Jump to content

548140465_Animationchallenge.jpg.32379dfa6f3bf4bba537689690df680e.jpg

Do I need to go bigger?


Recommended Posts

With my 25mm EP on an F5 scope do I need to go bigger to say a 32mm or even a 40mm EP?

I can see the sense of getting say an 8mm or 6mm but a 25mm seems fine to locate objects in the night sky. So what would a 32mm do for me? Wider field of vision to locate things maybe?

Link to comment
Share on other sites

The difference between 32mm and 25mm is not great & with a f/5 scope a 32mm EP is going to give you a 6.4mm exit pupil which will be too much for many people, especially if your sky is bright (full moon or light pollution). Personally I think it's not worth the money. OTOH a good 25mm (ish) wide field eyepiece would be an improvemnt on the rather nasty 25mm supplied with Skywatcher ... the 26mm Meade Series 5000 Super Plossl (60 deg apparent field) would do you nicely & have pretty much the same actual field as a standard 32mm Plossl (and you won't get bigger without going to a 2" eyepiece!)

Link to comment
Share on other sites

With my 25mm EP on an F5 scope do I need to go bigger to say a 32mm or even a 40mm EP?

I can see the sense of getting say an 8mm or 6mm but a 25mm seems fine to locate objects in the night sky. So what would a 32mm do for me? Wider field of vision to locate things maybe?

No, you don't need to go bigger, you're managing fine with what you've got. But if you want to talk yourself into getting a 32mm eyepiece then get the TeleVue plossl.

Link to comment
Share on other sites

Hi Stardad

I think you answered this one yourself in your initial question.

If your not sure you need it don't buy it.

Your 25mm is as Demonperformer states giving you a very large field.

IMO a larger field would be a bit of an occasional eyepiece that wouldn't get much use.

I would go for something you would use more often ( as i don't know what you already have i can't recommend any).

You may feel in a couple of years that a 32mm would indeed be great for star fields and the really big faint fuzzies

but until you feel you need one i would spend my money on something else.

Regards Steve

Link to comment
Share on other sites

You really should read BrianB's post again. If the exit pupil is too large a lot of the light you collect simply does not go in your eye. An EP with a higher magnification and a wider field of view will give you the wider field and get all the light from your scope into your eye. There is no arguing with this, it arises from sound physics.

Olly

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.