Quote:
Originally Posted by Shiraz
been thinking along the same lines Russ, but could not work out how to manage dither - really need two instances of the capture software running in parallel and talking to each other, so that both know not to image when dither is active. Looked a bit beyond my pay grade.
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Thanks Ray, I hadn't thought about the dithering, perhaps it wouldn't matter too much if doing L and RGB at the same time but if you were doing NB on one scope then its not shifting for a lot of subs. I had envisaged using SGP for the L/OAG and perhaps BYEOS with the smaller scope, you can pause and set delays on exposures quite easily. there would of course be even more mismatch on exposure length if it was the f6 v f4 scopes.
I also did some accurate line and circle work in ms paint which showed serious overlap of the tubes with the losmandy dvsbs in my mind's eye I thought the curve would 'create' some more useable space but it doesn't do it enough not even for the 8". I would say it is probably only suitable for 2x 8" at the most... and that I would need the saddle (middle to middle) atleast 310mm wide for the 12" and 8" option.
* however a 127 mak-cass with a 0.8 focal reducer would fit but would be slow.
so unless there are wider saddle options out there i'll just have to wait longer and go for a HEQ5 or NEQ6.
Quote:
Originally Posted by gregbradley
I am running 2 mounts at the same time at present (well I did one night and then needed some spare parts to continue!).
For me its the CDK17 on a PME and the AP RHA on an AP1600. The AP scope is quite widefield, the same as Mike Sionios. The CDK can either image at 3 metres or about 2 with a reducer. I am currently using the reducer as it matches my local seeing better and reduces imaging time.
So a Proline 16803 on the CDK with reducer is the same image scale as an 8300 sensor on the AP. The CDK can give more luminance detail and the RHA colour and or narrowband quickly. Both are fast scopes. 2 scopes and cameras is about matching the image scale.
If you have a dual mount wouldn't you be autoguiding with only one of them with an OAG and if you use dither they both dither at the same time?
I think also with that weight I can pretty much guarantee you your subs will not land on the same pixels one after the other.
Peter Reito is using a dual scope setup. I think he's spent a lot of time (and ongoing) resolving issues with this.
Obvious problems would be balance, alignment so they image the same thing and weight for the mount.
Thomas Davis images with 2 scopes, an FSQ and AP RHA. Not sure if its on 2 separate mounts or at the same time. He uses an STL11 colour for the FSQ and an STL11 mono on the RHA as I recall.
I used 2 different mounts as sometimes these setups will be in different locations but I built my observatory intending to have 2 setups at the same time so there is provision for a 2nd one. A 2nd one is a lot easier.
It was fun running 2 setups with 2 computers and setting up one and then adjusting the other whilst the other was doing something. I think it would end up being a whole lot easier than the flexure, mounting, aligning issues of scopes in tandem. Perhaps a smaller refractor on top would work. I have used an FSQ mounted on top of an FS152. One guider.
Too much weight and you will have tracking issues.
2 separate mounted systems can be framing the same image. You may need to allow for a small amount of cropping if they are not exactly the same. Perhaps it would be better if one was just slightly wider FV to give some tolerance.
Greg.
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thanks for taking the time for commenting Greg, i'm a big fan of your setups and its interesting to hear what others do too. I wasn't too concerned with weight (maybe if I went the 10") but yes balance will be BIG issue and some overlap is probably a good idea. I might just throw a refractor on top for now, I was thinking of giving the side by side a go till I could afford an additional mount (and guiding solution) but now that I've measured the narrowness of the saddle its not looking worth it/possible. the idea was for me to go one of those cooled mono dslr's and regular cooled dslr so sensor size was the same.