani]

Understood, but for shallow pics (<45 ft) is there a significant difference?

 

[herman]

What you have to realize is filters are fairly limited in their use. Anything past 10 ft or so and the amount of available red light has already started to drop a lot. In very clear water a filter can be useful down to maybe 30 ft but you still must turn the strobe off. As you get deeper, you need more and more red filter to increase the amount of non-red light they absorb. I say it that way because the way they work is not to add back red but rather to filter out all the other colors, letting more red pass thru. The deeper you go the less red light that is available so you need to reduce the other colors more and more. This forces you increase the shutter time and/or decrease the F-stop to make up for the difference (loss of ambient light). On the other hand your strobe is putting out white (full spectrum) light. If you fire it and that light passes through your heavy red filters needed at depth, you end up with the near field way over red and most likely over exposed due to the aperture needed to bring the far field to the exposure you want.

Blue and green far fields are just a fact of life, you can improve your shots by use manual mode and adjusting the shutter speed and F-stop to vary the near and far fields within the shot.

 

[koozemani]

Thanks, that helped!

 

[PatW]

If this is any help, even much more powerful strobes only help so much. Red light is absorbed in the first 15' of the water column. That means the red light from a strobe can only illuminate a red object correctly at 7.5' (for 15' round trip). A rule of thumb is that you want your subject to be within 5' of your lens. In order to shoot large objects like big fish, turtles, and other divers, one needs a wide angle lens. That fact goes a long way to explaining the popularity of 10-20 mm wide angle zooms among DSLR photographers.

 

[koozemani]

Its not the lack of red I'm worried about. These are links to the filters I'm specifically talking about.

Ikelite External Color Filter for Green Water - 2.2"

Ikelite External Color Filter 6441.32 B&H Photo Video

I am looking for something to help improve my pics in shallowish 20-45 feet with lots of natural light in decently clear water(30-60 ft vis) where the subject is outside the range of my strobe.

When I get home, I'll try to post a couple of pics that will show what I'm trying to work around.

 

[Gcrackr]

It IS the lack of red you are worried about. Water filters out the red of natural sunlight, giving you photos that have too much blue or green (depending on the settings of your camera). Withing the range of your strobe, the light of the strobe gives you all the colors of the spectrum, thus good color. Beyond the range of your strobe, a filter is a good choice. I use a Ikelite filter on my WA-20 wide angle lens with a compact camera similar to yours. I get good results, however: 1) you will need a "blue" water filter for the ocean ("green" is for fresh water), 2) my photos come out way too green with the filter but the auto color correct feature of any photo processing software gives me excellent results, 3) you will need to turn off your strobe when using the filter, and 4) filters only work down to about 40', maybe a bit farther in good natural light (i.e. mid-day no clouds).

 

[koozemani]

Ok now I get it. Thanks.

 

[Interceptor121]

Filters are very worthwhile for wide angle shots where the subject is anyway too big to cover with a flash.
They work well between 15 and 80 feet (this includes depth plus distance to subject) with the best results between 15 and 50
Using filters you can point the camera downwards in fact pointing it upwards creates problems

Alex mustard has a great website on magic filters and UR PRO has also loads of information (though mostly for film camera!)