Wide Field Mounting for Atik 314L+ with Camera Lens

[Chris]

Yet again Gina you don't hang about:D one thing that is good about the H-design is that it enables you to balance your scopes if one scope is heavier than the other, looking at what your doing with the ali plate would it be an idea to have the main dovetail 90 degrees for this purpose? just an idea also as an ex mechanical engineer:D

[Chris]

then again if you have the scopes very close together then scope balancing might not even be an issue?

[Gina]

Scopes in rings and set up on plate in turn resting on dovetail. Seems to fit together pretty well. The ST80 rings fit between the ED80 rings. The ED80 rings could be placed a bit further apart - they're currently attached to the plate through the original WF camera mounting holes.

I'm planning to mount the finder/widefield DSLR and lens under the dovetail at the front.

[Gina]

'Tis done

[Chris]

Awesome!

[Gina]

Thank you Have to say, it went well and I'm pleased. Just hope it fits alright on the mount and in the obsy - think it should be alright

[Gina]

To increase rigidity between main and guide scopes I could add straps/stays betewwn the camera mountings of the two pairs of scope rings or buy a thicker ali plate. The rings for the widefield Atik system can go on either scope rings. For long lenses the wider spacing would give better rigidity. I have yet to work out how to attach a motorised focuser. Maybe a plate attached to the rings.

[Chris]

Well Gina as its already on a plate I would go for option one: use the camera mountings on top of the rings to add extra supports.

[Gina]

Well Gina as its already on a plate I would go for option one: use the camera mountings on top of the rings to add extra supports.

Absolutely I think this will make for a very rigid structure.

[ianaiken]

Gina that's brilliant. How are you going to get the OTA's to line up in this design?

Secondly, slightly off topic. For the 80 ED when used with the SW 0.85x what adapters do you use with the 314L+ and the EFW2 to get the required spacing? My EFW2 and Atik fell off the other day so I think I need to get some better quality extensions/adapters. Also what spacing did you end up with?

You've also inspired me to look at my side by side. I think I can get my OTAs about 5 inches closer together on my bar so going to look at this during the week.

[Gina]

Gina that's brilliant.

Thank you

How are you going to get the OTA's to line up in this design?

They don't need to line up, as long as the guide system can find a star - and I've had no problem so far, usually a choice of several

Secondly, slightly off topic. For the 80 ED when used with the SW 0.85x what adapters do you use with the 314L+ and the EFW2 to get the required spacing? My EFW2 and Atik fell off the other day so I think I need to get some better quality extensions/adapters. Also what spacing did you end up with?

Female M48 to Male T2 Adaptor from Teleskop Service and the Atik T2 to M54 adapter for the EFW2 from FLO. I think that all adds up to the same as the EOS DSLR plus EOS adapter for the FR/FF but I need to check again.

You've also inspired me to look at my side by side. I think I can get my OTAs about 5 inches closer together on my bar so going to look at this during the week.

Good idea

[ianaiken]

Thanks Gina. I think the distance is 55mm so I would be interested to know if this is what you get. On the alignment I got mixed up with Carole who is dual imaging I see now that your guiding with one and imaging with the other (plus imaging with dSLR).

[Gina]

Just measured the spacing and from surface of FR/FF to camera surface is 30mm. Camera offset surface to sensor is quoted as 13.5mm by Atik making 43.5mm so it looks like I need a T2 extension of 55 - 43.5 = 11.5mm if the spacing required is 55mm. I'll need to check that 55mm figure.

[Gina]

TS do various lengths of T2 extension tube :- http://www.teleskop-express.de/shop/index.php/cat/c124_Adapter-----Extension-Tubes.html

[Gina]

We now return to the actual topic of the thread - mounting the wide-field Atik setup with SMC Takumar lens. The balance axes are still within the dovetail side to side and between 2" from the end and 2" from the back of the DSLR cooler - I'm happy with that

Here are some photos of the wide-field mounting - back on top of the ST80 guide scope but no longer heading for the skies like a skyscraper

[Gina]

Rig dismantled (not the bolts, just the scopes and Atik rig) and set up on the mount. Balance is fine. CdC and EQMOD all set up and alignment set up on the moon in the Live View DSLR finder. Now to get Artemis and the 314L+ working.

Guess what???? The sky is CLEAR all the stars are out though so is the moon. At least the moon makes a great alignment object. Once I get things working I can always do NB

[ianaiken]

Gina,

Looking good! I hope you make use of this tiny slot of clear sky you have right now! I've not seen the moon now for quite some time.

[Gina]

Thank you

It took me a while to get set up but I homed in to old faithful (M42). The moon was too bright for LRGB so I changed to Ha. First conclusion was that the focus needed changing appreciably to change from L to Ha with the SMC Takumar 200mm lens which was not the case on the ED80. So unlike the ED80, I couldn't set the focus and leave it. This meant that the second ring & bolts holding the front of the lens couldn't be used as that part moves in and out when you focus. Having removed the 2nd ring and adjuster bolts the pointing direction changed too much to keep the object still in the frame so I spent some time lining it up again. Finally I got M42 nicely in the frame and I popped off several subs of 30s which showed the core nicely. I then went to 60s but tracking alone was not sufficient so I started up guiding calibration in PHD. That went well for a couple of minutes and then the computer froze up and I had to do a cold reboot. By the time I got it all going again the clouds came back so that was that.

So, while the SMC Takumar telephoto lens is superior to other makes, it still shows considerable CA for AP so electrical focussing with computer control would seem to be highly desirable. Manual focus is alright for Ha but colour will need something doing about the focussing.

[Gina]

In the end I got 4 subs at 30s without guiding and 10 subs at 60s with guiding. Here they are stacked in DSS and processed in PS (Levels and Curves). These are uncropped to show the coverage with the 314L+ and 200mm telephoto lens. I was hoping to get 10 or 20 minute subs but the clouds had other ideas.

[Gina]

I've worked out how I shall drive the focus sleeve on the SMC Takumar 200mm lens. I plan to attach an aluminium plate across the four camera mounting points on the scope rings. That will not only stiffen up the guide coupling but provide a platform to mount a guide scope ring next to the filter wheel, a support for the lens hood and electric motor/gearbox driving the focus sleeve with timing belt and pulley.

Here's a rough drawing (needs a bit of imagination to fill in the missing parts ). I have shown two copies of my Atik kit - no I haven't bought another 314L+ and EFW2

Here's the SketchUp file, zipped for attaching here :- Telescopes_&_Cameras_02.zip

[Astrokev]

Your rig looks good GIna. Sometimes I wonder whether your interest in designing and making kit is the "end", with the imaging being the "means" , if you get my drift, rather than the other way round!

[Gina]

Your rig looks good GIna. Sometimes I wonder whether your interest in designing and making kit is the "end", with the imaging being the "means" , if you get my drift, rather than the other way round!

Thank you I agree that I do get a lot of satisfaction out of designing and making kit but the "end" is how well it works Actually, it's just as well that I do enjoy the production part - we don't get a lot of the "using" part, that's for sure I do get a lot of enjoyment from my imaging time sitting in my warm room - nice to get out of the house sometimes Often things can be frustrating with equipment trouble and the cloud coming over just as every thing is just set up and working properly. I also enjoy developing the images in Photoshop - gredually tweaking the curves and colours to bring out the detail. Yes, I guess you could say the actual process of capturing the images is quite boring - you set it up and let it run - but seeing the individual subs as they are captured is interesting and rewarding if good. I do go off and do other things once I've got everything set up and running well.

[Herbig]

I'm no expert but I think with the configuration you suggest would make balance difficult. If you have your dovetail that connects to the mount at right angles to the ones for the scopes or better still clamp saddles instead balance is easier to achieve. I see you live in East Devon, have you been over to the NLO? One of our members makes custom duel mounting bars at a reasonable cost. Most of the imagers there use them, they are very solid a rigid.

[Herbig]

Sorry ignore last post, first bit anyway. Only read the the first page of posts LOL!

[Gina]

I'm no expert but I think with the configuration you suggest would make balance difficult. If you have your dovetail that connects to the mount at right angles to the ones for the scopes or better still clamp saddles instead balance is easier to achieve.

I have tested balance and I can get balance with all the equipment variations I use by moving the dovetail on the mount. Sideways balance can be finely adjusted by turning the filter wheel though it's never far out.

I see you live in East Devon, have you been over to the NLO? One of our members makes custom duel mounting bars at a reasonable cost. Most of the imagers there use them, they are very solid a rigid.

Yes, I have been to the NLO but not recently. I expect to go again when the weather's better.