TMcL

I had asked this before in the general forum and have tried some of the recommendations but am still having issues. I'm looking for suggestions for taking photographs in an aquarium. My primary issue is in focusing. Not surprisingly, the camera wants to focus on the glass wall of the aquarium, and not on the fish that are further in. Because the fish are moving too fast I'm unable to focus manually. "Anticipating" where the fish will be and prefocusing also does not seem to be effective. Normally I would put my camera right up against the glass to prevent the lens focusing on the glass wall, but this is not possible because there is a physical barrier between the viewing area and the glass. I'm using a Canon 5DIV in AI Servo mode, using aperture priority set at f/11, and a Canon 24-70 lens. Light conditions preclude me from using a smaller f-stop to increase the depth of field. Any suggestions? Thanks.

TheStarvingArtist

My first question is how tight are you cropping the fish? Second, are the fish in motion 24/7? My suggestion is to use a brighter light source so you can control the light. Place a light at various places and angles to see what works best. If you have a lamp, move it close to the aquarium. Use manual so the entire area in your viewfinder will be in focus instead of keeping a little red dot on the fish. Pre-focus, and when a fish swims into your viewfinder, fire away.

rgrenaderphoto Loc: Hollywood, CA

The only technique I have used for this is to set a focus point in the tank, and spray and pray. Reset focus and fire off a another group. Chimp like crazy to see if you got them all. I assume you have a CPL on the lens to cut down glare from the glass?

E.L.. Shapiro Loc: Ottawa, Ontario Canada

Aquarium Photography- 2 considerations.

Firstly, my experience with any kind of glass enclosed display such as aquariums, dioramas in museums, store windows, showcases etc.: If you can shoot as close the the glass as possible- even right against the glass surface if you can and if it is permitted. I bring along a wad of soft paper toweling to clean the glass if it is smudged or dirty. I usually seek permission to do this. I have also home-made a device out of an empty filter frame. I carefully glued a little felt gasket around the rim so I will not accidentally scratch or mar the glass or Plexiglass surface. If I have to work at a distance for the glass, I might employ a CPL filter to minimize reflections. Sometimes a compromised degree of polarization is required so that good highlights on the subjects (in this case the fish and plants) are not totally negated. Shooting directly against the glass will eliminate reflection and the need for a CPL filter and its absorption of light which may cost you approximately 2 f/stops which may necessitate wider aperture and the resulting reduced depth of field, slower shutter speeds which many be problematic with moving subjects (the fish) or higher IOS setting which may slightly reduce quality due to noise. I have not experienced an auto-focus issue when working right against the glass and I an not sure if working at a distance from the glass or shooting through water will cause any interference with an AF system. If so, I would recommend manual focusing. .

2ns and just as important consideration: When you shoot in or through water there is a degree of refraction that alters the effective magnification of normal or longer lenses. Many cameras that are especially designed for underwater use have shorter that normal lenses, wide angle lenses and even fisheye lenses, Some underwater housings have supplementary optical devices to compensate for this issue. You may find that a wide angle lens will yield better results, especially in a large aquarium with a large volume of water to shoot through. A friend of mine who does alot of scuba and underwater photography recommends a fisheye lens 8 or 10mm for larger sea animals. Macro lenses are recommended of small and nearby objects. When I mention FISHeye- I am not making a joke or a pun!

A wide, super-wide or fisheye kinda focal length will generally provide more depth of field so scale or prefocusing or setting the focusing scale at the appropriate hyperfocal distance setting to provide adequate DOP and accommodate moving subjects may enable a better working method with more predictable and consistent results. Of course, you will need to coordinate your ISO setting, aperture or shutter priority options to come up with best compromises for DOP, motion stopping ability and image quality. Even if you operate in manual mode, the shutter speed/aperture combinations must be factored in to you working method.

Of course, in an aquarium environment, you are not underwater in any kind of danger or dependent on scuba gear so can change prime lenses or zoom in and out and experiment with your CPL filter and various camera angles in relation to the display.

TMcL

Thanks for your suggestions. Sorry, I should have mentioned that this is an indoor public aquarium, so the light is pretty constant and I can't use a flash or external light sources. I have tried pre-focusing but with very limited success. Additionally, the burst rate of my 5D4 is only about 7 FPS. (I've also tried shooting JPG to get a longer burst before running out of buffer.) I'm just not fast enough to use manual focus...

TMcL

Thanks for your response. Pre-focusing + spray and pray is pretty much what I'm doing now!! My success rate is about 2 or 3 halfway decent shots in about 300! I do use a CPL filter and shoot at an angle to the glass, so I do not have a problem with glare.

TMcL

Thanks for your response. I did not think to use a fisheye lense. I did try various lenses, specifically 35mm, 50mm, 24-70mm, and 70-200mm. To my untrained eye, the 24-70mm set at around 65mm seemed to provide the best results. (Perhaps because I have a CPL filter for the 24-70mm, but not one that fits the 70-200mm.) I don't think I have tried the 24-70mm set at 24mm, and I don't own anything wider than that ... other than a 18-200mm EF-S "kit" lens, which does not fit the FF 5D4. I will try and see if I can borrow or rent a super-wide, since trying to get this to work has become a bit of an obsession over time.

I had a thought after reading your message. My local vet has a rehab facility with an underwater treadmill. I thought it might be useful to see if I could mimic the aquarium conditions in a more controlled manner, since while the dog is moving, unlike fish in an aquarium it is doing so in a confined space so logically it should be easier to pre-focus. With permission (of the vet and dog owner ... but not the dog!) I took some shots using the 24-70mm set at 24mm. As you can see, the results are pretty awful. The entire shot is soft, so I assume I was not able to focus accurately in manual mode. Also notice that the part of the dog that is underwater (like the fish would be) is totally washed out.

Pretty frustrating, but as I said earlier, it's now become a challenge.