IR question

[nikmolson]

cab you get away with IR with just a filter? i have read you can just use the filter but exposures will have to be very long and if you really want to do them you have to replace your focusing plate or something a rather in your camera for one that doesnt block IR to not need excruciatingly long exposures. Now i have read an article on some forum where a guy just got a filter and everything seems to be working fine for him at slower but not super long shutter speeds. can it be done with just a filter?

[pyry]

can it be done with just a filter?

Depends on the camera. The IR-block filters in front of the sensor vary between manufacturers and even lines of products. Point and shoot camera typically allow more IR through the filter than SLRs do. As an example Canon's SLRs have quite effective blockers.

You can do a simple test without any extra gear, just the camera and an IR-remote. Put a longish exposure on (something like a second or so), aim the remote at the lens and press and hold a button. If you see the IR-emitter shine in the picture, you can give the whole thing a go with just a IR-pass filter on the lens. If the emitter is dim or doesn't show at all, you would need a modified camera.

[nikmolson]

great tip thanks alot!, if the camera does need to be modded is it something that can be done yourself? and once it is can you still take normal pictures the same as before?

[pyry]

great tip thanks alot!, if the camera does need to be modded is it something that can be done yourself? and once it is can you still take normal pictures the same as before?

Yes, if you know what you are doing. Some cameras are easier to modify than others - I did my Canon 300D meself and it took me 3,5 hours. And it has some issues with focusing because the replacement wasn't the right thickness...

Normal pictures after modification depends on what you replaced the sensor filter with. Clear glass on the sensor does allow normal pictures too, with an IR-block on the lens. IR-pass on the sensor doesn't, but because you don't need a black filter on the lens with it you can still meter and see through the viewfinder.

Here's what I'd do, if I were to get a replacement for my ye olde 300D - I'd get a 450D used and send it in to get a clear glass modification and focusing calibration. (Why the 450D? Liveview. It'll see through the IR-filter on the lens.)

[nikmolson]

well im not on much a budget to be sending my camera away, its only a nikon D60 in the first place:wink but i just tried the remote test (with what i think is a ir remote) and i got two blue dots showing up in the pictures, which i figured must have been ir and this was at about a 1/20 shutter speed, would i be able to get away with just a filter?

[pyry]

well im not on much a budget to be sending my camera away, its only a nikon D60 in the first place:wink but i just tried the remote test (with what i think is a ir remote) and i got two blue dots showing up in the pictures, which i figured must have been ir and this was at about a 1/20 shutter speed, would i be able to get away with just a filter?

Post the pic and we'll see. My IR-modified camera clips the emitters into white at 1/20s f/10 iso200. A normal 20D doesn't see anything at 1/20s f/2.8 iso800.

[nikmolson]

well i get nothing at the shutter speed you said, but at iso 200 and F10 i get this

1/4
http://i37.tinypic.com/34huog1.jpg

1/2.5
http://i33.tinypic.com/e6dqhj.jpg

and 2.5 sec
http://i36.tinypic.com/qn8mfn.jpg

[pyry]

well i get nothing at the shutter speed you said, but at iso 200 and F10 i get this


I have to say it doesn't look sensitive enough. You could get an ir-pass filter and try of course but I think you would be looking at exposure times in the minutes.

[nikmolson]

well i dont have any extra cameras or anything laying around or the money to get one modded so i guess eventualy il just pick up a filter and try it out when i have some patients and its not a windy day!