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Post by Broxton Carol on Oct 18, 2007 10:44:49 GMT -8
Heres a question you experienced picture takers may be able to explain to me. I have a 3 year old SONY underwater camera. In bright overhead light it gives clear well colored pictures that are great. However in darker water, or poor light, the pictures appear greenish, and I lose a lot of them that way. Whats wrong? Thank you. Chucko
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jviss
Pro Diver
Posts: 209
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Post by jviss on Oct 18, 2007 11:38:02 GMT -8
Chuck,
Are you using a flash?
jv
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Post by Broxton Carol on Oct 18, 2007 12:29:23 GMT -8
No, this occurs on days with overcast sky, or at deeper depths, that keep the light values down. The flash on it is no good.
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Post by Captain on Oct 18, 2007 15:47:33 GMT -8
Nothing wrong with the camera. The water absorbes reds and yellows first so all you get are the greens and blues as you go deeper or have low lighting condition. Flash is the only solution.
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Post by scubadiverbob on Oct 18, 2007 15:56:21 GMT -8
Green can also be caused by algea in the water. Try shorter camera to subject distances if your in fresh water. In the river, my camera sees 7 ft. with 30 ft. vis.
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Post by kgehring on Oct 18, 2007 18:29:13 GMT -8
Gotta have a flash. A mounting tray with flash would be ideal. It might also be possible to add a green water filter to help bring the color back. It works on the same principle as a red filter in saltwater.
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Post by SeaRat on Oct 18, 2007 21:55:59 GMT -8
A strobe will help, but only if you let it overpower the ambient light in the photo. I come from the land of green water, and if you have a combined strobe fill/ambient light photo, it will still be green in the background. This photo of the smallmouth bass has a green background because of the ambient light which allows the background to be seen. Part of the reason is because this was taken at about three feet away, in about ten feet of visibility. But if the strobe makes all the light for the photo, then you have a different background, one that is more "natural" feeling but which really is entirely artificial. This closeup of the three-spined stickleback is taken from only about three inches away, in the winter when it is cold and the fish would get in a Nikonos framer. The strobe was a Subsea 150 at 100 watt-seconds, which is the middle setting on this strobe. Stickleback, taken with a Nikonos II, 35mm lens, 1:3 macro ring and framer, Subsea 150 strobe at 100 WS. In tropical salt water, the water looks blue: Nikonos I, 35mm lens, off Key West, Florida at the US Naval School for Underwater Swimmers, ocean qualifying dive, 1967. A strobe-only shot will yeild more natural colors, but looks like it is taken at night. Canon F-1N, 24mm lens behind a dome port, Ikelite housing, Ikelite Substrobe MS, f-5.6. Note the loss of coverage with the Ikelite Substrobe MS compared to the Subsea 150 above. This is due to two factors, 1) that the former photo is a macro photo, and 2) that the Subsea 150 has an extremely wide angle beam, whereas the Substrobe MS does not. This photos shows off the wider angle of the Subsea 150 to a better extent, and is deep enough, and in the shadows enough, that the ambient green light is minimized (which is another way of doing it). Spawning redside shiners being attacked by the Umpqua Northern Pike Minnow (background). Canon F-1N, 24mm lens behind a dome port, Subsea 150 strobe at 150 watt-seconds, f-5.6. All photos Copyright 2007, John C. Ratliff. I kinda like the more natural look with the water as it actually is, rather than what we think it should be. John
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Post by Broxton Carol on Oct 19, 2007 5:00:38 GMT -8
The "ambient light" is the prime factor, Im beginning to see. no pun intended, to my problem. Ill be in florida diving for a week, so will have plenty pictures. The little built in flash in my camera is just not potent for good shots underwater, though it is sufficient for great pictures on land! I looked on ebay for a filter, but they are expensive, and for the use I get from the camera is one of these worth the investment?
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jviss
Pro Diver
Posts: 209
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Post by jviss on Oct 19, 2007 5:17:08 GMT -8
A filter that corrects color for underwater use is very dense, making your lighting much more difficult. A powerful flash is needed.
In addition, you might do some research to see if your camera has an underwater color balance setting, or if someone on the web has figured out how to adjust the color balance on that camera for good results underwater. Some digital cameras for which the manufacturer produces a housing have an U/W setting.
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Post by SeaRat on Oct 19, 2007 7:50:07 GMT -8
If you have the ability to scan the photos, or get them scanned when they are developed, you don't need any type of filter. Simply go into Photoshop and make changes. I'll post an example this weekend. Photoshop is better than a filter--with Photoshop you can correct any color problem. You shouldn't have much problem anyway in Florida. The water there is clear, and there will be little in the way of color correction problem (see the photo above that I took off Florida in 1967)... ...Okay, it's evening, and I have two examples for you to see. There are the same photo, and the first is the way it was recorded on the film. These are Umpqua Northern Pike Minnows spawning, taken with a housed Canon F-1N, 24mm lens, Subsea 150 strobe set to 150 Watt-Seconds, lens opened to f-5.6. Here is the same photo shown after I corrected it by adding red, subtracting green, and adding blue: There two photos are Copyright 2007, John C. Ratliff John
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Post by 2250psi on Oct 22, 2007 5:47:12 GMT -8
Chuck, You are right that filters can be expensive. I don't know what filters you looked at on ebay but you might want to look into a "magic-filter'. www.magic-filters.com Their website will answer your questions and although they are located in England some shops in the USA carry them. Reef Photo and Video, Ft Lauderdale, Fl does. www.reefphotovideo.com speak with Ryan and he can advise you. John, Strobe only shots do not have to look like they are taken at night. A lot of photographers turn their camera to the flash setting (sometimes noted with an "x") which is usually the highest shutter speed the flash can synch at which varies but usually between 1/125th and 1/250th of a second . This will typically cause black backgrounds especially when coupled with a small aperture setting of f11 or greater. The reason of course is because the ambient light doesn't have time to record on the image and the strobe is being used to supply all the light and will make the subject appear to be taken at night especially when suspended in the water away from any sort of background. The trick is forget about that default setting as you can use any shutter speed as long as it is less than the flash synch speed and it is fast enough to stop the movement of the subject. Usually UW you can go as low as 1/30th of a second as long as it is not a fast moving subject but 1/60th is a safer bet. Slower shutter speeds can produce a ghost effect as the flash records one image and the ambient light records a second. The trick is to decide how you want to record the background water and expose for that by choosing shutter speed and aperture then letting the strobe basically add the color to the subject. It is personal taste but most people find under exposing the water but a stop to a stop and half gives it a rich blue color rather than a washed out blue the diver is more accustomed to seeing. Sorry if this is info you are already aware of but then maybe it will help someone else. edit: John after reading your post again I saw you photo of the bass which is evident you were aware of what I was saying. My confusion came by interpreting your "strobe only" comment to mean using a strobe as opposed to no strobe. Sorry. Regards, Mike
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Post by SeaRat on Oct 22, 2007 9:30:19 GMT -8
Mike,
You are correct in all that you say. But realize that for a Nikonos (except the Nikonos RS), you are limited to shutter speeds with a strobe synchronization of 1/60th or 1/30th second. Higher, and the strobe is cut off by the camera's shutter, and only a portion of the frame is exposed (which is really maddening when it accidentally happens).
I talked briefly about my housed Canon F-1N camera and the 24mm lens behind a dome port. This is a wonderful setup, and with ISO 100 film I have used a f-5.6 lens setting for the strobe, and gone as low as 1/8th of a second for the shutterspeed. I'll try getting those and posting one (they are on a disk somewhere, and on my older computer).
John
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Post by Captain on Oct 22, 2007 10:00:56 GMT -8
Does anyone know the metric O ring sizes for the various O rings for the Nokonos ll. From measurements the lens mount O ring appears to be an M3.5 x 46. It is difficult to determine the body O ring because there is no easy way the measure the case and it is hard to be sure the O ring is perfectly circular when trying to measure it. I just bought a Nikonos ll body for 10 bucks that I will sacrifice in learing how to disassemble and replace the internal O rings.
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Post by SeaRat on Oct 22, 2007 11:14:16 GMT -8
Does anyone know the metric O ring sizes for the various O rings for the Nokonos ll. From measurements the lens mount O ring appears to be an M3.5 x 46. It is difficult to determine the body O ring because there is no easy way the measure the case and it is hard to be sure the O ring is perfectly circular when trying to measure it. I just bought a Nikonos ll body for 10 bucks that I will sacrifice in learing how to disassemble and replace the internal O rings.[/I][/quote] Oh my, please don't sacrifice the poor ol' Nikonos II, unless it is beyond hope. These are great old cameras, and you should be able to work on it without "sacrificing" it. Hopefully, the disassembly and reassembly will go well, and you'll have a reconditioned Nikonos II that you can continue to use. I'll check this evening to determine whether I can answer your question from my information on the Nikonos. John
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Post by Captain on Oct 22, 2007 11:35:37 GMT -8
Does anyone know the metric O ring sizes for the various O rings for the Nokonos ll. From measurements the lens mount O ring appears to be an M3.5 x 46. It is difficult to determine the body O ring because there is no easy way the measure the case and it is hard to be sure the O ring is perfectly circular when trying to measure it. I just bought a Nikonos ll body for 10 bucks that I will sacrifice in learing how to disassemble and replace the internal O rings.[/I][/quote] Oh my, please don't sacrifice the poor ol' Nikonos II, unless it is beyond hope. These are great old cameras, and you should be able to work on it without "sacrificing" it. Hopefully, the disassembly and reassembly will go well, and you'll have a reconditioned Nikonos II that you can continue to use. I'll check this evening to determine whether I can answer your question from my information on the Nikonos. John[/quote] I am not planning on it dying on the operation table. Hopefully everything will go well and I will have two operable Nikonos ll's. One with an 18mm lens and one with a 35mm lens. I have a copy of a Nikonos ll overhaul manual but it is not very well written and leaves a lot to the experience of the user which I do not have.
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