19 replies to this topic

[gitfiddle]

I have tried searching on google and at highpoint, agena, etc and cannot find who makes these tilt plates that have the adjustment screws on the edge of the plate so you don't have to keep removing your camera.

 

After testing my cameras, it looks like I have 2 with tilt issues:

1) asi2600mc pro

2) asi224mc cool (not 294. . . the smaller sensor 224mc cool) . . .this one's tilt is pretty bad. I don't know if the previous owner messed with the screws that hold the circuit board in place or what, but the tilt on this is much worse than the 2600 and the only thing I see that would cause it are those 4 screws (the zwo sticker that shows if that board has been messed with is intact). I suppose I could test without the cover plate on and just adjust those screws, but that makes me nervous.

 

Suggestions for these?

 

Jon

[gitfiddle]

Found this on one of the videos explaining how to build a laser tilt thing: https://agenaastro.c...ASABEgLpxvD_BwE

 

Anything that is less expensive?

 

Jon

[joshman]

Gerd Neumann CTU, https://www.gerdneum...lting-unit.html

 

I have one on my 2600MM and it's fantastic.

Edited by joshman, 11 August 2024 - 11:21 PM.

[gitfiddle]

Gerd Neumann CTU, https://www.gerdneum...lting-unit.html

 

I have one on my 2600MM and it's fantastic.
 

Thanks! Is the 2600 an m42? Which one did you put on your MM?

[joshman]

Thanks! Is the 2600 an m42? Which one did you put on your MM?

I got the M48 to screw directly to the scope side of the EFW.

 

So my imaging train is: Camera > EFW > CTU > Rotator > Focuser > Scope.

[gitfiddle]

I got the M48 to screw directly to the scope side of the EFW.

 

So my imaging train is: Camera > EFW > CTU > Rotator > Focuser > Scope.
Thanks! Is the 2600 an m42? Which one did you put on your MM? My backfocus on my rigs are 55mm for 2 scopes, and 25 for my rasa. Looks like htis thing is 11.3mm . .. how did you deal with that?

My backfocus on my rigs are 55mm for 2 scopes, and 25 for my rasa. Looks like htis thing is 11.3mm . .. how did you deal with that?

For 55mm, I've used  21mm zwo filter drawer, 16.5mm spacer,  plus the 17.5mm for the camera.

 

My rasa8 has a 25mm requirement ... so for the 2600 I use the Artesky filter holder for Rasa8. No idea how I could use this??

[joshman]

My backfocus on my rigs are 55mm for 2 scopes, and 25 for my rasa. Looks like htis thing is 11.3mm . .. how did you deal with that?

For 55mm, I've used  21mm zwo filter drawer, 16.5mm spacer,  plus the 17.5mm for the camera.

 

My rasa8 has a 25mm requirement ... so for the 2600 I use the Artesky filter holder for Rasa8. No idea how I could use this??

I'm using it on my Tak at the moment, so no real issues with backfocus for that setup, and it will work with my ED102 no worries (55mm backfocus, like you)

 

for the RASA you might be better off with the ZWO M54 tilter that has the screws accessible from the rear, or better yet, a photon cage?
 

[gitfiddle]

I'm using it on my Tak at the moment, so no real issues with backfocus for that setup, and it will work with my ED102 no worries (55mm backfocus, like you)

 

for the RASA you might be better off with the ZWO M54 tilter that has the screws accessible from the rear, or better yet, a photon cage?
 

What spacers are you using for the 55mm backficus? The 2600 is 17.5mm, this tilt plate is 11.3mm, filter drawer is 21mm, which leaves another 5.2mm? Is there something in your train that accounts for this?

 

For the rasa, I’d be adjusting on my little laser thing. I suppose the question is since I’ll be using the 2600 across a couple of rigs, how do I get things working so I don’t have to adjust tilt on my scopes that have their own tilt plates (redcat71 with)…if I adjust tilt on the scope, then it screws up my 183mc pro and 294mc pro that don’t have tilt issues.

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Edited by gitfiddle, 12 August 2024 - 12:52 AM.

[joshman]

What spacers are you using for the 55mm backficus? The 2600 is 17.5mm, this tilt plate is 11.3mm, filter drawer is 21mm, which leaves another 5.2mm? Is there something in your train that accounts for this?

 

For the rasa, I’d be adjusting on my little laser thing. I suppose the question is since I’ll be using the 2600 across a couple of rigs, how do I get things working so I don’t have to adjust tilt on my scopes that have their own tilt plates (redcat71 with)…if I adjust tilt on the scope, then it screws up my 183mc pro and 294mc pro that don’t have tilt issues.

My EFW bolts to teh front of the 2600, which requires the removal of the 5mm tilt adapter, so i have 12.5mm, then ~20mm for the EFW, then 11.3mm for the CTU, so i need to make up 11.2mm. I think I'd probably use a 10mm spacer, and make the rest up with shims. (or in your case, a 5mm spacer and the 0.2mm in shims.) though i would star test and adjust as needed.

 

I would leave the 2600mm, EFW and CTU always assembled and move it between setups. The CTU should be used to adjust sensor tilt only. you might need to square up and firm up your focuser drawtubes with a laser first, to remove any tilt on the scope side, then do your camera tilt adjustments with the CTU under the stars.

 

as a rough methodology,

• use a laser to get your scopes square and true
• assemble your imaging rig with the CTU wound completely flat.
• Make sure you have ASTAP downloaded
• Under a some nice skies have your scope pointing roughly straight up (i recommend pointing west of the meridian to give yourself ample time)
• Set your favourite imaging program to continuously shoot ~2second frames with a high gain, and save the images into a folder
• Use ASTAP to read and analyse each image for tilt as it comes in.
• dial in your tilt as needed.
  • a word of advice here, only make adjustments every 3-4 images, to allow the scope to settle from your involvement, and to "average" out the tilt requirement, patience is key here.
• To confirm, rotate your camera/EFW/CTU 90 degrees and let the tilt measurments continue. if the tilt measurement differs wildly, you've likely still got tilt in the scope focuser mechanism or camera connections. (you should probably do this step first, TBH)

 

ditch the compression ring attachments, and exclusively use threaded connections, we're dealing with micron level precision, and compression fittings aren't good enough IMHO.

Edited by joshman, 12 August 2024 - 05:45 PM.

[gitfiddle]

ditch the compression ring attachments, and exclusively use threaded connections, we're dealing with micron level precision, and compression fittings aren't good enough IMHO.

If it's threaded, I cannot spin the camera (I'm just talking about that rigged up thing, not taking my scope in the field to measure). I may be misunderstanding something. If I put it in a threaded design, then when I turn the camera, won't the sensor get closer to/farther from the laser as it is turned, thus 'mimicking' tilt?

 

I had thought about the downside of using that compression ring...the potential wiggle factor...even if I get it tight enough that I don't feel wiggle, but loose enough for the camera to spin, there may still be wiggle...I know it is far worse if I leave the laser thing horizontal as I have to cinch down the compression ring to hold the camera in place, then loosen it, spin, then tighten etc.

Edited by gitfiddle, 12 August 2024 - 07:01 PM.

[joshman]

If it's threaded, I cannot spin the camera (I'm just talking about that rigged up thing, not taking my scope in the field to measure). I may be misunderstanding something. If I put it in a threaded design, then when I turn the camera, won't the sensor get closer to/farther from the laser as it is turned, thus 'mimicking' tilt?

 

I had thought about the downside of using that compression ring...the potential wiggle factor...even if I get it tight enough that I don't feel wiggle, but loose enough for the camera to spin, there may still be wiggle...I know it is far worse if I leave the laser thing horizontal as I have to cinch down the compression ring to hold the camera in place, then loosen it, spin, then tighten etc.

laser tilt jigs usually use a bearing housing mounted at the camera centre of gravity to spin the camera, thus eliminating any wiggle or gravity-sag. The compression fitting has a "fixed" point at the sensor end, and the weight of the camera hanging off the back will be enough to throw out any measurements.

 

To better illisturate why the compression ring is a bad idea:

Differential flexure is a real issue in guiding, where micron sized differential movements between a "fixed" guidescope and the scope it is riding on, can cause streaking in the main image because the mount is guiding the guidescope, not the imaging scope. This is why Off-axis guiding is so good.

 

I guarantee that the compression fitting is likely to introduce more tilt than it solves, though if you were to vertically mount the arrangement, you could maybe eliminate most of the issue.

 

Tilt can be thought of as a difference in back-focus across the sensor plane. if 0.1mm of backfocus can be what it takes to perfect your backfocus across a sensor field, can you guarantee that you're not introducing that much difference as you rotate the camera?
 

[gitfiddle]

I guarantee that the compression fitting is likely to introduce more tilt than it solves, though if you were to vertically mount the arrangement, you could maybe eliminate most of the issue.

 

Apparently I left that part out. That is exactly what I do. I mount the laser thing on my mount, then put it vertical, so the camera sits on top. I tighten the 3 compression ring adjustment screws to barely snug, then back each off to where the camera can spin freely. I 100% agree with the issue of using this setup horizontally . . .

 

I'm actually not going to try and get perfection on this . . . but as it stands, the plots of my 2600mc pro when I spin the camera in 30degree leads to a noticeable circle about the size of a dime . . . the 224mc cool (not 294mc pro) has an enormous circle, probably the size of a hockey puck! Since I don't really use that one, I may see if I can improve that one by adjusting the 4 screws that hold the green circuit board down.

 

Here's an older version of what I have now -- disregard the 'red dot' thing at the bottom...that's now what you see on the L brackets--the top is the same though: The 2" compression ring focuser end sitting in a 3" scope ring where 2" bolts are used to hold the compression ring focuser end that the camera sits vertically in.

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[Oort Cloud]

For your 2600, the easiest solution is to pair it with the OAG-L for guiding. That allows you to bolt the EFW directly to the camera face, and the OAG-L directly to the EFW. Then, the tilt plate, which was removed from the camera face, gets bolted to the OAG-L so you can adjust tilt without disassembling anything.

I use this setup currently, and it is the bees knees. TBH, it keeps everything so well aligned and squared, that I did not have to adjust tilt at all once I connected it all. And when I want to swap OTAs, I simply undo the only threaded connection (OTA to tilt plate on OAG) and move the whole thing over to the next OTA, without any need to transfer a guide camera, as it is a permanent part of the imaging train.

[gitfiddle]

For your 2600, the easiest solution is to pair it with the OAG-L for guiding. That allows you to bolt the EFW directly to the camera face, and the OAG-L directly to the EFW. Then, the tilt plate, which was removed from the camera face, gets bolted to the OAG-L so you can adjust tilt without disassembling anything.

I use this setup currently, and it is the bees knees. TBH, it keeps everything so well aligned and squared, that I did not have to adjust tilt at all once I connected it all. And when I want to swap OTAs, I simply undo the only threaded connection (OTA to tilt plate on OAG) and move the whole thing over to the next OTA, without any need to transfer a guide camera, as it is a permanent part of the imaging train.

I've never really considered an OAG, but I didn't understand the benefit you are describing. I'll start looking for one to use with the 2600 (plus the tilt plate).

 

Thanks!

Jon
 

[gitfiddle]

ditch the compression ring attachments, and exclusively use threaded connections, we're dealing with micron level precision, and compression fittings aren't good enough IMHO.

Hey, what OAG do you use? I keep finding compression ring OAG's and am having a tough time finding which ones are threaded. Oh, and are you saying to look for both connections to be threaded, or just one (Ie, threaded where 1) the OAG connects to the OTA,  and 2) where the OAG connects to imaging camera)?

 

Thanks!

Jon

Edited by gitfiddle, 16 August 2024 - 02:00 PM.

[archiebald]

I know this may not to help the OP, and may be off topic, but to anyone else considering this type of problem, Player One cameras come with an integrated tilt plate that can be adjusted from behind the camera (no need to disassemble anything during tilt adjustment).  This is largely due to the squared off shape of the camera, but the design of the tilt plate may be worth looking at to see if the OP's existing hardware can somehow be modified.

 

Or, it might even be possible to adapt one of Player One's accessory tilt plate adapters to the OP's needs?  https://player-one-a...cooled-cameras/

 

There is also a couple of images on this page that might help, scroll down to "Front 3P and Rear 4P tilter plate" and "BFL Solutions" (two different sections)   https://player-one-a...-camera-imx585/

[Oort Cloud]

I know this may not to help the OP, and may be off topic, but to anyone else considering this type of problem, Player One cameras come with an integrated tilt plate that can be adjusted from behind the camera (no need to disassemble anything during tilt adjustment). This is largely due to the squared off shape of the camera, but the design of the tilt plate may be worth looking at to see if the OP's existing hardware can somehow be modified.

Or, it might even be possible to adapt one of Player One's accessory tilt plate adapters to the OP's needs? https://player-one-a...cooled-cameras/

There is also a couple of images on this page that might help, scroll down to "Front 3P and Rear 4P tilter plate" and "BFL Solutions" (two different sections) https://player-one-a...-camera-imx585/

The ZWO one works just as well, provided you bolt everything together, bc doing so requires you to relocate the tilt plate from the camera face to the front of the OAG, where it can easily be accessed while assembled.

[bobzeq25]

My rasa8 has a 25mm requirement ... so for the 2600 I use the Artesky filter holder for Rasa8. No idea how I could use this??

RASA 8 owner here, one who tried all kinds of camera mounting systems.

The only "cheap" (relatively) way to go here is to replace the Artesky with a custom adapter from Precise Parts. The problem is, you have to figure out the optical length, PP just makes stuff.

The RASA 8 can be a great scope, but it OFTEN is a handful.

[gitfiddle]

RASA 8 owner here, one who tried all kinds of camera mounting systems.

The only "cheap" (relatively) way to go here is to replace the Artesky with a custom adapter from Precise Parts. The problem is, you have to figure out the optical length, PP just makes stuff.

The RASA 8 can be a great scope, but it OFTEN is a handful.

I'll take the Rasa out when it cools off a bit since I put it on the eq6r pro . . . it may be close enough for me to just use BXT to fix stuff, but I'll enjoy the process of getting it dialed in when I'm up in the mountains again. Tried a Pleiades68 since it's fast, but there were all sorts of issues with backfocus not being right, focal length not being right and the rotator being a bit off . . . decided to return it and just get the more known and simpler redcat 71. FINALLY clear sky tonite so I'm taking it out for it's first test run.

 

thanks!

Jon
 

[gitfiddle]

To better illisturate why the compression ring is a bad idea:

Differential flexure is a real issue in guiding, where micron sized differential movements between a "fixed" guidescope and the scope it is riding on, can cause streaking in the main image because the mount is guiding the guidescope, not the imaging scope. This is why Off-axis guiding is so good.

 

I was looking at an OAG to see if it might help but in another thread where I'm asking for advice it sounds like there may not be much benefit on shorter focal length scopes like the RedCat71. I don't think you were suggesting that I do an OAG, but if it had guiding benefits in addition to stabilizing a tilt point, I figured I'd look into it.

 

Got any thoughts on that? I'm thinking if I am sure that my scope is dialed in and there's no focuser tube sag etc, then just using the tilt plate on the 2600 ought to be all I need.