Camera Sensor Collimation (with bonus M45 Pleiades)


Chris White
 

ASI6200MM + 130GTX + Field Flattener- 300s x 108
ASI2600MC + Stowaway + 0.8x Telecompressor- 180s x 152

My first attempt with DSO astrophotography was back in 2014 with my 300mm f2.8 camera lens on a star adventurer imaging the Pleiades.  I think I kept 25% of the subs and had about an hour of data with kind of round stars.

Fast forward to 2021 I decided to revisit this popular target with my updated gear and experience.

It's still one of my favorite targets to see people image and I find it beautiful and captivating and challenging all at the same time.

For this I used a mono camera for luminance on a 130GTX and an OSC camera on a stowaway.  It was my first try at dual imaging and while the image has a few warts, I'm pleased with it overall.  I have some tweaks to make to the gear and I'll probably take another pass at the data but for now... here it is.

C&C Welcome and high resolution here:  https://www.astrobin.com/luiz29/0/


Roland Christen
 

Great stuff! You got a whole lot of nebulosity in that shot.

I'm trying to fix the tilt in our 2600MC camera tonight. Having a hard time, plus it's super cold out there. Fingers frozen. How did you manage to get yours dialed in?

Roland

-----Original Message-----
From: Chris White <chris.white@...>
To: main@ap-ug.groups.io
Sent: Thu, Nov 11, 2021 8:29 pm
Subject: [ap-ug] M45 The Pleiades

ASI6200MM + 130GTX + Field Flattener- 300s x 108
ASI2600MC + Stowaway + 0.8x Telecompressor- 180s x 152
My first attempt with DSO astrophotography was back in 2014 with my 300mm f2.8 camera lens on a star adventurer imaging the Pleiades.  I think I kept 25% of the subs and had about an hour of data with kind of round stars.
Fast forward to 2021 I decided to revisit this popular target with my updated gear and experience.
It's still one of my favorite targets to see people image and I find it beautiful and captivating and challenging all at the same time.
For this I used a mono camera for luminance on a 130GTX and an OSC camera on a stowaway.  It was my first try at dual imaging and while the image has a few warts, I'm pleased with it overall.  I have some tweaks to make to the gear and I'll probably take another pass at the data but for now... here it is.
C&C Welcome and high resolution here:  https://www.astrobin.com/luiz29/0/


Stuart
 

Chris that is a super shot!!!

On Thu, Nov 11, 2021 at 9:29 PM Chris White <chris.white@...> wrote:

ASI6200MM + 130GTX + Field Flattener- 300s x 108
ASI2600MC + Stowaway + 0.8x Telecompressor- 180s x 152

My first attempt with DSO astrophotography was back in 2014 with my 300mm f2.8 camera lens on a star adventurer imaging the Pleiades.  I think I kept 25% of the subs and had about an hour of data with kind of round stars.

Fast forward to 2021 I decided to revisit this popular target with my updated gear and experience.

It's still one of my favorite targets to see people image and I find it beautiful and captivating and challenging all at the same time.

For this I used a mono camera for luminance on a 130GTX and an OSC camera on a stowaway.  It was my first try at dual imaging and while the image has a few warts, I'm pleased with it overall.  I have some tweaks to make to the gear and I'll probably take another pass at the data but for now... here it is.

C&C Welcome and high resolution here:  https://www.astrobin.com/luiz29/0/


 

>> I'm trying to fix the tilt in our 2600MC camera tonight. 

I'm contemplating that right now on my 2600mc as well. I'm probably going to build a collimation bench based on some ideas from starlight xpress


On Thu, Nov 11, 2021 at 6:36 PM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
Great stuff! You got a whole lot of nebulosity in that shot.

I'm trying to fix the tilt in our 2600MC camera tonight. Having a hard time, plus it's super cold out there. Fingers frozen. How did you manage to get yours dialed in?

Roland

-----Original Message-----
From: Chris White <chris.white@...>
To: main@ap-ug.groups.io
Sent: Thu, Nov 11, 2021 8:29 pm
Subject: [ap-ug] M45 The Pleiades

ASI6200MM + 130GTX + Field Flattener- 300s x 108
ASI2600MC + Stowaway + 0.8x Telecompressor- 180s x 152
My first attempt with DSO astrophotography was back in 2014 with my 300mm f2.8 camera lens on a star adventurer imaging the Pleiades.  I think I kept 25% of the subs and had about an hour of data with kind of round stars.
Fast forward to 2021 I decided to revisit this popular target with my updated gear and experience.
It's still one of my favorite targets to see people image and I find it beautiful and captivating and challenging all at the same time.
For this I used a mono camera for luminance on a 130GTX and an OSC camera on a stowaway.  It was my first try at dual imaging and while the image has a few warts, I'm pleased with it overall.  I have some tweaks to make to the gear and I'll probably take another pass at the data but for now... here it is.
C&C Welcome and high resolution here:  https://www.astrobin.com/luiz29/0/



--
Brian 



Brian Valente


Chris White
 

On Thu, Nov 11, 2021 at 09:36 PM, Roland Christen wrote:
I'm trying to fix the tilt in our 2600MC camera tonight. Having a hard time, plus it's super cold out there. Fingers frozen. How did you manage to get yours dialed in?
The curse of ZWO tilt strikes again! 

What scope do you have it on? 

I use the Gerd CTU with my ZWO's.  You can achieve the same result with the ZWO tilt plate but I find them pretty crude.  Just a tiny turn of the screw can be too much.  Interestingly, with my 2600 on the stowaway and reducer I had a small amount of tilt after I dialed in spacing.  (66.5mm) and found that a focus offset rounded out the stars and hid the tilt.  You might try a small offset to see if it improves things.  Otherwise the tilt thing for me was a little trial and error.  I'll make an adjustment then refocus using center star with Voyager.  Then see if I made it better or worse.

On my GTX I had significant tilt with the 6200.  The sensor failed and went back to ZWO for replacement.   I asked the tech to please make sure it was installed flat and he put extra care into getting it right.  When it returned to me it was virtually tilt free. 

Like Brian, I'm thinking about building a collimation rig.  There is a really interesting conversation about this on CN. https://www.cloudynights.com/topic/775953-asi6200-tilt-adjustment/


Chris White
 

On Thu, Nov 11, 2021 at 09:59 PM, Stuart wrote:
Chris that is a super shot!!!
Thanks Stuart!


Roland Christen
 

Thanks.
I had to give up for tonight. We had a sudden cloud burst with the scope facing straight up. Lens got nice and wet. Took a minute or so to get the roof rolled over, but laptop and scope are soaked. Oh well, them's the breaks in this business.

Rolando

-----Original Message-----
From: Chris White <chris.white@...>
To: main@ap-ug.groups.io
Sent: Thu, Nov 11, 2021 9:20 pm
Subject: Re: [ap-ug] M45 The Pleiades

On Thu, Nov 11, 2021 at 09:36 PM, Roland Christen wrote:
I'm trying to fix the tilt in our 2600MC camera tonight. Having a hard time, plus it's super cold out there. Fingers frozen. How did you manage to get yours dialed in?
The curse of ZWO tilt strikes again! 

What scope do you have it on? 

I use the Gerd CTU with my ZWO's.  You can achieve the same result with the ZWO tilt plate but I find them pretty crude.  Just a tiny turn of the screw can be too much.  Interestingly, with my 2600 on the stowaway and reducer I had a small amount of tilt after I dialed in spacing.  (66.5mm) and found that a focus offset rounded out the stars and hid the tilt.  You might try a small offset to see if it improves things.  Otherwise the tilt thing for me was a little trial and error.  I'll make an adjustment then refocus using center star with Voyager.  Then see if I made it better or worse.

On my GTX I had significant tilt with the 6200.  The sensor failed and went back to ZWO for replacement.   I asked the tech to please make sure it was installed flat and he put extra care into getting it right.  When it returned to me it was virtually tilt free. 

Like Brian, I'm thinking about building a collimation rig.  There is a really interesting conversation about this on CN. https://www.cloudynights.com/topic/775953-asi6200-tilt-adjustment/


Bill Long
 

+1 for the collimation rig. Peter is looking into a new bearing for the rig he has been using. I'm waiting on delivery of a new QHY600US-M camera and be plan to test it and my 268M on the rig.


From: main@ap-ug.groups.io <main@ap-ug.groups.io> on behalf of Chris White <chris.white@...>
Sent: Thursday, November 11, 2021 7:20 PM
To: main@ap-ug.groups.io <main@ap-ug.groups.io>
Subject: Re: [ap-ug] M45 The Pleiades
 
On Thu, Nov 11, 2021 at 09:36 PM, Roland Christen wrote:
I'm trying to fix the tilt in our 2600MC camera tonight. Having a hard time, plus it's super cold out there. Fingers frozen. How did you manage to get yours dialed in?
The curse of ZWO tilt strikes again! 

What scope do you have it on? 

I use the Gerd CTU with my ZWO's.  You can achieve the same result with the ZWO tilt plate but I find them pretty crude.  Just a tiny turn of the screw can be too much.  Interestingly, with my 2600 on the stowaway and reducer I had a small amount of tilt after I dialed in spacing.  (66.5mm) and found that a focus offset rounded out the stars and hid the tilt.  You might try a small offset to see if it improves things.  Otherwise the tilt thing for me was a little trial and error.  I'll make an adjustment then refocus using center star with Voyager.  Then see if I made it better or worse.

On my GTX I had significant tilt with the 6200.  The sensor failed and went back to ZWO for replacement.   I asked the tech to please make sure it was installed flat and he put extra care into getting it right.  When it returned to me it was virtually tilt free. 

Like Brian, I'm thinking about building a collimation rig.  There is a really interesting conversation about this on CN. https://www.cloudynights.com/topic/775953-asi6200-tilt-adjustment/


Chris White
 

Thanks.
I had to give up for tonight. We had a sudden cloud burst with the scope facing straight up. Lens got nice and wet. Took a minute or so to get the roof rolled over, but laptop and scope are soaked. Oh well, them's the breaks in this business


I feel your pain.  My rain event required my gtx cell and cp4 tonmake a trip back to you.  Hopefully you caught yours in time before the water seeped in to anything. Good luck!


Peter Nagy
 

Hello,

Here are pictures of my collimation rig:

https://peternagy.smugmug.com/Telescopes/SX-Collimation-Rig/

Please read the collimation procedure from StarlightXpress:

https://www.sxccd.com/support/maintenance-information/aligning-the-ccd-in-an-sxvr-camera/

I am using the following mounted ball bearings to rotate my camera:

https://www.mcmaster.com/7728T65/

It works fairly well but the ball bearings has a small play or wobble that can be a bit tricky but with little practice it works okay.

I've been looking for better mounted bearings that's wobble-free and I found one that uses tapered roller bearings instead of ball bearings which is supposed to have much less play or wobble than ball bearings:

https://thebigbearingstore.com/2-type-e-heavy-duty-two-bolt-pillow-block-bearing/

Cross section drawings of roller bearings:

http://www.molinebearing.com/assets/18_type_e_tapered_roller__features_18_19.pdf

It uses dual Timken tapered roller bearings that looks like it has minimal to no wobble. I ordered this bearings and hopefully it will be better. It will take about a week to get it.

If you have better ideas of how to rotate the camera freely, smoothly and wobble-free, please give us ideas.

Thanks,
Peter


 

Peter i just ordered this one too - it's a little less expensive than the mcmaster-carr unit as well



On Fri, Nov 12, 2021 at 5:55 AM Peter Nagy <topboxman@...> wrote:
Hello,

Here are pictures of my collimation rig:

https://peternagy.smugmug.com/Telescopes/SX-Collimation-Rig/

Please read the collimation procedure from StarlightXpress:

https://www.sxccd.com/support/maintenance-information/aligning-the-ccd-in-an-sxvr-camera/

I am using the following mounted ball bearings to rotate my camera:

https://www.mcmaster.com/7728T65/

It works fairly well but the ball bearings has a small play or wobble that can be a bit tricky but with little practice it works okay.

I've been looking for better mounted bearings that's wobble-free and I found one that uses tapered roller bearings instead of ball bearings which is supposed to have much less play or wobble than ball bearings:

https://thebigbearingstore.com/2-type-e-heavy-duty-two-bolt-pillow-block-bearing/

Cross section drawings of roller bearings:

http://www.molinebearing.com/assets/18_type_e_tapered_roller__features_18_19.pdf

It uses dual Timken tapered roller bearings that looks like it has minimal to no wobble. I ordered this bearings and hopefully it will be better. It will take about a week to get it.

If you have better ideas of how to rotate the camera freely, smoothly and wobble-free, please give us ideas.

Thanks,
Peter



--
Brian 



Brian Valente


Chris White
 

Thanks for the links Peter!  Will be very interested in how that new bearing performs. I want to Mount my ctu back through sensor so this would be perfect. Collimate with laser and see if that's easier than star testing. 

Please keep updating!


 

Back to the original topic, this is a really nice M45 Chris! Lots of nebulosity. I always debate how much HDR/detail to pull from the Sisters vs. let it blow out


Brian


Peter Nagy
 

I received the mounted tapered roller bearings from Amazon ( https://www.amazon.com/Moline-Bearing-19321200-Tapered-Diameter/dp/B00O16B6S4 ) today but unfortunately the wobbling is worse than my original mounted ball bearings. That's a bummer. I will return it to Amazon.

 

This one may be the best choice for a collimation rig but I won't order it because my current bearings is good enough.

 

https://www.mcmaster.com/6359k46/

 

Peter


Chris White
 

On Sat, Nov 13, 2021 at 03:41 PM, Peter Nagy wrote:

I received the mounted tapered roller bearings from Amazon ( https://www.amazon.com/Moline-Bearing-19321200-Tapered-Diameter/dp/B00O16B6S4 ) today but unfortunately the wobbling is worse than my original mounted ball bearings. That's a bummer. I will return it to Amazon.

 

This one may be the best choice for a collimation rig but I won't order it because my current bearings is good enough.

 

https://www.mcmaster.com/6359k46/

Thats a bummer peter.  The bearing you linked to from Mcmaster... I dont see grub screws for holding the nosepiece in place.  Does the top of the bearing assembly just squeeze down with those two big bolts on either side?  So loosen and tighten these to remove the nosepiece?


Peter Nagy
 

Chris,

Both of my mounted ball and roller bearings' 2" shaft have extreme tight tolerances to insert 2" nosepiece tight enough that's difficult to spin the nosepiece inside the bearings 2" shaft that the grub screws are not even necessary.

I'm expecting the same kind of tightness for the sleeve bearing I suggested. I'm assuming the two bolts on top of sleeve bearing would be used to adjust the tension on the nosepiece. This is very similar to SX collimation rig which also uses sleeve bearing or bushing but not adjustable tensioner.

I'm disappointed not to be able to find wobble-free ball or roller bearings. I've looked everywhere. Maybe Rolando or George knows? 

Peter


Roland Christen
 

I simply placed my camera (with 2" nosepiece) into a Feathertouch focuser. I set the camera at the first angle position, then tighten the holding screw and take a look at the reflected spots and mark them. Then I loosen, rotate the camera and re-tighten at 3 other rotation angles and mark the spot position. Got it down to zippo in about 5 minutes. Once aligned I can reproduce the spot positions exactly at any angle.

Rolando

-----Original Message-----
From: Chris White <chris.white@...>
To: main@ap-ug.groups.io
Sent: Sat, Nov 13, 2021 4:12 pm
Subject: Re: [ap-ug] M45 The Pleiades

On Sat, Nov 13, 2021 at 03:41 PM, Peter Nagy wrote:
I received the mounted tapered roller bearings from Amazon ( https://www.amazon.com/Moline-Bearing-19321200-Tapered-Diameter/dp/B00O16B6S4 ) today but unfortunately the wobbling is worse than my original mounted ball bearings. That's a bummer. I will return it to Amazon.
 
This one may be the best choice for a collimation rig but I won't order it because my current bearings is good enough.
 
Thats a bummer peter.  The bearing you linked to from Mcmaster... I dont see grub screws for holding the nosepiece in place.  Does the top of the bearing assembly just squeeze down with those two big bolts on either side?  So loosen and tighten these to remove the nosepiece?


Peter Nagy
 

Hi Rolando, 

I have thought of using a rotatable focuser but I wasn't sure if they were 100% wobble-free plus they are expensive. Maybe I could remove the FT focuser from my TEC 160FL scope and somehow mount it in my collimation rig and then put it back to my scope.

So rotating and tightening the FT focuser is consistent? How did you mount the focuser in your collimation rig? Do you have pictures of your collimation rig?

Thanks,
Peter


Bill Long
 

Hmmm I currently have a focuser here that isn't mounted on anything. It's the 3.5" AP focuser...


From: main@ap-ug.groups.io <main@ap-ug.groups.io> on behalf of Roland Christen via groups.io <chris1011@...>
Sent: Saturday, November 13, 2021 3:36 PM
To: main@ap-ug.groups.io <main@ap-ug.groups.io>
Subject: Re: [ap-ug] M45 The Pleiades
 
I simply placed my camera (with 2" nosepiece) into a Feathertouch focuser. I set the camera at the first angle position, then tighten the holding screw and take a look at the reflected spots and mark them. Then I loosen, rotate the camera and re-tighten at 3 other rotation angles and mark the spot position. Got it down to zippo in about 5 minutes. Once aligned I can reproduce the spot positions exactly at any angle.

Rolando

-----Original Message-----
From: Chris White <chris.white@...>
To: main@ap-ug.groups.io
Sent: Sat, Nov 13, 2021 4:12 pm
Subject: Re: [ap-ug] M45 The Pleiades

On Sat, Nov 13, 2021 at 03:41 PM, Peter Nagy wrote:
I received the mounted tapered roller bearings from Amazon ( https://www.amazon.com/Moline-Bearing-19321200-Tapered-Diameter/dp/B00O16B6S4 ) today but unfortunately the wobbling is worse than my original mounted ball bearings. That's a bummer. I will return it to Amazon.
 
This one may be the best choice for a collimation rig but I won't order it because my current bearings is good enough.
 
Thats a bummer peter.  The bearing you linked to from Mcmaster... I dont see grub screws for holding the nosepiece in place.  Does the top of the bearing assembly just squeeze down with those two big bolts on either side?  So loosen and tighten these to remove the nosepiece?


Roland Christen
 


So rotating and tightening the FT focuser is consistent?
I do not rotate the focuser. It is not reliable enough. I simply rotate the camera itself inside the focuser drawtube. Loosen, rotate then tighten with the thumbscrews. It's very repeatable. In my case i rotate inside the AP dovetail adapter, so it's ultra-repeatable, but even a simple 2" adapter is good enough if you gently press it square each time. No need to do a rotation inside a bearing. Just measure 4 fixed rotation points, make sure each fixed point the camera nosepiece is tightened via the drawtube thumb screws. Couldn't be simpler and more elegant.

Rolando


-----Original Message-----
From: Peter Nagy <topboxman@...>
To: main@ap-ug.groups.io
Sent: Sat, Nov 13, 2021 5:45 pm
Subject: Re: [ap-ug] M45 The Pleiades

Hi Rolando, 

I have thought of using a rotatable focuser but I wasn't sure if they were 100% wobble-free plus they are expensive. Maybe I could remove the FT focuser from my TEC 160FL scope and somehow mount it in my collimation rig and then put it back to my scope.

So rotating and tightening the FT focuser is consistent? How did you mount the focuser in your collimation rig? Do you have pictures of your collimation rig?

Thanks,
Peter