Wide field ep

[bish]

Hi all,

I am making a few changes and filling some gaps in my eps. I have been using a 26mm 4000 plossl since I had a SW150p. This gave x28, true fov approx. 1.8 degrees and exit pupil approx. 5.35.

I have changed scopes a few times and now use a SW 250px. Obviously I don't get such a wide fov, so am looking for a wider ep. I have recently bought a MV 24mm 68 degree which gives me a true fov of around 1.36 and I would also like something wider. The MV 28mm seems a bit too close to the 24mm to bother with.

Naglers or Ethos etc aren't a consideration due to price. I am toying with either of the following;

MV 34mm 68 - x35, 1.9 fov, exit pupil 7.19

SW 30mm Aero - x40, 1.7 fov, exit pupil 6.35

My main question is about the exit pupil, as it's never been a consideration before. I am in my mid forties and slightly short sighted and don't know whether a difference between a 6.35 and 7.19 exit pupil would make any difference. Obviously everybody is different. The other thing is that my area is very light polluted, so I guess that these wider field eps with larger exit pupil would be better suited when I go to a dark site?

Sorry for the long winded post.

Thanks.

[John]

If you have light pollution to contend with my advice is to try and reduce the exit pupil and up a magnification as much as your budget will allow to avoid washed out DSO's. If you could run to a Nirvana / UWAN 28mm that might be worth thinking about as that would give you a 1.9 degree true field at 43x and a reasonable exit pupil of 5.9mm. They have pretty close to Nagler performance and can be found for quite reasonable prices on the used market.

[Moonshane]

Just about to type the same thing! I have never used one but the reviews seem excellent.

[bish]

Thanks John and Shane. I would rather put a bit extra and wait to get the right one than spend £100+ on something that may not do the job I need.If I had the cash then a 26mm nagler would be top of my list - but a SW nirvana may well be the best middle ground then, especially if I can pick up a used one.

[John]

I've no connection with this ad:

http://www.astrobuysell.com/uk/propview.php?view=87624

[bish]

I've no connection with this ad:

 

http://www.astrobuysell.com/uk/propview.php?view=87624

Thanks John