Now where is that post?

[Demonperformer]

This is going to be one of those really annoying posts, that asks where a post seen about 3-6 months ago is ... I can normally track down such posts with a bit of effort, but I have been searching for this one for a lot of today, without any success ... maybe still-recovering from a chest-infection that has had me flattened for most of the last week is not helping ... anyway, apologies for my lack of success and I turn to all of you ...

It was a post about getting the spacing precisely right between a scope and a camera and it showed two different pictures (diagrams rather than images, I think), one of which had the stars in the corners rotating around the centre, and the other with the stars forming radial streaks (from centre to corner). It said that one of these means the distance is too small and needs to be increased, and the other means the distance is too large and needs to be reduced. Clearly, the (fairly significant) problem is that I cannot remember which picture goes with which condition.

I thought I had copied the images onto my HDD with notes as to which was which, but they seem to have disappeared as well ... so it could be that I just imagined it in a bout of delirium, but I don't think so ...

If anyone can provide me with a link to the post in question [and I know you guys are up to the task], I would be most grateful.

Thanks.

[Grant]

Is it this one? At the bottom:

 

[swag72]

Spacing too close

 

Spacing too much

[brantuk]

Search the entire forum for "back focus" and choose page 10 onwards for 6 moths ago. Sorry I can't be more specific unless you can provide known text from the original post. Hth

[MattJenko]

Has anyone actually confirmed that this is what happens? I have played about with spacing and everything which is not the right spacing looks like a version of the first image, not the second...

[Demonperformer]

Thank you all.

I think they must have been copied in a later post than 2014, but they are definitely the images about which I was thinking.

Knowing me, I shall probably end up with one half of the image going one way, and the other half is going the other ... watch this space!

Thanks.

[Demonperformer]

7 minutes ago, MattJenko said:

Has anyone actually confirmed that this is what happens? I have played about with spacing and everything which is not the right spacing looks like a version of the first image, not the second...

According to Ian's post at the bottom of the first page he has "seen both effects" and "It really does work!" ... which is good enough for me.