What colour lens?

[Dangerous Brian]

Hi all, I wonder if you can help answer a question I have. Why are my snaps red?

I went diving in Thailand last Feb and bought a urpro orange/red filter (which was recomended for this water) . I was wondering if this is the correct filter for the waters in Thailand.

 

[herman]

If you are shooting stills (not video) you use NO filter. If you are shooting video with no lights and deeper than 15ft, then an orange/red filter is helpful.

 

[MacHeath]

Hi all, I wonder if you can help answer a question I have. Why are my snaps red?

I went diving in Thailand last Feb and bought a urpro orange/red filter (which was recomended for this water) . I was wondering if this is the correct filter for the waters in Thailand.

The amount of colour correction required depends on several factors. The main factor is depth, as you go deeper there will be less red light available. So when you are deep, a red filter can be used to correct for the loss of the red light. If you were shallow when you took the pictures, then there would still be plenty of red light available and so a red filter would over correct. This would give you red photos.

so the message is, if you are shallow remove the filter. As to how shallow, that depends on the conditions.

If you are using a strobe, then a red filter won't help. Since if the light travelled far enough from the strobe to have the red component removed, the light from the strobe would be too weak to help with the photo anyway.

 

[Dangerous Brian]

Thanks for the info. I will take some test shots when I am there at different depths to see when I need to use the filter. I am new to U/W photography so this info helps a lot.

Happy snapping

 

[Chris Bangs]

I agree with herman, I never have like the results those filters produce. just not natural.

Anyway, are you shooting film or digital? if Digital, forget the filter as you have more control in your photo editing program, same for film if you plan to scan the images although film is a lot less sensitive to reds than digital sensors.


chris

 

[Dangerous Brian]

Right! I can add more red to the photo once its on my PC? I just thought that if the reds were not on the original shot you could not add red as it would not no which bit should contain red. (very new to U/W shots) I think I will read some threds about taking digital pictures, I am sure there will be some.

Thanks Everyone!

 

[herman]

You can also add red the the original image by adjusting the white balance on the camera (assuming you have that control ). If you are using a strobe, either internal or external the strobe light is the correct color anyway and no adjustment is needed. And yes, you can always add red into the photo using a photo processing program like Photoshop (CS, Elements or whatever)

 

[Chris Bangs]

If your camera can shoot in RAW mode use that. then you can select whatever white balance ( color temp ) that produces the desired results. RAW is by far one of the greatest advantages of digital photography.If shooting in RAW, it is as if you have every type of film in your camera at the same time

CB

 

[ChrisA]

I just thought that if the reds were not on the original shot you could not add red as it would not no which bit should contain red.
Thanks Everyone!

You are kind of right.

The way it works is like this: Inside the computer the image is stored in three "layers" a red, blue and green layer. When you view the image the layers a stacked and you see the sum of the red, blue and green. Your eye blends them together and you see full color. In a digital image the layers are conceptual but in film they physically exist. Either way same effect.

Now when they say "add red" when happens is the red layer is made more dense. Kind of like if they duplicated it and added the duplicate back in as a fourth layer. The reds would be more intense.

But if there was _no_ red light the red "layer" would be clear and there would be no way to bring up the reds using a computer. There is no option but to bring your own source of light with you if you are below 70 or 90 feet

A red filter can NOT add red light. All it does is block non-red light making what little red light is there brighter relative to the blocked blue and green. All that ANY filter can do is selectivly block something, no filter can create light.

 

[Dangerous Brian]

Right, now I understand 100% more than I did when I posted this thread. I will not be diving to far down, say 50 feet. It should be nice and bright and clear so I wont need to put a filter on and will just use my flash. Thank you all for your help. My shots should be much better now I understand a bit more.