james_screech

Thank you👍

I've accidentally removed the main menu from CdC, does anyone know how to show it again as I can't work it out?

Take a look at these. http://www.shedshedsheds.co.uk/products/garden-buildings/garden-observatory/ I had a flip top roof observatory made by them last summer. If you want to make one yourself the pictures can give you ideas. Another example of this type of observatory is: http://www.hnsky.org/observatory2.htm

I recently bought a second hand BRESSER Messier MC-100/1400 OTA. When the focuser is adjusted stars move significantly in the field of view, perhaps 0.5 degree per turn of the focuser knob. I assume there is a problem with the focuser not moving the mirror linearly in the tube but tilting it as it moves. This is born out as at times stars become comet shaped, implying that collimation is changing with focus setting. Is it possible to dismantle the OTA and improve the way the mirror moves (re-grease)? I've searched online but cannot find anything myself. Any suggestions would be appreciated. I've found instructions for collimating the scope but that's no good as changing the focus will require it being re-collimated again. James

I could try dimming the panel, I already have an opal acrylic sheet diffuser.

No, the same with the observatory closed at night and no lights on in the observatory.

I've tried rotating the panel and this had no noticeable affect on the gradient, I've also subtracted one master flat from another and I get a gaussian distribution of noise cantered around 0. So I think the panel is fine. I might just have to go back to using a tracing panel (similar to yours) with the scope pointing straight up instead of horizonal. I can only assume something in the image train is moving but I can't figure out what as I can't feel any movement when I put pressure on the camera. The gradient is dark in the bottom left of the image and brightest in the top right (3%-4% difference) as the panel in approximately to the east of the mount, this corresponds to an external vertical gradient due to the sensor orientation. I've checked and checked again that the scope is pointing directly at the panel. I had been hoping to use the EL panel wall mounted and controlled by a USB relay so I could control everything remotely from indoors.

Thanks for the information. However that's not my problem then as my exposure is less than 1 sec.

Nice writeup, you mention that the ASI1600MM-C give gradients on longer exposure flats, that's exactly the problem I've trying to solve for weeks since mounting a EL flat panel on the wall of my new observatory. Do you know what exposure is needed to avoid the gradients?

Teamviewer did the same for me, I filled out there non-commercial use form and after a few weeks it started working again, 4 months later it stopped again. So I now use TightVNC.

Something a bit different but still using a CCD/CMOS/DSLR camera, photometry of a variable star. Possibly a time series or an eclipsing binary, or short period pulsating star.

Can some one recommend windows software for an all sky camera. Ideally something that will run on XP as I was hoping to use my old ASI120MM / XP netbook for an all sky camera. Though I do have a spare Win7 netbook I could use instead. I'm aware of AllSkEye (doesn't support XP though ). James

Is there any free small application that can be used to measure FWHM / HFD from fits / DSLR images. Thank you James

Comet C/2020 F3 NEOWISE, Canon 7D Tamron 150-600 at 150mm, f5, ISO800 on a fixed tripod.

I'm currently having dealings with ShedShesSheds, I'm have a fold down roof observatory built by them, should have it in a few weeks. If you contact them use the mobile number as they tent not to respond to email, and one of the land lines (the one you need) on their website is wrong. James