How to Adjust Tilt using NINA & Hocus Focus

Updated video is now released in our three part series.

In this video we are discussing how to utilize NINA and Hocus Focus to adjust for tilt & backfocus using the ASG Photon Cage. We dive into running focus curves, calculating focus step size, and how to read and interpret the measurements so you can quickly adjust tilt & backfocus using the Photon Cage.

One quick correction/update lost in the fog of video taking was we discuss tilting in microns on the photon cage and the tilt microns that Hocus Focus gives in values of microns... remember the tilting location is out on the Photon Cage physical device edge, while Hocus Focus is giving tilt adjustments around the sensor which is much smaller... So... if it says 10 micron adjustment, remember that is on the sensor, a user would need to give more than 10 microns out on the Photon Cage ring... sort of lost that in the video, but felt we should note that here.

[jimwaters]

I appreciate you making this technical video. It answered many of my questions and helped me identify and resolve my optical tilt problem. Thanks again.

[Brisbane_Astro]

This and your other demonstrations convinced me to order a cage. Looking forward to getting it and dialing in my backfocus and tilt with ease.

[codykingham]

Great video. Kstars now has an Aberration Inspector with a similar output table. Looking forward to getting my photon cage and working it out with that.

[lmuairy]

beautiful video, thanks for the effort this is by far one of the best explanation to sort out tilt. will def try it over the weekend for my 2600mm

[paulhumberstone]

Fabulous video. Looking forward to trying this method. Many thanks!

[JethroXP]

FYI regarding Celestron telescopes and the Celestron focus motor:

"Thank you for contacting Celestron Technical Support.

The Celestron 8-9.25-11-14 focusers all use same 0.75mm thread pitch for the focus shaft.
The focus motor moves in 1000 steps per motor revolution
Each motor revolution moves the mirror 750 microns.
Thus each step on the motor movement moved the mirror .75 micron."

[drdave]

Wow..excellent, you taught me a lot! I will be using this to work out my tilt. How did you know what's top R and L and Bottom R and L as far as your camera's perspective?

[carlosizquierdo]

The video you have shared is incredible.
One question, what procedure should I do or what parameter can I observe to fine-tune my back focus?
Thank you

[gclaytony]

I adjusted the tilt on my 2600MM last night (using the ZWO OEM tilt plate). One thing you don't cover in the video is achieving some room to make an adjustment. Per the Photon Cage installation video (and how the ZWO Tilt Plate comes), all the adjustments are zero'd (flush) with the adjuster plate. That means the only movement possible is out, there is no "in" adjustment available at that point. My solution last night was to take the three adjustment screws in (pushing out) a relative difference based on the measurement for that region of the sensor (tough to get it right using a triable to adjust a rectangle).

Based on your AI results, it looks like you would want to double the out adjustments on those corners needing out, while going with just the 'single' out measurment on those corners needing to move in. That would at least get you into an area where you would have some room to move on each corner, or that is the way it appears to me. How do you handle this with a bottomed out starting point?

[alalal]

Hi and thanks for the So errr could this be used to climate a C8 SCT with Hyperstar?

[_Astrovert]

I tried to do this last night and found a bunch of .json files in but NINA was asking for a folder. Do I need to turn something on to have NINA save the AF images to a folder? I'm using the HocusFocus plugin for autofocusing. Thanks!

[paulwilson]

So in this modern era, we all have to purchase correctors for our expensive scopes. What do you do about your 2nd camera? How about your other telescope?
Oh well, I have the RASA 8 and I have, I think, worse tilt issues than even a typical one. For which there appears to be no cure. This scope is advertised as having a "flat field". Ha.
At any rate, I am struggling to now learn NINA. I went from my nice 2600s down to a 294 smaller sensor to try to help. I still have yucky stars, even out towards the middle!
I will continue to practice with NINA instead of being able to simply image with my ASIAIR Pro that is so much easer to use but lacks these tools.
My AstroDevices corrector (sigh) has 3 adjustment screws, not 4, so I wonder how this changes the adjustments. I have a nice 2600MM, it's of no use since I have "only" one corrector. I have a Tak 160ED on order. How do I use the corrected cameras on it?
This whole business is a can of worms.

[marktenboer]

The Sensor Model shows a red X on "Model Fit" - is that important ?

[orionm]

Which tilt plate is used for the illustration?

[crateer]

The cage us overpriced for what it is unfortunately..