Powermate - 80mm refractor

[rcheshire]

I'm thinking of getting a 4x TV Powermate for use on my 80mm f6.3 refractor. Is there a downside to this for DSLR photography - planetary at this stage.

Saturn and Mars are quite small of course without additional magnification. I'm wondering if there is a significant advantage in using a Powermate. Obviously a bigger telescope is probably the answer, but for the time being it's 80mm.

[dannat]

an 80m refractor is an unusual choice for planetary imaging, with a d-slr

the usual way is a webcam or ccd of some type capturing many frames stcaked together..the powermates are a great device though ( i don't know if the 80mm will hold the magnification..maybe the 2.5x)

[rcheshire]

Hi. Thanks. I didn't choose the equipment for planetary imaging specifically. It's my first telescope and I'm using it for astrophotography and visual work.

My understanding is, that increasing focal length reduces aperture. I guess my question is, when does aperture become limiting or impractical for DSLR astrophotography? There is a limit on visual observing, but I have read about the advantages of smaller apertures in terms of focus and definition - round stars - presume that smudginess is reduced.

I'm not sure, but I think this may be a matter of experience in the field and possibly a matter of opinion.

I guess there is plenty of literature on this subject, but there is no replacement for experience sometimes and I think this question may be one of those instances.