need a new mount

[120ST]

I currently have the Orion AstroView EQ mount with a single drive motor.

I have the Orion 120ST and a 90mm Mak-Cass. I'm NOT looking at getting another scope, what I have does fine for my needs/wants, so the load I put on the mount wont be all that much.

I'm looking to do a little bit more astrophotography besides the moon. Noting intense or anything, just some of brighter DSO's and star clusters that don't require hours and hours of exposure time. I will be using my Canon 60D at prime focus.

Im not really wanting a goto mount, I had them in the past but not wanting that now. Just something sturdy with good tracking. Basically I would like to manually move the scope to where I want, then turn on tracking so it tracks what i point at with a fair amount of accuracy with a good polar alignment.

Would something like the Orion SkyView Pro do a good job for like 2 to 5 minute exposures? Or would I be better off going with something like the Orion Sirius EQ-G? Again, Im not looking to put a heavy load on the mount, no more than 16 lbs ( 8 kilo's)

I have spent the last 5 days researching and Im pretty much confused.

James

[wouterdhoye]

Hi,

The heavier the mount the better in general. For deep sky imaging the most important part is the mount. Especially if you don't inted to use any sort of guiding. This will limit your exposures to maybe even less than a minute. Though by stacking and registering several short exposures you can get good results too.

Now 8kg isn't that small a load. So I'd stick to the sirius EQ-G. Know that for imaging stability is imperative. Often people substantially overmount their telescopes. I used a Losmandy G11 to image with an FS60C (60mm f/6) Now that's a bit extreme but it sure worked :-)

kind regards,

Wouter.

[120ST]

thanks for the input. Now on to begging the wife to allow me yet ANOTHER expensive toy.

[ollypenrice]

If you want to do long exposures at anything like a telescopic focal length (and you don't want to spend many thousands) you have to guide.

You also have to forget the idea that weight is the dominant factor. The dominant factor is focal length. The longer it is the better the autoguiding has to be. On mounts costing around £1000 focal lengths of 500mm are easy, a metre isn't too hard to acheive and at two metres a degree of expertise bordering on genius is required. For me the EQ6 is interesting up to a metre. Folks go far beyond that but I like 'easy.'

Olly

http://ollypenrice.smugmug.com/Other/Best-of-Les-Granges/22435624_WLMPTM#!i=2277139556&k=FGgG233

[120ST]

those are some excellent shots Olly, thanks for sharing. to give you an idea, those shots of yours are well beyond what I am wanting/expecting to do. I will be doing shots around 500mm to 900mm, and have been looking at guiding. Im trying to keep the gear down to a minimum, so I was investigating one of those self contained auto guiders that does not need a laptop/PC to use. I haven't done much research on them yet. something like this.

http://www.celestron.com/astronomy/celestron-nexguide-autoguider.html

I have been trying to find out if I can control / operate an auto guider with my Android Tablet (Android Galaxy Tab 7.0) so I would not have to purchase a laptop to be able to set up and control the auto guider. But I cant seem to find any info on the web except for star mapping software for Android tablets.

[wouterdhoye]

Hi,

A stand alone guider might be an option. I'm not aware of tablet operated solutions though. Now if you are not too ambitious and have a well tracking mount and make short exposures say up to a minute it may be possible to do unguided imaging with a short focal length. Say up to 500mm. Much then depends on the accuracy of your polar alignment, and off course the accuracy of your mount. It's a good place to start. If it doesn't work ot that way you can still add the guider. Definately make sure you have a remote shutter release. the slightest camera shake would ruin the exposure from the start. If your camera has a mirror up function you can reduce vibrations even further.

Kind regards,

Wouter.

[ollypenrice]

I must admit that I greatly prefer PC based autoguiders over standalones. You have more control.

Olly

[alan potts]

Oh dear Olly,

I should have been a site member 18 months ago when I bought the Lacerta standalone autoguider, something else for the bin by the sounds of it. It may work ,I've never used it.

Alan