1. So far you have told us nothing that will help us to make any suggestions?

2. What type of mount are you using?

3. What programs are you using to control the scope tracking?

4. Do you use Maxim, The Sky X, or another program?

5. Are you guiding or just tracking, if you are just tracking then your elongated stars which according to you is proportional to your exposure would seem to indicate your polar alignment is not quite what you are led to believe?

6. What method you to do your polar alignment?

7. Do you have T-Point and did you do a T-Point run to verify your Polar Alignment?

8. Did you use a Polar Scope, The Sky X, PemPro, or some other program to help with your Polar Alignment?

9. What kind of Imaging Camera are you using?

10. What kind of guide camera are you using?

11. Do you use a separate guide scope or an OAG?

12. Are you sure your guide camera is par focal with your imaging camera?

13. How are your focusing manually or with FocusMax or other such program?



Stéphane, Johnny 5 needs more input!!





Gary



Carpe Noctem



Sent from the Astro Cave via my MS Surface Pro 4 Tablet

















From: C14_EdgeHD@... [mailto:C14_EdgeHD@...]
Sent: Wednesday, March 23, 2016 12:47 PM
To: C14_EdgeHD@...
Subject: [C14_EdgeHD] New 11" EdgeHD





Hello,



I'm just new to this forum. I've had just one evening to use my new scope, but a couple of issues have come up that I would appreciate any comments on. The weather won't be good for a few more days, so I have some time to consider solutions btwn now and then. Astrophotography is the reason I purchased this scope



Mirror shift, or??? I get increasingly long star trails with increasingly long exposures. How great, if at all, is mirror flop, once locked down? It would be good to know if I can assume this is not an issue, and so can direct my attentions to the other possibilities. My polar alignment is excellent, so is my balance.



Focus. I discovered that focusing is perhaps incredibly easy. Take a dimmish star, move it to the edge of chip and focus it there. Any little bit out of focus quickly and dramatically elongates the star one way or the other. As apposed to focusing in the center where you have to judge more or less bloated. However, focusing this way I noticed that stars midway had red and blue slight comma type flaring. Not good.



And finally, is there a source for a variety of adaptors, that start with the 3.29 16tpi thread. Celstron seems to only offer the large or small T adaptor.



Thanks,



Keith

开云体育

开云体育

开云体育

开云体育

开云体育

My guess would be your elongated stars is a guiding issue. Are the elongated in RA or DEC? I have e 14” Edge and do not see any appreciable mirror flop especially because of the mirror locks. I use a rear focuser also. You may have DEC bouncing especially if your alignment is “perfect”. It could be teetering back and forth a bit and this can be exacerbated by poor seeing.



Imaging at f10 is also a lot more demanding than say f7 which is what I do. You may want to get a focal reducer.



Also you may have appreciable slop in your gear train. I personally know two people, my friends, that have had their AP mounts extensively worked on by AP because of the gears. I believe they are both 1100 mounts. Sorry these are facts.



As you stated you have a large guide scope hanging off. This adds to an already questionable setup. Any slop or backlash will just keep adding to the problem. You could try playing with the backlash settings in Maxim. I don’t know if you calibrate your guider when you move the scope to different declinations but doing this every time might help a little.



If you are using the stock flexible orange doe tail this also can cause flexure. I use cradles on my scope,



You could try setting the scope balance a little heavier in the East but this will only help in RA Guiding your mount can still bounce around in DEC.



If you are using the stock screw focuser you must always finish the focus, which I am sure, you already know.



If you think the 5.750 back focus is a problem I think you can put that to bed. There are thousands of 11 inch Edge Scopes out there and from what I do ”Not” hear this is not a problem unless you have many loose joints in your image train.



My suggestion get a QSI camera with a built in filter wheel and a off axis guider. This will eliminate a lot of your problems.





Gary



Carpe Noctem



Sent from the Astro Cave via my MS Surface Pro 4 Tablet







From: C14_EdgeHD@... [mailto:C14_EdgeHD@...]
Sent: Wednesday, March 23, 2016 4:15 PM
To: C14_EdgeHD@...
Subject: RE: [C14_EdgeHD] New 11" EdgeHD





Hi Gary,



Thank you for your quick reply!

I was hoping to avoid getting into all the possibilities your questions imply, and so before getting into them, I wanted to limit my question to just the issue of mirror flop. Maybe another way of asking would be... lets say that an OTA tracks perfectly, for 15min, with the mirror locks set, imaging at f10, would mirror flop be an issue that would likely show up in an image?



I appreciate your questions,

I'm using an AP 1100 mount, MaximDL tracking prog, Starfish autoguider, TeleVue NP101 guide scope, piggybacked on the C11. Drift aligned, to the point that it'll stay on track within 1/2 hr either side of the meridian, unguided, for at least 5 min. Using full frame DSLR camera, Focus on guide and imaging camera excellent. Seeing average.



Really, my biggest suspect is the NP101 piggybacked on the C11. It's 14lbs of weight hanging at various angles, and thereby effective distances, beyond the tube. My previous setup was a 10" Meade with a 4lb guide scope. I had very few image shift issues with it.



My second suspect is related to the 5.75" back focus, with the camera hanging beyond even that. It takes a lot to keep that immobile. My Meade setup was much more closely coupled.



But still the question, or degree, of mirror flop remains. If it's not acceptable over a 15, or at least 10 min period, then I will have to abandon hope of using a guide scope, and resign myself to OAG. And I hate them. They are a pain.



Regards,



Keith





[Non-text portions of this message have been removed]

This is a long read but I am a very wordy person so beware.



I use a rotator because of exactly what you mentioned, the inability to frame a good guide star. With a rotator I have a much greater chance of being able to find that guide star while still being able to keep my desired DSO in the image camera FOV.



For several years I used the Optec Pyxis Rotator. A fine piece of equipment which easily handles the QSI 683wsg which is also an excellent trouble free camera. You already have the “Shorty” Focuser so the QSI with the built in filter wheel is a perfect fit for the 5.750 back focus and Starlight Instruments has a perfect spacer to put the QSI camera CCD in the middle of the .800 inch focus range. I, like you, also used the Feather Touch focuser from Starizona and the Micro Touch controller so your configuration will duplicate what I had.



Yes 95% of the time I rotate to get the proper guide star and “proper” is the key word! It is imperative that your guide star NOT be saturated. A blobby guide star will give you an incorrect centroid. Too weak of a star will be more likely to succumb to the star fading in and out when seeing is not good. You should strive to get a star that gives you about ? the saturation level of your camera around 45,000 adu. Note that hot pixels in your guide star box can influence your guiding or double stars. You may want to decrease the size of your guide star box to 16X16 if seeing is good, your guide star is good, and you take care to do a simple auto dark to remove hot pixels. Note that if your seeing deteriorates precipitously and your maxim move is set to high your mount may move the guide star out of the box resulting in a loss of guide star warning. It is always good to do a simple auto dark if possible so hot pixels will not be considered in the centroid calculation or have the guider program lock on the hot pixel.



With my 14” Edge I have found at f7 that a 9 mag Star is just about right to give me the proper adu level for a guide star and guider calibration. Do not be fooled by using a star that is saturated, 64,000 adu. 7 or 8 mag may be too much. You guiding will look good on your graph but will be false because the centroid calculation will be wrong. The proof will be in your ability to get round stars which of course is your metric for evaluating your subs. Your only measure of how good your mount and ultimately your guiding is will be to measure stars with Maxim using the “Information” screen and hovering over a Non Saturated star in, say, a 10 or15 second exposure. With the annulus rings around a star you will be able to measure adu, elongation, and FWHM and much more in an instant. I usually calibrate on 9 mag stars but after that my system is capable of guiding on mag 12 stars or dimmer depending on conditions of course but I usually go for a 9 or 10 if possible. You takes what you can get!



There is a common misconception and it is this. A lot of people think that they have to calibrate the guider on a star that is within their field of view of the DSO they are going to image. Not so!

Just move your scope off to a good candidate in the near vicinity of the proper magnitude and calibrate then do a “Slew Prior” or find and slew to return to your object but make sure your Auto Dec is turned in your guider configuration.



I have a neat trick that I employ and it is this;



In The Sky X in both the guider box and image box I define a small circle in both boxes in the FOV elements. So essentially I have a small circle in the center of both frames guider and image.

When I locate a good star to calibrate on I move the background in The Sky so the guide I want to calibrate on is exactly on that circle in the guide star box. Now I click on the circle in the image camera box and slew to that point. The star you selected to be in the guider box will now be centered exactly and you can calibrate. After just slew back to your object and start to image.



The “Information Window” tool is one of the greatest tools for measuring what your conditions are and ultimately your success. This will allow you to measure the elongation of the stars in your subs. Up to about 10% elongation can be tolerated but beyond that after combining your subs will result in very large, in my experience, large stars! They will tend to be more round after combining but excessively large. Usually if you seeing is such that it is worse than 3 - 3.5 arcsec/pix just hang it up! You can read this directly with the information scree.



The “Information window” in Maxim is an invaluable tool in determining the quality of your subs, focus, and seeing. I use it all the time.



I recently upgraded my Rotator and Focuser to the Optec Gemini combination. It is a Rotator and Focuser in one compact unit with a tremendous 20 lb. capacity This new Focuser and Rotator combination which I have coined the RoFo, IMHO, is a cutting edge fantastic piece of equipment and quite possibly the most advanced piece of gear out there and the readouts are literally the best I have seen allowing you to choose any units you like for either the rotator or focuser. I had contemplated buying the FLI Instruments Atlas Focuser but when I inquired about their products they seemed to care less and quite frankly was turned off by their lack of willingness to help me. For this I thank them because I did not purchase the Atlas focuser which in hind sight would have been half the instrument that the Gemini is. When I bought the Pyxis rotator the Gemini had not yet been invented but after its release I sold my Pyxis and upgraded to the Gemini which is a dream come true. Optec, IMHO, is on the leading edge of equipment design and Jeff, the owner is a great guy to do business with. This has been my personal experience. He has even visited my observatory on his way to Tucson Arizona when he was at the Tucson Telescope show which I considered an honor. This guy is the real McCoy. He actually answers the phone when you call Optec a lot of the time.



On the guide exposures I think you are just about right. Of course the better your tracking and seeing the longer you can go without a correction. I typically use about a 4 second exposure. The key here is to adjust the level of your guide star exposure to the optimum Adu level without saturating the star. You can do this with the exposure length to an extent. With a dimmer guide star 6 seconds is certainly within the criteria for obtaining a good centroid. I usually use a 1 or 2 second delay afterwards helps the mount settle out after a bump in guiding. Ultimately your elongation will be the guide. Like my friend and mentor Parijat always tells me time and time again. “looking at the subs will tell you if your settings are correct”. If there is no wind and seeing is good you can push this a bit as long as your polar alignment is good and your mount “tracks” well.



All this talk is fine but ultimately seeing is the monster waiting in the background to make all of the above useless blather. I have spent many, many hours always tweaking my settings and my friend and mentor Parijat tells me he rarely changes anything because ultimately seeing is the cause of all guiding problems. Like you said you have about 3-4 nights a month of good seeing. I fortunately have a lot more but seeing conditions will drive you to drink. My philosophy was to optimize my equipment to the point that I was going to be in the poor house but to put to rest a part of the equation that I had control over and that was the mechanical aspects of my setup. I just did and do not want to work around any mechanical issues which of course is possible but to me not wanted.



I believe I have reached the limits of that criteria now with a Paramount ME, 14” Celestron Edge with Andy Homeyer Scope Cradles, QSI 683wsg with built in OAG, Gemini RoFo, 10,000 lb. concrete pier in a permanent observatory with a second floor observation deck, and using The Sky X direct guide which I have just switched to after using Maxim for years. I believe The Sky X does not allow the same metric of control over guiding that Maxim does with its many tweaks but I at this point I like it. I wish it had more control especially the ability to change the aggressiveness in both Ra and Dec independently like in Maxim but unfortunately I have not been able to do that. Still I like it and will continue to gain experience with it.



I have strived to eliminate all things mechanical within my control and leave only the things which I have no control over for fretting over. In the end seeing is the monster which dictates all that can be achieved.



I hope this helps you and know that not everyone has the funds, the equipment, or the willingness of commitment to have a good setup but to be quite honest I have seen pictures that I would die for acquired with equipment that pales in comparison, dollar wise, to the amount I have invested. It just goes to show the old adage still applies to all fields of endeavor. It is the SKILL and commitment to learning and time invested that in the end is what really pays off. Almost anyone any make pretty pictures with the best money can buy but money can’t buy what I just mentioned. SKILL, learning, and commitment to learning how to work with what you have is the ultimate determining factor as to what you can achieve.



I am by no means an expert but I try and I have fun setting there tweaking my equipment and playing astronomer even though I would not make a pimple on ones derriere. Sometimes it is the journey and not the destination that makes it fun for some of us. I spend a lot of time “Astro Surfing” just seeing what I can get instead of actually going all the way. It is all fun. Even that amazes me. What astronomers of old would have given to have the equipment that we have setting in our backyard.



By the way I make the KISS Focuser so if you get an SBIG or QSI camera you might want to investigate that on YouTube and as a bonus you can see what a “Swave and Deboner”, guy I am. He He He!



Take care,



Gary



Carpe Noctem



Sent from the Astro Cave via my Dell XPS Laptop

















From: keithnk@... [C14_EdgeHD] [mailto:C14_EdgeHD@...]
Sent: Thursday, March 24, 2016 6:58 AM
To: C14_EdgeHD@...
Subject: Re: [C14_EdgeHD] New 11" EdgeHD





Thank you Alan for your comments regarding the QSI. Your and Gary's comments have prompted me to look into it. Looks like an excellent camera, and a formidable competitor to SBIG offerings.



Your set up is similar to mine, so would you mind a couple of other questions? Sorry for wandering off topic a bit.

Do you often or occasionally have to rotate the camera in order to get a usable guide star?

Do you image many galaxies? I occasionally have difficulty finding a good guide star in the areas away from the Milky Way.

What guide star exposure times do you use? With my previous mount, I'd been using 2-4 sec, but with the AP1100 I'm considering as much as 6sec, or more. The shorter times are in danger of chasing the seeing rather than actual tracking deviations. The longer exposures would definitely increase the choice of available stars. The down side of those longer exposures is the time it takes to re-center the guide star after a dither move. Even at 2 sec, some of those re-centering actions take 60 or more seconds. Doubling or quadrupling those times add up. Especially where I live, where 3-4 good nights per month are about as good as I get.

Wow!? Amen! is mostly what I have to say...

I had to chuckle at your comments about? how "seeing" can trump and confound all. So true.

I know what you mean about equipment. It wasn't until I?finally graduated to?an AP quality?mount that I could finally,?dependably,?distinguish between seeing, or something else. It's good to know when to hang it up, and not waste your time with results that just won't improve on?prior efforts.

Thanks for the rotator/focuser discussion. I figured if I am forced to?an OAG, I'll need to rotate....?but?95% of the time? No,?I'll not easily?give up?trying to?get?a separate guide scope to?work. Really, an OAG can cover issues of sag and flexure and even?mount issues, and depending on exposure time, even poor alignment. So by working on and improving these, I'll either be successful, or improve and understand my setup better, should I?be forced to?OAG'ing.

Thanks for all the other comments you made. I recognize and understand what you're talking about on every one. Yes, they have been a help. The only thing I would expand on, is your discussion of the best adu for a guide star. In the short while that I was using my TeleVue NP101 as?a guide scope (at f4.3), the stars down to 20,000 adu were so sharply and strongly?distinguished from the background as to be totally usable.?That meant that mag 9 stars were very usable even tho?only 101mm aperture.?It wasn't until?it got down to 13,000 adu?that things got dicey. Although I didn't have time to pursue that line in any detail.

Regards,

Keith

开云体育

Yes if you are using an OAG you will in order to get a star that is not saturated and in a good position have to rotate to get a star in the 9 to 12 adu range. Granted time of year and location in the sky will provide a larger choice but a good star should fall in that range with an SCT. Stars of mag 8 or less will be saturated and are not good for guiding IMHO.



Gary



Carpe Noctem



Sent from the Astro Cave via my MS Surface Pro 4 Tablet







From: C14_EdgeHD@... [mailto:C14_EdgeHD@...]
Sent: Thursday, March 24, 2016 4:23 PM
To: C14_EdgeHD@...
Subject: RE: [C14_EdgeHD] New 11" EdgeHD





Wow! Amen! is mostly what I have to say...



I had to chuckle at your comments about how "seeing" can trump and confound all. So true.

I know what you mean about equipment. It wasn't until I finally graduated to an AP quality mount that I could finally, dependably, distinguish between seeing, or something else. It's good to know when to hang it up, and not waste your time with results that just won't improve on prior efforts.



Thanks for the rotator/focuser discussion. I figured if I am forced to an OAG, I'll need to rotate.... but 95% of the time? No, I'll not easily give up trying to get a separate guide scope to work. Really, an OAG can cover issues of sag and flexure and even mount issues, and depending on exposure time, even poor alignment. So by working on and improving these, I'll either be successful, or improve and understand my setup better, should I be forced to OAG'ing.



Thanks for all the other comments you made. I recognize and understand what you're talking about on every one. Yes, they have been a help. The only thing I would expand on, is your discussion of the best adu for a guide star. In the short while that I was using my TeleVue NP101 as a guide scope (at f4.3), the stars down to 20,000 adu were so sharply and strongly distinguished from the background as to be totally usable. That meant that mag 9 stars were very usable even tho only 101mm aperture. It wasn't until it got down to 13,000 adu that things got dicey. Although I didn't have time to pursue that line in any detail.



Regards,



Keith





[Non-text portions of this message have been removed]

Stan
Right on. OAG eliminates several problems.

Gary

Carpe Noctem

Sent from my space ship via my LG V10 Phone

My C11 (NON-Edge) had a loose primary that would not maintain collimation when I moved it (especially from one side of the Meridian to the other). The solution was to pull the corrector, get my hand down the tube and tighten up the primary mirror retaining ring, which I found was almost loose feeling (not anywhere near hand tight even). After that it maintains collimation rather better. It didn't completely solve my own mirror flop issue but it's smaller in magnitude now.

My C11 primary is also tilted slightly and can't be corrected without more work. My 7" Meade Mak didn't have any of these problems (neither OTA has a mirror lock, and I don't "image" but I do use video cameras). I agree that the Meade is made better and has less problems in my experience. Also saw no problems on a friend's ACF 8" F10. I used his ACF for 3 years, and my Mak at 500x and 666x respectively, visually, quite often (on double stars).

Regards,

Alistair G.