Archived posting to the Leica Users Group, 1998/04/27

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Subject: [Leica] Re:Noctilux[vsCanon50f/1tests]
From: Donald Ingram <Donald_Ingram@compuserve.com>
Date: Mon, 27 Apr 1998 17:21:10 -0400

>Message text written by Danny Gonzalez
>I own both the Canon 50/1 and 85/1.2 lenses and am in NYC. If you're
anywhere near, =

>maybe we can test the lenses? If not, I'd be glad to go out to the roof
and answer your =

>questions. Just tell me what I need to do and with which film.

Hi Danny,

Thanks for the offer - putting the canon 50 and 85   lenses through there=

paces, perhaps with the Leica 50 and 75 alongside,  would be  a clash of
the titans which  I would love to see and no doubt  produce some very =

interesting results.

But I will probably not be in your vacinity for a while  - wrong continen=
t
, I live just North of Inverness Scotland.


If however you are interested in giving it a go -  pushing your lenses to=

the limits  here' s a few pointers for fixed camera star photography:

Use a exposure of 600/lens_focal_length  any longer and the rotation of t=
he
earth starts to show up as star trails
e.g. 50mm gives 12 seconds or 85 gives only 7 seconds =


If its totally dark i.e. no moon or city lights - it's impossible to get
too much exposure - If the lens is up to it - but as the exposure of a
point source builds up beyond the minimum, what was once a single point
starts to spread out. This is the problem the Noctilux handles so well, b=
ut
the Noct -Nikkor was hopeless at. =

If you have it, the LFI article 'Lens and Image quality ' on pages 28,29 =
of
 LFI 8/96 shows  what happens  very clearly.

e.g. totally dark try -  50 f/1 @ f/1 for 12 s with Kodak TMZ pushed to
50,000 ASA
This will even record  the milky way  bright and clear =


But if the moons out or there is city skyglow  using a film much faster
than 1600 ASA for the same exposure and you will get pictures that look
like they were taken during the day and only the brightest stars ( i.e.
those in the classic constelations ) will show up.

As for films: =

I have found both  Provia 1600 and Kodak EPH push very well to push  +4 (=

as long as you intend to print it  - other wise push +3 ) =


I only started trying color neg this year, but Kodak PJC at push +3 seems=

to show more detail than TMZ at 50,000ASA - I think its because of the
better red sensitivity.

A more straight forward test : with the Noct-Nikkor, I found that with
1600ASA film at f/1.2 and say 20 seconds, distant street lights had a
significant halo which reduced significantly with each stop the lens was
closed.

If things go well, I would not  intend to seriously  think about buying t=
he
Canon or any  other lens until the winter and dark skies come around agai=
n.
I would not want to put you out of your way.

If there is any thing I can do in return let me know.

Thanks   Donald.