Using UV/IR block filter with reflector for L channel, or not?

[Jannis]

So it appears I'll be having a few hours of clear dark sky tonight, and i was thinking of having a go capturing some L data of M63, the sunflower galaxy.
As I have only dark skies for about 2-3 hours, I don't have much time to test out new targets and stuff - but i did manage to capture a handful of DSLR frames of M63 earlier, and was hoping i could use it as color.

So then here's the question - I know for refractors it's a given that one need to block UV and IR for L to get a sharp picture, but I wonder if this is really needed for reflectors?
The reason I'm wondering this is because I'll be attempting to capture loads of 1 minute exposures for optimal sharpness, and i want to capture as much light as possible. I'll be using the QHY5L-II Mono.

While i had great success previously with M51 using this method, i keep wondering if using the UV/IR cut filter was a good or bad decision?
I'm thinking if i hadn't used the filter i would have capture more light giving me a better SNR ratio as the QHY5L is highly sensitive outside the filter range, but I'm also not sure how good my Explorer 200's mirror would focus this entire range? Would i simply gain SNR by removing the filter, or would i gain SNR at the cost of sharpness?

Hope someone could help me out with this before i go out tonight...

[ollypenrice]

Is there no glass in your system? Coma corrector, for instance? That is a refracting system.

I don't know what the gain would be from removing the L filter but you would need to do some more elaborate processing to avoid putting bloated L stars into the final image. (I often avoid using L for field stars, for instance, since pure RGB stars are often smaller and more colourful.

On balance I'd just run the L filter!

Olly

 

[Jannis]

Thanks Olly! :-) 

Im aware i cant use it filterless with any glass in the systen, but from what i experienced i wont need the coma corrector at this small fov. Its because of this i thought maybe no filter would be best.

But i see what you mean with bloated stars, and so i think for tonight at least ill go the safe way with the uv/ir block and MPCC. :-) 

[ollypenrice]

Worth a bit of experimenting, though, at some time. I've never done this.

Olly

[Jannis]

True, if there's a chance of capturing more wanted photons without any additional cost it's worth a try for sure. After all my wallet is currently so empty even the dust in there feels lonely...
Looks like i might have to wait for next season though. Looks like these days it's only dark enough for ~2,5 hours, not enough to be able to make a proper comparison...

For now it looks like a quick process of 300x 1 min with the Polemaster and a UV/IR block filter in place gave some results at least, and a significant improvement over what i was able to capture with the DSLR only, but it looks like i will still need loads more data for this target. And for sure need more color data...