Jump to content

Narrowband

5 mm for a 6 inch Reflector


PeterJB

Recommended Posts

I own an f/5 6 inch reflector with 1.25" 25 mm and 10 mm eyepieces with a 42 degree FOV and a 2x Barlow lens. I'm considering getting a 1.25" 5 mm long eye relief eyepiece with a 45 degree FOV which would give a magnification of x300 with the Barlow in. This would also give a FOV of 0.15 degrees. The specification of my scope says a maximum magnification of 300x. Would this eyepiece work well with the Telescope?

Link to comment
Share on other sites

A 5mm on it's own would be good - 150x is very useful. I'm sure you will have realised by reading other posts on the forum that 300x won't be much use though. It might be a theoretical maximum for a 150mm scope but in practice the seeing conditions we get rarely make more than 250x useful and very often you get the best images at substantially less than that.

Link to comment
Share on other sites

Hi,

Adding my tuppenceworth, when getting down to such short focal-length / high mag eyepieces, when using the 150P/Eq3-2 combination, I found the biggest problem to seeing was the time it took vibrations to settle down - any slight touch of the focusser or eyepiece led to big shakes in the FOV for several seconds!

I agree with what's been written already - 150 - 200x should perhaps be what your routinely aiming at for max mag for your set-up. I guess that a 7 or 7.5mm with 2x barlow will give you magnification around the 200x mark which might be sensibly achieved.

Clear Skies,

Jim

Link to comment
Share on other sites

magnification isn't everything resolution is, and 150mm should give you some excellent views , i have just come back from wales and the dark skies let me see

m81,m82, m3(fantastic) m38,m37, plus many more and all at low/medium power.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • 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.