Alkaid

Hi everyone, Had the F5 102 out on Jupiter last night. Knowing that this would be a tough, perhaps futile test, popped in the Contrast Booster at x100. The planet had a nice tone to it which looked normal to me, fawns and browns etc. After some time and patience whilst the scope acclimatised and detail had to be teased out due to atmospheric dispersion blurring in and out, I picked out the GRS, plus a few other distinct zones. Not bad at all for a little F5 achromat with the planet so low down. I didn’t bother trying it without the filter, from previous experience the image would have been a mess under these conditions. Then to Saturn, very small but clear, with a few moons in the vicinity. Then our own Moon, the brown hue of the CB filter being immediately noticeable, but the image was good. As it was almost full moon I did not linger, just a quick look. Liking the CB filter in this scope... Cheers Steve

Phillip, I think the issue with a CAT is narrow FOV. For terrestrial you really do need a bit of wide field to open up the view I feel. Whilst a CAT can work well for looking at say a bird, it can take a while to find the bird whilst you’re panning around. I reckon the refractor would be a better match. Cheers Steve

You know, if it is predominantly over water as you say, an ED refractor would be better. You’ll be able to push the power a bit without any thermals ruining the image. Perhaps a little 72mm ED or 80mm ED model would be more suitable? Over water, my short focal ratio achromat starts to produce “poor” images at about x50. An ED version would go much higher if required. Don’t forget though that the wide field of view is also desirable and you get that with lower powers.

I use my 102 achromat frequently for terrestrial use. What I have found is that the best views are over water (no thermals). You can’t really push high powers for long range terrestrially due to the air currents coming off the land so the achromatic refractor at low power (x20) works quite well, with a wide field of view and is inexpensive.

If anyone suffers from Hayfever, I can attest that it has more than once killed off any early morning summer get ups for me. If I take a tablet, I'm considerably knocked out during the night and very groggy the next morning (even with the non-drowsy type!). If I don't take a tablet I'm groggy from the pollen! One of my favourite months is September, as then the pollen is gone and I can finally set an alarm and get up to do this. Keep writing your reports everyone, I really enjoy reading them to see what I've missed!

Nice! Looking forward to your Mars reports. I'm waiting for it too with my C8.

There’s also tracking base mounts for dobs, eliminates the constant nudging. One of those coupled with the 10” optics would be really good for lunar & planetary at high powers.

The best advice.....is just like this.....when you don't have to spend any more money!

Should deliver nice coma free views, the optics will be nice. I think that a lot of the cost went into the ‘light switch’ mount, where it does all the alignment for you. For that reason it’s aimed at beginners, or experienced visual observers who don’t want the hassle of setting up. However most experienced observers probably see the mount as a bit of a gimmick and don’t mind spending time on alignment set-up. They’d rather save some money instead. If it’s 2nd hand and a good price, it might serve well?

This is a pretty general statement, but on high contrast detailed observing, (think Moon's terminator & crater shadows, Saturns Rings) the central obstruction does not have much effect. However, on low contrast objects (separating reds and browns on Jupiter, albedo markings on Mars) then the effect of the obstruction really does take hold. There's a few old threads on this subject and I think that the general consensus was that if you subtract the diameter of the obstruction from the aperture, you end up with an equivalent scope without obstruction. For example, my 8" SCT is "very good" (to me!) on the Moon and allows me to see everything that that aperture should, seeing permitted. But if I then went for Jupiter and started trying to separate the reds and browns, my scope would behave more like this..... 8" aperture minus 2" obstruction = 6" refractor. It's an interesting subject.

That’s a pretty cool post, I like the pic of the scope and planets in the background.

Hi and welcome! Good news - you most certainly can see galaxies with that scope. You can see M31 (Andromeda Galaxy) quite easily, this was the first galaxy I had seen when I started out and was mesmerised. It will appear as a faint blob generally, but if you get out to a true dark sky site, it is very good. And...when you’re at the dark site, many other fainter galaxies are well within reach of your scope. The Virgo galaxy cluster is a cluster of riches. Have fun! (Half the fun is hunting them down).

I can see that with the star de-focused you’ve got nice collimating rings. What’s the pin pointy spot in the middle? (You normally don’t get that in a de-focused image). Cheers.

Ah, gotcha - apologies for misunderstanding. I must admit that I would like to try an Edge someday, but I would love to stretch to the 925 if I could. It's rather pricey though...

You’re describing the new ones, all Chinese. Unfortunately the history of the C8 is so varied that it can be rather hard to find out what era an older one came from. Before a certain year, they were made in the US, in all of the colours you mention.