Ad
Ad
Ad
Pages: [1]   Bottom of Page
Print
Author Topic: IR-filters and DSLR?  (Read 2260 times)
Lisa Nikodym
Sr. Member
****
Offline Offline

Posts: 1702



WWW
« on: January 30, 2005, 08:01:26 PM »
ReplyReply

I think that exactly which filter works best may depend on which DSLR you're using. I have a Nikon D70, and use a B+W 093 filter (which is a Wratten #87C) for landscapes (the images come out magenta, but I desaturate them in the RAW conversion). I don't have any IR experience with any other cameras or filters, though. A web search for "IR" and your particular camera might turn up more info online.

I found the following two web sites to be useful:

http://wrotniak.net/photo/infrared/

http://www.naturfotograf.com/D70_rev05IR.html

If you'd like to see an example of what I've done in IR this way, here's a recent one (after desaturating and upping the contrast in Photoshop):

IR photo

Lisa
Logged

Lisa Nikodym
Sr. Member
****
Offline Offline

Posts: 1702



WWW
« Reply #1 on: February 03, 2005, 11:14:24 AM »
ReplyReply

One more IR side note which might be useful:  I find on my D70 that if I set the camera's exposure compensation to -2 and then let it figure the exposure, I get a reasonable-looking histogram.

Lisa
Logged

Lisa Nikodym
Sr. Member
****
Offline Offline

Posts: 1702



WWW
« Reply #2 on: February 03, 2005, 02:00:04 PM »
ReplyReply

Quote
Don't forget that the autofocus on cameras may not work with IR.

Good point.  Since my IR photos are all distant landscapes anyway, I set the camera to manual focus and then focus to infinity.

Lisa
Logged

Mike Saxon
Newbie
*
Offline Offline

Posts: 13


« Reply #3 on: February 06, 2005, 08:22:41 AM »
ReplyReply

Quote
... (the images come out magenta, but I desaturate them in the RAW conversion)...
Just happened to take some IR landscape shots today in sunny Brunei, using the Nikon D70, kit lens and Kodak Wratten 88A gel.

I did a Pre-set White balance with the filter ON (this practically eliminates the red/magenta cast that any of the other white balances give). The result was an almost neutral B&W image. Best exposure was at +2 EV using Aperture preferred metering, and autofocussing with the filter on! Of course, no viewfinder image was visible, so a tripod is needed to compose before putting on the filter.

Mike
Logged
dnone
Jr. Member
**
Offline Offline

Posts: 71


WWW
« Reply #4 on: January 30, 2005, 05:30:13 PM »
ReplyReply

Hi everybody!

does anybody have any experience with IR-filters and dSLRs?

which ones to use -87C,88A,etc..- especially in landscapes?

and which manufacturers would you recommend?

thx
dn
Logged
dnone
Jr. Member
**
Offline Offline

Posts: 71


WWW
« Reply #5 on: February 03, 2005, 10:02:14 AM »
ReplyReply

hey lisa,

thanks a ot for your reply, very useful especially the links..

dn
Logged
howard smith
Sr. Member
****
Offline Offline

Posts: 1237


« Reply #6 on: February 03, 2005, 11:47:27 AM »
ReplyReply

Infra red filters are deep red.  No surprise.  However, people cannot see infra red, so a really good IR filter should appear opaque to the human eye.  It is best to look at the spectral transmission curves of filters.

For example, I used an ultraviolet filter.  It had a filter factor of about 10 stops, and I could not see through it.  The b&w results were totally unpredictable and unusual.

True UV and IR photographs have some interesting forensic uses.  I took some images of the Santa Barbara Mission.  I could easily see where the building had been rebuilt after major earthquake damage (and repainted).  The building looked normal to the eye, but the new construction was easy to see with true UV and IR.

Don't forget that the autofocus on cameras may not work with IR.
Logged
howard smith
Sr. Member
****
Offline Offline

Posts: 1237


« Reply #7 on: February 03, 2005, 02:05:04 PM »
ReplyReply

The IR focus shift can be substantial depending on the lens.  There used to be a red dot to reset the focus with.  Some Canon L lenses have no shift.  In fact, many lenses have trouble with red light.  APO lenses solve that problem.
Logged
Lisa Nikodym
Sr. Member
****
Offline Offline

Posts: 1702



WWW
« Reply #8 on: February 06, 2005, 12:23:07 PM »
ReplyReply

Quote
I did a Pre-set White balance with the filter ON (this practically eliminates the red/magenta cast that any of the other white balances give). The result was an almost neutral B&W image. Best exposure was at +2 EV using Aperture preferred metering, and autofocussing with the filter on! Of course, no viewfinder image was visible, so a tripod is needed to compose before putting on the filter.

Thanks, Mike.  I'll try the pre-set white balance trick.  You also caught me in a typo - I should have said +2 EV, not -2.

Lisa
Logged

dede
Newbie
*
Offline Offline

Posts: 1


« Reply #9 on: February 28, 2005, 10:34:46 AM »
ReplyReply

Just tuned in to this discussion and the use of tripod was a good one Mike. I have used my D100 to take infrared using a B+W92 red filter placed on the lens AFTER focusing. then adjustments in PScs..works well but kind of awkward.
My question is for the entire board- I have just gotten a new EPSON R-D1 Digital Rangefinder. It is an amazing camera with built in filters for monochrome shooting. But, I cannot find out if I use an infrared filter if it will work. Epson is less than knowledgeable! HELP from anyone who can. I have been shooting infrared for years using a Medium format Mamiya and Infrared film but am starting to love the digital way of doing things. Thanks Dede
Logged
Pages: [1]   Top of Page
Print
Jump to:  

Ad
Ad
Ad