Re: AW: [APML] OT: M51

[Philip Perkins <philip@astrocruise.com>]

Hi Andreas,

Regarding the RA shift when reversing Dec, I posted this question on the 
AP-GTO list and Roland sent me a reply by private mail (it included a 
description of the cause and an image).  If anyone else is interested 
please let me know off list and if Roland doesn't mind I'll forward the 
info to you.

Concerning E-6 processing, unfortunately it is a lot more complicated than 
C-41 processing.  It involves double the number of chemicals, double the 
number of steps, and some of the temperatures must be held very accurately, 
like within 0.3 C, otherwise serious colour shifts can occur. The time, 
temperature, and agitation have to be continuously monitored and accurately 
maintained. In fact I think that E-6 can only be done really successfully 
in an automated processor or developing machine.  My remote location is 800 
miles away in a very remote place, with very limited facilities, and I 
don't want to get involved in carting processing machines there, when in 
fact I am happier using colour negative in the first place.  OTOH C-41 
processing is no more complex than B&W processing, it's just that 
temperature tolerances are tighter.  But they are not as tight as with E-6 
and the consequence of incorrect temperature is much the same as with B&W - 
to pull or push the development - but effect on colour balance is 
minimal.  I can easily do C-41 at my remote location but E-6 is another 
ball game I'm afraid.

Thanks
--Philip

At 15:58 30/04/03 +0200, you wrote:
>Hi Philip,
>
>once again an excelent image!
>At your website you mention a shift of the RA when reversing the DEC.
> >From time to time I notice the same effect on my setup. Could you
>explain a bit more detailed what causes this effect and how you could
>get rid of it?
>
>Another question concerning E6 processing: I started doing this last
>year and didn't find it too complicated. Why do you think the C41
>process would be easier to do on a remote location than E6? In fact it's
>a matter of holding the temperature in both cases, isn't it?
>
>Best regards
>Andreas
>
>:=================================
>: Andreas Roerig
>: Bahnhofstr. 16
>: 65599 Dornburg-Wilsenroth
>: Tel. 06436/28137
>: http://home.t-online.de/home/a.roerig
>: (Letzte Aktualisierung: 27.03.2003)


Philip Perkins - philip@astrocruise.com
Wiltshire UK & Luberon France
Astrocruise - http://www.astrocruise.com

_______________________________________________
Astro-Photo mailing list
Astro-Photo@seds.org
http://seds.org/mailman/listinfo/astro-photo