Instrumentation and Equipment

Hello all,

This is my first post in this forum. I have a question and I think people here can help.

Me and some friends have a telescope at E-Eye, which we use primarily for astro photography. We also have a photometric V filter, which we lately have been using for performing measurements of variable stars (in particular V1391 Cas). In our filter wheel, we have an empty slot, and we are planning to purchase a secondary photometric filter to fill the last slot.

While doing some basement cleaning I happened upon an old JW Fecker made Pickering Photometer. Its now upstairs for refurbishment. In this form of photometer the viewer simultaneously sees the star being measured and an artificial star who's brightness may be varied with a variable density filter. A series of filters can also be inserted to vary the artificial star color.

All the Best,

Peter

What telescope mount do you use and do you use the guide chip for your autoguiding?

I recently purchased this low-lux IP camera for $51. It is an easy plug-and-play with PC, and comes with the free CMS software to allow display on the computer. It has good 1080p resolution, is full color and weatherproof, so easy to install and use, OOTB. www.aliexpress.com/item/32550636905.html

ATIK Cameras has announced a webinar about CCD and CMOS cameras, 

"This webinar will focus on CCD and CMOS sensors, and the key comparisons between the two technologies. All webinar attendees will also receive an advanced copy of our white paper on the subject, to help provide an opportunity to become familiar with the topic at hand.

My question is about matching dynamic range with A/D conversion.  The way I have been doing this is by finding the dynamic range and converting it to the number of stops.

stops = log₁₀(full well capacity ÷ read noise) ÷ log₁₀2

So, if I have a camera with a full well capacity of 32,000 electrons and a read noise of 4 electrons, then the number of stops would be

stops = log₁₀(32,000 electrons ÷ 4 electrons) ÷ log₁₀2

stops = log₁₀(8,000) ÷ log₁₀2

stops = 12.97

I currently have an SBIG ST-7E NAGB.  Should I use that over my ASI183MM-Pro and if I have a chance to upgrade to an ST-8XM, should I take it even if I have to either user a Barlow lens or buy a scope with a longer focal length for the 9-µm pixels in the ST-7 and ST-8 or should I just stick with the ASI183 with its 2.4-µm pixels with my current scope which has a focal length of 731mm even if the 183 only has a 12-bit A/D conversion.  Also, would it matter since the ST-7 and ST-8 has a 15 electron read noise as opposed to the 3 electron read noise of the 183?

Someone was posting a question about what camera to buy.  At some point in the thread, someone mention issues of linearity with CMOS and that they should try to buy a CCD camera because CMOS cameras have issues with linearity.

So, I did a linearity test on my ASI183MM-Pro using my homemade light box for flat frames.  I took 13 sets of .FIT images, ten in each set, at an exposure interval betweeen 1 to 13 milliseconds in increments of 1 millisecond each.  I recorded the average ADU for each .FIT file and then calculated the average ADU of the average ADU for each set of ten.

Hello! Just curious for one of my dream projects.

    How linear is the 16803 chip with ABG?

    The PDF states non-linearity less than 1%; however, do folks have any experience/suggestions about how linear the chip is up to its ADU limit of 65,536 counts? Thank you.

Mike

I'm looking for a step up from the "squeeze bulb" to blow dust off of my optics.  The products I have found so far are compressed aerosols.  Does anyone have experience with these?  Are there any residues?  There does not appear to be dry nitrogen or dry air available in a consumer pakage.  Of course, a high-pressure CO₂ spray would be best, but I doubt I will fnd that in a spray can!

Tom