dweller25

OK - forget about the 8” Newt then as they need more space 👍 it’s a tough call between a C8 , CC8 and Mak180. The SCT will be best on DSO’s as it has a true 8” aperture but contrast is not great, the Mak seems to gets consistently good reports for sharpness and contrast but it’s only 7”, the CC8 has been around for a couple of years now and has had variable reviews. Good luck with your decision……

That’s exactly what I do too John…. Heated room to unheated conservatory for a couple of hours then outside. The conservatory is around 5’C higher than outside so I find I still have to use active cooling. I am going to try putting the scope in the garage for a couple of hours late afternoon to see if that helps…..

I have to store my scopes in my home, so they will always be warmer than outside temperatures, thus the CC I had still took a good 30 minutes to cool with a cooling fan blowing onto the primary. Where do you store your CC8 John ?

Hello @Marian M and welcome to SGL 🙂 Mak 180, C8 or CC8……. Hmmmmm I would get the Mak180 and wrap it with a couple of layers of reflectix to reduce the thermal gradients inside the OTA. They have good contrast. But, the C8 has slightly higher resolution, slightly better light gathering and is lighter too. The C6, C8 and C9.25 I owned in the past did not have great contrast. For visual you do not need the Edge version. The CC8 is heavy and cannot be wrapped so you will have to wait for it to cool and it may have tube currents as it’s open fronted. My GSO CC was not operating at full aperture, I believe due to the secondary being too small - by design - to keep contrast good. In my opinion it is the most compromised design of all these three designs. I suspect a much cheaper 8” F/6 Newtonian will be just as good as any of the above scopes.

It sounds like the little grub screw may have come loose on one or more of the cogs that mesh together. It’s a fairly easy job to slide them down the axle so they mesh correctly and then tighten the securing grub screw with an Allen key.

Stellarium is a very good free night sky simulator.

Hello @andyrawlins I have the same green Vixen GP which I use for visual only. I keep the scope weight down to around 6.5kg maximum for best results and use a counterweight big enough to allow good balance close to the EQ head rather than at the far end which can set up vibrations. I also had the same tripod as you but found it not stable enough so changed to a Berlebach UNI. 10kg of kit is possibly a bit too much for imaging. It s a very good mount used within it’s capabilities. Perhaps you can look for a bigger Vixen GPDX - that will take 10kgs and you can use your existing Starbook. Or consider a lighter more compact scope - I use a Mewlon 180 on mine and it is very stable at x400. Hope that helps.

You get some great deals buying second hand - most astronomers look after their kit so it can be a good option. I would not stress too much about immaculate optics as all scopes become less than perfect eventually. Newtonians can be easily cleaned and recollimated, SCT’s need accurate reassembly and collimation after cleaning. Refractors don’t need disassembly for cleaning so no need for recollimation. Remember that the bigger the scope the more thermal management will be needed and they will be more affected by seeing conditions. Apologies if you know all this 🙂 You have a good budget 👍 PS - I know it’s not an SCT but this 6” ED refractor is in stock 😈…… https://www.firstlightoptics.com/pro-series/sky-watcher-150ed-ds-pro-eq6-r-pro.html

Awesome - as usual 🙂

I have tested a Baader BBHS prism and BBHS Mirror in an F/8 refractor, the prism had a slight edge in contrast to my eyes, possibly because it was slightly dimmer.

the answer is simple.

You should be able to just fit two layers without removing the dovetail. I found it essential to also cover as much of the rear as possible.

😂

Are you concerned about them wearing out ? My FS128 is 23 years old and the rack and pinnion are fine.

Yes 👍

It’s a nice scope @Fedele and hard to replace as not many were made. Would suggest around €2250 (£1900) as long as it has all the original Takahashi accessories and is in mint condition.

Thoughts but not personal experience re the 90mm Mak……. I would buy a 130mm table top Dobsonian as it will cool quicker and has more resolution.

@Stu Does the AZ100 have the multibase location nuts like the AZ75 ? I have a UNI28 but with a Vixen GP/EQ5 fitting. If not it would be a great if it could be changed…….

Thought I was on CN for a minute 😂

Wow, excellent job, it looks great, well done 👍

Well, theres no harm in asking whilst it’s in development….. Apples and pears go well together 🙂 Sadly the AZ100 is too heavy for me 🙁

Not quite John - it would be nice to have the choice of slo-mo control on the lighter mount 👍

I have been waiting for a lightweight, quality alt-az mount for some time BUT in my opinion it needs SLO-MO controls for smooth high power observations - PLEASE 🙂

Finally - a lightish high quality alt-az mount. I am very, very interested in this mount. Look forward to seeing how much it weighs….. BUT - In my opinion it needs slo-mo controls to make it ideal.

Best view for me was at twilight, managed to see the darker North and South polar regions and the North and South equatorial belts. The GRS was on show but it was very subtle and Io’s transit shadow could just be seen. Seeing got gradually worse and clouds stopped play at 20:15. 🤷🏻