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Can the M8 do infra red photography?


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Question: Can the M8 do infra red photography?

 

According one camera blog "All digital sensors are sensitive to IR. Camera makers put a filter over the sensor to BLOCK the IR". I've heard about the M8's challenges with IR sensitivity -- have just picked up a new body -- and wonder will it be "fixed" and is there still a way to shoot in the style of infra red film.

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Of course it can (as long as you don't put a UV/IR blocking filter on the lens). There are several threads on technical issues and some with pictures. Mark Norton recently used one of his M8's to photograph the light coming from the LEDs on another M8 that are used to identify which coded lens is installed. He shot in a darkened room, so he probably knows how to set exposure for an IR source of known intensity, comparing the IR exposure to the visible light exposure. Shooting with an IR-pass filter on the lens sensitivity is high enough that you can use the exposure meter (and a tripod) to get started and then adjust from there.

 

scott

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Yes it does IR very well. You need an IR filter - I use a B+W 093. You need to adjust the focussing though - transfer the setting from the rangefinder to the right hand f5.6 marking (when seen with the camera around your neck) for a starting point.

 

See this thread for an example...

 

http://www.leica-camera-user.com/landscape-travel/23074-tatton-park-cheshire.html

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The M8 has very usable IR sensitivity. Use one of the appropriate filters, I use the Hoya R72, and don't expect to be able to focus accurately at large apertures. In general the advice to move the focus point to about the f/5.6 position on the focusing scale is about right, but trial and error is a better method – every lens type varies in this respect.

 

The key is to get the exposure right and in my experience there is no substitute for trial and error. I have seen recent posts advising an exposure of +6 EV, six stops more, which under some circumstances I’m sure is correct but I have found that under some conditions, photographing young foliage for example in sunlight, it is more like +2 EV to +3 EV. You just can’t tell by looking.

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You dont need exposure compensation AE nails exposure exactly, both in IR and UV. There are several threads with examples on the M8 forum.

 

There you go! Some people say the AE works perfectly in the IR and some say it does not - my experience is that it does not - but what do I know?

 

How you get the correct exposure it up to the individual user - I would certainly NOT advocate dialling in +EV and relying on AE.

 

I think the point being made in my and other posts is that the nominal 160 ISO of the sensor falls to somewhere in the range 2 -> 40 ISO when using only IR. Of course this is a "False " number in a strict technical sense but it gives a guide. If 1/160 sec @ f/16 is correct for normal pictures in direct sunlight, (the old f/16 rule), then with an IR filter in place the exposure is going to be between about 1/40 to 1/2 sec @ f/16. This is useful information.

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I've only ever used the meter readings and have been happy with the results. I normally just desaturate and adjust the levels. Certainly I don't deel that there's a need to overexpose by 6 stops. Perhaps it's filter dependant? I'll post an unprocessed image later today when I get home.

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The proof of pudding is in the eating perfectly exposed with AE!

M8 ISO 160 Summaron 3.5cm/3.5 goggled @ 5.6, 1/22nd. Converted in C1LE with M8linear and WB on the gravestones, no postprocessing.

 

L1000074.jpg

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....... Certainly I don't deel that there's a need to overexpose by 6 stops. ........

 

Clearly there is some missunderstanding here - to say the least!

 

Nobody, absolutely nobody, is suggesting "Overexposing".

 

The original question was could the M8 be used for IR photography? Answer - Yes!

 

The effective sensitivity, relative to normal daylight photography, is anything from 2 to 6 stops lower depending on the precise conditions. With the camera set to 160 ISO the exposures required with an IR filter fitted are going to be the equivalent of something in the range 2 -> 40 ISO. That is to say perfectly usable with care and if necessary a tripod.

 

Any problems? - Yes. It will be very difficult to get an infocus image at large apertures and some lens types will benefit from an adjustment to the focus which moves the lens further from the sensor, some will only benefit very slightly, if at all, from any focus adjustment. It's a case of trial and error. The old 35mm f/3.5 Summaron is well known to be a good lens in this sort of application, it is also a very good enlarging lens! Other lenses give variable results and as far as I know there is no reliable literature on this point.

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That seems about right, Peter. My exposure was 1/22nd @5.6.ISO 160 It was low sun, so sunny f16 suggests 1/160th @ 8.0. That is about 5 stops difference. But no need for a tripod or high ISO there, I can handhold my M8 at speeds down to 1/4 with a 35...

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That seems about right, Peter. My exposure was 1/22nd @5.6.ISO 160 It was low sun, so sunny f16 suggests 1/160th @ 8.0. That is about 5 stops difference. But no need for a tripod or high ISO there, I can handhold my M8 at speeds down to 1/4 with a 35...

 

Sorry if I missed this, but which filter were you using? Exposure data and image colors suggests something like and R72 or B+W 092 (89B).

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092 filter.

 

I used the same exposure technique that I use always.

With low contrast I use AE and -1/3.

With high contrast and deep DOF I use AE and expose for the highlights, AE hold and recompose, with shallow DOF I use manual, expose for the highlights, recompose and refocus.

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i have an old wetzlar ir filter for the summarit. this old lens and old filter with AE on the m8 and i think a pretty wide open aperture......

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Before I got a proper filter for my 35mm/2.0 I held a Hoya R72 up in front of the lens to check for IR sensitivity and focus. The first shot is one of those test snaps.

 

The second photo is with the B+W 093 filter.

 

I think the M8 has great potential for hand-held IR.

 

Sure beats the .5 to 1.5sec exposures I was stuck with a couple months ago.

 

antigua

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Thank you! All most helpful. I was reading some threads on other blogs that were talking about buying new cameras or modifying old cameras purely for infrared photography. Its good to know that the beloved M8 can do just what I want right out of the box! :)

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Here is one taken a couple of nights ago with a pre-historic Kodak Wratten 89a (belonged to my father) on the M8 with the 50 Elmar. About 6 seconds at f2.8 focussed at f4 mark.

 

Wilson

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