Planetary eyepiece

[DaveGarland]

Would a 4mm planetary eyepiece be too much magnification for a Skywatcher Explorer 130EM 130mm?

[Stargazer Jack]

I was thinking about this too. I have the 900mm focal length version which means I would get 220x which seems OK but would like confirmation

[Simms]

I have a 4mm TMB Planetary and to be honest it's my least used EP, it's OK for planetary viewing, but not as vivid or sharp as my 6mm & 9mm - I have a SW200pds with a FL of 1000mm

[rwilkey]

Hi, I would say it is pushing it a bit for this country, to be on the safe side with my f/5 I use an 8mm Hyperion and then Barlow it down to 4mm and have had great results on planets - this way you have the best of both worlds and an eyepiece you'll use more often.

[Stargazer Jack]

Hi, I would say it is pushing it a bit for this country, to be on the safe side with my f/5 I use an 8mm Hyperion and then Barlow it down to 4mm and have had great results on planets - this way you have the best of both worlds and an eyepiece you'll use more often.

What Barlow do you use? Would it be worth changing from the SW standard to a better one?

[sulaco]

Hi,

I have the SW Explorer 130pm and found anything below 6mm didn't give great views, 6mm is great for planetary viewing

[rwilkey]

Hi, in my example I used the Skywatcher 2" ED Barlow from FLO. But I also have the Celestron Ultima which I haven't used in anger as yet, bought for my C100ED scope. I understand from this Forum that the Tal Barlow is very good and reasonably priced, the Ultima is an unabashed luxury.

[sulaco]

I bought the Revelation astro 2.5X and find it excellent both in build quality and viewing

[Cosmin]

Can somebody who owns a NexStar 6SE tell me please what is the maximum recommended magnification for planets? I just bought an 8mm TV Plossl (187.5x) but I haven't had the chance to try it yet because of the bad weather, but what about a 7.4mm TV Plossl (202.7x)? Under a dark, unpolluted sky and good seeing would this be too much?

Regards,

Cosmin

[Moonshane]

Can somebody who owns a NexStar 6SE tell me please what is the maximum recommended magnification for planets? I just bought an 8mm TV Plossl (187.5x) but I haven't had the chance to try it yet because of the bad weather, but what about a 7.4mm TV Plossl (202.7x)? Under a dark, unpolluted sky and good seeing would this be too much?

Regards,

Cosmin

unfortunately the answer to this is not a simple one and in my view is as follows:

the one that gives the best image (i.e. sharpest/most contrast and detail) allowable by the seeing and other conditions.

for any scope the maximum usable magnification is about 2x aperture in mm so in your case (and my smaller scope's case) 300x. But I often use higher than this on double stars (where you just want a clean split) and sometimes the moon but often the seeing restricts observing to 150x-225x on planets (where you are looking for fine detail). as always, the optical quality has an effect.

my modus operandi is to push the magnification with different eyepieces until the image breaks down then take a step back to the last one with a sharp image. even then this can vary within short periods of time.

[DaveGarland]

Thanks for your views. I think I will opt for a 6mm instead and see how I get on.