IR Photography help.

[lightwave]

Can't find a more appropriate section. Mods may move at their preference.

OK here goes.
Having got a IR72 filter, have been trying my hand using the unmodified 60D. Have tried exposure times from 30 seconds to 90 seconds. Beyond 90 seconds is way unusable as it overexposes a lot (at least in the bright sunlight that I tried). But I am just not getting the results. I am sharing a simple pic I took from my balcony at 8 am today. 30 seconds exposure. Took at two different white balance settings. First is on Auto WB and the second on Custom setting after zooming on to green leaves as described by Vikram and a lot of different sites as well.
Problem: The green of the trees and leaves just does not come out white like it is supposed to in IR imaging. The sky is a little dark but not darker than the trees. I have purposely included some buildings in the frame where they are whiter than the trees as well. What seems to be the problem? Something I am doing wrong? Something wrong with the 60D? Something wrong with filter?

1. Image on AWB:



2. Image with Custom WB:

[hayath]

Doc from what lil I've read - the final result depends on some inversion of specific color channels, etc.

Vikram would definitely be able to pitch in with specifics and more details

[VikramF]

Could you post another pic here with the WB set to the lowest temp? 2000K via your Custom Setting.
The leaves aren't even going light grey which means something is quite wrong.
AWB has never worked for me.

Assumption:
1. You've looked through the same filter at those trees and they look white through the filter.
2. You've done the IR sensitivity test using a remote? some IR filters don't show anything and those filters aren't to be used (I have bought 5 filters of which 2 were just very dark red filters and useless. 3 others gave me decent results).

PS: It took me a year of shooting before I got the settings I needed for my camera. The D80 was easier to figure out than the D300 (which I never figured out). The D700 is only now getting me ok(ish) results.

EDIT on Seeing Hayath's reply - the blue skies from channel inversions, but if the greens aren't white to begin with, you can't get them white later.

This is what my straight RAWs look like with the cam set on min WB (2500K in my case ... at 2000k on your cam, I'd expect it to look even whiter).

[theqca]

Im sailing in a similar boat When i set the minimum WB the pic turns blue...so its either blue or white like LW's pic or Red like LW's pic.....and inverting channels dont get me no blue skies either 

[amitk26]

By Any chance this filter is 920nm instead of 720nm ?

I have no experience in IR photography but just looking at the picture you are getting the normal spectrum colors which should have been cut by 720 IR filter , There are 3 commonly available IR filters 720nm , 850nm and 920nm. 920nm is near IR and allows lots of visible spectrum so I asked.

[lightwave]

The trees don't look white when I look through filter. I didn't try this too often as it is said it might be harmful to the eyes.
The min WB I can manually set is 2500K. I get similar red pics like the AWB one I posted
@Hayath What you suggested doesn't work. I tried but greens have to go white first.
@Amit This is the 720nm filter.
@Vikram could you share your method of the remote sensitivity test. Would like to try it. Will at least know if the filter is a lemon. It's Neewer brand and I don't see many complaints online about it. Would like to test it as you describe. If you had 2 lemons out of 5 buys I can see me throwing away this one. I strongly feel the filter is to blame.
Thanks all for replies.

[VikramF]

Im sailing in a similar boat When i set the minimum WB the pic turns blue...so its either blue or white like LW's pic or Red like LW's pic.....and inverting channels dont get me no blue skies either 

Hmmm ... in your case I know the filter works as what I got from it were white trees with a sky very similar to LW's second pic (which is actually closer to what you're supposed to get according to the tutorials).

Keep trying, if it isn't working for you, you can return the filter no issues (take several months, no problem).

[VikramF]

@ LW: Here's the remote test: http://dpfwiw.com/ir.htm#remote

[amitk26]

@Amit This is the 720nm filter.

Actually I was wrong earlier , It is a cutting filter so exposure time should be less on 720nm compared to 920nm.
However since you are recording so much of visible light spectrum it looks it is not cutting enough.

I suspect that this filter is cutting well below 720nm

I didn't try this too often as it is said it might be harmful to the eyes.

IR is similar to heat waves and lower in energy then visible light so IMHO should not be harmful like UV
I may be wrong though.

[theqca]

Keep trying, if it isn't working for you, you can return the filter no issues (take several months, no problem).

nopes...im not gonna give up that easily and im ignoring ur barb about taking "several months"

[lightwave]

I'll try the filter test tonight and if the filter is good between the two of us we should be able to crack it in a few days. If the filter is faulty I'll crack the filter and get a new one lol.

[fmeeran]

IR is similar to heat waves and lower in energy then visible light so IMHO should not be harmful like UV
I may be wrong though.

IR can and will damage eyes. The problem is that since it is invisible and your eyes can't detect it, there is no blink response under bright light and further as there is no or not much visible light, the iris opens completely letting more of the IR enter the eye.
Please do not use the viewfinder with IR filter on.

[lightwave]

OK. Remote test done. I can see very easily the dot cast by the remote when button clicked to send the IR signals. So what could be the cause for the dark leaves compared to the brighter sky? Filter is letting in some visible light too? But that is not the case with the Opteka that Ayaz has since Vikram has tested that one. So some work needed to get to the cause.

[theqca]

As a last resort...when all else fails...we'll plan a trip to bangalore

[theqca]

@LW - Hey...maybe its the lens? have u tried different lenses? maybe some of them are more suitable to IR than others....could be some coating on the glass thats responsible for messing things a bit? i just got my 28mm 2.8 serviced - will try some pics with that and check...

[VikramF]

IR can and will damage eyes. The problem is that since it is invisible and your eyes can't detect it, there is no blink response under bright light and further as there is no or not much visible light, the iris opens completely letting more of the IR enter the eye.
Please do not use the viewfinder with IR filter on.

YOUCH!!

But .... the IR filter isn't the full range of IR, only near IR (reflective) and not far IR (heat emission) .... not sure if that has any effect on the damage caused to my eyes, but I assure you that at around 15-stops, the IR filter is nearly impossible to look through unless one chimps through the IR filter held up close to your eye towards a sunny scene. Through the viewfinder - forget it, so it's barely for about 1-2 seconds (he says, hoping his eyes aren't irreparably damaged  )

OK. Remote test done. I can see very easily the dot cast by the remote when button clicked to send the IR signals. So what could be the cause for the dark leaves compared to the brighter sky? Filter is letting in some visible light too? But that is not the case with the Opteka that Ayaz has since Vikram has tested that one. So some work needed to get to the cause.

OK - so all that test did was tell you that your camera sensor is sensitive to IR and so it's not the sensor that's blocking IR. It says nothing about the actual filter (my comment earlier was on the internal cut-off filter and not the screw on). As you can see the dot quite clearly, your sensor is fairly sensitive to IR (my D80 showed a dull spot, my D700 shows a bright spot).

So:
Camera - check
Filter - No check in LW case, but check in Theqca's case.
Subject - the leaves need to be lighter green and not dark green (those Ashoka trees in the foreground in LW's shot are usually good options when sunlight falls on them. Peepul, Mango are a no, no - always comes out black). Bamboo is always fantastic.

Settings - that's the next check.
WB:
a) shoot at f/8 with your WB set to 2500k - about 30 secs in bright sunlight (the time will differ based on camera)
b) shoot at f/8 with WB custom set against sunlit green grass - again 30 secs
post pics here please

Processing:
Not sure which RAW processing software you're using ... but check that it's not showing an 'auto' something preview. Or even better, shoot RAW + Jpeg for now.

PS: G2 was getting white leaves btw, he was facing other issues

@LW - Hey...maybe its the lens? have u tried different lenses? maybe some of them are more suitable to IR than others....could be some coating on the glass thats responsible for messing things a bit? i just got my 28mm 2.8 serviced - will try some pics with that and check...

Lenses cause hot spots not blockages - so an unsuitable lens will show a central brightness (usually goes away if you start opening up the lens to about f/5.6)

[lightwave]

OK. Before I take the pics for step 2, how about Filter test? What am I supposed to see if I hold it up to the eyes. Nothing? Or a very dark red view of what I normally see? I held it there for just a second and have not yet gone blind and could see a very dark red world. But the leaves are not white with the eye too. Is this view acceptable when seeing through the filter?

[theqca]

Here's what i ended up with...at around 130 seconds f8...tried AWB (the red one) and manual WB...

[lightwave]

Your results are much better than what I am getting. At least the foliage is turning white. Can you see ANYTHING if you try to look through the filter with your eyes?

[VikramF]

OK. Before I take the pics for step 2, how about Filter test? What am I supposed to see if I hold it up to the eyes. Nothing? Or a very dark red view of what I normally see? I held it there for just a second and have not yet gone blind and could see a very dark red world. But the leaves are not white with the eye too. Is this view acceptable when seeing through the filter?

Nope - when you peer through it (cup your hands around the filter and look at some light coloured foliage - the leaves should appear white. If not, the filter is just a deep red filter and not a true IR72 filter (that happened with my first filter - pointless for IR, but a great B&W filter).