Re: [APML]: Color Film and Filters

[Mike Regish <mregish@village.yvv.com>]

 You cannot see red through the Orion Ultra-block filter.
>They do this. We used a red substrate on our filter to eliminate blue
transmission.
>It does pass IR around 850nm to 900nm, a problem for CCDs but not Tech Pan.
>
        I have been following this thread with great interest as I have a
badly light polluted back yard. I also have the Skyglow and Ultrablock
filters. Now that I can polar align for long exposures (thanks again Chuck),
I'm trying to figure out from this discussion just what I'll be able to do
from the relative comfort and convenience of my back yard. 
        The Ultrablock filter is advertised as a visual filter only-not for
photography. Are you saying it CAN be used for photography? 
        I'm also suprised (pleasantly) to hear that the Skyglow can be used
for color photography. 
        I just purchased a complete darkroom setup (second hand) and am in
the process of building a darkroom, so I'll be able to start experimenting
(crappy weather permitting) to my little heart's content soon. I got a color
enlarger head, but don't know color printing or processing yet. It would be
nice to be able to do at least SOME photography from my back yard. I have
the eyepiece filters, so there will be some aspects (prime focus, off-axis
guided for instance) that I can't use a filter for, but if there is a chance
I'll be able to do more with the filters, I may invest in the visual back
filters eventually.
        Hope you all have better weather than I'm getting. Cold front is
going through now, I think. Maybe in a couple of days...