Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Equipment Discussions >> Reflectors

Pages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | (show all)
astrocrafter
Vendor (JP Astrocraft)


Reged: 11/24/10

Re: First Light On My 20" f/3 Lockwood/JP Astrocraft new [Re: johnnyha]
      #5604823 - 01/04/13 01:37 PM

I usually use my 6" scale as a knife edge on the plastic pipe to determine the focal plane when installing the SIPS.
John


Post Extras: Print Post   Remind Me!   Notify Moderator  
turtle86
Pooh-Bah Everywhere Else
*****

Reged: 10/09/06

Re: First Light On My 20" f/3 Lockwood/JP Astrocraft new [Re: johnnyha]
      #5605163 - 01/04/13 04:35 PM

Quote:

Thanks Rob, I haven't had a chance to use it yet but it's pretty obvious, this should give me about 6X more fine focus over the little 10:1 stock knob, which on such a fast scope is really appreciated. This should be a no-brainer for anyone at f4 and below.




Totally agree. My old SCT had a large focuser knob that I found helpful even though it was a slowish f/10. My present Starmaster is f/4.3 so I figure a larger knob will be all the more useful, especially when others view through the scope and on cold nights when I'm wearing gloves. I'm sure that the 1.75" knob will suit me fine, but wish I had room for that jumbo 3" one. What a conversation starter...


Post Extras: Print Post   Remind Me!   Notify Moderator  
Bob S.
Carpal Tunnel
*****

Reged: 07/14/05

Re: First Light On My 20" f/3 Lockwood/JP Astrocraft new [Re: turtle86]
      #5605386 - 01/04/13 07:01 PM

You know you have been bit by the bug in more ways than one when after 5 days of trying to get over the flu, you are out testing an eyepiece Well, it was only for 5 minutes but I HAD to do it because my Leica ASPH Vario Zoom had not been coming to focus with the use of the SIPS. I was lacking just a fraction of an inch of in-travel but that is about as good as a mile when it comes to the SIPS because moving the mirror up just causes you to have to move the SIPS relationship.

Fast Mike was kind enough to clue me to this with his 28" f/2.75 Lockwood/Webster which was also not allowing the ASPH to come to focus. Well, John Pratte being such a nice guy, asked me to send him the two-inch adapters I have for the ASPH's and he machined a ridge off of the top part of the adapter that allowed the Leica ASPH to go into the SIPS equipped Feathertouch 9mm deeper. This silly little 9mm's allows me to now be able to have the Leica racked out a full half-turn of the gross focuser knob which gives me lots a leeway to get the eyepiece to come to focus. As some of you know who have been following the eyepiece forum here on CN, the Leica is one very high-performing zoom that allows widefield views with the performance that matches and can even exceed a Zeiss Abbe Ortho II under some circumstances. Unfortunately/fortunately, I am too sick and the skies are too *BLEEP* to risk a hospitalization. I can't wait to see how the ASPH performs in this new scope. Will be reporting on that in the coming weeks if the skies clear up here in North Florida. Bob

Edited by Bob S. (01/04/13 07:55 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
a__l
professor emeritus


Reged: 11/24/07

Re: First Light On My 20" f/3 Lockwood/JP Astrocraft new [Re: Bob S.]
      #5605742 - 01/04/13 11:08 PM

Quote:


Brendan, For Fast Mike and I, we put in the 17mm Ethos, back it out 1/2 turn of the fine focus knob, lock the focuser and then tune the SIPS to get the sharpest image in the 17mm Ethos. Fast Mike and I happen to have the same focus position but each persons eyes are different so you have to first use the proper SIPS method and then see how far off the bottom of focus the 17mm Ethos has to come to be at sharp focus. Using the Ethos instead of the tape allows for a clearer observation of best focus position for the SIPS as opposed to looking at an object on cellophane tape. Bob




Bob, you get to combine the SIPS and MallinCam? What do you use 2" Focuser Dob Adapter is back or MFR-3 Focal Reducer or no?
You reduce the length of the tubes or use a different method, or no?


Post Extras: Print Post   Remind Me!   Notify Moderator  
Bob S.
Carpal Tunnel
*****

Reged: 07/14/05

Re: First Light On My 20" f/3 Lockwood/JP Astrocraft new [Re: a__l]
      #5606155 - 01/05/13 09:08 AM

Quote:

Quote:


Brendan, For Fast Mike and I, we put in the 17mm Ethos, back it out 1/2 turn of the fine focus knob, lock the focuser and then tune the SIPS to get the sharpest image in the 17mm Ethos. Fast Mike and I happen to have the same focus position but each persons eyes are different so you have to first use the proper SIPS method and then see how far off the bottom of focus the 17mm Ethos has to come to be at sharp focus. Using the Ethos instead of the tape allows for a clearer observation of best focus position for the SIPS as opposed to looking at an object on cellophane tape. Bob




Bob, you get to combine the SIPS and MallinCam? What do you use 2" Focuser Dob Adapter is back or MFR-3 Focal Reducer or no?
You reduce the length of the tubes or use a different method, or no?




A___I, I have not had a chance to experiment with a Mallincam in the telescope at this point. My first and only attempt, I had taken out the SIPS glass but had not returned the focuser to the non-SIPS position which is about 2" closer to the primary. It was an operator error that I will hopefully not repeat. The weather has been poor for astronomy in North Florida and my wife and I both have been dealing with a really nasty case of the flu which we seem to be finally improving from after being symptomatic for 5-6 days. Bob


Post Extras: Print Post   Remind Me!   Notify Moderator  
a__l
professor emeritus


Reged: 11/24/07

Re: First Light On My 20" f/3 Lockwood/JP Astrocraft new [Re: Bob S.]
      #5607682 - 01/06/13 01:44 AM

Bob, but for what you have cleaned the glass SIPS? F/3.0 coma and big enough for Mallincam (probably?). Incompatibility SIPS and Mallincam?
I would be very interested to read the result of using SIPS (complete) + Mallincam + yes/no FR ...


Post Extras: Print Post   Remind Me!   Notify Moderator  
Busguy
member


Reged: 06/14/07

Loc: Kentucky
Re: First Light On My 20" f/3 Lockwood/JP Astrocraft new [Re: a__l]
      #5608546 - 01/06/13 02:38 PM

I'm also anxious to hear the answers on the SIPS + Mallincam and how you achieve final focus.

Post Extras: Print Post   Remind Me!   Notify Moderator  
a__l
professor emeritus


Reged: 11/24/07

Re: First Light On My 20" f/3 Lockwood/JP Astrocraft new [Re: Busguy]
      #5610773 - 01/07/13 07:25 PM

I asked an additional question in the subject Video and Electronically Assisted Astronomy:

I want to determine the position of the focus for Mallincam.
The focuser on my Dob set to eyepieces Ethos-17,21 and Nagler-31.
Here
http://www.televue.com/engine/TV3b_page.asp?id=214

Eyepiece Specifications for TV eyepieces.
Table Notes F - Approx. location of field stop (negative number is above reference surface).
For E-21, 17 and N-31, respectively -0.38, -0.39 and -0.38.
This is the minimum benchmark. Below focuser travel impossible.
If you remove the Mallincam (focus OK) and set TV eyepiece. Which TV eyepiece is in focus (does not need to turn the knob focuser)? Or near the to the focus?
If you are using a 1.25/2" adapter for Mallincam or desired TV eyepiece I also need an height adapter on above surface focuser.
If the TV eyepiece is 1.25/2" skirt, it is correct to use a 2" eyepiece position.
Thanks.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Bob S.
Carpal Tunnel
*****

Reged: 07/14/05

Re: First Light On My 20" f/3 Lockwood/JP Astrocraft new [Re: a__l]
      #5614610 - 01/09/13 10:25 PM

A___I and Busguy, I was finally able to plug in my Mallincam Xtreme with the 1.25" nosepiece and a 10mm spacer with my SIPS in place and the camera came to focus on M42. I only had about 1/4" of out-travel available but it worked! I was frankly a bit astonished.

Tonight, even though the weather has been terrible in North Florida and was pretty lousy all day, the seeing was very steady at times and I was able to use 373x and 474x on Jupiter with the CBLMS (Comprehensive Boundary Layer Mitigation System) running. The best views were at 373x with my 4.7mm Ethos. The GRS and following white ovals were prominent at times. The long blue festoons in the NEB were also pretty apparent and I am scheduled to get cataract surgery which will greatly increase my blue sensitivity. I was suppose to have the right eye done today but am getting over the flu and was in no condition to get eye surgery. Wasn't even in good enough shape to work more than about 2 hours today but when it came to astronomy, I was so photon starved that I was out for more than 2 hours tonight. I guess my priorities are still good Bob

Edited by Bob S. (01/10/13 06:11 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
a__l
professor emeritus


Reged: 11/24/07

Re: First Light On My 20" f/3 Lockwood/JP Astrocraft new [Re: Bob S.]
      #5616752 - 01/11/13 07:13 AM

Quote:

A___I and Busguy, I was finally able to plug in my Mallincam Xtreme with the 1.25" nosepiece and a 10mm spacer with my SIPS in place and the camera came to focus on M42. I only had about 1/4" of out-travel available but it worked! I was frankly a bit astonished.





Bob, I'm glad that it worked!
I do not understand the nuances.
1. SIPS was set with a view to focus Ethos 17 and focuser with a maximum travel inside?
2. You have used 1.25/2" adapter (with Mallincam)? What is the height this adapter above plane focuser?
3. What is a 10mm spacer? Where it is set?
4. Height focus Mallincam 1/4" (travel focuser 1/4" outside of focus from the ethos 17)?
If you can, please place the a picture with dimensions.
Thanks.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sgt
Pooh-Bah
*****

Reged: 12/17/05

Loc: Under the southern horn of the...
Re: First Light On My 20" f/3 Lockwood/JP Astrocraft new [Re: a__l]
      #5617542 - 01/11/13 04:19 PM

Bob, sorry if I missed it but can you give an assessment of the Leica zoom on and off axis at f/3+paracorr? Thanks.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Bob S.
Carpal Tunnel
*****

Reged: 07/14/05

Re: First Light On My 20" f/3 Lockwood/JP Astrocraft new [Re: Sgt]
      #5617557 - 01/11/13 04:28 PM

Quote:

Bob, sorry if I missed it but can you give an assessment of the Leica zoom on and off axis at f/3+paracorr? Thanks.




SGT, I will let you know. I will be using it with my SIPS system and will let you know how tight the stars are and how tight they are out to the edge of the field.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sgt
Pooh-Bah
*****

Reged: 12/17/05

Loc: Under the southern horn of the...
Re: First Light On My 20" f/3 Lockwood/JP Astrocraft new [Re: Bob S.]
      #5617661 - 01/11/13 05:50 PM

Thanks Bob.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Bob S.
Carpal Tunnel
*****

Reged: 07/14/05

Re: First Light On My 20" f/3 Lockwood/JP Astrocraft new [Re: Sgt]
      #5618060 - 01/11/13 09:34 PM

SGT, It is too early in the evening to tell about my early exploits but I can tell you that the Leica ASPH is currently in my 20" scope in a 4x TV Powermate and the views of Jupiter, M42, and the Eskimo Planetary Nebula between 389x and 777x are pretty darn wild. The 2x Powermate that was limiting me to 389x was just not enough power for tonight. Finally, I get to really air this scope out! Bob

Post Extras: Print Post   Remind Me!   Notify Moderator  
Bob S.
Carpal Tunnel
*****

Reged: 07/14/05

Re: First Light On My 20" f/3 Lockwood/JP Astrocraft new [Re: Bob S.]
      #5618320 - 01/12/13 12:47 AM Attachment (59 downloads)

The coyotes were literally howling, the owls were hooting and a Leica ASPH vario zoom 8.9-17.8mm with 60-80 degree AFOV got an intense workout tonight in my 20" f/3 Lockwood/JP Astrocraft. The NELM was just under mag 6 tonight as measured by my Sky Quality Meter and the seeing was quite steady. Earlier experiments tonight with the fans on Jupiter and Rigel showed that the (Comprehensive Boundary Layer Mitigation System) is working superbly. I tuned the SIPS to perfection on Jupiter using a 5x magnifying loupe and checked collimation of the scope after it had been cooling with the CBLMS running at full speed for about 1.5 hours. I was looking at Jupiter with the Leica ASPH and was finding that 194x was not even making the eyepiece or the scope breathe deeply. I popped the Leica ASPH into my 2x TV powermate and now was running views of the planet between 194x-389x. Still the views were showing that I could use more power. In goes the 4x TV Powermate coupled to the Leica ASPH for views between 389x-777x. Predominantly, the views at about 389x to about 600x showed periods where the planet looked like a CCD image. The orb of Jupiter seemed suspended in black space. The contrast of atmospheric features against a jet black background was jaw dropping. Now, for the first time since this past years WSP in the Florida Keys, I was able to view comfortably at over 550x. With the ASPH in the 4x Powermate and a 2" OIII filter, I had the scope go over to the Eskimo Planetary Nebula in Gemini which is an object on good nights that can take a lot of power. The Eskimo was not to disappoint either then or hours later at ridiculously high mags. I am used to viewing it with my former 28" f/3.5 Lockwood/Starmaster and so noticed that the brightness was way down with the OIII filter and only 20" of aperture compared to the views I would get with the 28". Now, I had not had a chance to see the Horsehead and Flame Nebulas with my new scope. I put a 2" H-Beta filter into the bottom of my ASPH and was zooming in and out on the Horsehead and Flame Nebulas. I actually like the view better in my Leica at 17.8mm with 60 degree AFOV than my 21mm Ethos or 17mm Ethos with the h-b filter and their 100 degree AFOV.

Of course, in the high mag mode, I had to see the Pup in Sirius. Sirius was a superb pinpoint of a star and I used it for further high-mag testing of the primary mirror. I did a test of the fans on this object and each time I turned off the CBLMS, the star would get more flairs. The tightest views were with the CBLMS running and so it was left on all night. Back to Jupiter with the 389x-777x eyepiece arrangement and Jupiter was strutting the GRS along with beautiful festoons and white ovals and a dark barge or two in the NEB. The amount of different colors I was seeing in the GRS, festoons, ovals, barges and belts was very impressive. At between 550x-777x, I was able to make out reliable but faint albedo markings on Ganymede in what I think was the Southern half of the Jovian Moon. This is only the third time that I have been able to do that and it was best seen when I moved Jupiter out of the FOV. I forgot to mention that I used the ASPH with the 4x Powermate on M42 and was seeing the A-I stars (not the H-stars). The G and I stars were only intermittently seen with averted vision. This is only the second time that I have seen the I and G stars without my image intensifying eyepiece. BTW, I tried my Micro IIE Gen 3 image intensifier and was unable to get it to come to focus with the SIPS system in place. I was lacking just a bit of infocus. I finished off the session tonight first returning to the Eskimo and seeing his face briefly with a full parka surrounding his face and nose. I then went back for a last look at Jupiter and the seeing was getting a bit soft even at a lowly 389x. It was time to wrap it up and glow in the aftermath of my best viewing session to date with my new telescope. It also represented the best magnification I was able to successfully deploy in the past year here in North Florida. For some reason, obtaining 1000x plus nights like we used to get have been very difficult for the past two years. I did some high-power testing of the mirror on Sirius and Betelgeuse and the mirror is superb! Mike, I found that the Leica showed pinpoint stars to the edge with tighter star points when it was in either the 2x or 4x Powermates with those items behind the SIPS. Without a barlow, the stars were a bit less tight and not so uniform across the FOV with just the Leica ASPH and the SIPS. The views were not bad but just not perfect like they were with barlowing. I am including a picture of the setup. You will note that all focusing was done with my 3" Feathertouch optional focuser wheel which made focusing a dream. I cannot say enough good things about this 3" focuser wheel for critical focusing at high-mags. To say that I am pleased with the scope and the performance of the Leica ASPH with the TV Powermates would be an incredible understatement. I am frankly ecstatic! I am very much questioning if I need all of my fine Ethos ep's (I have the whole set). As some know, I had done comparisons of the Leica ASPH with my Zeiss Abbe Ortho II's along with a host of other orthos and ep's and the Leica was a good as or at times better than the Zeiss glass and this is no small accomplishment. It's performance on Jupiter was so convincing tonight and the fact that it was being used in a f/3 scope with a Starlight Instruments Paracorr System (SIPS) that made the AFOV perform like an f/12 scope leads me to wonder how much glass I need? I am forever indebted to John Pratte for making such a stout scope with an ultra-stout focuser board/UTA that easily handled all of the weight placed on it. This is without a doubt, the finest 20" scope I have ever been priviledged to be the steward of. Bob

Edited by Bob S. (01/12/13 09:26 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mike Lockwood
Vendor, Lockwood Custom Optics
*****

Reged: 10/01/07

Loc: Usually in my optical shop
Re: First Light On My 20" f/3 Lockwood/JP Astrocraft new [Re: Bob S.]
      #5618969 - 01/12/13 12:20 PM

Bob, all I can say is wow.

Things have sure come a long way since I bought these 20" f/3, 1.25"-thick Pyrex blanks back in 2006. I could never have forseen what they have become.

Thanks for your report, and for trying a lot of things that most people would not.


Post Extras: Print Post   Remind Me!   Notify Moderator  
claytonjandl11
sage


Reged: 04/06/06

Loc: East Bay, N. Ca.
Re: First Light On My 20" f/3 Lockwood/JP Astrocraft new [Re: Bob S.]
      #5619150 - 01/12/13 02:11 PM

Very nice report Bob, keep them coming.

There are times that miss the views from a large apeture scope. I remenice when I had my 20" SM and would scan the the night sky and I kept bumping into these obscure little galaxies, and I'd check my sky atlas to see what I was seeing. Not to mention how different and in your face the "eye candy" DSO looked compared to my smaller apeture Apo's, just one word, WOW!!!

The only thing I don't miss is the size and weight of that scope, and the hassel of using a ladder, setting it up and tearing it down. But not in your case, with the fast F/ratio keeping yor feet on the ground and those superb optics and the abilty to customize your scope. Between your posts and advise, and looking thru some of my freinds large apeture, fast F/ratio with top of the line optics like yours, and the lighter overall weight and portabilty of these scopes have made me belive in these type of reflectors. For me it has always been a case wanting the sharpest veiws with ease of use and portabilty. In other words "The juice had better be worth the squeeze". In this case you and others like yourself have proven this. I can't wait to get my 16" Spica Eyes scope!!

Nick T. :-)


Post Extras: Print Post   Remind Me!   Notify Moderator  
SACK
member
*****

Reged: 08/11/11

Loc: TX
Re: First Light On My 20" f/3 Lockwood/JP Astrocraft new [Re: Bob S.]
      #5619221 - 01/12/13 02:58 PM

Hi Bob,
How does the 5X loupe help you for sips adjustment? How do you use it and are there other uses, i.e. collimation? Sounds intriguing.
Thanks for the ongoing reports and insights!
Jonathan


Post Extras: Print Post   Remind Me!   Notify Moderator  
Project Galileo
scholastic sledgehammer
*****

Reged: 11/14/07

Loc: Jefferson County, Colorado
Re: First Light On My 20" f/3 Lockwood/JP Astrocraft [Re: SACK]
      #5619308 - 01/12/13 03:44 PM

Congratulations on the fine results. You have a special telescope there my friend.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Bob S.
Carpal Tunnel
*****

Reged: 07/14/05

Re: First Light On My 20" f/3 Lockwood/JP Astrocraft [Re: SACK]
      #5619349 - 01/12/13 04:06 PM

Quote:

Hi Bob,
How does the 5X loupe help you for sips adjustment? How do you use it and are there other uses, i.e. collimation? Sounds intriguing.
Thanks for the ongoing reports and insights!
Jonathan




Thanks for the kind words Mike, Nick and Doc. Jonathan, the 5x loupe is a large magnifying glass that I used to increase the image size of Jupiter on the SIPS cellophane tape method to determine when the SIPS was resolving the object perfectly at the focal plane. By using an image magnifier, I can better discriminate the focus on the tape and when the SIPS is tuned to the correct position to provide optimum coma correction for the eyepieces. If you look at the image on the cellophane without magnification, I think it is harder to discriminate when the SIPS is turned in/out just the right amount. When I find that perfect focus point, I then can lock in the SIPS and then check to see that I have not drifted off that perfect spot. It usually takes a time or two to properly tighten the SIPS without degrading the image just a touch because you are dealing with a tightening ring and also rotation of the focuser to lock it in place. As Fast Mike pointed out, he can then use his 17mm Ethos to establish where the best focus is with the eyepiece projecting the target instead of the cellophane tape on the SIPS adapter tool. I measured the distance from the back of the SIPS lens to the edge of my SIPS focusing tool and it was exactly 55mm for my scope. From now on, I can just use that figure to set the distance and not worry about any of the other shenanigans. Simplicity is why I bought the SIPS and I do not want to have to be fiddling with it very often. Bob

Edited by Bob S. (01/12/13 04:09 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | (show all)


Extra information
8 registered and 8 anonymous users are browsing this forum.

Moderator:  ausastronomer, Phillip Creed, JayinUT, okieav8r 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 18716

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics