A Question about taking IR with DSLRs

[night86mare]

Ok, this is actually the continuation about a query from me that started from another thread (which has been locked by the TS)..

Apparently you cannot compose scenes with DSLRs with the filter on. I asked a few of my friends who are also avid photographers about this but they said they are not experienced with IR. But apparently the viewfinder is what you see through the lens, so there's a high chance that you won't be able to see anything with the IR filter.

Then I asked one of them if you will see roughly what you see through the IR filter held up in front of your eye, and he said yes, can. But maybe a bit darker. So on cloudy days, even my H2 with its live view cannot compose easily. My question is, on sunny days, must one necessarily still do the standard procedure which I've read here and there, i.e. to compose without filter on, and then shoot AFTER you've screwed the filter on. It's not the extra work that dissuades me, but I think a lot of things which might look good in IR may not be realised if one must keep doing that. Because with my H2 I can see what's going on in the IR world (so to speak).. =(

Oh. And I'm talking about an unmodded DSLR of course. And of course, DSLR with live previews out of the equation, until they become very common.. =D

What I want to know is that - is it entirely IMPOSSIBLE to see anything? =(

Was reading up stuff on howstuffworks.com, and it says that what you see through the viewfinder is what is seen after passing through the lens. I'm not familiar with how a DSLR works. So in my H2, when I make the aperture setting in M mode larger (i.e. smaller f-stop) my live preview becomes brighter. Is this the same case for a DSLR?

[Francis247]

Originally Posted by night86mare Then I asked one of them if you will see roughly what you see through the IR filter held up in front of your eye, and he said yes, can.

We tried it before, we can see through the filter if you are looking directly into the sun which is not advisable.

Originally Posted by night86mare What I want to know is that - is it entirely IMPOSSIBLE to see anything? =(

True. Unless it is a very bright light source.

[StanGetz]

Hello nightmare, i hope i get this correct.

First we need to know what we are capturing when we say IR photography. It is not just any other effects, else, we can just use photoshop, no need for IR filter.

IIRC, Infra-red photography is about capturing subjects in the infra red spectrum which is in the 72nm (if you use the Hoya R72) wavelength of the light spectrum and above..

In human terms, I am quite sure our eyes are unable to picked up this spectrum, hence we use a IR filter to block up to rest of the wavelengths until the infra red spectrums.

You are also correct that DSLR is thru the lens. but if your eyes cant see subjects in IR spectrum, how do you expect to see anything at all??

Hope im in some way or another correct in some sense. May other fellow bros help out here.

[hASHbrown_kopitiam]

Originally Posted by night86mare Ok, this is actually the continuation about a query from me that started from another thread (which has been locked by the TS).. Apparently you cannot compose scenes with DSLRs with the filter on. I asked a few of my friends who are also avid photographers about this but they said they are not experienced with IR. But apparently the viewfinder is what you see through the lens, so there's a high chance that you won't be able to see anything with the IR filter. Then I asked one of them if you will see roughly what you see through the IR filter held up in front of your eye, and he said yes, can. But maybe a bit darker. So on cloudy days, even my H2 with its live view cannot compose easily. My question is, on sunny days, must one necessarily still do the standard procedure which I've read here and there, i.e. to compose without filter on, and then shoot AFTER you've screwed the filter on. It's not the extra work that dissuades me, but I think a lot of things which might look good in IR may not be realised if one must keep doing that. Because with my H2 I can see what's going on in the IR world (so to speak).. =( Oh. And I'm talking about an unmodded DSLR of course. And of course, DSLR with live previews out of the equation, until they become very common.. =D What I want to know is that - is it entirely IMPOSSIBLE to see anything? =( Was reading up stuff on howstuffworks.com, and it says that what you see through the viewfinder is what is seen after passing through the lens. I'm not familiar with how a DSLR works. So in my H2, when I make the aperture setting in M mode larger (i.e. smaller f-stop) my live preview becomes brighter. Is this the same case for a DSLR?

I can't see anything thru the viewfinder when i have the Hoya R72 on. (Edit: saw abit when pointed at the sun) Camera: D50 with no modiffication done.

Join the IR outing next time and look thru fellow snapper's camera. Hope it will enlighten u.

[Francis247]

Originally Posted by StanGetz Hello nightmare, i hope i get this correct. First we need to know what we are capturing when we say IR photography. It is not just any other effects, else, we can just use photoshop, no need for IR filter. IIRC, Infra-red photography is about capturing subjects in the infra red spectrum which is in the 72nm (if you use the Hoya R72) wavelength of the light spectrum and above.. In human terms, I am quite sure our eyes are unable to picked up this spectrum, hence we use a IR filter to block up to rest of the wavelengths until the infra red spectrums. You are also correct that DSLR is thru the lens. but if your eyes cant see subjects in IR spectrum, how do you expect to see anything at all?? Hope im in some way or another correct in some sense. May other fellow bros help out here.

Hi Stan,

It is 720nm not 72nm.

[StanGetz]

Originally Posted by Francis247 Hi Stan, It is 720nm not 72nm.

Oops! thanks Francis. my bad.....

Well i guess, if it is in a light spectrum our human eyes cannot see, definately even thru the filter we will be unable to see anything at all. Jus a bright red dot at most if u point it to the sun.

[night86mare]

Originally Posted by Francis247 We tried it before, we can see through the filter if you are looking directly into the sun which is not advisable. True. Unless it is a very bright light source.

I know what you mean about being not advisable.

But for above statement, it's with relation to camera viewfinder, and not.. The naked eye, I presume?

\sian

[night86mare]

Originally Posted by StanGetz You are also correct that DSLR is thru the lens. but if your eyes cant see subjects in IR spectrum, how do you expect to see anything at all?? Hope im in some way or another correct in some sense. May other fellow bros help out here.

?!

My copy of the Hoya R72 filter, when I look through it right now, even on a rainy day I can see some light, that's why I'm confused. You mean usually cannot see?

Of course now very dark, can only see silhouettes of buildings. But when it is sunny, I can see the details of the buildings.

Hope you get what I mean.

[night86mare]

Originally Posted by hASHbrown_kopitiam I can't see anything thru the viewfinder when i have the Hoya R72 on. (Edit: saw abit when pointed at the sun) Camera: D50 with no modiffication done. Join the IR outing next time and look thru fellow snapper's camera. Hope it will enlighten u.

Ho ho. Ok. Looks like I'll be definitely keeping my H2 in future for more relaxed IR shots.

That's the main reason I'm asking, if not I dump my H2 liao. Don't really use the longer end of the whole zoom range anyways.

Thanks for all your replies guys, really appreciate.

[night86mare]

Well, to give a better idea of what I'm trying to say;



This is something like what I can see on a bright day through my R72.

[TrailsofLife]

Take out the filter and compose then put on filter to shoot. Use a tripod.

Think there's no other way.

[night86mare]

Originally Posted by Max 2.8 Take out the filter and compose then put on filter to shoot. Use a tripod. Think there's no other way.

Ok, thanks. Basically what I was asking, just to make sure.

Thread closed!