Return to the Cloudy Nights Telescope Reviews home page

Astrophotography and Sketching >> Film Astrophotography

Pages: 1

Reged: 06/19/12

Loc: Dedham, Massachusetts
Tech Pan with UHC Filter?
      #5676124 - 02/12/13 03:47 PM Attachment (19 downloads)

I've always wondered how sensitive film is to the OIII wavelength, specifically Technical Pan. I've heard a lot about h-alpha, but not a lot about OIII, at least in relation to film astrophotography. Being curious, I bought a Televue Nebustar UHC filter (a narrowband OIII filter seemed way too narrow for film). I used my trusty old Tech Pan, with its fairly even response throughout the whole spectrum and its lack of reciprocity failure. I finally got a clear night, and figured M42 would be a nice bright target with a lot of OIII emission. Well, here are my results. The filter completely removed my light pollution, and the contrast seems increased in comparison to my unfiltered shot. On a different note, my negative seemed a bit fogged, and also there are what seem to be light leaks on the edge of the frame and around the sprocket holes. Could my very old camera or developing tank have light leaks, or could this be some sort of uneven development (I think the film crinkled a bit when I loaded it onto the reel)? Also, has anybody seen the mottled pattern that appears on my shots? I am thinking it could be uneven hypering, but I really have no clue.

Thanks and clear skies,

Exposure: 29 minutes
Lens: 152mm f5.9 Achromat
Film: Hypered Tech Pan
Guiding: Manual w/off axis guider
Also, Excuse the dreadful scan!!

Post Extras: Print Post   Remind Me!   Notify Moderator  

Reged: 10/01/05

Loc: Lost In Space
Re: Tech Pan with UHC Filter? new [Re: AstroMan0]
      #5681593 - 02/15/13 02:03 PM

Looks sort of like a developing issue, hard to tell without a scan of the entire negative.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1

Extra information
0 registered and 2 anonymous users are browsing this forum.

Moderator:  1965healy, WOBentley 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled

Thread views: 371

Jump to

CN Forums Home

Cloudy Nights Sponsor: Astronomics