Archived posting to the Leica Users Group, 2006/11/25

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Subject: [Leica] M8 & Infrared //Erwin Puts article on the subject
From: abridge at gmail.com (Adam Bridge)
Date: Sat Nov 25 10:57:20 2006
References: <200611241934.kAOJYJiv075075@server1.waverley.reid.org> <000e01c7106f$889ddd90$bf34a33e@symke> <37433C73-86F1-4550-B882-6A3FF7BAFA19@comcast.net> <p06230906c18e38cbc07d@10.0.1.7>

Henning, I've done no IR at all, ever. In reading comments I notice
that there are often lens scales showing IR focusing differences. Does
this vary from lens to lens? Is there a way to compute the difference
and create a spreadsheet or do I do it manually and make a table of
results? Does the setting for infinity change? Longer wavelengths
focus closer or further than visible light? I don't remember and my
mind can make reasons why its either.

Thanks for answering basic questions.

Adam

On 11/25/06, Henning Wulff <henningw@archiphoto.com> wrote:
> At 10:10 AM -0500 11/25/06, Leonard Taupier wrote:
> >Simon,
> >
> >I don't think Edwin's comments or M8 evaluations exactly address
> >what Jim Christie asked.
> >
> >First off, using a RF camera like the Leica M is easier than with a
> >SLR. The IR filter can stay on the lens without obstructing the view
> >of the scene. IR film is more sensitive than a digital sensor so
> >hand holding the camera is more of a possibility with film. With the
> >digital SLR you need to either frame and focus the scene with the
> >camera on a tripod and with the filer removed, or prefocus and use
> >an external viewfinder with the filter on.
> >
> >IR sensitivity of current digital cameras can vary from so so to not
> >at all (Nikon D200).
>
> Actually I found the IR sensitivity of the M8 to be not much
> different and possibly even greater than that of Kodak HIE, the most
> common high sensitivity film. The shot I showed was handheld at
> f/8-11 at 1/30 sec at 1250 ISO with an 87 filter. With Kodak HIE
> you'd be a couple of stops down with an 87 filter. With an 89b filter
> the sensitivity of the M8 was similar to that of HIE, but at the
> longer wavelengths that the 87 passes the M8 was more sensitive.
>
> It's a little bit hard to compare because the spectral responses are
> different at different wavelengths, and also I didnt't really have
> enough time to do a thorough job. Most of my time with it was just
> taking pictures and trying things out to see if it met my
> expectations. Which it did, and more.
>
> >In order to take images at all one must set the ISO very high (800
> >or higher), hope you get an image at all  and live with the
> >resulting grain. The resulting image must then be converted to
> >monochrome or desaturated and the contrast increased for acceptable
> >IR photos.
> >
> >Henning shared an IR photo with us that was taken with an M8,
> >handheld and at a lower ISO than what can generally be taken with
> >the current digital cameras. It was a beautiful image, sharp, very
> >good depth of field and lower grain than what I normally see from
> >film. I may be wrong but from memory I believe it was taken at ISO
> >640 (or so). The short answer to Jim's question is YES.
> >
> >Len
> >
> >
> >On Nov 25, 2006, at 3:56 AM, animal wrote:
> >
> >>Hello,
> >>Erwin Puts article on the subject as well as his second review of the M8
> >>http://www.imx.nl/photosite/comments/c029.html
> >>http://www.imx.nl/photosite/leica/M8_2/t007.html
> >>
> >>seasons wishes
> >>simon jessurun
> >>amsterdam
> >>the netherlands
> >>
> >>
> >>
> >>
> >>
> >>----- Original Message ----- From: "Jim Christie"
> >><jim.christie@sbcglobal.net>
> >>To: <lug@leica-users.org>
> >>Sent: Friday, November 24, 2006 8:34 PM
> >>Subject: [Leica] M8 & Infrared Photograph
> >>
> >>>I've been trying to follow and understand the problem issues with the 
> >>>new M8
> >>>and I have the following question. Does the IR problem mean that the M8 
> >>>is
> >>>more sensitive to IR light and, therefore, if you shoot for Infrared
> >>>photographs without the proposed filter and use a normal IR filter 
> >>>instead,
> >>>will one get more Infrared light and possibly better IR photos?
> >>>
> >>>Jim Christie
> >>>
> >>>
> >>>
> >>>_______________________________________________
> >>>Leica Users Group.
> >>>See http://leica-users.org/mailman/listinfo/lug for more information
> >>
> >>
> >>_______________________________________________
> >>Leica Users Group.
> >>See http://leica-users.org/mailman/listinfo/lug for more information
> >
> >
> >_______________________________________________
> >Leica Users Group.
> >See http://leica-users.org/mailman/listinfo/lug for more information
>
>
> --
>     *            Henning J. Wulff
>    /|\      Wulff Photography & Design
>   /###\   mailto:henningw@archiphoto.com
>   |[ ]|     http://www.archiphoto.com
>
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information
>

Replies: Reply from henningw at archiphoto.com (Henning Wulff) ([Leica] M8 & Infrared //Erwin Puts article on the subject)
In reply to: Message from jim.christie at sbcglobal.net (Jim Christie) ([Leica] M8 & Infrared Photograph)
Message from s.jessurun95 at chello.nl (animal) ([Leica] M8 & Infrared //Erwin Puts article on the subject)
Message from len-1 at comcast.net (Leonard Taupier) ([Leica] M8 & Infrared //Erwin Puts article on the subject)