Stacking two filters

[StarlightHunter]

Hi there.

I recently adquired a ASI294MC-Pro camera and I read OSC cameras works better using IR/UV filters to avoid star bloating.

I adquired two filters from Aliexpress, both of brand Svbony. One is the UV/IR and the other one is the CLS filter as I live in a very poluted area.

The thing is the CLS is not a CLS-CCD filter, so it does not block IR, so I wanted to know if it is "wise" to pile up both filters so I can block IR/UV and city lights.

Had anyone tried this before?

I attach some photos of the CLS filter and a test I did with my DIY spectrographer

Edited October 29, 2019 by StarlightHunter

[ebdons]

Hi depending on the optics of the scope I use cls (non ccd) with ir cut only on frac optics achro apo sct etc, when use on my newt then no need for the ir cut I found and yes you're correct about star bloat but I use the IDAS NB1 and NGS1 on my apo and achro and they both limit star bloat albeit the NB1 is better, I don't know if this is what you're asking? ton

[StarlightHunter]

27 minutes ago, ebdons said:

Hi depending on the optics of the scope I use cls (non ccd) with ir cut only on frac optics achro apo sct etc, when use on my newt then no need for the ir cut I found and yes you're correct about star bloat but I use the IDAS NB1 and NGS1 on my apo and achro and they both limit star bloat albeit the NB1 is better, I don't know if this is what you're asking? ton

Yes, That's exactly what I was asking. Thanks. I've an SW ED72 APO so I should need IR correction on a non filtered camera.

Newts and non refracting telescopes do not need IR filters AFAIK.

I was more concerned about reflections, focus problems or even less light coming to the sensor because of two filters being stacked.

[ebdons]

yes reflections are an issue even in IDAS filters sometimes, my astronomic UHC+ir cut  produced mega reflections on my 825m but nothing on my 174mm and I don't know why except a ccd v cmos change, but I found that stacking the filters the opposite way, ie ir cut after main filter produced slightly different results albeit small, there should be hardly any lack of light if the filters are stacked well, but putting the main filters first and then adding the ir cut after should result the same but it depend on the setup I guess, but folks on here will no more than me as I am a newbie still. ton

[StarlightHunter]

Ok. The best option here is to check on field

I will need to find some time and clear skies to do some testing.

Thanks!