View Full Version : Shooting in high contrast situations
degrassi
03-02-2004, 1:50 PM
nice pic [smilie=qcool.gif]
I also have black sand and white shells in my shell dweller tank and i find it extremely difficult to take pics. The camera never wants to focus.
Any tips of fixing this?
good question, degrassi, I hope the guys can give you a good answer. This is a good dicussion, let's keep it going, should be educational. I personally only use Natural gravel, so I could not even imagine the focusing problems and exposure problems that come from this. Like in the first photo, I dont know if there is a way to make both the black sand and the white shell exposed properly without software manupulation. Looks like the shell is a bit washed out.
degrassi
03-02-2004, 5:12 PM
When i try taking pics of my ocellatus in their shells i can't get the auto focus to focus on the fish. Sometimes the it focuses on the shell but its way too bright and doesn't come out. I dont' use a the flash and i tried adding more lights to the tank. Its a 10g and i had 4 15w bulbs(i also tried it with 2 bulbs and 3 bulbs). Still can't get the camera to focus on the fish.
Here is one of the pics i have tried to take.It is from when i first got my camera and the only pic of my shellies i have as none of them ever turn out. I guess brownish fish on a black background swimming next to a white shell isn't the easiest thing to take a pic of [smilie=biggrin.gif]
http://im1.shutterfly.com/procserv/47b3ce26b3127cce8fe57cec78e80000002610
I guess brownish fish on a black background swimming next to a white shell isn't the easiest thing to take a pic of
That is a perfect observation of the situation here.
degrassi
03-02-2004, 5:21 PM
so do you think it will be possible to get a good shot of my fish? they are pretty drab looking,they are ocellatus "blue" not hte brighter "gold" ones. Say i was to take out the whitish shells. How can i get a good pic of the fish on the black sand? Or is it just hopeless because adding more lgiht didn't seem to help.
do you have any manual controls to your camera?
on my camera, I dont have a manual focus but I have a manual setting to tell the focus to focus center left right or auto, I usually set it for center...
degrassi
03-02-2004, 5:24 PM
I have a canon A 70. It does have a manual focus but i can't figure it out. I also have the setting where i can pick the position o fthe auto focus. I will try that.
some one here with a Canon might be able to help with the manual focus...
my cam doesnt have a manual focus so I cant offer any help with that...
ok benny, and everyone...
I am going to put a little twist into this discussion about contrast with bright and dark objects...
in this pic we have a lite colored subject on a dark colored object and a dark colored subject on a light colored object. I hade to make some brightness and contrast adjustments in photoshop, but to much of an adjustment would wash out the large rock.
An Ancistrus sp4 laying on the sand and Ancistrus sp3 on the rock.
http://www.our-oasis.net/fish/images/ancistrus.jpg
feel free to see if you can make adjustments to this pic...
FYI: the large rock in the picture is called "paradise coral" (thats what my LFS calls it), it is mined out of dry lakes and caves, it is not live rock but is typically used in reef setups as a base rock. in a freshwater setup it provides an excellant ph buffer for a rift lake setup.
Nicholo
03-03-2004, 2:10 AM
Also, I believe certain sensors focus better on different orientations. I have a Canon G3 and the autofocus looks for vertical contrast to focus on. If I'm taking a portrait, I'll go for the eyes of course, but I'll sometimes try to catch the edge of the eye or somewhere where I will be assured of a vertical "line" near the eye. Of course, for fish, I always use manual focus. If the A70 MF is anything like the G3, it is fairly easy to get used to. In the G3, you get a zoomed square in the center of the LCD do you have a good sense of whether the subject is in focus. I typically, set a close focus distance and just move my cam slightly toward or away from the glass to "move" a fish into precise my focus range.
meriadoc
03-10-2004, 12:39 PM
thats not really the sensor that is picking the area to focus and meter on.
the camera itself has its what you call metering mode, which can be, normally either spot, matrix, or evaluative metering. Spot metering is probably the best of them all, as you can tell the camera what area to expose for, and it will apply that particular calculation over the entire image. whereas the other methods generally just average out the light to make the best judgement. OF course, when its BLACK AND WHITE high contrast situations, the camera and metering will get highly confused.
Some cameras like the nikon coolpix 2500 will generally only focus on areas that are in the middle of the frame - which can be highly infuriating. Some cameras also will only focus on an + style area - the subject that falls anywhere along that -- or | area will be in focus.
when it comes to high contrast situations, you really have two choices, expose for the highlights, or expose for the shadows.
you could always use the manual method of exposure, or what they call the zone system (which, comes in handy when shooting snow or white sand for an example) always OVER expose one or two stops higher as the camera will normally average out to a nice medium (18%) grey. Over exposing will make your whites white.
Under exposing blacks as another example will bring out the detail.
-- Lisa