May 19 2022
Last night I got the Mak out for the first time since 2020. Literally had to use a broom to wipe off the cobwebs and accumulated dust. Luckily no paper wasps had taken up residence in the crevices this time.
A number of things were accomplished:
- Identified the laptop that has the configuration for the Mak and the widefield setups.
- Put a desktop image on each to help keep track of the systems. Note that system 1 has SV4 and film configs. System 2 is the one for the Mak, it's also the Win 10 device. System 3 is the one for the wide field setup.
- Reconnected VNC with reboot and resetting network to private.
- Refocused the guide cam on the ST80 and gathered new library of darks (identified with guider serial number!)
- Mounted red dot finder on the ST80 (not aligned yet).
- Used the new metal stalk that I got from agena astro. Nice to know that the finder scope is still dead on.
- Cleaned the filters on the QSI camera and noted the filter positions. There were some deposits on them, removed with a microfiber cloth.
- New bahtinov mask in place, @focus3 runs but misses final focus position. Not sure if it overshoots or undershoots. Will figure out in coming days. Will need to see if the final focus position number keeps moving which indicates slippage. If not, then it's backlash and a large number may need to be dialed in.
To be done:
- Patch PHD2 to latest version.
- Patch CCDAP to latest version.
- Clean front element of Mak.
- Assemble all the bahtinov masks and put in lens box.
- Figure out the focus backlash on @focus3. (also check @focus2). Confirm CCDAP will do it - and confirm if it will work in a dim field.
- Re-initialize CCAP with PHD2 controller.
- Login to Gemini to check battery state.
- Cleanup wire mess at mount, zip tie cables as needed.
- Identify why the USB hub in the power box doesn't work - had to directly wire the USB.
- Open ND filter gels and do flats (or use daylight flats).
Once I do all the above, I can finally do a run on a galaxy and see how it looks.
Update May 20
Last night I ran @focus3 about 30 times with varying settings. Slowly approached the best backlash settings for the focuser. Because the Mak has a moving mirror, it's best to approach focus from just one side. Unfortunately, the range of focus spans about 1000 units and the standard backlash correction in the routine wasn't enough to properly adjust it out.
Finally settled on a rather large backlash setting of 620 units with a search range of 180. Sounds odd, but it gave consistent results with the bahtinov mask in place.
Once the camera was properly focused, switching the filters did not alter the focus. This makes sense since there is only one refractive element in the imaging train (corrector plate on the Mak). This means that I can set the system to focus using the L or LP filter and not waste time on refocusing for different bands.
Tonight I'm ready to try the initialization and other steps to take some shots of M51.