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Old 05-03-2008, 03:23 PM
DJDD
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Camera Body Front Filters

Hi all,

I have been looking at terrestrial IR-pass filters, similar to the Hoya R72 or Wratten gel filters BUT i also saw on the hutech site the Camera Body Front Filters:
IR720-FF (Visual blocking, IR pass)
http://www.sciencecenter.net/hutech/filters/ffilter.htm

These are a bit expensive compared to the Wratten or Hoya options, although probably are better...

Does anyone know of any other brands that do a similar thing?


cheers.
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Old 07-03-2008, 05:03 PM
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This mob do some - but Canon only

http://www.telescope-service.com/fil...OS_Klemmhalter

I use a Hoya R72 over the lens for IR. Works fine, but on a non-modded camera, you can expect shutter speeds of 10 - 30 seconds.
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Old 09-03-2008, 02:37 AM
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I realise that you didn't ask about it, but there is always the conversion route. I used Life Pixel for my filter. The advantage is that auto focus, exposure metering, and the view finder all still work, and you don't need to always mount it on a tripod. The disadvantage of course is your camera becomes dedicated IR. I did a Canon 10D that wasn't worth much on the resale market, so it really didn't put me out much. Your D80 is probably worth more than you want to mess around with, but you could always pick up a spare older body on eBay, depending on how serious you are about IR and how disposable your income is
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Old 09-03-2008, 11:12 PM
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I had my 30D converted to IR by David at http://khromagery.com.au/index.html

With a R72 over the lens, I got 'normal' shutter speeds for IR - eg in the sun with the camera at 100 ASA, shutter speeds of 1/500 and f5.6 and that type of thing. With a B+W 486 or 489 filter over the front of the lens and a white balance done, the camera took 'normal' photographs.

Obviously, an insert filter is much cheaper and easier than an over-the-lens filter, but then you can't use (with Canon cameras) the EFS lenses.

Have a look at some tests I did:

http://www.iceinspace.com.au/forum/s...ad.php?t=15205
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Old 11-03-2008, 10:43 AM
DJDD
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Hi all,

sorry for the late reply- i was on holiday for a few days!

thanks for the replies, as well.

Suzy_A:
thanks for the link to telescope-service.com.
i may contact them as they may know of teh Nikon equivalent. The filter is for terrestrial use not astronomical and I do not really want to mod the Nikon. The IR shot from your link on IIS is very moody- just what I like about IR photography.

the insert filters should be cheaper but the ones from Hutech are very expensive still...

citivolus:
thanks for the pointer to Life Picel.
Unfortunately, we do not want to mod the Nikon so that route may not be the way to go. However, perhaps I should look for a second hand camera that i can mod as you suggest.

thanks again.

DJDD
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Old 11-03-2008, 03:46 PM
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On another IR point - if you take a photo with a dig camera (or even a film camera) using a R72 or similar, you end up with a very red image. See the example below.

This is as the R72 still lets through a lot of red light - the '72' is the cut-off point of 720 nm. You get a better 'raw' image if you use a R90 filter which cuts abover 900 nm.

You can partially correct by manually setting the white ballance - take a photo of a white sheet of paper (or grey card) and then use the image to do a white ballance.

But to fully correct it so that it closely approximates proper IR film such as Kodak HSIR ('High Speed [50 ASA] IR B&W) or Kodak Ektachrome IR, you need to Photoshop it. These films (do they still exist?) have different sensitivities to normal film - the B&W is actually sensitive from the UV to the IR, but at the IR end goes way past normal B&W film - see http://www.kodak.com/global/en/profe...002_0333ac.gif

The colour IR film still have three layers - yellow, magenta and cyan - and is also sensative from UV to IR, but the red and cyan in particular are much more senstaive to IR than is normal film. Really, the three layers havebeen swapped around - the yellow is red - yellow - green sensitive, the red is yellow - orange - red sensitive and the cyan is red - IR sensitive. These then give the 'typical' IR photo when used with a R72 or R90 filter.
http://www.kodak.com/global/en/profe...009_0537ac.gif

To get similar results with dig, you need to invert the three colours and do a colour shift. There are a few Photoshop 'actions' that do this - a good one is David's from http://khromagery.com.au/resources.html

Also have a look at http://khromagery.com.au/digital_ir.html and scroll about 3/4 the way down - there is a shot of Melbourne with the various ways of processing. It goes from red to 'typical' IR colour film look - dark blue sky, red foliage etc, although these do vary quite a bit depending on the lighting conditions etc.

As I mentioned in a previous post, you can do all this with a non-converted camera and the R72 filter, but expect shutter speeds of 10 - 30 seconds in full sun.
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Old 11-03-2008, 03:50 PM
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Forgot to add an unprocessed raw image...
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