I might be crazy - new scope: a mak newt!

[toc (Tim)]

We'll...haven't been stargazing for a few months, but I took stock and decided to replace my c8 and 90mm refractor - with a 7.5 inch skywatcher mak Newtonian.

Heads up, I will be putting a c8 and a mergez 90, with field flattener on the forsale board soon!

[Shiraz (Ray)]

nothing crazy about that Tim - really good choice I think.

[Astroman (Andrew Wall)]

I agree, Mak-Newts are nice scopes, wish I could afford one. Look forward to your results.

[brian nordstrom (As avatar)]

Tim , have always had a thing for these Mak/Newts ever since they come out years ago and have always got great reviews , refractor like sharpness and views , good choice and I hope we get a first light report .
Brian.

[LightningNZ (Cam)]

A great choice I think. If there's a scope that could lay claim to being a good "general purpose" scope it may be the Mak-Newt. I've always been pretty tempted by them.

Hope it works out well,
Cam

[Ken]

Great choice I have a Orion version for many years, for imaging it is a bargain with its flat field and pinpoint stars with no coma corrector in sight
Clear skies Ken.

[toc (Tim)]

So far it's just sitting in the corner - it's been crummy weather in Melbourne. I'm also waiting for a laser collimator, although I suspect it's pretty close.

My only concern is how I'm going to rotate it in the tube rings, because it's not à lightweight, and it tends to slip when I loosen it. The cgem seems well able to carry it though.

[LightningNZ (Cam)]

Do you mean it slips out of the rings and potentially onto the ground or when stopped the focuser banging into the rings?

If so just place another ring with a smooth edge around the scope and don't attach it to anything else. I think they are referred to as Wilcox rings after Eric Wilcox who has popularised them. A very simple idea and very effective. The contact with the main rings also acts as a useful brake to keep the rotation smooth.

Cheers,
Cam

[toc (Tim)]

No, it's not going to slip out of the rings, but it will slide downward as I turn it. It's not a problem for AP - (I won't even bother to rotate it) but for visual, I can see some frustrations as I accidentally move the mount out of alignment.

I guess I could attach a second ring on the ota to stop that.

[toc (Tim)]

Had some time under the stars last night with the scope - I can't really make a fair comment on the optical performance - I've got no way to collimate it at the moment, since I'm still waiting for Bintel to send me a laser Collimator which I ordered last monday.

A star test showed that it is actually pretty close, and will only require some minor tweaks I hope.

I really should have just spend the evening looking at globular clusters, but I wanted to see how it would go with guiding on the CGEM - I had really good results a few weeks ago with my little refractor, and I been going on a software spending spree with BackyardEOS, Nebulosity, and SkySafari pro (I have a skyfi and an ipad)

After some rookie mistakes with balancing the OTA (a quick visit to 'the astronomy shed' youtube channel fixed that) and some cabling mishaps I finally did some runs with my 7D - terrible results Not sure what I was doing - PHD showed that it was locked on for the whole time, but every frame had stars in odd zig-zag patterns - not drift, but possibly tube vibrations, or wind? Anyway, the 7D ran out of batteries, so I switched to my Nikon D600 and got much better results with a cable release, so Im not sure what happened.

The other issue was my Orion 'All-in-one' 'video finder' that I purchased from Bintel. Have to say this is a real bummer - not so much the camera itself, but the crummy software 'astro-cap'. Around 50% of the time it just crashed - the other 50% was me frustratingly trying to get an exposure that worked. I tried using 'sharpcap' but it didn't work at all with the Orion. I tested this thing during the day, and it all seemed to work reasonably well, but under the stars it was a different story. I might just use a telrad from now one

I got the camera as more of a one shot planetary cam so Im not really that upset, but for once it would be nice to find something that actually works

Looks like it could be fine tonight, so I might have another crack with the 7D. I'm using a little 50mm finder guider, so perhaps my PHD settings need changing.

[Kunama]

Originally Posted by toc

So far it's just sitting in the corner - it's been crummy weather in Melbourne. I'm also waiting for a laser collimator, although I suspect it's pretty close.

My only concern is how I'm going to rotate it in the tube rings, because it's not à lightweight, and it tends to slip when I loosen it. The cgem seems well able to carry it though.

To stop it sliding downhill get a third tube ring glue some felt to one edge and clamp that ring above the ring nearest the finder so that the felt is between the 2 rings, then you can loosen your tube rings and rotate the tube without any worry about it sliding out of balance.