PhilB61

Field of view will vary depending on what eyepieces/camera you use so best to use of of the online checking tools. With astronomy tools website you can add in your equipment, telescope, eyepiece or camera and chosen targets, to see what the field of view will be. For traditional long exposure astrophotography (anything over about 15 sec) I think you will be severely hampered with either of those mounts as they are both Alt/Az not Equatorial mounts and because they are too lightweight, ie you would be under mounted. The results would likely be bloated and not round stars plus field rotation. It can be done with stacking thousands of extremely short exposures but this brings it's own challenges and issues. If you want to stick with those mounts then a smaller and lighter telescope, no more than an 80ed would be better, and more forgiving but still with the issues related to Alt/Az mounts for DSO photography.

To plate solve a previously taken image go to the Framing tool, at the top on Image source choose "file" then "Load Image" browse to your file location and select. On next screen enter any missing data, pixel size etc then choose which solver to use. With ASTAP it should solve within a few seconds, maybe a bit longer for blind solving

It probably depends on what plate solving software and database you are using in NINA. Have you tried just plate solving an image in NINA with exactly the setup you will be using, if that works fine I imagine 3PPA will also work.

Whilst it may be physically possible to use the focus knobs, especially the fine focus (as it exerts a geared reduction) what you are doing is forcing the reduction gearbox in the EAF the wrong way with consequent very high torque which could potentially strip the gears. I have previously seen ZWO support on their forum saying it shouldn't be done and that manual focus should only be done via software or the optional hand controller. The reason it's harder with power applied is that the stepper motor exerts an electronic braking force.

Hi to SGL, lot's of great info and advice from Vlaiv. Just to add I originally used an expensive Nikon telephoto lens on a D3200 and whilst it gave me some good first images, changing the lens for a much cheaper SW 72ed telescope brought an immediate improvement (much better focusing and colour correction). You have a good start with the mount, just don't overload it either weight wise or too long a focal length or you will just make getting consistent round stars much more difficult. I would definitely think about guiding otherwise you will be limited to short exposures but then you will also need a laptop or similar to interact and control the mount. In addition to the basic equipment you will need to consider what software to calibrate and stack your images and then post process. Lot's of free options available, I use SIRIL but there is DSS and others, for post processing I also use SIRIL and GIMP plus Starnet and GraXpert. Lot's of good tutorials and videos online

You could do some rough focusing on a distant object in the daytime, once you have decent focus you can just make a note of the position. The focus position for astronomical objects will be slightly inwards of this position. If there isn't a scale on the drawtube it's simple enough to neatly measure and draw something out on a small piece of paper and attach to the drawtube with clear tape. I did this for a SW 72ed.

I suspect this is an issue with the intervalometer rather than the camera. On the wireless one I used with my Nikon (different brand to yours) I could watch the display and see the commands as they were sent to the camera. Maybe you could do similar and see if the commands sent are as you programmed them.

I would probably start by doing a factory reset of the camera, just in case there are any strange settings the previous user had setup

It's hard to say what went wrong without knowing what intervalometer you used, what settings, what camera settings etc

Back focus distance is a term usually used to describe the spacing from a flattener/reducer to the camera sensor, which is critical for good star shapes. This spacing is set by the manufacturer of the flattener/reducer not the telescope manufacturer although of course they could be the same. What are you using the term for in relation to this telescope?

Check the field of view of each setup on astronomy tools website, or similar, for your typical targets. Also I wouldn't want to be planning on mosaics if I was just starting with imaging, a whole other world of pain and frustration....

I think you are correct, if all else is equal then larger diameter with more teeth should theoretically be able to track more accurately. But then you need to consider any other factors such as differences in motor, reduction gearboxes or belt drive etc.

A 90mm refractor will collect more light and hence image quicker than a 70mm with the same focal length and possibly resolve slightly more detail.

Agree very nice image, I suspect from your comment that there is some history to your guiding issues. My only thought is why not do without the ST4 cable altogether, with the benefit of one less cable to worry about and no need to recalibrate on every target.

Hi and welcome. First thing you need to do is add up the power requirements of all the things you envisage powering from this and see if it can deliver. I noticed that some versions of that supply max out at 5 amps which I'm sure won't be enough once you add everything up. Mount, camera, guide camera, laptop, dew heaters etc. If you just want to power the mount only it may be better to buy something cheaper from one of the astro shops such as FLO. Be aware that that telescope will be a hard learn for astro photography even on that mount due to it's size and bulk, a smaller widefield scope might be a better choice for learning and keep the dob for visual, at least for now.

Sirilic is a separate front end gui for Siril, which I believe helps automate the use of scripts. Both use the same processing "engine" As I've always processed with Siril manually that's what I'm comfortable with.

I have recently started stacking multiple nights data, but doing it manually in SIRIL rather than Sirilic. What I do is take the pre processed lights from each night and put them into a new sequence. Then register the whole combined sequence, review under the plot tab. This allows me to cull some of the outliers which I may have left in a smaller stack. Then stack as normal which also allows for all the subs to be normalised. Obviously if you have already registered then you will be doing it again but I have tried to avoid that. I have found SIRIL to be very quick when pre processing/registering/stacking 250+ light files plus calibration frames from my AA26C (IMX571). I can't imagine how many subs you would need for it to take over 4 hours.

Can't help with your new telescope choice but I'm with Adam above. It would take a very significant impact to knock things that far out to not be able to focus. If the lens cell is firm and non of the elements are loose (try gently shaking) and the focus tube is secure then it can really only be a spacing issue. I presume you are manually focussing, can the tube move freely over it's whole range. Have you tried with an eyepiece with/ without the flattener to try and narrow down the issue, you may need a diagonal for visual to get the necessary backspacing. Some of this testing could be done in the daytime if you have a distant object to try and focus on.

I have had occasional issues with banding although not as prominent as yours, try ticking the Dither box it's supposed to reduce or prevent this type of issue and has worked for me.

I would also agree with AstroBuySell UK, it's a very active website with an astro specific audience. I have bought via the site a number of times over the last few years all have been very positive experiences, not sold anything yet. I have also had generally good experience with eBay both buying and selling.

Doesn't this mount use the spring loaded worm block like the CEM series? Unless it's actual free play, ie movement with almost no force applied, which it doesn't look like to me, then what you are actually doing by trying to rotate the mount is just causing the worm to ride up slightly on the worm gear and compress the preload spring. Unless you have problems with star shapes or guiding I wouldn't worry it's not a fault. If you really do have excessive backlash then the mount manual has instructions for adjusting in the appendix section.

Good information and interesting, I wonder how much additional current is drawn in warmer ambient temps or if cooling to a lower temperature, I guess the CMOS cooler could be the highest current drain.

I can confirm that Asifitsview applies an auto stretch whenever you open a file, it can be turned off after hitting the histogram button. I would also recommend that you give SIRIL a try for both your stacking and processing that way you can do all in the same application, lots of tutorials online. I am a longtime GIMP user, but SIRIL has much better astro specific tools.

Recently put together a new imaging rig consisting of APM 80/480 triplet with AA26c (IMX571) camera on CEM25P mount. Previously used an unmodified Nikon D7500 and Skywatcher 72ed. Not had much chance to test with the poor weather in the UK and a few issues, with cables and guide camera. But now on an extended trip to Spain in our campervan. This is my first successful imaging run, having had a few more usb and power supply issues. The image is just over 2 hrs total from last night and this is a very quick and dirty process in SIRIL. No background extraction or calibration frames used yet, although I did take flats, need to take darks and bias before a proper process. There are a few issues, I think backspacing needs optimising and possibly some tilt, and guiding still not great as my old asi120c keeps dropping frames, definitely need to sort my cable management. I intend to get more time on the target over the next few weeks. I hope you like it and comments welcome

For lunar imaging should be fine scale wise, and as you will be taking high frame rate videos to stack guiding won't really be an issue. Scale wise also ok for the smaller galaxies but not for the popular larger nebula or Andromeda for example. For DSO though the biggest issue could be tracking and guiding accuracy, depending on what mount you are using. At your pixel scale I would think you need to guide reliably well below 1 arcsec to not have elongated or trailed stars.