Hello
Happy to have the observatory open this last couple of nights, first time since early Dec. Be gone Summer!
I have acquired a Sigma Art 135mm lens and coupled it to the QHY600C. The weight of the lens certainly is an issue and off axis is not pretty so this image is cropped a small amount. I have some stop down rings coming.
I take it the lens has an electronic aperture? Some older lenses like Nikon have a little tab that slides on the mount to open/close the aperture. You can fix it in place with a tooth pick or similar. But a modern lens with electronic aperture probably can't unless you put it on your DSLR, set it to a particular aperture then turn the camera off but the lens may default on power off to wide open - but worth a try?
Stop down rings are better though as they don't create sunstars out of every bright star.
I take it the lens has an electronic aperture? Some older lenses like Nikon have a little tab that slides on the mount to open/close the aperture. You can fix it in place with a tooth pick or similar. But a modern lens with electronic aperture probably can't unless you put it on your DSLR, set it to a particular aperture then turn the camera off but the lens may default on power off to wide open - but worth a try?
Stop down rings are better though as they don't create sunstars out of every bright star.
Greg.
I used to have a Sigma Art 85 and that’s how I set the aperture on my Nikon. Once it’s set though it stays which is good.
Hello
Happy to have the observatory open this last couple of nights, first time since early Dec. Be gone Summer!
I have acquired a Sigma Art 135mm lens and coupled it to the QHY600C. The weight of the lens certainly is an issue and off axis is not pretty so this image is cropped a small amount. I have some stop down rings coming.
“ I have shifted my focus (pun intended) back to setting to work my QHY900 cameras and in particular, the QHY900 OSC combined with a newly acquired lens: Sigma Art 135mm f1.8.”
Did you get the mono version? What about the other bits - filter wheel, etc?
Yep, I go the mono package with 7x 2” FW, OAG, and ZWO’s LRGB/Oiii/Sii/Ha filter set. I actually didn’t look too carefully ‘cos I actually planned on getting Astrodon or Chroma filters. Anyhow guess I’ll just use the ZWO filters first and upgrade later.
Most exciting. I look forward to seeing some results as well. I think it should be fabulous.
From what little I have read it seems on Cloudy Nights that QHY is not great with drivers but is good with no dew and icing. Also good with no amp glow.
ZWO though seems to have a good reputation for reliability, service and drivers.
I also like just 2 gains. The other system of various adjustable gains sounds complex and you could easily end up with mismatched darks and flats and biases.
Even with 2 you need to be on the ball. Try to calibrate an image with the wrong set and you'll have trouble.
80%+ QE plus deep wells whilst small pixels is an engineering feat not done with CCD.
I also like just 2 gains. The other system of various adjustable gains sounds complex and you could easily end up with mismatched darks and flats and biases.
It's not easy to change camera settings by accident...when using the ASCOM driver, you have to deliberately go into the Settings dialog to change them.
There is also the function to set your own presets, which also has to be as a result of a deliberate action (it's hidden in the Advanced settings).
I am waiting for my new, full frame image circle scope to arrive. I am really going to have to put some thought to one of those though budget pressure would say the OSC version would be more likely, buying a filter wheel and filters to suit would kill me!
It's not easy to change camera settings by accident...when using the ASCOM driver, you have to deliberately go into the Settings dialog to change them.
There is also the function to set your own presets, which also has to be as a result of a deliberate action (it's hidden in the Advanced settings).
I meant you forget to set it to the right one rather than switching by accident.
I sometimes have this happen with my FLI cameras which have a slower download but lower read noise setting and another setting which is faster downloads (good for focusing) but higher read noise. I set to the faster downloads for focusing and then forget to set it back to the slower downloads but lower read noise for the actual imaging.
You can't calibrate the fast downloads with the slower downloads calibration files.
It's not easy to change camera settings by accident...when using the ASCOM driver, you have to deliberately go into the Settings dialog to change them.
There is also the function to set your own presets, which also has to be as a result of a deliberate action (it's hidden in the Advanced settings).
Quote:
Originally Posted by The_bluester
I am waiting for my new, full frame image circle scope to arrive. I am really going to have to put some thought to one of those though budget pressure would say the OSC version would be more likely, buying a filter wheel and filters to suit would kill me!
From what little I have seen so far the mono has way less noise. Perhaps cheaper to simply use a Sony A7riv.
I meant you forget to set it to the right one rather than switching by accident.
I sometimes have this happen with my FLI cameras which have a slower download but lower read noise setting and another setting which is faster downloads (good for focusing) but higher read noise. I set to the faster downloads for focusing and then forget to set it back to the slower downloads but lower read noise for the actual imaging.
You can't calibrate the fast downloads with the slower downloads calibration files.
In my experience with ZWO's driver, it remembers the last used settings, so it's very much set it and forget it. If you never go into the Advanced settings in the ASCOM driver, gain/offset/USB speed will not change.
It's pretty fool-proof...I've managed to get by with it for years
The M31 image is the most spectacular but some nasty halos around bright stars with some odd diffraction spikes in the FSQ106EDX4 images.
That most likely is the filters - their Baaders. Also same imager but using Tak CCA 250 does not seem to have the same reflections. They kind of ruin otherwise good images.
You'd have to wonder about the antireflection coatings on the camera window though.
I'd be looking for that defect in ZWO or QHY IMX455 images to see what's causing that.
I am still working to optimize my systems and of course fires and smoke have kept me closed for weeks also.
But I have been open the past few nights.
These 2 images taken tonight: They basically demonstrate the potential of the 36cm f2.2 RASA.
Both images are 3 mins in duration, QHY600M, Baader f2 Ha filter. One is binned 2x2, the other unbinned.
Images are also cropped...no flats acquired yet.
