Keyboard Shortcuts
Likes
- C14EdgeHD
- Messages
Search
|
Re: Mars March 21, 2014 from DEC
Hey Chris,
Planetary imaging revolves around seeing. The strategy is to be at the camera when seeing is above average. I use clear sky clock, Unisys Weather, Weather Underground and Meteoblue to predict when seeing will be the favorable. This strategy is not foolproof---good seeing can manifest in average or below average forecasts. You need to put an eyepiece on it to verify. It may be that in your location, seeing is just not that good. If this is the case, lower magnification must be used, OR road trips to good seeing must be arranged. Control what yoy can---collimation must be checked and or tweeked before every session. The scope MUST be acclimated to outside ambient temperature. Don't put your laptop under the front end of the scope----you and all heat sources must be behind the business end of the scope. Be patient....if seeing seems to be improving, hang around a while. Use a motorized focuser for fine adjustments. I stll focus by hand for 75% of my captures, but I learned how to do it years ago. If there is any question, get the motorized focuer. Dan Llewellyn |
|
Re: Mars March 21, 2014 from DEC
Dan;
I have near the same setup as yourself (Televue barlow instead of Zeiss) but get much fuzzier images.? My biggest difficulty is getting focus with the Imaging Source camera. The problem I have is that at large magnification, atmospheric instability? prevent s good focus.? What is your approach? Chris Hemstock |
|
Re: Secondary centered in 8" Edge
There is no requirement for spherical SCT secondaries to be centered w.r.t. the primary apart from enabling uniform field illumination. This is because, being a sphere, a decentered secondary can have its axis aligned again by merely tilting it. Centering of the corrector, however, is critical. Decenter it and you'll get astigmatism. I would leave it alone. You can't possibly observe the difference in field illumation from such a small decenter.
Tanveer. On Wed, Mar 5, 2014 at 1:11 PM, Howard <feeways@...> wrote:
|
|
Re: Secondary centered in 8" Edge
Howard
¿ªÔÆÌåÓýStan Thanks for responding. I use metaguide software and webcam to get very fine infocus collimation nailed in my poor seeing. Defocused the doughnut is not centered though...i guess cause the mirror is not centered. I know this does not affect the view as i observe infocus obviously. However, it annoys me. What is the way to center that secondary? Adjust the corrector or remove and center the secondary in the corrector itself? Howard On 5 Mar 2014, at 20:47, <stan_ccd@...> wrote:
|
|
Re: Secondary centered in 8" Edge
It may be of little or no consequence because the spherical secondary need not be exactly centered for optical integrity.? SCTs are fairly?tolerant of both secondary decenter and primary tilt.? "Edge HD" is probably a bit less tolerant due o the internal corrector lenses. Do a good star collimation then assess the image. Stan |
|
Secondary centered in 8" Edge
My secondary holder is not centered in my 8" Edge.
Here are the measurements as measured with digital callipers from the secondary mirror's Fastar retaining ring to the inside edge of the lens retaining cell.... 1. 12oclock position.....78.2mm 2. 6oclock position.......79.3 mm 3. 3oclock position........79.5mm 4. 9oclock position........77.5mm Can the corrector lens be adjusted with the 4 grub screws making sure not to rotate it to bring the secondary holder dead center?......... Or must the corrector lens be removed and the secondary holder loosened on its baffle and then centered in the corrector lens itself? Help!!! Howard |
|
Re: Mars - March 2, 2014
¿ªÔÆÌåÓýNo, I use the ZWO 120 mm (monochrome) camera with filters. I have a color camera but don¡¯t really use it. Thanks! ? Brian ? From: C14_EdgeHD@... [mailto:C14_EdgeHD@...] On Behalf Of stan_ccd@...
Sent: Monday, March 03, 2014 12:03 PM To: C14_EdgeHD@... Subject: [C14_EdgeHD] RE: Mars - March 2, 2014 ? ? Very nice! (I may have to visit Georgia someday ). Since you use a Bayer cam, I presume those individual R,G,B are deconstructions? ? Your web site "equipment" sections has no mention of C-14 and you are pictured with an RCOS (BTW, I've owned/used several RCOS, who's?demise?is very sad.).? Did you replace?the RCOS with C-14? Or do you operate both OTAs? ? Stan |
|
Re: Mars - March 2, 2014
Very nice! (I may have to visit Georgia someday <g>). Since you use a Bayer cam, I presume those individual R,G,B are deconstructions? Your web site "equipment" sections has no mention of C-14 and you are pictured with an RCOS (BTW, I've owned/used several RCOS, who's?demise?is very sad.).? Did you replace?the RCOS with C-14? Or do you operate both OTAs? Stan |
|
Re: OSLO model of C9.25" classic and Edge-HD version ?
Christian, I have a 9.25" Celestron. ?It's about 20 years old, has been stored in my den and totally out of the weather and very lightly used. ?I don't know what an OSLO model is, however. ?Mine is for sale. ?Contact me off-list and we can discuss if you're interested. Mike Harp ?----- mike_t_harp@... On Saturday, February 22, 2014 12:40 PM, viladrich christian wrote:
?
Hi All,
I am looking for the OSLO models of the Celestron C9.25 and C9.25 Edge-HD. Does anybody know where I can find something ? Thanks ! Christian Viladrich |
|
A C8 Edge-HD turned into a large Ha solar telescope ...
¿ªÔÆÌåÓýDear All,This link might be of interest for those wanting to turn their Celestron into a large size H alpha solar telescope : The basis idea is to have a special coating on the Schmidt plate (just like Baader D-ERF pre-filter), and then to install a telecentric system at the focus. Looks like the ultimate large size H alpha solar telescope ... Best regards Christian Viladrich |
|
Re: A Plethora of Questions Regarding C14 Astrophotography
Yes, I agree with the wind problem for a C14... well any scope for that matter but the bigger OTAs really catch it. ?That's why I have my "tent" setup when I go portable... I think there are some shots of it up on my astro photo site. ? if anyone is interested. Al Al Acker A On Sat, Feb 22, 2014 at 10:02 AM, <dale.liebenberg@...> wrote:
|
|
OSLO model of C9.25" classic and Edge-HD version ?
¿ªÔÆÌåÓýHi All,I am looking for the OSLO models of the Celestron C9.25 and C9.25 Edge-HD. Does anybody know where I can find something ? Thanks ! Christian Viladrich |
|
Re: A Plethora of Questions Regarding C14 Astrophotography
Hi Dave, Yes, the C14 is quite heavy for the DDM60. But I did manage to trim down, replacing the heavy STL with a FLI ML and getting rid of my rotator. But the wind is still a factor with the large wind area of the OTA and quite a bit of flexure in my pier. Adding on the dome has also helped. I'm not sure if a solid tripod as you will be using will eliminate the flexure caused by wind. In theory, the DDM with motor drive and sensitive encoders should respond well and counteract the effects of?wind gusts. Dale |
|
Re: A Plethora of Questions Regarding C14 Astrophotography
"rumors that the C14 is, in fact, a small scope" "1) ASA DDM60pro?.. or?... AP 1100GTO" Probably doesn't make that much difference. I recommend AP because of long experience but I can't really?judge?ASA.? It adds significant cost (maybe for future upgrade?) but the AP1100 hi-res encoder/tracking system is amazing. "2) Corrector Plate Reflection Halo" I don't buy it. It is difficult to imagine an optical path that would bring in a significant correlated reflection from the corrector.? The artifact in that image looks much more like a reflection from a reducer or corrector or filter or other element near the camera.? In any event, that star is impossibly bright and atypical of 99% of the target fields?for C-14. "3) Celestron's EdgeHD Reducer..." There are numerous reports of difficulty with the reducer.?If you plan to chronically reduce then also consider a classical SCT with the Celestron 0.63x reducer/corrector or Starizona 0.5x (see the Starizona site for ray traces of those options). "4) Cooling" For high-res (prime FL or Barlow)?get a cooling system (not so important for reduced imaging). There are several different ones.? I forget the name or web page but a member of this forum did a robust study of this issue (maybe he'll chime in here). "5) OAG and Guide Stars..." Part of that equation is the FOV and sensitivity of the guide camera (e.g. ZWO ASA120MM is very sensitive but small).? The key to OAG is pre-planning the rotation and offsets via "The Sky" (or similar). Stan |
|
Re: A Plethora of Questions Regarding C14 Astrophotography
>>I own a C14 on an AP1100. Both are in theory portable, but frankly I would only take them into the boonies if it is for more than one night. Agree. ?For my portable setup, I have all the computers etc in a small utility trailer and set up a 10x10 EMT box that I use as a ?"tent". ?The EMP supports tarps on the sides ( for walls ) and can cover the scope in the daytime. ?My C14 sits on a MEII mount and I would NOT want to set this all up for a single night of viewing. ??
Al Al Acker On Fri, Feb 21, 2014 at 5:46 AM, <samirkharusi@...> wrote:
|
Lou Halikman
Tanveer Gani