Setting up the E160-ED for Full Frame Imaging

Julien Dufour:
Hi William,

I'm interested in your topic.

I'm spending a lot of time on dealing with tilt issues. And with the APS-C sensor avec the 2600MM.
Getting the Epsilon ready for the IMX455 FullFrame must have been quite a journey !

Did you upgrade the 160ED ? A respectable new focuser ?

Looking forward to read more about it

CS 
Julien

Yeah, I added the Optec Leo focuser, which was a good quality upgrade overall. The big trick was getting the field just right, as the small pixels make that a challenge with any field, but with the full frame chip it is really sensitive. I have tin foil in place now to get the field okay, but that is not precise enough so I will be installing the Octopi Camera Interface soon that will help me dial in the last few tweaks I need to get it just right.

Julien Dufour:
Hi William,

I'm interested in your topic.

I'm spending a lot of time on dealing with tilt issues. And with the APS-C sensor avec the 2600MM.
Getting the Epsilon ready for the IMX455 FullFrame must have been quite a journey !

Did you upgrade the 160ED ? A respectable new focuser ?

Looking forward to read more about it

CS 
Julien

Julien,

I've done a ton of analysis to address tilt and spacing error which are both equally important with this scope.   You can use ASTAP or Nina to process the analysis and guide you to a better result without guesswork. I'm happy to do a writeup here on astrobin if helpful. 

I also have a new e160ed that I will be dialing in with my imx455 camera. I use an octopi, which is the best device for spacing and tilt. I've successfully used others as well, but octopi is king. 

I'll contribute more e160 stuff in this thread as i get first lights. 

Should be fun!!!!

You should post your work on tilt and spacing here on Abin, fresh with everything you learned along the way. I think people would enjoy that.

OK.  I've gotten my first light with my e160ED! 

It's a single frame, manually focused with the stock focuser.  It's with my QHY600, so the big chip.  I'm super excited that the frame looks as good as it does with no tilt or spacing correction!  I can't wait until my LEO arrives and I can really dial everything in. 

Here is where I'm starting:

Kewl! 

Something I would recommend when you install the Leo is check the collimation with the Tak tools. If it's off by much, adjust the saddle to correct the collimation as best you can first before dialing in the collimation. With mine, I had tilt from the saddle (from rushing installing it to try it out that night). I'm pretty certain that if you adjust the saddle as best you can from the start, you can eliminate some or a lot of tilt from the get go. I wish I had done that, but once you touch the secondary & primary collimation, you can't use the collimation as much more than a rough guide for adjusting the saddle.

Adding a very important learning here – if you do replace your focuser with the Leo, and you intend to not use guiding – you absolutely must set the motor to high-speed mode. The residual torque it generates, in high torque mode, will leave long waved residual vibrations that will not show up in short images, but will in long ones.

Adding a very important learning here -- if you do replace your focuser with the Leo, and you intend to not use guiding -- you absolutely must set the motor to high-speed mode. The residual torque it generates, in high torque mode, will leave long waved residual vibrations that will not show up in short images, but will in long ones.

Huh, interesting!

Wouldn't you want to do this even if you are guiding? Even if the vibration frequency is low enough to be guided out, I would think having less stuff for the guider to correct for would be a good thing.

This looks really interesting Chris!  I may have to ditch my GTX130 for a TAK.  The short form factor would work about 10x better on my Mach2 and I like the idea of the bigger field.

John

John Hayes:
This looks really interesting Chris!  I may have to ditch my GTX130 for a TAK.  The short form factor would work about 10x better on my Mach2 and I like the idea of the bigger field.

John

I won't be getting rid of the 130gtx, but I did sell the qtcc reducer. I just wasn't happy with the field quality for imx455.   I really love super widefield so let bill be the guinea pig on the new tak, and after he proved it out I bought one. (Thanks bill!)

The field is massive and the correction is excellent.  Really looking forward to dialing mine in. Octopi is a must!

It's definitely been a solid scope, sans the focuser. For imaging here in the PNW the speed is pretty much the main selling point since we don't get that many nights as you know.

We did get over a pretty long stretch of time and I used that to see how well it could do on a long integration.

https://www.astrobin.com/bcrh5x/F/

At 65 hours that's the longest narrowband integration I have done yet and I think the Epsilon performed marvelously. Still some stuff to work out with spacing and tilt, but the Pegasus Wheel, and Octopi go on today so hopefully testing and tweaking can happen soon.

Daniel Carter:
I am going to get the Optec Leo on order for my E160 tomorrow (just got my 160 on Friday).  They said it would probably be about 8 weeks until it gets to me (bummer). Do you have any tips or advice on installing the Leo?

Thanks,
Daniel

Hi Daniel,

Installation of the Leo is very straightforward. There are 4 screws on the focuser you remove, and they have nuts on the inside of the tube you need to be mindful of. Also, these nuts are painted flat black, so you will want to be careful not to scuff that off or have something like chalkboard paint handy if you need. These screws and nuts are also used during the install of the Leo. I was able to remove and reinstall them with no issues with scuffing. Please ensure you remove the corrector prior to removing the stock focuser.

There are an additional 2 hex bolts on the inside of the stock focuser (more clearly inside of the tube connected to the stock focuser) that you need to remove, and these are not used in the installation of the Leo.

Install the Leo saddle using the 4 screws and nuts you removed from the stock focuser. You may need to pay close attention to alignment of the 4 holes on the Leo saddle, to the 4 holes drilled by Tak into the tube. With some careful finesse (and a few curse words) they should all set squarely and straight. Do not install them crooked. Take your time.  

Once installed, place the dovetail adapter provided by Optec, which has the same threads as the stock drawtube, into the drawtube and lock it down with the set screws. You may need to connect the controller and move the drawtube out to access these set screws. Once that is all done collimate the telescope with the Takahashi collimation tools (with the corrector still removed). Prior to that, and this is very optional, you may want to thread the Optec dovetail in a few (say 3) revolutions to increase where the focuser will come to focus. At proper back spacing from the corrector, I come into focus at 18k steps out of 112k available. This does not cause me any problems, but I did want to note that for others. To do this there is a gold ring above the saddle you unlock, then thread the dovetail assembly in, and lock the gold ring back down. I did not need to do this myself, but it's a worthy call-out.

Once you have collimated the scope, thread the corrector back on, and add your imaging system. Metal back distance is 56.2mm + filter considerations. You may find that you need to tweak this (as I did) which is a whole other ball of wax you can dive into once you make it to this point.  

Congrats on your E-160ED. It is a beast of a telescope and while somewhat of a journey to get perfectly dialed in, the results speak for themselves.

-Bill

Daniel Carter:
Bill,

Thanks for the info! I was really hoping the Gemini would work on the 160 since I already have one for my AG Optical iDK. Optec emailed me back and said that it works on the 180 but not the 160 which was a bummer.

I do have a quick question regarding camera rotation. I have read that some people have had their scope lose collimation when rotating their camera. This was mostly with a stock focuser. Is that something you've witnessed with the 160? 

Thanks for your help!

Daniel

Hi Daniel,

There is a very small change in the collimation even by only rotating the dovetail adapter you collimate through on the Optec. There may be a way to eliminate this, which I assume Chris White will probably figure out since he knows this game much better than I do. 

I am trying out the M54 manual rotator from Agena, so that could be a solution for folks worried about collimation changes. 

-Bill

Daniel Carter:
I am going to get the Optec Leo on order for my E160 tomorrow (just got my 160 on Friday).  They said it would probably be about 8 weeks until it gets to me (bummer). Do you have any tips or advice on installing the Leo?

Thanks,
Daniel

Ditto what Bill said. Take your time installing the saddle. I rushed when I installed mine and it caused me some grief and had to go back and readjust it. The saddle is much easier to install with the OTA on it's side and the focuser facing up. You might want to use the Tak collimation tools with the Leo attached to do a sanity check on the saddle installation and maybe do some tweaks. Just get it in the ballpark but if you do want to make some tweaks, the collimation tools are a handy way to see how much and which way your tweaks move things.

Daniel Carter:
I'm still waiting on Optec to get me an invoice together so I can reserve a Leo. However, I just ordered the Gerd Neumann CTU. Is that the same place the Astronomik filters are shipped from? I ordered the MaxFR filters several months ago and I recall that name on the shipping docs. If that's the case, the shipping is super fast to the US from Europe. I figure I can use the CTU on either the AGO 12.5" or the Epsilon.

I also ordered a custom adapter to get from the corrector to the CTU. 

Now, I get to play the waiting game and be jealous of the fantastic photos you keep posting, Bill.

I am going to get the E160 out on the mount (as soon as it isn't cloudy) and check the results on each side of focus to make sure I don't have any issues with the optics. From what I've read, there have been a few bad versions of the E160 getting shipped. 

Thanks for everyone's input so far!

Daniel

Yes, Gerd Neumann also makes and sells Astronomik filters. You will definitely want to test the optics to make sure nothing is awry with them. There were some cases where people got bad primary mirrors. My copy was not affected, and Chris White recently bought an E160 and his is fine as well.