Quote:Not every optical system has enough backspace for a OAG.I have a newton astrograph, with the canon 5 dmk2; there is zero backfocus left.The Wyne corrector has only 58mm of backfocus.You can not even use a SBIG STX 16803 with filterwheel.I'm waiting for this new guiding system due to guiding troubles, but placing a led near the imager is practically impossible without drilling a hole into the focusser Garret van der Veen
Quote:The device takes us closer to point and shoot astrophotography. You can just slew to an object and start shooting.
http://www.astrobin.com/users/orion69/ TS 150 mm APO Triplet, Feather Touch 3.5" focuser, Micro Touch Focusing System CGEM on custom made platform Atik 383L+ mono, Atik filter wheel, Baader LRGBC + narrowband filters SX Lodestar + TSOAG9 Dew-Not heater
Quote:most of them are in a private google group that's invitation only.
Black Creek Observatory C11 EdgeHD C8 AT6RC Eon80mmED
Quote:You can just slew to an object and start shooting only with high end mount without guiding. So, no it does not.
8" GSO RC with CSL Moonlite FocuserTelevue TV60isLosmandy G11 with Gemini 2 (with Ovision upgrade)
SBIG STT-8300m with Self Guiding filter wheel
A wide assortment of lenses for my Canon.
Quote:Dave wanted to know why didn't chime in here. [sic erat scriptum]
Quote:I don't just spout off.
Quote:Save your money and go with the 5. I don't know to many people using a 3 on SII
Quote:Here's what Don told me at the Advanced Imaging conference. The greater the light pollution your dealing with the lower the number you want. I'm in the country with 4.5 skies, so I could use the 5nm. Had I been closer to town with more light pollution I would have coughed up the extra for the 3nm. I don't think you can get much better than the AstroDon E2's. I did my research and there's nothing close to para focal as they are. That does come at a price though.
Quote:What about dithering? After each dithering, will it have to re-calibrate the artificial star with guide star since the guide star moved due to dithering?Peter
Quote: QSI 683wsg with integrated filter wheel and OAG has back focus of 50mm to 53mm depending on T-thread or 2.156" adapter. Wouldn't this camera work?
Quote:6. The second part of the post with AP's new setup for refractors is a far better solution to OAG.
Quote: Quote: QSI 683wsg with integrated filter wheel and OAG has back focus of 50mm to 53mm depending on T-thread or 2.156" adapter. Wouldn't this camera work? I want to use 35x24mm ccd arrays...because it give me a large field.My 5 dmk2 has a coolerbox (-22 Celsius inside) the imaging result are very good only limited by seeing, light-pollution, and poor guiding (I'm working on this: new guider telescope, PEC for mount etc.)Garret van der Veen
Quote:Quote:6. The second part of the post with AP's new setup for refractors is a far better solution to OAG.
I will try to be as diplomatic as I can. I think once again you chose your words poorly. What do you mean by "better"? "Better" in terms of getting rounder stars than using OAG? IMHO, not necessarily. "Easier" would have been a better choice of word. I can see that placement of guide scope on OTA's tube or focuser rather than on dovetail/tube rings so the guide scope will follow the OTA's flexure and will be better in sync with the main camera. But it is not 100% foolproof because there could still be unwanted hidden flexure anywhere that can happen anytime that will result throwing out some subs but A-P guide scope setup is definitely better than traditional guide scope mounted on top of dovetail/tube rings. OAG may not be 100% foolproof but darn close to 100% since guide camera knows exactly what's happening with the main camera and guide scope does not.
Quote:I told George he took my idea from pics I sent him last year and made it 10x better and correctly mounted!
My Astro Photos
Quote: I have compared guiding results using an SBIG off-axis internal guide chip camera and see little if any difference.
Quote: How do you know how much is flexure, and how much is the construction quality of the OTA, the PE of the mount, and how much is caused by setup?
Quote:The REAL problem with OAG, as I see it, is not the PITA factor, but the backfocus issue with some gear combinations.
Quote:Using a guidescope mounted on the actual telescope body (NOT rings) is certainly a lot easier than an OAG, especially in more barren areas of the sky. I have been testing the new Astro-Physics guidescope arrangement (using their 60mm finder scope) directly mounted on the backplate of an almost 4,000mm focal length Cassegrain and it works superbly at different pointing angles, thermal, and gravity loads. I have compared guiding results using an SBIG off-axis internal guide chip camera and see little if any difference. (Or at least any variation could just as easily be seeing related) Whereas I would not say that the results are "better" they are no worse. Obviously the mechanical/strutural integrity over the whole chain is critical, but as long as weak points have been identified and an intelligent approach is adopted, there appears no reason in principle why a guidescope solution cannot work at longer focal lengths.
I had a concern that the nylon tightening bolts in the AP Guidescope rings would not be as solid as metal, but at AIC George from AP told me that the nylon tipped metal bolts were harder to procure and I should see no difference. I find myself tightening those things as much as possible, but so far he is right and I have not noticed any difference. Good job AP!
Anyway, just one data point.
Quote:Now we're getting back to opinions again, for many people OAG is a PITA, but I'm sure you guys have mastered it so it's not for you. Here's my issue. I'm buying a 14" Planewave. To add the combination rotator focuser is an extra $3500. Now if I add a MMOAG it's another $900. Why on God's earth would I do that if I can achieve what Aquatone is achieving great success with AP's new design?
Quote:How do you know how much is flexure, and how much is the construction quality of the OTA, the PE of the mount, and how much is caused by setup?
http://www.faintfuzzy.net Stuff C14, C8, Orion XX14i, Meade 8" ACF, AT6RC, AT102ED, Orion ED80, PST, AP1600GTO, CGE, CG5, ST10-XME/CFW8, QHY8PRO, Optec TCF-s, Microtouch Focuser, Pyxis LE, Hyperstar for C8.
Quote:I'm buying a 14" Planewave. To add the combination rotator focuser is an extra $3500. Now if I add a MMOAG it's another $900. Why on God's earth would I do that if I can achieve what Aquatone is achieving great success with AP's new design?
Quote:Then, stack the images with no registration. It's interesting to see what flexure looks like when it adds up over the whole night. Note that this assumes that you are not dithering.
Quote: Congrats on getting your guiding to work well with A-P guide scope guiding a 4000mm focal length scope. Can you still achieve round stars at 30 minute guided exposures (for narrow band imaging)? Peter