Olympus-OM
[Top] [All Lists]

[OM] Re: 1 stop difference between 2 series & 1 series focusing screen?

Subject: [OM] Re: 1 stop difference between 2 series & 1 series focusing screen?
From: John Hermanson <omtech1@xxxxxxxxxxx>
Date: Fri, 27 Jul 2007 08:34:25 -0400
I haven't checked this in a while.  OM-1/1N meter may be calibrated to a 
2 series screen and a 50, errors start to creep in as you go longer and 
shorter. With 100mm lens, I think the error is about 1/4 stop. I used to 
detail this on my old website:

"Error in OM-1, 1N can be adjusted out as it can in 2/2N (as part of an 
overhaul), though there may be some error in the needle indication 
starting with telephoto lenses due to the angle of light coming through 
the focus screen and how the cds cells on either side of the eyepiece 
lens see that light. This error starts to show with 100mm lens and 
increases slightly as the length of the lens increases.  100mm error 
causes about 1/4th stop overexposure. 180mm f2.8 lens sees a 2/3rd stop 
error and so on. No meter errors are encountered with these screens when 
used in the OM-2S, 3, 3Ti, 4, 4T, or 4Ti.   "

___________________________________
John Hermanson
Camtech Photo Services, Inc.
21 South Lane, Huntington NY 11743
631-424-2121 | Olympus OM Service since 1977
http://www.zuiko.com  |  omtech1 AT verizon dot net


Moose wrote:
> usher99@xxxxxxx wrote:
>> Oops is right.? My comments apply to the OM2 and 2N's I have.? I should have 
>> remembered from the Odyssey 1N.?? Just when I thought I graduated from 
>> Zuikoholic 101.? Wanted to give a heads up on the changing compensation 
>> required for different focal lengths.
>>   
> Well, I may have missed something all these years, but I'm not aware of 
> any exposure compensation required for different focal lengths on 
> OM-1(s) bodies. Using a two series screen ahould only require a simple 
> exposure compensation for the screen, but nothing for different focal 
> lengths. Or have I missed something?
> 
> I certainly have no practical experience. I have 2 series screens in a 
> couple of 4 series bodies, but have never used one in a 1 or 2 series body.
> 
> You aren't confusing this with the exposure compensation issues of using 
> OM lenses with adapters on E-thingies, are you?
> 
> Moose
> 


==============================================
List usage info:     http://www.zuikoholic.com
List nannies:        olympusadmin@xxxxxxxxxx
==============================================

<Prev in Thread] Current Thread [Next in Thread>
Sponsored by Tako
Impressum | Datenschutz