Vroobel

Hi Michael, The dedicated ZWO Canon EF filter drawer has 26.5mm optical path length which together with the 2600MC's 17.5mm back focus gives 44mm. After screwing the adaptor to the camera it stops in a random position. The lens is about 1.3kg heavy, so I use dedicated for the Sigma lens ring holding it in the position like after attaching to Canon body. I operate only with horizontal or vertical positions of the sensor, so it's very important to me to keep it. That's why I finally used two paper spacers which shouldn't cause so bad results. My previous experience with M42 135mm vintage lens says that changing the distance between the lens and the camera affects only a position, where you reach focus at infinity. E.g. for a typical 20mm long ZWO filter drawer v.2 with 1mm long EF/M42 adaptor it appears at around 3m. I expected that it will also happen to the Sigma and indeed, the position of focus at infinity looks like in the picture below. If moving the focus position is accompanied by the significant distortion then the Sigma lens + ZWO EF filter drawer + 2600MC is not acceptable for me and I have no idea what to do next.

So which is the proper one? I tried to find it.

Hi, Around two months ago I bought a brand new Sigma 40mm F/1.4 Art and tried it with a full frame Canon 6D. After some test, I found that the F/1.4 gives coma even if it's praised as the best wide-field lens ever, especially for AP. I stopped at F/1.8 which is still fast enough in comparison to my F/4.6, F/5 and F/5.6 scopes. Here are views of the corners and edges of a stacked image respectively without any correction and after applying a BlurXterminator (F/1.8): I told to myself: ok, it's acceptable, I should be able to use the F/1.4 again when I buy a ZWO EF filter drawer and move to an ASI2600MC-Pro APS-C camera. So I bought the adaptor with the filter drawer and screwed all components together. I tried the F/1.4, as the Sigma doesn't have an iris ring and the aperture depends on a body setting. An M42 thread didn't allow me to obtain a horizontal or vertical position of a sensor which I prefer, so I used some thin Baader spacers, but here is what I got: I shouldn't cheat myself, it doesn't look good, after all, it's the APS-C and should be almost perfect. I replaced the plastic spacers with two rings cut out from an 80g/m2 xero paper - they are thinner. But it changed nothing. I got an idea that maybe I should screw the aperture down to the F/1.8, but how to do it? Based on a following CN thread I attached the 6D body, set a BULB mode, pressed the shutter release button and... detached the body - the iris remains in the F/1.8 position. That's a great trick! Well, here is what the F/1.8 with APS-C single sub looks like (sorry for the clouds, I didn't invite them): https://www.cloudynights.com/topic/837147-sigma-art-40mm-14-canon-mount-no-aperture-ring/ Nothing better. Looking at this rule... ... I would say that the camera is too close to the lens and it usually makes sense, but not in a case of my Askar FMA230, which behaves just the opposite and I had to reduce the 55mm back focus to 52.5mm (and I'm not the only one). Has anyone had any experience or idea to say what's going on here? I'm completely confused and I don't know what to test next. I'm limited by clouds, so I don't want to make blind tests. I would appreciate any ideas.

Of course, not. That's theory.

Remember that the NAS also may break. The proper backup should follow a rule of 3-2-1: 3 different backups, placed in 2 different locations, at least 1 offline (e.g. detachable USB).

The ASIAir is OK if you consider simple ZWO-only equipment. Leave the idea if you aren't ready for it. The NINA is powerful and have a lot of features not existing (yet?) in the ASIAir which work with everything.

I can recommend this, if you are familiar with IT, Linux, Raspberry Pi etc. : https://pimylifeup.com/raspberry-pi-openmediavault/ I use it with a USB 3.0 12TB WD Black HDD with real pleasure. Factory-made solutions are OK, but they are much more expensive.

While I have it.

I would like to see it after a BlurXterminator process in Pixinsight. Could you please share it somewhere uncompressed and in a highest size?

The flat frames (hopefully) will eliminate effects, but not the reason. It's worth to know where is the problem. 🙂

How you know that the dark areas aren't caused by dust in your optical train? 😏 That's funny, two days ago I perfectly cleaned my refractor, reducer, filters and camera, but one stubborn spot was still in the flat frames. Nothing on the glass and nothing on the camera as well. Do one proper flat frame at home then rotate the camera by 90 degrees and do another flat frame. If the spots are still in the same place then they are on the camera indeed. If they move then they are elsewhere. My spot moved, so I gave up. Flat frames are just for that to remove the dust moths. BTW, any dust located directly on the sensor surface creates small and sharp shadow.

Your new flats work well. I see slightly uneven background which would be darker anyway. 🙂

More, much more integration time, then it will look better. 😉 Open the AstroBin website, type name of the object or its catalogue number into a searching field to see how much time others need to reach expected results.

Yeah, it must be exciting if we take the power causing the jet into account. 😳 So unique and mind-smashing things captured from Bortle 9 backyard are impressive. I had similar feelings when captured a trace of the James Webb Space Telescope. 😊

I'll try to capture it with 10" 1285mm Newtonian.

That's not too informative if you have more than one scope, camera, etc. 😉

Goog job as well! 👍 Guys, you didn't mention your setups, could you update it please? 😊

Well done, congrats! 🤩

First light of this setup: Altair 102EDT F/5.6 & 2600MM with filters. Filter offset for a first time and the Lion Nebula if the sky allows.

... if you have decent filters. 😏

... and the best if it's not surrounded by a fence? 😏 Wood be good if such place exists between Manchester and Liverpool. 🤔

Thanks. Presently I use a designed and printed Bahtinov mask, but will consider ZWO EAF in future. I know that Astromechanics from Russia makes dedicated ASCOM-compatible EF focusing modules, but they won't work with the ASIair.

There must be a tiny headless allen socket screw which is loose. I don't have this mount, so cannot say where it is. Try to remove the timing belt to find it.

The postman brought a ZWO Canon EF filter drawer today. My alternative to a Canon 6D mobile setup is finished now and finally I can play with wider fields and L-eXtreme filter under Bortle 9. 😊 5kg in total.

I used nearly the seme: WiFi extender behind a kitchen window, all index files downloaded, all plate solve settings according to YT tutorials but the PA continuously failed. I had to use SharpCap to do it. It was very annoying.