I recently bought an IR 850nm Filter for my 18-700 (72mm) lens. When I put it on my lens I see nothing but black? is this supposed to happen? when I take a picture there's nothing but darkness.... i'm confused on how this filter works?
Yep, it's working!
The IR850 means it passes infrared with wavelength longer than about 850nm. That's well above the wavelength of visible red light. Unless your camera has been modified to remove the IR cut filter, you will require very long exposures. It will be possible to get an image, it will just take many seconds to do so, even in bright light.
Focusing must be cone with the filter removed, or by setting with the distance scale.
Ah kirbic thank you very much!! I had a feeling it was something along those lines.... I saw some pics taken with the filter and there were a lot of cloud trails. Thank you again for the info i'll have to get out and do some long exposures.
hahhahhahah GinaRothfels ..... didn't even pick up on that mistake lol... 18-200 is what I meant .... thats what I get for watching creativelive and trying to type!
Ok, so I finally figured out the exposure for the IR filter... now my issue is that it's coming out very Purple in color... I know it's supposed to have a color cast but from everything I read it should be red.... also.. i know when you take it into photoshop in the RAW dialogue you use the white balance eye dropper and that helps with the effect.... when I use the White balance eye dropper it just changed my image into a black and white and thats it... the sky doesn't go orange and the leaves on the trees don't go as white as I see in tutorials... ? any ideas on what i'm doing wrong?
The colours you get are dependent on the filter. So you may just get a monotone, where it might be better converting to black and white, or you do have some colour which you can play around with.
850 is pushing it for IR film. B&W IR film runs in the 750 to 900 nm range. So you are pretty close to the edge of what it can handle. 720 would be much better for film use.
For digital it should work fine. To set your white balance on a digital camera, take a picture of some nice green grass, and use that to set the white balance. That will give you the white foliage that is so common in IR photography.
