A Little advice, please

[Emperor315]

Hi All

As some will be aware I recently got my first telescope. SW Evostar 90!

In some ways I am blown away and in others I'm a little disappointed. My main disappointment lies with the lack of detail on planets. I have managed to view Mars, Venus, Saturn and Jupiter. All of which, while amazing to see, lack detail. I can make out the phase or Venus very clearly though.

What i'd like to know is this; what is preventing me from getting the detail I desire?

Here are the specifics (taken from The Widescreen Centre):

Magnifications (with eyepieces supplied): x36 & x90

Highest Practical Power (Potential): x180

Objective Lens Diameter: 90mm

Telescope Focal Length: 900mm (f/10)

Eyepieces Supplied (1.25"): 10mm & 25mm (branded as 'Super')

x2 Barlow Lens

From reading this I think I can double the power of my scope with an eyepice. Is this correct? If so, would you have any recommendations for a good, but fairly affordable, eyepiece? i have read through the sticky on eyepieces which has been really useful but I think I need a more tailored response.

Thanks for your continued support and advice, this really is a fantastic community!

[Polar Bear]

Hi Emperor

your Evostar 90 has a focal length of 900mm. Using your 10mm EP will give you 90x magnification (900 / 10 = 90 ) and using the 2 x Barlow with it will double the magnification to 180x (90x (x) 2)

This is about the maximum usable limit of magnification for your scope.

The lack of detail could be down to the viewing conditions and the general 'poor' quality EP's that are generally supplied with starter scopes.

If after viewing over several nights the quality of your views does not improve you may consider an upgrade to better quality 10mm Eyepiece and 2x Barlow lens.

Have a look at the sponsors page (First Light Optics) and you should find these for about £35.00 each (the Tal 2x Barlow gets good reviews as does the Celestron Omni Plossl ) although I am sure others will be suggested by members.

Just remember to keep your expectations reasonable as to what can achieved with your scope.

Paul

[Emperor315]

Cheers Polar Bear! Much apprciated

I'm trying to keep my expectations reasonable. I was looking to see if it was worthwhile upgrading the eyepieces or if I am already getting the max out of my scope. But you have answered that for me. I think over the next couple of months I'll pick up some better quality eyepieces and take it from there.

[ronin]

I guess that you will need to consider upgrading your eyepieces.

If your supplied eye pieces follow form the 10mm will not be great and the barlow not great also.

Jupiter is getting low now and you may well not get a clear view, Venus is pretty indistinct anyway - cloud covered so no detail and usually not sharp. Mars needs lots of magnification and good conditions, more then your scope.

That leaves Saturn. Try to get about 120x for Saturn, 150x would be better but not sure how well the scope will handle 150x - sort of on the limits I suspect.

To get 120x means 7.5mm eyepiece, 150x means a 6mm eyepiece.

What make/brands fit: Could try Vixen NPL at 6mm and 8mm, being plossl's the eye relief may be small. TMB Designed planetary's at 6mm, 7mm, 8mm, 9mm Pick whatever.

Stick a post up asking if anyone has used these on the same scope and how they performed.

[Emperor315]

Thank alot, Ronin. I am pleased that the main issue here seems to be the quality of the eyepieces (and perhaps my expectations!) as opposed the a capabilities of the telescope.