Gidday

[techoz (Steve)]

Hi, thought I would say hello to all and get to know some of the locals. I have been into astronomy quite a while, started with a crappy Tasco reflector about 30 years ago. Actually got some Halley's comet shots with that (using a piggy-back Nikon FA). I also managed to build a CCD camera, maybe you have heard of the CCD Camera Cookbook. Never did much with it, was very time consuming to set up and is primitive compared with what's available today. Currently have a Vixen 150mm reflector that I am looking to upgrade from, maybe to a Nexstar 5SE is my current thinking. I want to provide a pathway to more astrophotography and I think this looks ok.
Anyway, looking forward to hearing from you guys and maybe to help with my selling/buying!

[billdan (Bill)]

Gooday Steve,
Welcome to Ice in Space, sounds like you have had some fun with astronomy over the years.

Regarding the Nexstar 5se, this scope is on an Alt/Az mount and therefore will limit your imaging time. Bright objects that require short exposure times will be OK, but anything over 30 secs will cause you grief with star trailing and field rotation. These issues can be overcome by throwing more money into the mix but why bother.

Do you have a tracking equatorial mount for the Vixen 150mm, an EQ mount is much better for long exposure imaging and the 150mm Vixen will produce good images.

Cheers
Bill

[Allan_L (Allan)]

Hi Steve,
and hi Bill.

I don't know much about astrophotography, or the aptitude of the 5SE OTA for this use. I believe it is F10, Schmidt Cassegrain, if that makes any difference?
Am I correct in saying it is OK for planetary photography, but not so much for DSO's?
(I remember Paul H used to do some amazing planetary imaging with his old F10 C9.25 - albeit on a dedicated EQ mount)

But I do know a little about the little brother, the 4SE, and last I heard, the 4SE and 5SE were supplied on the same Tripod.
And that tripod has a "Built In" Wedge.
This would actually allow your 5SE to be used in Equatorial mode, as I understand it.
And so, the mount allows for equatorial tracking in Sidereal Mode.

A shortcoming may be the fact that the mount, while computerised, is only a single arm mount. This may make it a little unsteady, especially in windy conditions?

As I said, I am unsure how good it would be for photography, I don't remember hearing too many people singing its praises for this purpose.

found on a cloudy nights discussion thread:

The first problem inherent in all the SE mounts is the use of spur gears which produces a lot of backlash. The slop in the gears makes it impossible for the mount to do the precise tracking needed for long exposures.

The second problem is that while the mount has a wedge, there are no fine adjustments to let you accurately polar align it. Adjusting the altitude of the wedge is done by just tilting the mount by hand and tightening a screw agains the riser bar. Adjusting the azimuth of the wedge is even worse since the only way to do it is to pick the entire tripod up and turn it.

[billdan (Bill)]

Hi Allan,

Was not aware of the built in wedge of the SE series, sounds like that will eliminate field rotation. However that extract from Cloudy Nights does not give you any confidence.

As far as the wind is concerned, most of us give up when the wind starts gusting, the scope only has to move a dozen microns and you end up with double stars everywhere. Well my 8in F5 is a weather vane anyway.

The reason why SCT's are said to be not so good for DSO's is mainly due to the long focal length. A lot of the larger DSO's will not fit into the small FOV, Galaxies will be OK though.
The 1250mm focal length of the 5SE is not too long and would be OK for DSO's

Cheers
Bill

[techoz (Steve)]

Hi, thanks Bill & Alan for your comments.

I am happy with the Vixen as far as stability & optics are concerned but I thought I could update to a scope with similar features but which was easier to set up and lighter in weight. I was going for the 5SE as it does have the built-in wedge while the 6SE it is an add-on (about $600 I think). I have seen a DIY wedge which would be cheaper and maybe possible to build in the fine adjustments that the Celestron wedge doesn't have.
But now I am put off a bit by "the slop in the gears". Maybe I need to look at spending a bit more to get something decent.

Steve

[billdan (Bill)]

Steve, if you're keen on the 5SE why not try the search engines within Cloudy Nights or Stargazers Lounge Forums. See if you can find some sort of consensus about the scope regarding imaging.

Cheers
Bill