a mentor in infrared photography perhaps?

The Bayer matrix of the IS-1 isn't special, according to the guy from Fuji who ran a workshop on it here. It's just the IR/UV cut filter that is missing. It's quite normal for absorption-type (ie dye) RGB separation filters to pass IR. As you point out, the degree of IR transmission may be different from one filter to another, particularly for IR near to 700 nm.

The IS-1 is not a great camera - it has a hot spot at many aperture/focal length settings, apart from anything else. The IS-Pro is a much better camera, but at the time I made that comparison the IS-Pro was not available. I use my IS-1 more for scientific use than pictorial, so the hot spot is not all that important.

Best,
Helen
 
Someone asked about in-camera white balance?
http://www.jr-worldwi.de/photo/index.html?ir_wb.html

Also this is a fairly good guide to IR sensitivity across camera models:
http://www.jr-worldwi.de/photo/index.html?ir_comparisons.html


The IS-1 is not a great camera - it has a hot spot at many aperture/focal length settings, apart from anything else. The IS-Pro is a much better camera, but at the time I made that comparison the IS-Pro was not available. I use my IS-1 more for scientific use than pictorial, so the hot spot is not all that important.

Best,
Helen

:( Me hates the hot-spot! Hehe, but that sounds uber-interesting "scientific stuff!" :headbang: What are you into? I play with microscopy occasionally. I have this mic: http://www.nikoninstruments.com/lv100d/ but in a slightly older body style.
 
My most recent Digital IR shot:
Sol_II_Small.jpg

Taken two or three days ago.

This has to be one of, if not, the coolest photo I've seen on this website. I'd say others have more detail to composition and whatnot, but I am truly seeing a common subject in a very unique light. Well maybe not light, but some sort of electromagnetic radiation :)
 
This has to be one of, if not, the coolest photo I've seen on this website. I'd say others have more detail to composition and whatnot, but I am truly seeing a common subject in a very unique light. Well maybe not light, but some sort of electromagnetic radiation :)

Why, thank you kindly Senor Hound! It's a heck of allot of processing to pull that image out of the grey gook that the imager and filter deliver - kinda like processing for deep space shots. With this test I wasn't even sure if that was the actual data correctly presented or not till I checked it with the real-time sun imaging facilities at NASA (I think it is) and when the Sun spots and dark spots lined up I was like, kewl! It worked. :) The flares didn't line up at all so those are likely just a result of lens flare and processing. That was taken with an IR 96 Fuji Tri Acetyl Cellulose filter - which actually suck pretty bad in terms of optical quality but for $12 ea. what the heck right?
 
i did some work around my backyard today and i've noticed that hotspots appear most often when i'm zoomed out at 18mm, and less/if at all when i'm around 50mm and on. here's a test picture I shot and manipulated/color swapped on PS.

blemish.jpg



nasty hotspot :(
any idea on how to get rid of it or avoid it besides buying a new lens? :meh:
 
BTW, a new lens may or may not help things. Make sure the shop will let you test it out before you buy. Show them the cash and they usually do. ;) Remember it's the reflective properties of all of the elements I mentioned in the post above. Somehow IR light is trapped and bounced around between them producing the bright hot spot. I would guess that the lens is the biggest contributor but still it may only be 50 or 60% of the total problem. <shrug>
 
Right. I have no idea what the numbers are. I mean the number of combinations that make hot-spots vrs. the number that don't, but I think by looking at some of the sites that try and catalog them, that there's far more that don't have a hot-spot than that do. 70/30??
 
Right. I have no idea what the numbers are. I mean the number of combinations that make hot-spots vrs. the number that don't, but I think by looking at some of the sites that try and catalog them, that there's far more that don't have a hot-spot than that do. 70/30??

You would think that but there's plenty of evidence showing that hot spotting can occur with any lens and it seems to have no relation to construction. In fact a canonnite friend of mine is having trouble finding a lens that doesn't hot-spot.

This thing is caused by light reflecting off the LP filter. And hotspots are greatly reduced on converted cameras (often completely) and don't exist at all on film cameras.

As for which lens do and don't, a quick google search, first page I came up with and there's many more with such a list. There are generally about as many lenses which are good for IR as those which aren't, but since this is flare and flare depends on coating, many of the zooms are L series:

Fixed:
Recommended for IR:
Canon EF 28 mm f/2.8
Canon EF 35 mm f/2.0 (*)
Canon EF 50 mm f/1.8 MKI
Canon EF 50 mm f/1.8 MKII
Canon EF 100 mm f/2.8 macro
Canon EF 135 mm f/2.0 L
May produce a hot spot, etc.:
Canon EF 85 mm f/1.8
Canon EF 200 mm f/2.8 L
Gives hot spot:
Canon EF 20 mm f/2.8
Canon EF 24 mm f/2.8
Canon EF 50 mm f/1.4
Canon EF 50 mm f/2.5 macro
Sigma 30 mm f/1.4

Zoom:
Recommended for IR:
Canon EF-S 10-22 mm f/3.5-4.5 USM
Canon EF 17-40 mm f/4 L
Canon EF 24-70 mm f/2.8 L
Canon EF 24-105 mm f/4.0 L
Canon EF 28-135 mm f/3.5-5.6 IS
Canon EF 70-200 mm f/4.0 L
Canon EF 75-300 mm f/4.0-5.6 IS
Canon EF 100-400 mm f/4.0-5.6 IS L
Gives hot spot:
Canon EF 16-35 mm f/2.8 L
Canon EF-S 18-55 mm f/3.5-5.6
Canon EF 24-85 mm f/3.5-4.5 USM
Canon EF 28-70 mm f/2.8 L
Canon EF 35-80 f/4.0-5.6
Canon EF 70-200 mm f/2.8 L IS

source: http://heim.ifi.uio.no/~gisle/photo/ir.html
 
This thing is caused by light reflecting off the LP filter. And hotspots are greatly reduced on converted cameras (often completely) and don't exist at all on film cameras.

Right, that's the same thing I was just saying. Nice find on that list BTW! :thumbup:
 
No worries, if you follow the link there's Nikon lenses in the list too, along with details of just how bad many cameras are with regards to lowpass filtering.

The D200 and the 40D rate amongst the worst for IR photography.
 

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