My Astrodon MMOAG has been a very workable guiding solution but its quite thick so sometimes it won't fit in the available backfocus. For example when using a reducer.
There are a few thin OAGs out there mostly Teleskop Services. Anyone used one of their OAGs? I am thinking of the larger one.
Anyone used the Hutech ones? Or the ONAG?
I can see the reason for the STXL guider built into the filter wheel or the QSI built in filter wheel and OAG. OAGs are a pain and are fine if you stick to one setup. But change around like I do and it can be a mess of adapters.
http://www.teleskop-express.de/shop/...rt-design.html
What about this??
Only needs 35.5mm
I have an ol' Chinese slide mirror version and find it very handy to be able to position the pick off mirror to suit the chip size...
The SX filter wheel is an option but a more expensive and less flexible option (I have 2 FLI cameras and at the moment all 3 cameras use the FLI filter wheel). It would also require a new set of filters and extra adapters to fit but yes the mini would work the USB perhaps with a thinner Planewave adapter. The advantage is I could get 36mm 3nm Ha and O111 later for half the price of 50mm square filters.
The 35.5mm TS unit would be too thick as I have about 19mm available for an OAG. The 9mm plus adapters may just make it but its close as to whether it would come to focus.
The ONAG from Foresight Innovations seems interesting especially with their new autofocuser but 66mm and too small an opening for a 16803 chip.
At this stage it seems between a 9mm TS OAG or the SX filter wheels.
Being such a critical piece of gear its surprising how few decent OAGs there are on the market.
Its supposed to be less susceptible to seeing as it guides in the NIR rather than the entire spectrum as with OAG. But it has the camera come out the side like a Newt and I wonder if that could cause balance issues. It also requires 66mm. I wonder why its so large?
I think it's "large" because the mirror clearly must reflect the entire light cone and the mirror has to be positioned at 45 degrees. I think it is about as small as it can be when you add enough thickness to the box to account for rigid tube fittings.
Did you notice that there is also a large model ONAG now? (ONAGXT)
The Atik filter wheel is amongst the thinnest I've seen.
I use the SX wheel with 7x36mm filters and the TS9OAG.
I love the TS9 for the plethora of adaptors that they have for it.
I got the 48mm version on both sides as the load would be spread a bit more on the SX than the T2.
The SX wheel also has almost all the adaptors you can think of.
The Atik filter wheel is amongst the thinnest I've seen.
I use the SX wheel with 7x36mm filters and the TS9OAG.
I love the TS9 for the plethora of adaptors that they have for it.
I got the 48mm version on both sides as the load would be spread a bit more on the SX than the T2.
The SX wheel also has almost all the adaptors you can think of.
Cheers
Alistair
Thanks for that. I read a few posts about the TS9 that seemed a bit cool towards it. Any flex? The Lacerta one got a good review.
Thanks for that. I read a few posts about the TS9 that seemed a bit cool towards it. Any flex? The Lacerta one got a good review.
Greg.
Hi
I havent noticed any flexure with it. You do need to tighten the guidecam screws well. Other than that no issues.
Holds the wheel and camera as in the pic quite well.
The atik wheel below is a bit pricey but is only 22mm and takes 7 filters. The sx mini has a max of 5.
Sx usb is 27mm. Point to note with these is that the adaptors are 2mm.
the unmounted filters basically sit in the recess, and there is a plastic screw with a washer that holds it down as you may be able to make out in that page.
so its not too different mainly due to the 4mm taken up by the scope side T2 or M48 adaptor. they remove this and fix the OAG directly to the FW face which you can't do with other OAG's.
Thanks very much for the photos and links. Yes this is for the CDK and reducer. Without the reducer there is plenty of backfocus - about 250mm.
The reducer works at various distances with ideal at 45mm and OK up to about 60. I am currently at around 45mm but its guide scope guided. The chip is 17mm in the SX camera, the FLI filter wheel is 19.9mm thick, the adapters on the reducer add about 6.5mm, the adapter on the filter wheel only adds a few mm.
I ordered the mini usb with OAG specifically to get closer to the 45mm. So its 17 to the chip it the camera, around 28mm for the filter wheel +some adapters, maybe 10mm so I would be at 55mm or less if I can get the adapters thin enough. So the FLI CFW and TS9 sounds like about 28mm + adapters. Very similar but does not require a whole new set of filters!
Perhap I should order one and see if I can use it. What adapters did you use for your TS9 to attach it? The FLI filter has about a 76mm opening.
Greg,
Ring the teleskop shop. This is the OAG I got for a 3" korr reducer but I rang them about connecting a qhy guider to it and they came up with the goods. The oag is 10mm thick. Yes they speak english.
robin.
Thansk Robin I will. One concern is the prism able to be lowered enough to catch the light from a 42/48mm adapter as the TS9 is I think more open than that?
My MMOAG prism would not go down but its got a much larger opening - about 85mm or so.
Just something I am wondering is why use the reducer? Why not use a larger format camera at native focal length with an OAG, filter wheel and camera? You can always crop and you get rid of the problem you have now.
