I have the hoya r72 filter for my 350D. What is the best way to focus on the subject given that the IR filter is too dark to see through? Now I just use a small aperature and hope for the best, but shutter speeds are so slow. I would like to not have to use such slow shutter speeds. Suggestions please.
Focus before putting on the filter, put the lens in manual mode, and then put the filter on and press the shutter...
As simple and obvious as that.
Actually, it depends on the lens. For some (non-USM), if you leave it on AF, it is rather difficult to move it, so screw the filter on it before switching to MF, but make sure you switch to MF because it will start seeking focus as soon as you press that shutter.
I use auto focus with my nikon d50 and olympus c2020 with the ir filter on. If i remember correctly my canon 350d would not focus very well if at all with the filter on probaly because it is a lot more insensitive to ir light. Just focus manully then put the filter on but as you say putting on the filter can alter the focus.
Yes, big time. The sun or light will reflect off the lens on to the IR filter. I used my ball cap and laid it over the top of the camer/lens/filter worked ok. Haven't had a chance to use it more than once, any other ideas on blocking the light?
[I`ve heard some people struggle with light leaking in the sides if the filter is not touching the lens. Have you tried an ir cokin filter? [/quote]text
Focus before putting on the filter, put the lens in manual mode, and then put the filter on and press the shutter...
As simple and obvious as that.
But surely IR focuses differently to visible light?? So you need to adjust (unless your camera can autofocus THROUGH the filter)
one of my favourite zoom lens, the OM 70-210mm f/4.5, has a little red line that shows you how much to adjust - you focus without a filter, then twist unitl you reach the red line.
Having said that, I haven't yet used IR myself, but I'm SURE that it doesn't focus the same as visible light 'cause its a longer wavelength
I can't say anything about the Canon A10, but if you need to find out just point a TV remote at it and fire both at the same time. If the camera shows the IR light from the remote then you are good to go. As far as focus, I set the camera to manual, focus, then screw on the filter. This works well with the Nikon 18-70mm due to internal focus. If you need or want the shutter speed to be quicker, you can either open up, or adjust your ISO to say 400. At 400 the noise shouldn't be too bad.
I find that my system works quite well for IR. I use a kenko gel filter holder that I screw a 82mm IR filter onto. To compose or focus takes just a twist to release the filter to drop away.
If you have smaller lenses (I require at least 77mm for my largest lens) you can use other simular gel holders like the Nikon AF-1. Of course you can also you gel filters like the $25 Lee 4x4" 87-P.
