CANON 10D & IR - Very blurry images

hi,

i am having trouble getting sharp pictures using the IR filter on my 10d. basically, i compose the shot, set the aperture (?sic) to largest and the shutter to slowest, and the shot comes out all blurry. like NOTHING is sharp. never had such problems with my g3, lemme tell ya.

any tips/clues would be greatly appreciated.

thanks,
Saqib.

Not an expert here, but I can tell you from what I've read that the focus distance is differend in IR than in visible light, also, because of the long exposure you need a quite sturdy tripod and a non-windy environment and if you're shooting trees, leafs in particular, it shouldn't be a close-up, for obvious reasons, obviously.

I used to do some nice IR photos with the G3 - it used contrast to focus, and once focused, you can turn on Manual Focus and have the focus locked. I did this BEFORE putting on the IR Filter. Easy to do with the G3 as it screws on the adapter ring, not the lens itself.

For the dSLRs, you can't exactally focus the shot, turn to manual, and successfully screw in the filter without difficulty in maintaing and not bumping the focus off. You can surely try.

I still do not think you will be completly satisfied with the results from the dSLR and the IR filter. I was only moderatly impressed by the G3 results after applying a color fixing action.

I was going to give mine a try tonight and see how it works. I will try and post some results if it works well, and then write up my workflow for the IR.

The only true IR you will get will be with film, or a digital camera designed to take IR photos only.

Tripod is a must - my typical speeds are half second - at f2.8-4 on mediun sunny days. Trick I found is to go to manual mode, compose, focus, switch lens to MF noting the focussed position, put on filter, set aperture as above, shutter as above, run sample shots and alter settings to suit. The 300d/10D sensors are not really that IR friendly and the longish expsure ensures movement blur in the subject on all but the stillest days - but it does work

BIGGEST, MOST IMPORTANT STEP HAS NOT BEEN SAID!!!

You MUST get a Custom WB with the FILTER ON for the colors to be correct. Otherwise, you will end up with a pink image. I use a white card (the back of my gray card) to get this...

Actually, it's important only if you planning to get false color infrared. The true infrared has no color. If you want to get something that looks like a classic film IR shot, then the image has to be converted to B&W. By the way, film infrared is always kind of soft.

you guys must think i have a REAL steady hand to take an IR shot of 30secs without a tripod

i tried to compose a shot and then take the ir shot, but again very blurry. the only reason i am using such a long expo time is because anything shorter and i get a black image.

as far as the WB goes, that auto-adjusts in photoshop. i don't bother messing with that meantime.

i need to get webspace to show you all what i mean hehe. my g3 did really nice shots using the same method of compose, add filter, wide aperture, slow shutter and click it all worked swell. dang 10D

What lens and aperture?

Note: the wavelength of Near-IR (NIR) light is longer then that of visible light, thus for all practical applications you need to adjust the focus. For NIR this means that you need to move the focus point about 10-20% closer to the camera to get sharp focus. Then it is just a matter of holding it steady for the time required (as in use a tripod if you are not already).

I recommend the following.
- with the filter off using autofocus find the focus point.
- turn autofocus off and see where the range is set at
- carefully put on filter.
- adjust the focus to a closer distance by about 10-15%
- take some pictures adjusting shutter/aperture settings as needed (histogram should be a bit dark) (good starting default is 10 seconds at F4 on a sunny day (if I remember right) (30 seconds at f22 seems to also produce good results if I remember right)
- take several shots adjusting the focus a little bit each way. Repeat as necessary for different aperture/shutter settings.

One of the results should be in focus.

The slowest I have gotten a decent IR shot was at 4 seconds, with my 50/1.4 at f1.4 and ISO 400. Since I hate anything above ISO 400 and IR just makes it worse I have not tried it at higher ISOs. Note NIR light goes up to 1.2um* in size which is getting a bit large for detectors at 7.8 for the 10D, luckly the cutoff for camera's the IR filter appears to be around .85um

Just my memory and opinion, although I have recently been playing with IR on my Canon XL2, it has been awhile for my 10D.

P.S. Don't have one, but I suspect the G3 has a greater depth of field then the 10D at the same aperture setting.


* visible 0.4 to 0.75, NIR= 0.75 to 1.2ish, SWIR = 1.2 to 4.0, MWIR, 4.0 to 8.0ish, LWIR = 8.0 to 12.

lens: used both 28-105 (i think) - USM and also 75-300mkII USM

i will try playing around with the autofocus thing and let you know how it goes.

appreciate all the input people