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Source for Potometric filters

njsg's picture
Joined: 2013-09-25

Hi all,

 I'm new to the group and am wondering if anyone out there has a V- filter that  can be screwed to 2" nose of my  SBIG , available for sale. Or  if anyone knows of a source for an V-filter




V filter
tcalderw's picture
Joined: 2012-11-12


I bought my V filter from Chroma Technology  (  It was 1.25",  but they have 2" as well, reasonably priced.  Bandpass graph attached

Photometry Filter Source
CTX's picture
Joined: 2010-07-08

A popular source of Photometry Filters, in both 1.25" & 2", is Astrodon: simply and let your fingers do the walking :)

Also, do not overlook Custom Scientific:

Ad Astra & Good Observing, while I am at, I am on the mentoring team, so if you any questions along the way (and there is no such thing as a dumb question) feel free to email me:

Ad Astra & Good Observing,

Tim Crawford, CTX


2" V filter
rmu's picture
Joined: 2010-07-23

I like the Astrodon V filter, that is the one I use. Unfortunately, 2" size has been made without screw ring, and the ring from another 2 inch filter doesn't fit.

Edit: I've seen the other brands sell the two-inch filter unmounted too :/  

What model is your camera? Even with a KAF-8300 chip you can use a 1,25" filter if you can put it close enough to the camera window, if you don't use an f ratio minor than 5.

PS. I din't know about Chroma company. It seems their photometric filters doesn't have as much as transmission as astrodon filters, but I praise them for being honest and transparent showing good and precise transmission curves (with downloadable numerical values).

The camera I have is a
njsg's picture
Joined: 2013-09-25

The camera I have is a STF8300c - I suppose that  I can go the 1.25" route if I have to. Though I did noitice that  Chroma will mount the filter for at no additional charge. I might investigate that  a bit more.

Thanks for all the responses.



Photometric filters
BPO's picture
Joined: 2010-07-28

Just for reference, Baader Planetarium supply photometric filters.,20212#tab_bar_0_select


Carlos Tapia's picture
Carlos Tapia
Joined: 2011-02-04

If you're going to buy a new photometric filter go to Chroma or Custom Scientific (the second made the filters for SBIG). Don't buy the Baader or you will have a few problems in Nova or Supernova photometry.

Or buy the Astrodon if they have the 2" thread (I don't remember if they have it).

AAVSO 49 Bay State Rd. Cambridge, MA 02138 617-354-0484