dan_adi

Other reflector designs are more suited for this job. RCs, CDKs, Newts. With regard to resolution, in average seeing, going above 8 inches in aperture won't improve things. This is why big scopes are built in Chile, and not in backyards. As an example your C11 has the same or slightly worse FWHM than my 8 inch, even though your bigger scope should provide more resolution. My best subs can reach an average of 1.8". The seeing imposes a limit. In this case Aperture helps in getting to the desired SNR faster, in less time. So, if resolution it's very important to you, you need better seeing along with aperture.

I think you are being to hard on your self. It is a wonderful image. With help in the forums you can improve things. I image from sea level, average seeing, moisture, few clear nights, bortle 5. Even so, I started imaging 4 years ago with a 12 inch Meade sct. I struggled for a year with it. I was getting a soft background, focusing problems, flat problems from time to time. Long story short, I gave up on the SCT. To much hassle with poor results. Then I went the refractor route. I admit I went over board and got a CFF 8 inch f 6.5 apo because I could afford it, but the fact is, a refractor, what ever it's size, is much easier to work with. The background was much better, no flat problems, no focusing problems, no collimation problems, no mirror shift. Since I got the refractor and ditched the SCT, I actually started enjoying the hobby. For flats and imaging I use Prism v11. It figures the exposure time automatically, I simply tell it how many flats I want and where to save them. I take flats after ever session, to be safe. So for 3 years I've been enjoying the hobby even in my poor sea level conditions. You can search my image here on stargazerslounge forum: Abell 2218. I've gathered 100 hours useful data for the Luminance and currently I am at 20 h for green filter. The image posted has minimal processing because I am learning as I go. So my advice...cheer up, ditch the SCT, get a refractor or a better suited for imaging reflector. Keep the SCT for planets.

Wonderful image.

I use a 8 inch refractor with the older Mesu. It does ok during light winds, but it has a smaller surface area than the big newton. One thing you could try is placing a longer saddle on the mount, so the contact surface between scope and mount increases. I use a 60 cm long saddle. It could also be that the scope is simply too big for the mount. It's not always about the weight. PS: I saw you use a tripod. Don't. Make a steel pier or concrete

I had a few clear nights. I ended up adding around 8000 ticks to RA ticks. It seems I don't have RA corrections in one direction anymore. I wonder why these numbers aren't set accordingly from the beginning. I'm in my 5th year and still optimising. Those 10 micron mounts seem more and more appealing. Anywho, below is a guiding run after optimisation. Spikes are dithering. Current RMS 0.27".

Prism version 11.

In the CCD equation, the math is done for a specific filter. So if the calculator said you need 84 hours for a SNR=100 using the L filter, then this is what you need. For a different filter (R or G or B or I or etc) the same SNR=100 will produce different exposure time, not 84 hours, because there is a different bandwidth , different QE, different filter extinction etc. So, my approach is to compute the exposure time needed for a SNR using the L filter. RGB data is added to make the picture prettier. Here is the calculator I made to better understand my hobby https://clearskies.go.ro In the process of converting it to a windows app... I am one of those guys that has Linux as a main OS so bare with me :)) it will take some time

Thanks, will try until I nail it down.

I'm late to the party, only took a look at Voyager last night. It connected to all the gear with no problems. The part that gave me an error was the robo focus module. When I try the V curve wizard it errors with: 'the starting HDF is too big'. Any thoughts on how to setup focusing? I use optec Leo focuser. Thanks

Thanks, I will try it.

Last night was clear for a couple of hours. I substracted the calculated ticks and it was a little bit worse. I didn't spent all night tinkering since I wanted to do some imaging too. Next clear night I will add the ticks since substraction made things a little worse. Thanks

I balance using an amp meter after I do it by feel. Yes 0.3 RMS is quite good. I will test and see what happens. I don't have to make a big adjustment just a few thousands ticks. Could it be also the guide speed in servo config? I have the default 0.33x. Did you try 0.5x sidereal?

I plan to move to Voyager and phd2. Last night I guided with phd2. The RMS was good at 0.33 arc sec. I also noticed that RA corrections are all in the same direction. I checked my RA drift, it's around 1.2 arc sec per min. Did adjusting the ticks in RA worked for you? My guess is I should substract the calculated ticks from the current value, since adding them would slow the tracking further. Did you add or subtract? Thanks

Can anyone share their phd2 settings with the mesu? I'm giving voyager a try in a while, in conjunction with phd for guiding. Also does anyone know the resolution of the mount encoders and scope encoders on the new version of the mount? The fist version has almost 8000000 ticks/rev for the motor encoders and 10000 ticks /rev for the scope encoders. Was curios if the newer model got an upgrade for encoders too. Thanks

Balancing is not an issue if this is the only main concern. With the friction drive you will get some resistance but it is not a problem. In my case I use a voltmeter/amperemeter just to be sure. I don't use ASI air so I can't give you any advice.

Any updates, reviews on the new MK2 version of the Mesu? How are they performing in the wild?

I see, thanks for the explanation.

I came across this site https://www.radio2space.com/product/spider-230c-compact-radio-telescope/ and I was wondering how pointing and tracking is achieved.

Hello, How do you point and track an object with a radio telescope? With optical scope we have plate solving, auto guiding , but what about radio scopes?

Seeing affects all scopes. If you have 3" seeing and the best refractor in the world you will not get 3" fwhm stars. This is because there are other sources of error that can add up during an exposure, like tracking error, focus error, collimation (mostly for reflectors), focuser sagging, loose connections, wind, etc. I image with a 8 inch apo refractor, and if the reported seeing for the night is for example 1.5-1.8 ", my stars have a median fwhm between 2.2-2.8". The scope is paired with a good mount (Mesu) and a good focuser (Optec Leo). I don't know how this imaging experience translates to visual observing, but my guess is the lower quality scope will add more errors, so if you compare 2 scopes, in the same bad seeing situation, I would expect the higher quality glass to pull ahead, but by how much? So, if you plan to upgrade your scope to a better one, do it for the nights with good seeing, not for the nights with bad seeing. In good seeing the higher quality one will pull ahead for sure

So, making pinhole in the cover lens won't work

Hello, I was wondering if I would be able to focus the scope during the day by making a tiny hole on the scope lens cover? I'am trying to get many data points for focuser position and temperature for AI training model. The scope is located as such that I have a 360 degree view of the sky, but no trees or roof tops I can focus on.

Indeed, 0.02" per tick means Renishaw 26 bit encoder. If DDM 100 uses finer encoders, that could be the 32 bit Renishaw.

My thoughts also .... 10 micron benefits from a little bit of guiding, while ASA and probably Planewave, Nova120 etc. will do fine on their own. Don't know from where the difference spawns. Maybe because 10 micron don't use Renishaws? or simply there is a limit on performance with worm drive, no matter what encoder you choose.

Don't think you will find evidence with 10 micron. Maybe ASA or Planewave ... Anywho, .. I see the benefit in ease of use, by adding some absolute encoders to a mount. But I would also guide on-top of a model. Get the best of both worlds. What the model can't correct, an off axis guider will. I do have an intent of ordering a Mesu with 26 bit Renishaws AE. They are not as expensive as I thought, around 2100 EUR.