Instrumentation and Equipment

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For discussions on all aspects of equipment, from building new devices from scratch, to what ready made products are the best for your current setup. Attached the "Instrumentation and Equipment" observing section.

58 485 By MMU 2 days 22 hours ago

On-Axis Guider - How Often Do You Lack a Guide Star?

Affiliation
American Association of Variable Star Observers (AAVSO)
msheald Thu, 06/17/2021 - 11:12

Hello! I'm trying to decide on an on-axis guider vs. guide scope for my new setup.

    For those running a scope remotely or unattended, how often do you lack a guide star using an on-axis guider? I won't be using a rotator since that creates lots of problems with flat fields.

    I use SGPro to acquire images. When the guide star is lost, the program aborts till the time limit of the observation is reached and then the routine goes to the next target. Thank you and best regards.

Mike

DSLR characterization

Affiliation
American Association of Variable Star Observers (AAVSO)
SGEO Mon, 06/14/2021 - 21:18

I'm working through the Basic CCD Testing section 8.2 of Richard's Image Processing book, applying the tests to my Canon Rebel T5.

I'm thinking that I have to add some wrinkles to the testing:
   - separate test series for different ISO's
   - Debayer the test images and do each color separately 

Other things I should look out for?

One thing I see with a quick test is that the darks look just like the bias shots... 
I'm wondering if the Canon is doing some tricks for me that I need to understand.

Optical Structures (Astrodon, Jmi, Farpoint) Seeking Investors

pbealo@comcast.net Sat, 06/12/2021 - 15:32

I received investment information for Optical Structures. They seem to be looking for pre-IPO investors with a goal of doing an IPO within 24 months.

While interesting, I have no idea how that relates to how they will continue, or not, to invest in new products such as photometric filters.

If anyone wishes the documents, I can email them to you.

Peter

 

Question about dark frame scaling -new CMOS cameras

Affiliation
American Association of Variable Star Observers (AAVSO)
RGN Sun, 06/06/2021 - 10:06

I would like to know if dark frame scaling is possibile with new CMOS cameras in the event of a camera that shows zero amp glow such as the QHY600 or QHY268. Since the electronics of these new cameras are also very stable I wonder whether one could even skip master frames and just subtract one single dark frame of corresponding exposure or one single scalable dark after subtracting a single bias. Of course gain, offset and temperature match the ones of the calibrating frames.

 

Gianluca

Beginner with no camera

Affiliation
American Association of Variable Star Observers (AAVSO)
Andrew Bennett Tue, 06/01/2021 - 16:52

Hello All: I'm a beginner and this is my first post to an AASVO forum. I have searched for answers to the following questions and have found some. It would be a great help if you were to supply even just Y/N answers to any. I'll abide by the first answer to any question, but if you answer otherwise then I'll go scratch my head for a while. Anyway, thanks for reading this far!

 

I have a Takahashi CN212 on a Losmandy GM8 mount. The CN212 is  212mm f/12 true Cassegrain  convertible to a  212mm f/4 Newtonian.

 

Linear response curve QHY 294M (Sony IMX492 sensor)

Affiliation
American Association of Variable Star Observers (AAVSO)
Remco Kemperman Sat, 05/15/2021 - 12:41

I have made a response curve for my QHY294M camera. So i thought other with a Sony IMX492 sensor might benefit from it too.

For this I took flats of different exposure time and plotted the median and the maximum pixel read out against exposure time. I averaged the ADU count of 3 frames per exposure time.

As you see, for thethe sensor has a linear response up to about 62.000 of 65.535 ADU. This is linearity up to 95%, which is really good in my opnion. To be save I will expose my targets stars no further than 60.000 ADU in photometry (92%).

What type of telescope (reflector) for photometry?

Affiliation
Bundesdeutsche Arbeitsgemeinschaft fur Veranderliche Sterne e.V.(Germany) (BAV)
MatthiasK Sat, 05/15/2021 - 10:20

Hello,

I am doing photometry with a 90/500mm refractor and a Canon 450D. I consider to buy during the next 1-2 years a new telescope and camera. I do not want to go to big telescopes, maybe something like 8" maximum. But I wonder which type, Newton, SC,..., is best to use for photometry? I am not experienced with reflectors.

Thanks,

Matthias

Photometry with QHY 6 Mono CCD

Affiliation
American Association of Variable Star Observers (AAVSO)
GeoLek Fri, 05/07/2021 - 19:38

Greetings,

I create a new post because I am interested in exoplanet/variable star photometry. I plan to use a QHY 6 cooled Mono CCD which is an excellent guiding camera and a very good entry level ccd for astrophotography. I want to ask if anyone has used this ccd camera for photometry and if yes,how good were your results? I do not expect precise/excellent results but I hope I will get some decent results until I manage to buy a very good Mono CCD camera.