Proposed imaging rigs.

[DaveS]

OK, at present my main rig is an ASA DDM60 Pro (With USB hub and cable management) carrying a TS Photoline 130 f/7 and a piggyback TS Imagingstar 80mm f/4.4. I also have an old HEQ5 with Megrez 90 and ST80 guider.

Incoming I have an ODK12 which will go on the ASA DDM85 Basic (Basic ASA mount. Yeah, right) I already have here and carry a Moravian G3 16200, and a set of LRGBSHO filters. This will bin 1x1 for L and 2x2 for RGB. Not sure about NB yet.

Now, my plans are to keep the DDM85 / ODK12 / 16200 as a constant system, not changing anything, while the 130mm will take a range of equipment, either a straight flattener or an APM Riccardi 0.75 reducer. The camera will usually be a SX Trius 694, but could be an ASI1600, or an OSC (071? 294?) for galaxies, for fun. The 80mm will keep an ASI 183 (Which is a good match for resolution) but may vary the filters between HaLRGB or an assortment of NB. The Megrez 90 will usually have the ASI 1600 and a Hotech flattener, though I do have a TS 0.79x reducer available.

How do people think this plan stacks up? Especially @ollypenrice @kirkster501 and @gorann who all have experience with big reflectors and apo 'fracs.

[ollypenrice]

First question would concern your seeing. What will it support and how often will it support it? At high resolution expect it to be very variable indeed. It certainly is where I live and that's at 3000 feet. This variability makes mono a no-brainer: shoot RGB on nights of bad seeing and luminance on good stable nights.

Then there's the question of changing kit around. I'm absolutely allergic to doing so since I worship at the shrine of, 'If it ain't broke...' Some people love tinkering. There's no right answer, just personal preference.

On the 130 I'd use the reducer to open up the FOV but for no other reason. I would expect to use this instrument more often than your others but this is based on nothing more than a hunch.

May I cheat and say, in closing, what I would really put in the back of your ODK? An Atik 11000. Read the numbers and they are terrible. Take the pictures and they have a certain charm which grows on you because the data is just - nice. Processing involves no fighting.

Olly

[DaveS]

Thanks Olly.

TBH I've not really tried to quantify my seeing beyond "that looks pretty sharp" or "those stars look bloated". Something to do. I don't have much in the way of built up areas around me, and to the south nothing.

The main reason for sticking to the 16200 was the size, the ODK12 will still be well within diffraction limited at the corners, while the 11000 might push it a bit, also pretty well no vignetting through the train at that size while the 11000 will start to vignette. And I can't afford either a 16803 (Let alone an FLI Kepler 4040) or the 50mm sq filters. Even Baader are getting pricey, and as for Astrodon .

At bin1 the ODK / 16200 gives a slightly questionable 0.61"pp, while at bin2 it gives a much more reasonable 1.21"

Thinking about the 130, the main reason for "fiddling" is to have a versatile imaging system, at native fl and the 694 the FoV is very similar to the ODK / 16200, while I can go wider with swapping in the reducer, or other cameras. It would, though be set up for a sustained run, rather than chopping and changing on a nightly basis.

Going to do some more playing with the FoV calculator in Astronomy Tools.

[ollypenrice]

9 hours ago, DaveS said:

Thanks Olly.

 

At bin1 the ODK / 16200 gives a slightly questionable 0.61"pp, while at bin2 it gives a much more reasonable 1.21"

 

I bet that will prove to be your most productive option. It should give great results.

Olly

[DaveS]

Thanks Olly, I think you're right. It will be interesting to see just what I get, and how often the seeing will really allow anything like 0.61"pp. Having said that I'm sufficiently barking (Or even Dagenham ie beyond Barking) to put the 694 on the ODK and image at 0.4".

[alan potts]

Stunning images Olly, just stunning, give me something to aim to get half as good, can't even work the 071 and don't wish to spend Atik 11000 money even though I could.

Alan

[DaveS]

Yes, stunning images, and showing just what the old 1100 can do.

A pity I haven't been able to get the big rig up and running before starting work on Deer Lick and Stephan's Quintet with the 130 as the ODK1 and 16200 would have been ideal, while I could have been imaging M33 with the 130. Never mind, M33 looks to sit nicely on the 16200 with the ODK12.

[Laurin Dave]

If you have it already why not put the 16200 on your 130 whilst you wait for the ODK ? Got on one my Esprit 150 and it works well with decent resolution at 1.2"pp and double the fov of the ASI1600 and no artefacts on bright stars.

Dave

[DaveS]

Unfortunately I don't have it yet, because I wasn't in a tearing hurry, and was waiting on getting more funds, which I now have. I think there's a bit of a lead time on Moravian cameras, as I will be having a filter wheel attached.