Using the "Multi Reticule" tool

[AstroNikko]

Hi Robin,

I'm hoping you could shed some light on how to use the new Multi Reticule tool.

My understanding so far:

• Enable the Multi Reticule tool by selecting it from the Reticules dropdown menu in the toolbar
• Enable reticules using the checkboxes under Show in the Reticule Controls window
• Set the active reticle using the radio button under Adjust in the Reticle Controls window
• Left-click to adjust the position the active reticle
• Right-click to adjust the radius of the active reticle

A few of the tasks I'm looking to understand better are:

1. How do you reset the Mutli Reticule tool?
2. Is there a way to align the reticles to a single reticle after initial placement?
3. Can the coordinates of a reticle be entered manually?
4. How do you open the Reticule Controls window after it's been closed?

I'm using this tool to assist with secondary mirror alignment with the focuser. Using a ZWO ASI290MM mini with 2.1mm CS lens pointed down the focuser, I've set the ROI and adjusted Pan and Tilt to center the opening of the focuser tube as best as possible. There are limitations in how precise the image can be centered. So I then adjust the position of the reticule. Each should be centered on the same position, but I've yet to figure out how to do that elegantly. Currently just eyeballing it with click and drag.

It'd be nice to have the option to individually reset the position of each reticle, and center them with respect to a specific reticle.

Screenshot 2022-10-11 02.33.34.png (701.07 KiB) Viewed 2305 times

Thanks in advance,

Nikko

[admin]

Hi Nikko,

firstly, if you haven't already found it, I posted a thread on how I used the tool to try to collimate here : viewtopic.php?t=5610

Thanks for the feedback on actually using the tool, to answer your specific questions


How do you reset the Mutli Reticule tool?

Right now you have to close and re-open SharpCap. I think a Reset button against each will help solve that problem.

Is there a way to align the reticles to a single reticle after initial placement?

Only manually - is that a problem? It's easy enough to show 2 and move the second to match the center position of the first. I am thinking that anything in the little window that would let you copy the location of one to another would have to be pretty complex and therefore not as intuitive or easy to use.

Remember that you can use the zoom functionality in SharpCap (either from the toolbar or CTRL+Mouse Wheel) to zoom in when placing reticules to do it accurately

Can the coordinates of a reticle be entered manually?

No, but that's not a bad idea

How do you open the Reticule Controls window after it's been closed?

Choose a different reticule and then go back to the multi reticule too. Probably I should make it so closing the window deselects multi reticules, which will make this an obious step if you want it back.

Hope this is useful info - I will make some tweaks based on your feedback for the next update.

cheers,

Robin

[AstroNikko]

Thank you, Robin!

Thanks for sharing the collimation guide. Looks fantastic! I skimmed through it, but will need to read in depth later. Already seeing a few things I need to change with my workflow. Thank you!

A reset button for each reticle in the Reticle Controls window sounds great. Should be all that's needed. I didn't know about the CTRL key modifier for zoom with the scroll wheel. That's really helpful, and really should be all I need.

I was using the multi reticule again last night. Aligning the reticles wasn't too much trouble, but can be tedious. Having a Shift key modifier to enable snapping to the nearest reticle would be a welcomed feature addition, though.

It'd also be nice to have a Shift key modifier when right-clicking to select the nearest enabled reticle, setting it active for adjustment and changing the radius of the reticle in a single action.

As for window functionality, I like the idea of disabling the reticle when the window is closed, but it'd be nice to still have the option of having the reticle on screen without the window taking up screen space. Perhaps with the addition of a minimize button.

Here, I've repositioned the reticles after collimation to check my work, and show how far off center certain elements are.

Screenshot 2022-10-12 01.34.02 crop.png (601.83 KiB) Viewed 2279 times

Screenshot 2022-10-12 01.34.43 crop.png (572.54 KiB) Viewed 2279 times

Screenshot 2022-10-12 01.37.07 crop.png (603.79 KiB) Viewed 2279 times

Thanks again!

Nikko

[admin]

Hi Nikko,

glad that you are making progress. Be careful about trying to align everything on the same center - I think at least one of the views of the secondary should be offset, since it has to be off center in the tube (away from the focuser).

I will look into the ideas of shift dragging and selecting by click.

cheers,

Robin

[AstroNikko]

Thank you, Robin! I appreciate it.

Thanks for the advice. I agree. So far, I think I have everything lined up where it should be in the X direction, but there shouldn't be any offset in the Y direction. The reflection of the secondary (cyan reticle) is offset as it should be. The image of the secondary (yellow reticle) appears tilted off-center downward, though. I had it centered, but when adjusting the collimation screws to center the reflection of the primary (green reticle), they tilted the secondary downward off-center. I may still have some rotation to work out as it appears slightly out of round.

I've been using this guide to help me better understand secondary offset. For the Explore Scientific N208CF, the offset is designed into the secondary holder.

N208CF_SecondaryHolder_Top_sm.jpg (471.38 KiB) Viewed 2252 times

N208CF_SecondaryHolder_Bottom_sm.jpg (467.68 KiB) Viewed 2252 times

With this offset built in, all I really need to do is make sure the vanes of the spider are adjusted at equal lengths so that the secondary assembly is centered on the physical axis of the OTA.

When I started out with this task, my main goal was to see if I could center the secondary under the focuser. Prior to using the the guide camera with CS lens technique, I was under the impression that there wasn't enough travel in the assembly to get the mirror center (more about this starting at 7:35 in this video). I was pleased to find that I was wrong. Saved me a lot of trouble.

I do still think I have an issue with the Hotspot being slightly off center, which I still have to address. Other than that, I think this has been a success so far! I do need to follow the steps laid out in your guide for finding the center pixel on the sensor. Once I had the secondary centered under the focuser, I switched to using a laser collimator to complete the collimation. With the center pixel marked, I shouldn't have to do that.

Thank you again! This new tool and your guidance have been incredibly helpful.

Nikko

[admin]

Hi,

that all sounds good - if you do work out good techniques for dealing with the rotation of the focuser (along the axis of the primary), then it would be interesting to hear them. That's something that I struggled with working out how to do.

cheers,

Robin