A few questions

[John.Osborn]

I have a few questions to ask
1- When I tried to view pictures in buy and sell I just get a black screen, what software do I need
2- Which is better for planetary viewing 6” refractor or 8” cas:shrug:

[Larryp]

I would go with the 6" refractor. For planetary observing, you want all the contrast you can get, and that's the refractor's advantage.

[Geoff45]

Assuming they both have excellent optics, the refractor will rule.
Geoff

[barx1963]

I am not aware you need special software to view pics. Are you able to view pics in the images section? One possibility is anti virus software not liking jpgs.

With refractors and planets quality is important. Cheap refractors will still have aberrations and colour fringes that look horrible with bright objects like planets, but a good quality refractor will give lovely images.

Malcolm

[MattT]

I use my 6" f8 achro for planets and can say it's fantastic. For the moon and Jupiter I use the Baader semi-apo filter and it removes the violet fringing brilliantly. Never use the filter on anything else. The image is really close to what I see in my 4" ED f9 refractor but brighter. I have never looked through an 8" Cas so can't comment on that part. Add bino's and :eyepop: Of course a 6" refractor is a large heavy thing.
Matt

[Stardrifter_WA]

Hi John,

I sometimes have problems viewing pages, which appears to be a Java/HTML problem. If you have a black screen try left click and click "inspect elements". This may fix the problem. If this fixed it, then download a Java update and uninstall older Java versions.

As for a 6" refractor or 8" reflector, it will depend on how much you want to invest into the instrument.

Per inch of aperture, a refractor is considerably more expensive than a reflector (per inch of aperture). A good 6" triplet Apochromat refractor can cost in excess of $6,000 new. A 6" achromat refractor, on the other hand, is considerably less, however, they can suffer from chromatic aberration (CA). To overcome this CA costs heaps.

In addition to the cost of the refractor you will need a substantial mount.

An 8" Dobsonian can cost as little as little as $500 new (from Bintel) through to to several thousand for a good scope and mount.

It really comes down to how much you want to spend and what you want to do with it.

Cheers Peter