dslr sensor tilt rather than focus tube something?

[TiffsAndAstro]

so i noticed in all my dslr images i get roughly same pattern as the two images below. there is some variance and these are from stacked images. looking at a few random frames, stacking might exaggerate the effect a bit.

after i rotated my camera approx 180 degrees (not specifically to test ths issue) i noticed the same effect. always top left is smallest then bottom right then top left then bottom right. the amounts vary a bit, as above. when i 'normalise' (think that's the right term) within one image them based on top right (smallest value) they are fairly consistent between each 4 images. 

 

i think this tells me my focus tube/optical train isn't the problem (ie dslr weight pulling tube to one side) but that the dslr sensor itself is tilted? which should disappear if i replace the dslr with my new camera?

if the effect is still there with the new camera, it means the new sensor is tilted (which i can theoretically adjust via screws around the sensor) AND/OR the focus tube is still being pulled to that same side?

this IS possible, as i rotated the camera and the ota in its rings. so im a bit confused....

 

Edited June 16 by TiffsAndAstro

[Stuart1971]

If the tilt does not move sides when you rotate the camera then is means it’s the optical train that’s tilted and not the sensor in the camera, if it was the sensor then the tilt would swap sides when you rotate 180 degrees…

[michael8554]

I disagree.

If the left side of the sensor is tilted, then the left side of images will always be tilted, whatever the rotation.

Michael

[TiffsAndAstro]

The second two images were taken after I rotated the camera by about 180 degrees from where the first two images were taken  and the pattern seems roughly the same same.

[TiffsAndAstro]

25 minutes ago, michael8554 said:

I disagree.

If the left side of the sensor is tilted, then the left side of images will always be tilted, whatever the rotation.

Michael

This seems to be what I see in those images. Possibly with a slight reduction in the two images after rotation by 180 ish degrees

[TiffsAndAstro]

57 minutes ago, Stuart1971 said:

If the tilt does not move sides when you rotate the camera then is means it’s the optical train that’s tilted and not the sensor in the camera, if it was the sensor then the tilt would swap sides when you rotate 180 degrees…

The effect seems to be on the left hand side of the images before and after rotation which makes me think it's the dslr sensor is tilted.

Hoping to be sure before I put a new camera on and decide to play with it's tilt adjustment screws unnecessarily. 

Edited June 17 by TiffsAndAstro

[WolfieGlos]

There was a long topic on it here on SGL with the 72ED and tilt issues, here you go, and another one.

Best of luck with it, @AstroNebulee managed to sort his (using a 533MC if I recall) but I gave up trying to sort out the tilt on mine. Lee must get fed up of me linking him on these topics 😁

Like you Tiff, I also suspected my DSLR sensor, but I had the same result with two different cameras - one modded and one un-modded. I also experienced what you are showing with rotating the camera. When I upgraded to my Starfield 102, the same cameras showed next to no tilt right off the bat. So based on that, I'd suggest it lies elsewhere.

My personal take on it, with hindsight, is the focuser. Looking at the SF102 on FLO, look at the last picture and notice the bar underneath. The 72ED doesn't have this, and I suspect it leads to the drawtube flopping down under weight.

HTH.

[TiffsAndAstro]

20 minutes ago, WolfieGlos said:

There was a long topic on it here on SGL with the 72ED and tilt issues, here you go, and another one.

Best of luck with it, @AstroNebulee managed to sort his (using a 533MC if I recall) but I gave up trying to sort out the tilt on mine. Lee must get fed up of me linking him on these topics 😁

Like you Tiff, I also suspected my DSLR sensor, but I had the same result with two different cameras - one modded and one un-modded. I also experienced what you are showing with rotating the camera. When I upgraded to my Starfield 102, the same cameras showed next to no tilt right off the bat. So based on that, I'd suggest it lies elsewhere.

My personal take on it, with hindsight, is the focuser. Looking at the SF102 on FLO, look at the last picture and notice the bar underneath. The 72ED doesn't have this, and I suspect it leads to the drawtube flopping down under weight.

HTH.

ty for this i'll have a good read. as the tilt seems to move with the camera orientation, im hoping you're wrong

i have a 533 possibly on the way to me as i write this, so i guess that will help determine it once and for all.  would hate to have to return the telescope as i like it.

[Stuart1971]

4 hours ago, michael8554 said:

I disagree.

If the left side of the sensor is tilted, then the left side of images will always be tilted, whatever the rotation.

Michael

You are correct, not sure what I was thinking there, got totally confused….😂

[Stuart1971]

Hmmm, I’m still a bit confused, as if you have sensor tilt and the sensor is tilted away from the scope on the left side, this means it’s closer to the scope on the right side, then when you rotate the camera the sensor is now  tilted towards the scope on the left side, and away on the right side, so yes still tilted but on the opposite side..🤔🤔

[TiffsAndAstro]

15 minutes ago, Stuart1971 said:

You are correct, not sure what I was thinking there, got totally confused….😂

Don't be so hasty, I'm usually incorrect

[TiffsAndAstro]

11 minutes ago, Stuart1971 said:

Hmmm, I’m still a bit confused, as if you have sensor tilt and the sensor is tilted away from the scope on the left side, this means it’s closer to the scope on the right side, then when you rotate the camera the sensor is now  tilted towards the scope on the left side, and away on the right side, so yes still tilted but on the opposite side..🤔🤔

I'm going with as the issue is very similar at zero camera rotation and at near 180 degrees rotation, it's a problem with the sensor.

I think the may be some focus tube slop or something, but not too much.

Also I reasons for optimism. Mine is the later version of the scope, so it might have been addressed a bit and also a square sensor will be a bit less prone to showing it.

Mine doesn't seem as extreme an issue as others seem....

[Stuart1971]

3 minutes ago, TiffsAndAstro said:

I'm going with as the issue is very similar at zero camera rotation and at near 180 degrees rotation, it's a problem with the sensor.

I think the may be some focus tube slop or something, but not too much.

Also I reasons for optimism. Mine is the later version of the scope, so it might have been addressed a bit and also a square sensor will be a bit less prone to showing it.

Mine doesn't seem as extreme an issue as others seem....

Check out my video on testing for tilt with a laser pen on a homemade jig, it works very well and will put your mind at rest…👍🏻

[michael8554]

25 minutes ago, Stuart1971 said:

Hmmm, I’m still a bit confused, as if you have sensor tilt and the sensor is tilted away from the scope on the left side, this means it’s closer to the scope on the right side, then when you rotate the camera the sensor is now  tilted towards the scope on the left side, and away on the right side, so yes still tilted but on the opposite side..🤔🤔

What you say is correct with respect to the the scope sides, but the sensor tilt doesn't alter - it's always on the left side of the displayed image:

[TiffsAndAstro]

18 minutes ago, Stuart1971 said:

Check out my video on testing for tilt with a laser pen on a homemade jig, it works very well and will put your mind at rest…👍🏻

I think I already watched it. Would be perfect except for my lack of jig or laser pen

My main concern was slapping my new camera on it (if it ever arrives) and mistaking 533 sensor tilt for focus tube issues.

I have experience with a total of one focuser, but it seems nice enough to me. I can get bahtinov analyser within a pixel on a 500px box easy enough. The lock screw annoyed me a bit as it throughs that off by 8px when I tighten it, but I've learned to take that into account. Ish. Also I barely tighten it recently.

533 and back focus adapters and focus drawer probably weigh more than my dslr so who knows?

I'm sure it will be happiness and joy once I screw it all together.

And clouds.

[TiffsAndAstro]

6 minutes ago, michael8554 said:

What you say is correct with respect to the the scope sides, but the sensor tilt doesn't alter - it's always on the left side of the displayed image:

I think this is what I have, dslr sensor tilt. I'm pretty sure I had same thing previously using my rubbish* vintage lenses. I blamed the T2 cannon adapter and a Pentax to canon cheapo adapter at the time.

 

* Rubbish for astro. For day time or moon stuff they are pretty decent for the cost.

Edited June 17 by TiffsAndAstro

[Stuart1971]

1 hour ago, michael8554 said:

What you say is correct with respect to the the scope sides, but the sensor tilt doesn't alter - it's always on the left side of the displayed image:

I’m not sure your flipping is correct there…🤔

[WolfieGlos]

2 hours ago, TiffsAndAstro said:

i have a 533 possibly on the way to me as i write this, so i guess that will help determine it once and for all.  would hate to have to return the telescope as i like it.

That should help, the 533 has a square sensor so it won't pick up right into the corners like an APSC sensor will.

Funnily enough I did return my scope to FLO (after a lot of testing, and too-ing and fro-ing), and they kindly took it back and sent it off to ES Reid to be checked. There was an issue which was rectified, and it was vastly improved the first time I used it. But then I still experienced problems after I messed about with spacers trying to perfect it. So simply put, I gave up.

[TiffsAndAstro]

12 minutes ago, WolfieGlos said:

That should help, the 533 has a square sensor so it won't pick up right into the corners like an APSC sensor will.

Funnily enough I did return my scope to FLO (after a lot of testing, and too-ing and fro-ing), and they kindly took it back and sent it off to ES Reid to be checked. There was an issue which was rectified, and it was vastly improved the first time I used it. But then I still experienced problems after I messed about with spacers trying to perfect it. So simply put, I gave up.

Yeah, I read those threads you kindly linked and they just scare me.

This is my first scope and setup, hopefully completely by my eagerly awaited sv605cc. I'm not expecting perfection, just good enough to impress myself. I can already take passable images of f£&£ing galaxies from my suburban back yard for not that much Dosh. Galaxies!

I guess I'll just have to see what happens if I get my new camera attached properly. A bit of tube sag/whatever hopefully won't be the end of the world.

I do have an observatory/astro club 10 mins drive away, if I can ever get there, and they might be able to assist with focus tube stuff. They seem  very friendly.

I should add, I just want a nice pic of m31 and horsehead which with my gear will be far superior to what was possible back when I was at uni  a hundred years ago. A few apods would be lovely, but I'm better at managing expectations than i was back then

Edited June 17 by TiffsAndAstro

[AstroNebulee]

4 hours ago, WolfieGlos said:

Best of luck with it, @AstroNebulee managed to sort his (using a 533MC if I recall) but I gave up trying to sort out the tilt on mine. Lee must get fed up of me linking him on these topics 😁

Not all I don't mind. Hopefully the links and thread can be of use to people. 

It was a zwo asi294mc pro. In the end it was my imaging train (the whole focuser silver ring part that connects to black 72ed tube) that was the issue not my camera 😊. So just collimated the scope and all was good. 

Clear skies 

Lee 

[TiffsAndAstro]

22 minutes ago, AstroNebulee said:

Not all I don't mind. Hopefully the links and thread can be of use to people. 

It was a zwo asi294mc pro. In the end it was my imaging train (the whole focuser silver ring part that connects to black 72ed tube) that was the issue not my camera 😊. So just collimated the scope and all was good. 

Clear skies 

Lee 

Read your posts on those threads and feel bad for you. Probably me too.

Astrophotography is like a box of chocolates....

[WolfieGlos]

6 hours ago, TiffsAndAstro said:

I can already take passable images of f£&£ing galaxies from my suburban back yard for not that much Dosh. Galaxies!

Yeah, I still pinch myself over just what you can see and image from my back garden. When I tell people you can do it with a camera and a 135 or 200mm lens they don’t believe me! When you consider wildlife photographers need 600mm or more, I can frame a whole galaxy with 400mm!

If you have slight tilt it can actually be fixed in post by using BlurXT if you step up to PI and invest in it, but I would always say fix the source of the issue first.

Edited June 17 by WolfieGlos

[TiffsAndAstro]

57 minutes ago, WolfieGlos said:

Yeah, I still pinch myself over just what you can see and image from my back garden. When I tell people you can do it with a camera and a 135 or 200mm lens they don’t believe me! When you consider wildlife photographers need 600mm or more, I can frame a whole galaxy with 400mm!

If you have slight tilt it can actually be fixed in post by using BlurXT if you step up to PI and invest in it, but I would always say fix the source of the issue first.

Definitely good advice to fix problem than deal with symptoms. 

I'm guessing I'll go PI at some point, I can fix eggy stars in siril to some extent, but they still can look bad in other ways.

I'll post a tilt result of the 533 8-11 days

[Stuart1971]

5 day flash sale now on the Svbony camera range, comes out at £460 for the IMX533 colour, (camera only option) with the full import duties and VAT included delivery option…pretty darn inviting TBH….🤔

 

[TiffsAndAstro]

20 minutes ago, Stuart1971 said:

5 day flash sale now on the Svbony camera range, comes out at £460 for the IMX533 colour, (camera only option) with the full import duties and VAT included delivery option…pretty darn inviting TBH….🤔

 

Cost me £514 all in with a filter drawer and one or one filter holders. And either a UV/ir cut filter or DNb or maybe both but unlikely. And a power supply. Or not.

If it arrives and works well it's a bargain I think. 

ATM I'm thinking should have got zwo 585 uncooled and drawer set from a UK shop.

If you have filters and stuff £460 sounds great....