BRESSER MESSIER AR-90S/500

[AstroNebulee]

Hi

What are your thoughts on bresser messier ar-90/500 for a refractor, I've already got a celestron astromaster 130eq and looking for a good budget refractor. This would be for viewing the moon and planets as I can use my astromaster better for dso's I believe. 

 

 

Edited July 7, 2020 by LeeHore7

[John]

Hi,

I think your 130 Astromaster should do quite a lot better on the moon and planets than the 90mm F/5.5 refractor will.

The 90mm F/5.5 achromat refractor will produce quite a lot of chromatic aberration which limits its usefulness at high powers.

The 130mm Astromaster F/5 newtonian optics gather much more light, have better resolution and are apochromatic so do not have issues with chromatic aberration.

If you want a refractor that is good for the moon and planets you need to look at something around 102mm and with a focal length of around 1000mm so F/9.8 or F/10.

 

[johninderby]

Being a short focal length achro it is really for low power wide field use. Will be lots of CA (flalse colour) if yountry observing planets at higher magnification. The Bresser AR90/900 would be better suited for lunar / planetary observing.

A small mak would be far better though for lunar / planetary as it will have no CA unlike a low cost refractor and is very compact and portable. Something like the Skymax 102.

https://www.firstlightoptics.com/maksutov/skywatcher-skymax-102-ota.html

Or the Bresser 100 mak which being a bit longer focal length should be slightly better on lunar / planetary.

https://www.harrisontelescopes.co.uk/acatalog/bresser-messier-mc-100-1400-optical-tube-assembly.html?gclid=EAIaIQobChMIy-LrwYG66gIVlO7tCh1sQgarEAQYASABEgK9ZPD_BwE

Edited July 7, 2020 by johninderby

[AstroNebulee]

Hi guys

Thank you again for some wonderful advice, I will do some further research on the refractors, it's just I never seem to get views of Jupiter's bands (I know they'll only be faint) even using my astromaster, I used 20mm, 10mm and 7.5mm all barlowed x2 with and with a skyglow filter and blue tint filter which I know are very marmite.