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 | (show all)
FastMike
sage


Reged: 09/22/10

Loc: Florida 27° 15' N
Re: Webster F3 24" new [Re: gatorengineer]
      #5859675 - 05/14/13 11:39 AM Attachment (16 downloads)

Quote:

You and Mike L have an entirely different explanation of the functioning of the sips device.




I know it's confusing if you never used a SIPS before. Maybe Mike L can explain it better.

When using a SIPS the Paracorr lens never moves once it's installed. So what you seen in the picture below is where the Paracorr lens is always located. Which is why I keep saying a larger 3" focuser is not needed.

The SIPS lens can be moved when first installing the SIPS. This is done to set the lens at the proper distance from the primary. Once the distance is set the lens is locked down and never moves again.

Here is a link to installing the SIPS from Mike L.

http://www.loptics.com/documents/SIPS.pdf

Try this the next time you use the Paracorr 2. Adjust it to the proper setting for an eyepiece (A-B-C etc) and focus the scope. Next look into the UTA and note where the Paracorr 2 field lens is located. The lens on your Paracorr 2 will be at the exact same location as a SIPS lens would be. Now put in a different eyepiece and use the tunable top to focus (don't use the focuser). Note the position of the tunable top (A-B-C etc). If you did it right the tunable top will be in the correct position (A-B-C etc) for the new eyepiece you are now using. Now you can now go the rest of the night without ever using the focuser again, just use the tunable top to focus.


Post Extras: Print Post   Remind Me!   Notify Moderator  
gatorengineer
Carpal Tunnel
*****

Reged: 02/28/05

Loc: Hellertown, PA
Re: Webster F3 24" new [Re: FastMike]
      #5859835 - 05/14/13 12:40 PM

Mike,

I appreciate the tip, but the Optimal locations for the different eyepieces a 17E, is different than the 3.7sx on the paracorr 2, necessitate the focuser... If I werent waiting on the 30mm 100 degree explore, I might go to a SIPS, but I need a 3" focuser for that beast, along with about 30 lbs more of tail weight....


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jarad
Postmaster
*****

Reged: 04/28/03

Loc: Atlanta, GA
Re: Webster F3 24" new [Re: gatorengineer]
      #5859861 - 05/14/13 12:53 PM

Quote:

I appreciate the tip, but the Optimal locations for the different eyepieces a 17E, is different than the 3.7sx on the paracorr 2, necessitate the focuser...




Yes, that is the whole point of the SIPS - the focuser does not move the paracorr lens, it moves the eyepiece relative to it. As someone else pointed out a few posts back, the SIPS basically replaces the tunable top of the paracorr with a Feathertouch focuser. You adjust the paracorr to the proper position once, then the focuser adjusts the eyepiece relative to the fixed paracorr.

Ideally, you should be doing the same thing with the Paracorr II. Focus one eyepiece with the tunable top set properly for it, lock your focuser, then when you switch eyepieces you don't move the focuser, you just change the tunable top setting.

Jarad


Post Extras: Print Post   Remind Me!   Notify Moderator  
gatorengineer
Carpal Tunnel
*****

Reged: 02/28/05

Loc: Hellertown, PA
Re: Webster F3 24" new [Re: Jarad]
      #5859895 - 05/14/13 01:13 PM

That would work if Ethos Eyepieces were parafocal, or had the same Paracorr setting. They dont....

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: Webster F3 24" new [Re: gatorengineer]
      #5860066 - 05/14/13 02:26 PM

Quote:

That would work if Ethos Eyepieces were parafocal, or had the same Paracorr setting. They dont....




Tuning the Paracorr IS parafocalizing to put the focal plane in the right spot: The tunable top positions the eyepiece so that when focused, the focal plane is always 135mm above the bottom of the lens group.

That is all the Paracorr "setting" does - the lens group is unaffected.

The tunable top simply makes up for the physical differences in how the eyepieces are constructed. With the SIPS, the focuser does it.

For the Paracorr 2 (either SIPS or tunable top), the focal plane must be 135mm from the bottom of the lens group for optimal performance.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jarad
Postmaster
*****

Reged: 04/28/03

Loc: Atlanta, GA
Re: Webster F3 24" new [Re: gatorengineer]
      #5860081 - 05/14/13 02:32 PM

They don't need to be parfocal or use the same setting - that is the point of the focuser or tunable top. The paracorr lens stays still, the eyepiece moves.

In the picture of the SIPS that Mike L posted above, the focal plane is at the line just above the "47mm" at top right. The lens at the bottom does not move relative to the focal plane or relative to the mirror. You put the eyepiece in the focuser, and the focuser moves the eyepiece only up or down to place the eyepiece's focal plane at the telescope focal plane.

The tunable top does the same thing, only without as fine a motion (so most people adjust it to the closest setting, then use the focuser, which does move the paracorr lens slightly away from where it should ideally be).

Once again, the paracorr lens stays still, the eyepiece moves. If you change eyepieces and they are parfocal, the eyepiece won't need to move either. If they are not parfocal, the focuser will move the eyepiece only, not the paracorr lens.

Jarad

Edited by Jarad (05/14/13 02:34 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pinbout
Postmaster
*****

Reged: 02/22/10

Loc: nj
Re: Webster F3 24" new [Re: Jarad]
      #5860981 - 05/14/13 09:21 PM

I never used either so here's my question, I find myself adjusting focus cause of seeing conditions... a lot, so would I keep my hand on the tunable top or the focuser for those nights when seeing is not so good a lot.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Jarad
Postmaster
*****

Reged: 04/28/03

Loc: Atlanta, GA
Re: Webster F3 24" new [Re: Pinbout]
      #5861559 - 05/15/13 07:13 AM

Assuming you have the tunable top set correctly, you make adjustments with the focuser.

Jarad


Post Extras: Print Post   Remind Me!   Notify Moderator  
mark cowan
Vendor (Veritas Optics)
*****

Reged: 06/03/05

Loc: salem, OR
Re: Webster F3 24" new [Re: Jarad]
      #5868090 - 05/17/13 08:30 PM

Hi y'all,

I chatted with Wayne at Starlight Instruments about the SIPS, this thread and the confusion factors, ended up just revising a couple of paragraphs in the installation instructions to clarify what seemed to be unclear to me. They took that and used it, but I'm not trying to take away from Mike L's time and effort in preparing the instructions and enabling the product development in any way.

Here's where it all is: http://starlightinstruments.com/store/index.php?route=product/product&pro...

Anybody who'd like to review the documentation there and provide feedback to Starlight, I'm sure they'd appreciate it. This is the information that people get when they're trying to figure out how to use it. One point that I'm not yet sure is clear there is what Mike addressed early on, the relative position of the PII corrector, the original FP, and the new FP with the PII installed. This seems to be the heart of the matter regarding confusion about field illumination, but it also needs to be taken into account while laying out the OTA.

Best,
Mark


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: Webster F3 24" new [Re: mark cowan]
      #5868359 - 05/17/13 10:49 PM

Quote:

One point that I'm not yet sure is clear there is what Mike addressed early on, the relative position of the PII corrector, the original FP, and the new FP with the PII installed.



I think the diagram is quite clear. This diagram was developed based on conversations that I had with Al Nagler.

Quote:

They took that and used it, but I'm not trying to take away from Mike L's time and effort in preparing the instructions and enabling the product development in any way.
Here's where it all is:



Well, since your name is now literally in the .pdf file name, one of your companies is mentioned right by it on their site, and I am merely a footnote in the instructions, someone in fact did take away from the many hours of effort that I put into that manual and all of the photos that go with it.

Wayne should have contacted me, the author, to help clarify and update those paragraphs if that was desired. You don't make minor changes in a written work and then put someone else's name on it.


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


Reged: 11/24/07

Re: Webster F3 24" new [Re: Mike Lockwood]
      #5868374 - 05/17/13 10:57 PM

There is another flaw in the instructions to the SIPS (in the early instruction at least). Not focus the image with the E-17, 21 and N-31 (at a certain myopia).
Or with myopia needs another choice FP during the initial installation? How?

Edited by a__l (05/17/13 11:19 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: Webster F3 24" new [Re: a__l]
      #5868430 - 05/17/13 11:23 PM

Quote:

There is another flaw in the instructions to the SIPS (in the early instruction at least). Not focus the image with the E-17, 21 and N-31 (at a certain myopia).



No, that's not a flaw in the instructions, that's a design issue that you should bring up with the manufacturers.

Changing the instructions will not change it.


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


Reged: 11/24/07

Re: Webster F3 24" new [Re: Mike Lockwood]
      #5868446 - 05/17/13 11:30 PM

SIPS this is fully complete device, including design.

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


Reged: 08/21/11

Loc: Nashville
Re: Webster F3 24" new [Re: FastMike]
      #5868494 - 05/17/13 11:56 PM

FastMike and Mike Lockwood, I want to thank you guys for your contributions to this thread. I've been fascinated by the 28" Webster/Lockwood f/2.75 since I first read about it. I've read and re-read every post and article I could find on it. Please keep posting. And Mike L., please keep making those big, fast mirrors.

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


Reged: 09/22/10

Loc: Florida 27° 15' N
Re: Webster F3 24" new [Re: eastwd]
      #5868544 - 05/18/13 12:24 AM

Quote:

FastMike and Mike Lockwood, I want to thank you guys for your contributions to this thread. I've been fascinated by the 28" Webster/Lockwood f/2.75 since I first read about it. I've read and re-read every post and article I could find on it. Please keep posting. And Mike L., please keep making those big, fast mirrors.




I posted more information recently on Mike Lockwoods yahoo group including 10 links to CN on past discussions as well as an eyepiece review using my f/2.75 scope.

Here is the link. You should check it out if you haven't seen it already.


Post Extras: Print Post   Remind Me!   Notify Moderator  
mark cowan
Vendor (Veritas Optics)
*****

Reged: 06/03/05

Loc: salem, OR
Re: Webster F3 24" new [Re: Mike Lockwood]
      #5870509 - 05/18/13 11:38 PM

Quote:

Quote:

One point that I'm not yet sure is clear there is what Mike addressed early on, the relative position of the PII corrector, the original FP, and the new FP with the PII installed.



I think the diagram is quite clear. This diagram was developed based on conversations that I had with Al Nagler.




They didn't have the illustration you posted earlier in this thread on their product page for some reason, and I asked them to fix that specifically. I agree it made it clear, but if it couldn't be seen it wouldn't make it clear.

Quote:

Quote:

They took that and used it, but I'm not trying to take away from Mike L's time and effort in preparing the instructions and enabling the product development in any way.
Here's where it all is:



Well, since your name is now literally in the .pdf file name, one of your companies is mentioned right by it on their site, and I am merely a footnote in the instructions, someone in fact did take away from the many hours of effort that I put into that manual and all of the photos that go with it.
Wayne should have contacted me, the author, to help clarify and update those paragraphs if that was desired. You don't make minor changes in a written work and then put someone else's name on it.




I've forwarded these complaints to Wayne and asked them to remove any credit to myself (which I never asked for). Credit belongs where credit is due, but in the end it's up to them how they handle their product documentation.

Best,
Mark


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | 3 | (show all)


Extra information
11 registered and 39 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: 2874

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics