Skywatcher planetary eyepiece

[Rob Atkins]

Hi all

I have a Celestron SkyProdigy 130, and I want to get as good a view of the planets as I can, but I don't want to spend a fortune.  I've looked at the Skywatcher Planetary Eyepieces at FLO (2.5 mm, 4mm, 5mm).  Are they any good ?  In particular, would the 2.55 mm be OK with my telescope which has a 650mm focal length ?  If not, any others I should consider ?   Grateful for any advice.

Rob

[wookie1965]

They recommend 50x per inch of aperture is the maximum magnification so if im right your 5 inch scope will magnify 250x the eyepiece which will do this is 2.5mmwhich would give you 260x.That would only used very rarely as seeing conditions would have to be brilliant you better off with a 8mm or max a 5 mm for Planets and the moon, the BST starguiders get good reviews on here at £49 each they are reasonable also Celestron X-Cel are good as well they are a bit dearer about £65. 

[ronin]

I assume that the scope is a parabolic.

It is f/5 and Celestron used to advertise that all their reflectors were parabolic. Still wish they specifically said it. I think they now just presume you know of this.

A 5mm should work and a 4mm should be OK, a 2.5 I would say is pointless.

The eyepieces look like the 58 degree ones produced by Barsta, Skywatcher have others in the Barsta offerings, so that makes a little sense. Barsta seem to be producing reasonable/good eyepieces. So promising.

The focal lengths are I suspect a selection for the full range and the full range matches close to the TMP Planetary's that are offered. I also think that the TMB's are classed as 58 degree eyepieces.

Cannot locate any detailed specification for the eyepieces, but it would be fair to assume they are the same design in a slightly different lump of metal.

I am going to assume that these are a slight remodelling of the TMB eyepieces, the remodelling being the main housing. The optics being the same.

The 5mm would give 130x, that is enough to show Jupiter and should show Saturn and the rings. Seeing the rings depends as much on contrast and sharpness as it does on magnification.

The 4mm would give 162x, again enough for both planets.

If you are thinking of Mars I suggest a lot bigger scope and eyepieces.

I have the BST's and 2 TMP's, actually have a 4mm TMB and to be honest it is a lot less comfortable to use then the BST's. The BST's I can place my eye up to it and see easily, I never seem to find the right location with the TMB's.

[dannybgoode]

I am just starting out in the EP collecting phase of the hobby and have invested in a good 7.5mm and will use a 2x Barlow to achieve the shorter FL's required for very high magnification.

My thinking being I will be using the 7.5mm far more than the very high mag FL so would rather invest a good amount in this EP than split my spending between 2 or more EP's some of which will only get best use in the odd occasion when seeing is at its best.

[Rob Atkins]

Thanks guys for your good

advice.  I won't go for the 2.5 mm but I'll continue to mull over whether I should pay a bit more.

[ronin]

Is there a club you could get to. People may have eyepieces for you to try out on an observing evening.

[Rob Atkins]

Hi Ronin - that's a helpful suggestion but I'm not a clubby sort of person really.  Probably not the wisest course, but I prefer it to be just me and the stars ...     I did wonder about turning up to one of the talks in Cambridge observing sessions some time, just to experience it, but haven't followed it up. Thanks for the suggestion.