Hi,
Still trying to figure out the best way to add an UV/IR-cut or LPS filter for my 294MCPro.
It's my first color ASI, my other ASI setups all have filter wheels.
(I plan to not switch filters often)
My first idea was to acquire the two mentioned filters mounted in 1.25" cells, then use the supplied T2-1.25″ filter adapter (
But I suspect this could lead to vignetting with certain setups, considering some measurements:
- The sensor is 23,2mm.
- The typical free diameter of a 1.25" filter cell (I measured two) is 26,3mm.
- Some optics have bigger rear elements than other. e.g. 31mm for the EF200L lens.
- Interestingly, the rectangular-like plate holding the AR-window provides a diagonal opening of 28mm.
Maybe I'm making a case out of thin air, but I do suspect that a few cases can have slight vignetting issues. So I'd like to know all my options before starting out :)
If I want to do this "right" I will ask Gerd Neumann (Astronomik filters) for a quote on these filters mounted in a custom filter holder based on this common T2-1.25″ filter adapter, probably starting out from 31mm unmounted filters. (another pro with this choice would be an even lower filter unit)
Anyone with thoughts on vignetting in this case?
Did you solve it without a M42 filter? Not having the filter upstream of a possible off-axis guider?
Thanks.
