Tilt in focuser

With the reducer you are seeing further off axis so an aberrations will be more apparent. No doubt it's there at F/7, just out of the field of view of the sensor.

How do you know you have tilt? Are you seeing mis-shaped stars in the corner or are they just out of focus but still round. 

Lastly, how is your collimation?

Dear all,
I have an Esprit150 -not a 120- but since these scopes share the same focuser and there's no Esprit150 dedicated forum, I ask here
The fact is that I've noticed some mild tilt on it. Not seen when imaging at its native f/7 ratio, but more apparent in one corner when imaging with my 0.8 point reducer. I know it's not a reducer problem as I've tried a couple of different ones with similar results. SO my question is, do you know how, and if it is easy, to correct for tilt in this focusers?
I'm happy imaging at f/7 anyway but would like to know how easy/complicated would it be to try to fix that myself -or even if it's better not to touch it and make things terribly worse.
Best,
Ferran.

My focuser was awful on Esprit 120ED. Sky Watcher confirmed that it was awful. I took a simple, but expensive route: rid of their focuser and put Moonlite one with high resolution motor. System became perfect. APC-sized sensor. No problem. Precision during focusing is phenomenal; zero backlash at -10 to +35 temperatures. 

All the best!

Clear skies!

Armen

With the reducer, this setup becomes demanding enough that all the factors like quality variability in spacers and accessories on down to tilt in the sensor can add up and translate to tilt that is apparent in images. It comes to a point where it may be necessary to correct for tilt in the optical train to meet a higher standard, if needed.

For what it’s worth—maybe not much, because copy variation exists—I have a tilt corrected camera with quality adapters which I move between my equipment, and the stock Esprit 120ED focuser on my copy of the telescope has not been a source of any material tilt issues. But I *have* encountered major quality control issues in things like adapters, for example one ZWO spacer I owned was almost 0.4mm off on one size relative to the other.

Add a tilt corrector to your imaging train: https://starizona.com/products/zwo-m54-tilter 
If you have a sample image, it would be helpful to rule out any other issues, such as back focus. If the misshaped stars are in all corners and not just one corner/side, then this would indicate that your back focus is off. Baadar makes some suitable spacers that I have used on my WO Pleides 68, which is very sensitive to back focus. If you have limited clear nights, I would recommend a back-focus adjustment ring for easy adjustments without disassembling the image train https://agenaastro.com/catalog/product/view/id/11230/s/askar-m54x0-75-thread-spacer-ring-backfocus-adjuster-with-variable-16mm-20mm-extension/?gad_source=1&gclid=EAIaIQobChMI9YqR1f3qiAMV3ZlaBR12ISSjEAQYASABEgKWe_D_BwE
I will be adding this to my Esprit 120.

Have you ever had a problem with your Esprit150 Focuser slipping out of focus? I've never had a tilt issue, but recently, this happened.

I hate to bring this up again but since the problem persists, how do you know it's tilt that's the issue. A sample image would really help.