UR Pro Filter

I just returned from my honeymoon in Saba - a wonderful little island near St Maarten. My wife used a Canon S40 and UR Pro filter. I had my CP5000 and DS125 but the strobe flooded on our first dive and I did not have a filter. We both got shots of the same eel at about 75ft. The following pics are unedited except for size. I know there is no substitute for a good strobe(s), but I wanted to show how well the filters do work. I was going to make a shim for a 4" filter to fit on my dome port but got too busy with the wedding. Darn. Any comments? Still learning here

S40 + UR Pro filter

CP5000 - no strobe, no filter

I'm glad to see someone posting results with filters and I believe their usefulness is being overlooked. Haven't been seeing any wide angle shot with filters.

The top photo differentiates the yellows and browns from the green moray.

The bottom does not.

I shoot exclusively with out using flashes. . I find no real good reason to use any type of filter underwater when you can white balance and get similar results with out the loss of light. A UR PRO will not only filter the blue light but will filter about two F stops of ambient light. If you decide to use a filter you should white balance threw it as well. This will take care of the excessive red in shallow water, and improve the over all white balance at deeper depths. My experience is that some digital cameras can white balance underwater better and more accurately than others. My Nikon 900,950,and 990 were excellent as long as their was sufficient light. My Nikon 5000 was terrible and couldn’t white balance even in shallow water in good conditions. My S2 Pro has been some what of a challenge to white balance, but I’m now getting good results. So my point being, you’ll have to experiment with your own camera as to how well it will work. You can bet on that if you using a filter in auto white balance mode it will definitely improve you color, but you may not need to use one if your camera will manually white balance.

Marc

I guess I should have added that she did manually white balance with a slate. I never tried with my CP5000. I didn't use it much as the strobe was shot.

Anyone else try using the CP5000 without a strobe with manual white balance? Any suggestions? (I intend to repair the strobe but still want to know)

I suppose I am partial to filters because my first experience with uw imaging was video and they seem to work well in that application.

Saba, the "Unspoiled Queen of the Caribbean". Did you dive with Sea Saba? Love 'em. Lynn is great.

Filters.....

Filters are non-discriminating they filter out the same wavelengths regardless of depth, so their impact varies from shot to shot. Generally, u/w photographers don't use filters, since they use strobes to light up the subject. It definitely helps most shots if you have no strobe, but can alter the look of blue water backgrounds.

Videographers use filters because they cannot get the same color temperature out of video lights as one would with strobes. Plus, the ambient and reflected light is changing with every camera movement, diver movement and change in subject to camera distance.

If you get the latest firmware update for the CP5000 you can shoot Nikon NEF (RAW) format. You can then change the white balance when you open the image in Photoshop. For warmer colors go to Cloudy.

How did your strobe flood? This is at least the third time I've heard of the DS125 flooding. User error? If so, please share so as to educate the rest of us.

A further point with video is that their lights don't have nearly the continuous power that strobes deliver with their short durations. Videographers are severely limited in their ability to deliver light compared to still photographers. That's why filters are much more important to them.

That's also why still photographers can learns something from video. Filter plus white balance is always superior to white balance alone. Videographers also try to combine filters with lighting, and to the extent they are successful their technique is applicable to digital still.

Without filters, the blue and green channels dominate the exposure and you end up underexposing the red channel. The result is higher levels of red noise or no reds/whites/yellows at all. The goal is to expose red, green, and blue equally on white pixels rather than fixing it after the fact. Filters are what you use to do that when you can't use artificial light.

White balance is a wonderful thing, but it is handicapped when you don't white balance the light entering the lens. Would you deliberately underexpose your shots 4 or 5 stops knowing that you can crank up the gain to compensate? That is what you are doing to red when you white balance without a filter.

Sorpio,

I didn't open the strobe as I think it voids the warranty but I noticed some small droplets of water behind the LEDs and around the bulb. The strobe would charge and get warm while in the off position. I delivered it to my local dealer on Friday where I purchased it in June.

It worked flawlessly for my first trip in June, but failed on our first dive of about 100 ft last week. I noticed the whine sound of a charging strobe while waiting during our surface interval.

It is a good strobe and I hear Ikelite backs their products so I am not worried. Looking forward to using it this spring

If you open the lower image in photoshop and hit auto levels in the image/adjustment menu you will see exactly what Craig is saying: Noise on the Red channel.

The manufacturers of these CMOS sensors are still thinking "Video" and do not build a delay into the red channel, before or after the fact. This is how your eye works and the reason the receptors are arranged in a hemispherical attitude - digital is lacking due to the fact the sensor is flat.

The image without the filter is over exposed by at least 0.5 to 1 stop, and the image with the filter is at least 1 - 1.5 stops under exposed. Both exposure problems easily rectified for next time. As was mentioned choosing the correct idiogram will produce warmer colours but will increase the exposure time giving the subject time to move just enough to become blurred. White balance may solve a lot of problems but it can be a pain in the ass!

To cut a long story short always use a strobe with a tentitively prepared o-ring.

Digital photography by its very essence is more complicated than one might first invisage, but it is easily learned and a lot more forgiving cost wise.

Good luck with your further photographic endeavours.