Agfa 1280 for IR and Sony TRV65 for focusing IR image

[ANDPPH@xxxxxxxxxxxxxxxxxx]

This is just a report on some experiments to prove/disprove the useability of
the Agfa 1280 camera to make photographs by near infrared radiation. It works
but one needs huge amounts of infrared and when using the deepest IR filters
the image is very dim and needs to be boosted so much (I use Photoshop) that it
turns quite grainy and detailless. With the lighter IR filters the image has a
reddish cast which can, of course, be eliminated by changing from color mode 
to greyscale, again, in Photoshop or other software.

I was not able to make a simultaneous full color photograph and an IR image
behind a filter that I was holding in my hand. Want my opinion of the use of
the 1280 as an IR recording camera? Marginal in quality but fun to do
especially with deep red filter or weak IR filter where a strong red image is
formed. Better yet, the highest quality images are fomred where IR is abundant
and this is probably on some Caribbean island and what better excuse is there
to book a trip to such a destination?

The other item consists of finding an application for a Sony IR sensitive
camera (Nightshot)(!). I was going to get a TRV85 but gulped at the price and
settled for a 65 with a 2.5 inch LCD. Anyway, the camera is quite sensitive to
IR and even with an 89B it responded well especially when sensor sensitivity
was boosted to the max. I found the built-in IR LED illuminators ok but they
give a decided hot-spot when used ... at any range. If one is not concerned
with surveilance, a better source to use in my opinion is a small tungsten
floodlamp. I used a 75 watt lamp to light a classroom and had no trouble seeing
an IR image of every part of the room with a 78 filter covering the lens. 
                                            
Going further, this opens up an interesting application I had not thought of
before. How about checking the focusing mark of your lenses by placing a
groundglass in the film plane, an IR filter over the camera's lens and then
looking at the IR image formed by the lens on the groundglass with the Sony IR
sensitive camera ... and seeing whether when one makes the proper focus
adjustment the image does indeed come to the sharpest focus. Might even look
through the camera's viewfinder at the split-image focus indicator!

Or, one could use the camera to check on the focus of view camera's used for IR
recording. Just aim the camera at the view camera's groundglass. These cameras
do not have an IR focusing mark and one must rely on various improvised
techniques and usually still is left with the nagging feeling of whether the
adjustment was right or not ... or use a very small aperture. May have to use a
hood of some kind to eliminate or minimize ambient light from the groundglass.

BTW, an experiment that I was conducting some time ago having to do with making
a protective leader for IR film so that it could be loaded in daylight ...
well, the experiment was not very encouraging. It seems as though the felt trap
is just about totally transparent to IR so any leader material I used always
leaked and fogged the film within ... sometimes less sometimes more. Could be
used in a pinch but for more safety loading and unloading in pretty much
darkness or very subdued fluorescent illumination is to be recommended.

so long for now,

Andy  o o  0 0 o . o  Andrew Davidhazy, Imaging and Photo Tech
       \/\/\/\/\/\/   http://www.rit.edu/~andpph  716-475-2592  
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