3x Barlow Lens Blurry

[NosyTrader]

Hi all,

I'm very much a newbie who has recently purchased a Celestron Nexstar 8 and incredibly happy with it! I also purchased a 3x Barlow Lens from 365astronomy in the UK. My problem occurs when i try to use the 3x barlow (attached between the eyepiece and diagonal).

When I try to view Jupiter with my 13mm plossl I can't seem to focus on e.g. Jupiter. The planet is always blurry and non sharp. If I use the 40mm that came with the scope the image is much better, but with using the 40mm with the barlow, I may as well use the 13mm without the barlow to get about the same magnification.

I thought that the telescope would be able to handle the 3x barlow with the 13mm as the max useful magnification is 480x according to the celestron website.

Any advice appreciated!

[knobby]

Website claims on max magnification are very misleading ! you're probably only going to manage 200 - 250 x mag with a 200mm scope and only then if the conditions are good.

Are you letting the scope stabilize to match the outside temperature for a while (although i guess in abu Dhabi its warm all the time)

[Pondus]

470-480 is way too much magnification on Jupiter. ('Seeing' conditions).

I have no clue what the average seeing is in Abu Dhabi, but your 13mm gives you 156x which is quite normal.

Maybe you should go for a 9-10mm eyepiece for those good observing nights on Jupiter.

Rune

[michael.h.f.wilkinson]

For Jupiter I can on good very nights use my 7mm (290x) in my C8 (same optics as your scope), but nothing beyond. I prefer using the 10 and 8mm EPs usually. Your 3x barlow could still be of use for imaging

[damnut]

Hi There,

Echo comments above. Usually the magnification limit is 2*aperture in mm so for a 203mm scope = 406X. I can only agree with  comments above, even when I had a 10"sct rarely used more than 150x

[NosyTrader]

Thanks so much to you all for your responses! I wasn't expecting any so soon! Very much appreciated!

I do tend to let the telescope sit for a while outside but as you say, it's always quite warm here. My best big battle will be with humidity which is likely to pick up very soon!

Thanks again all, seems like I've made a classic "more is better" mistake here!