Infrared for D70?

TopPop · Apr 4, 2005

I've been really intrigued lately with infrared photography, and have been wanting to try some work on my D70 with a Cokin IR filter. However, I'm afraid of any permanent damage which may be done to the CCD as a result of prolonged exposure to IR. Is anyone familiar with the D70 and IR filters? If so, any info would be MUCH appreciated.

Cheers,
Chris

Digital Matt · Apr 4, 2005

You will not damage your CCD. Using an IR filter does not increase the exposure to IR light. It only blocks visible light. The D70, like most DSLRs has a infrared blocking filter over the CCD, to cut down on IR light, seemingly to reduce noise levels, and because in a normal photograph, you are not seeing the IR spectrum, and you don't need it. When you put an IR filter over the lens, you block the visible light. Quandary. You are now blocking visible light with your filter, and IR light with the filter over the sensor. Not much light is getting through. You need long exposures, to get your shots. Depending on the strentgh of your filter, you could need anywhere from 6 seconds to 10 minutes. A filter like the Hoya R72, which blocks visible light below 720nm, is a good candidate for digital cameras, because you are not blocking the entire visible spectrum, hence you have a blend of normal and IR light. I've used that filter on a 20D and Digital Rebel with great success. Typical exposures were around 13-20 seconds. When using a #87 filter, which blocks 100% of visible light, I need a 5-10 minute exposure.

How well does the D70 handle noise in longer exposures? I heard that it didn't do so well.

TopPop · Apr 5, 2005

I haven't had too much experience with noise-inducing situations for the D70. I noticed quite a bit of noise when I was shooting a concert, but I had the ISO set to 1600. The little extended exposure that I've done seemed to be fine if I had the ISO lower. I've seen some decent IR pics on the internet that have been taken with the D70, however I don't know if they were taken with the DIY "modded" version. I guess I'll just have to try it and see! The filter I will use will be an 89, so it (won't?) block out all visible light (?).
But as long as it won't harm the sensor, I think that I'm going to go for it. Thanks again for the information!
Cheers,
Chris

Dollface · Apr 13, 2005

Another question I have to ask:

If I shoot infared without a filter, but use red celephane instead, what kind of effect would I get? Is it basically the same thing, just cheaper and well, let's sayn it - more dodgy.?

Digital Matt · Apr 13, 2005

Red cellophane is not the same thing as an infrared filter. The filter specifically blocks visible light, while letting IR light pass.

SLOShooter · Apr 13, 2005

You can hack the firmware of the D70 to allow for handheld IR photography without a filter, but of course, you won't be able to take visible spectrum untill you put it back to factory specs.

deadjoe · Apr 17, 2005

can you provide me with a link to the firmware hack? not sure if its against the rules to post in here, pm or email me if you can, thanks!!!
roon

Bob_McBob · Apr 19, 2005

It's not a firmware hack, it involves physically replacing the hot mirror filter in front of the CCD. Certainly not for the faint of heart.

deadjoe · Apr 19, 2005

Bob_McBob said:
It's not a firmware hack, it involves physically replacing the hot mirror filter in front of the CCD. Certainly not for the faint of heart.

ah, ok, i know about that and i'm not "hacking" my d70 to bits ;-)
thanks
roon