Eyepiece question

[leeq]

Hi All,

I had a question about an eyepiece I shipped back from the US when we repatriated to the UK.

It's a GSO Plossl 40mm 1.25" FOV 44deg (allegedly).

Now given that I just purchased (arrived today) a FlexTube 300p Auto, the math is telling me that it will give an exit pupil of 8.0.

With that in mind:

1. What problems will this cause me? (I'm 41yo)

2. Should I even bother using it?

My last opticians visit scored me at 20/15 vision, so there isn't anything going bad there just yet

But any advice will be gratefully received.

Many thanks in advance!

[mdstuart]

If the exit pupil is too large you will loose a bit of the light..Also with a short F scope you will get stars as dots in the centre but they will show coma towards the edge. But hey i will give a nice view of those large objects such as the double cluster or the andromeda nebula.

As I understand it you will need to pay more to get a really good low power lens which will have less coma.

Mark

[leeq]

Thanks Mark,

I appreciate the quick response, and the easy to understand answer!

Cheers,

[Astro_Baby]

I'd concur - I have a 38mm - too big an exit pupil doesnt worry me - after all I'm not paying for all that light I am wasting

The coma isnst too bad in mine and most people quite like the big views it offers especially of diffuse objects like open clusters.

I have seen it argued that coma isnst the end of the world unless its super bad because the human eye only focuses on quite a narrow field anyway.

I'd try it and see if you like the view. If you do then all is well.

[James]

I'd give it a try. There's a chance that the secondary mirror may be visible when looking through it and if so you probably won't want to keep using it but until you try it...

James

[leeq]

Thanks everyone!