On 10 Jun 01 at 3:28, Neil K. wrote:
>
> Argh. I wrote:
>
> > So. It appears that either the list on Willem-Jan's Web site is
> >incorrect on this detail point or the Rebel S II has an IR diode
> >mysteriously hidden away somewhere else.
> >
> > Since it seems to me that the only logical place to put an IR
> >sensor would be as close to the shutter as possible, I'm presuming
> >the latter is the case.
>
> Naturally, I meant "former."
>
> Also, revisiting Willem-Jan's Web page on the subject, it appears
> that someone has tried HIE film in the Rebel II with no ill effects.
Well, that more or less applies to most EOS'es, including those with
known IR-LED's....as the problem itself (having IR-LED's) is most
often not at all as bad as Canon wants us to believe.
Add a printer that skips 1-2mm off the image, and any problem is
gone....8-))
> There also seem to be varying reports regarding whether or not the
> fogging enters the image area, so it appears the theory that there's
> a great deal of variation in IR fogging from camera to camera within
> the same model type holds water. My Elan, for example, fogged up
> quite a bit of the visible image area.
I once thought I saw a relation between grade of model and
fogging-extend, the higher the model, the less fogging....as if Canon
at least tried to decrease the problem on those models which were
most likely to be used with IR film.
And it seems they at least did a good job in case of the 1v (while I
still have questions about it's data-back cut-out (which is a problem
with other brands and models too, even those without data-back (but
having the same cut-out pressure plate, for cost reasons))
> Man. Aren't there IR diodes with a shorter wavelength of light? I
> appreciate the utility of IR sprocket sensing, but there are enough
> of us out there who like to use HIE from time to time.
Well, actually, there is a little trick, which is mentioned somewhere
in the files on my homepage (not sure whether in one of the
camera-related chapters, or in a chapter on its own):
You can tape a piece of deep-red to IR-filter on the sensor, which
will decrease the amount of fogging, while still allowing the sensor
to count the perforations.
Might even have been a piece of normal black&white film (contains
silver, because only metal-based neutral-density materials block IR to
the same extend as visible).
Oh wait, here it is, separate file, not-yet-HTML'ized:
http://www.a1.nl/phomepag/markerink/irledtip.txt
And for more indepth discussion, I recommend you sub_scribe to the
Infrared Photography Mailinglist:
http://www.a1.nl/phomepag/markerink/ir_list.htm
--
Bye,
Willem-Jan Markerink
The desire to understand
is sometimes far less intelligent than
the inability to understand
<[EMAIL PROTECTED]>
[note: 'a-one' & 'en-el'!]
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