Veloce 200 collimation issues

Eduardo

Hello, Lukas
In the latest previews from the Veloce 200 I couldn't detect the elongated stars of previous images, but they are difficult to assess from a preview. Do collimation issues still persist or have them already been fixed?

Eduardo

lukas_demetz

Hi Eduardo,

they are still there. It is okay-ish, depending on what you want to do with the data. The top right corner is the worst with elongated stars (basically it is not in the focal plane). As the field of view is huge it is difficult to fix it. We are waiting Officina Stellare's assessment on what to do next, as it might require a little collimation, too...

On the other side, it works pretty well for astrometry and also some pictures coming in indicate it works quite well.
There is also a reflection by an unknown cause (I guess the filter wheel) that as to be removed to have nice pictures 🙂

Eduardo

lukas_demetz Hi, Lukas,
Thank you for your quick answer. I assume you'll keep us informed of any progress as usual
Eduardo

lukas_demetz

Hi there,

FYI, tonight we will have a collaborative meeting with Officina Stellare engineers and opticians as well as our guys on-site to try and tackle the issues. I hope we will end the call with at least a plan of attack as to what causes the issues and how to solve them.
If I may dream a little it would be great to have them removed altogether, but I don't think that's that easy 😅

lukas_demetz

Small(ish) update: We are investigating the issue that sometimes we do have a large reflection on the borders of the image. Good example is the Horsehead Nebula:

It seems to happen if there is a bright star closo to the border of the field of view. Moving the FOV a little can already solve the issue:

My recommendation is: Try to image a single frame in Luminance of your desired target and see if there are some glares. If not, you are good to go and continue. If yes, try to move the FOV by a little and test again.

For the time being this is the only workaround. We will take out the SII filter one of the next days and see if it is caused by the filters, plus look through the OTA with a searchlight and see if we can spot any reflecting border/ring/surface. Those fast optics are tricky...

I also plan on switching to Astrodon filters in the near future to reduce some halos (especially bad on O3 filter, due to a reflection from the corrector coatings), but we want to evaluate better the issues and their causes before doing big works. Once we move the camera the tip/tilt will change again, so expect possible disruptions during our testing.