Archived posting to the Leica Users Group, 2003/12/24

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Subject: RE: [Leica] Fw: looking for line pairs with a stabiliser and a Leica and question
From: "B. D. Colen" <bdcolen@earthlink.net>
Date: Wed, 24 Dec 2003 17:05:30 -0500

Of course! :-)

- -----Original Message-----
From: owner-leica-users@mejac.palo-alto.ca.us
[mailto:owner-leica-users@mejac.palo-alto.ca.us] On Behalf Of animal
Sent: Wednesday, December 24, 2003 5:03 PM
To: leica-users@mejac.palo-alto.ca.us
Subject: Re: [Leica] Fw: looking for line pairs with a stabiliser and a
Leica and question


we want to take pictures of something from our workplace at night What
else? silly man

- ----- Original Message ----- 
From: "B. D. Colen" <bdcolen@earthlink.net>
To: <leica-users@mejac.palo-alto.ca.us>
Sent: Wednesday, December 24, 2003 10:45 PM
Subject: RE: [Leica] Fw: looking for line pairs with a stabiliser and a
Leica and question


> And, just out of curiosity, this has what to do with photography or 
> any real world use of Leica equipment? Just wondering. ;-)
>
> -----Original Message-----
> From: owner-leica-users@mejac.palo-alto.ca.us
> [mailto:owner-leica-users@mejac.palo-alto.ca.us] On Behalf Of animal
> Sent: Wednesday, December 24, 2003 3:58 PM
> To: leica-users@mejac.palo-alto.ca.us
> Subject: [Leica] Fw: looking for line pairs with a stabiliser and a 
> Leica and question
>
>
> Sorry for the earlier empty post.
> Here goes.
> A collegue and myself wanted to find out if we could get 80 line pairs

> per millimeter using a Leica and a Kenyon gyro stabiliser. We could 
> not find those data in literature so last night, while also doing a 
> test of Laphroig versus Lagavullin, we decided to give it a try 
> ourselves.
>
> We scribbled some lines on a piece of paper with a group of line pairs

> one 1 cm per pair and the other 5 mm per pair. With a Noctilux 18 
> meters away we calculated the image on the film to be 36 and 72 line 
> pairs per millimeter. We suspended the camera and running gyro from a 
> bungee cord and started. First exposure was at 1/250 second and f1.0 
> going in stops to 1 second and f16.0.
>
> Then we tried the same sequence while handholding the camera and 
> bracing ourselves in a doorway.
>
> By then we became to doubt the ability of a 4000 dpi scanner to 
> resolve our results. While one would assume that 4000 dpi translates 
> to 80 line pairs per millimeter,some knowledgeable people we asked 
> suggested that 60lp/mm is about the best such a scanner can do. So we 
> had to aim a little lower and did the same test with an aasummicron90 
> mm and the stabiliser starting at 1/60 and f2.0  .
>
> Although our test was hastily done it still yielded some suprises to 
> us. The biggest being that the stabiliser clearly is able to permit 
> shots at 1 second. Others were that the noctilux was still giving good

> results at f 4.0 and 5.6 and stayed that way until f16.(we realise 
> that the focus shift of the lens could have been to our advantage at 
> those apertures if we started out with a focus error). Also suprising 
> was that at f 8.0 and smaller the summicron image is starting to fade.

> Lastly it shows that it is hard to find the testcard when handholding 
> the camera. On the page the first column is the stabilised noctilux 
> the second is the same handheld(stopping at 1/8th) and the last is the

> summicron. The film used was Kodak E100 GX . The  question is to get 
> rid of focusing errors .can one set the lens accurately at infinity 
> just by putting the index on thatmarkingAnd if so at what distance 
> would one have to put the target? 
> http://www.leica-gallery.net/apekop/folder-6004.html
> best regards
> simon jessurun
>
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Replies: Reply from "animal" <s.jessurun95@chello.nl> (Re: [Leica] Fw: looking for line pairs with a stabiliser and a Leica and question)