F 6.3 focal reducer?

[Glenbo58]

Been asking advice for lenses foe deep sky viewing with my Celestron 8 Ultima SCT. Some have asked if I had a focal reducer & that I should get one.
I have a 2in. Diagonal & am considering a 2'"GSO Superview 30mm or 2" Q70 38mm. as these fit my budget. Would I really benefit from a focal reducer & why?

[smeyer8015]

It increases the true field of view to almost 1.5 degrees.

[Bigzmey]

SCT (and Mak) field of view is limited by the baffle tube diameter (which in case of 8" SCT is 37mm). Since 2" 38mm Q70 has field stop of ~45mm, you already loose some light to the vignetting.

Adding focal reducer to the light train will result even in more loss of light due to the vignetting. Yes, you will have larger field of view, but it will be unevenly illuminated and you will reduce effective aperture of your scope.

It may be OK or even useful under certain scenarios. For instance with reducer you will be able to fit more of Pleiades in the FOV with your scope. And since they are bright target you would not care about some light loss. But if you hunt fainter target I would not use the reducer.

I got the reducer when I bought my 8" SCT (largely based on recommendations on forums ) but after experimenting with different EPs I don't use the reducer anymore.

Whether with reducer or not I would recommend Q70 38mm over SV 30mm for your 8" SCT.