Padraic M

From what I'm reading, SATA SSDs are slightly faster than eMMC but much more reliable. NVMe SSDs on the other hand are ~10 times faster. I've just ordered the Quieter 2 129GB with an extra 1TB of NVMe SSD, and have had the oh-no moment of wondering does it actually support NVMe at all, or just SATA? Will just have to wait and see I suppose! This guy on youtube gives a good review. https://youtu.be/99aBuPNrwBc

One other point - the 256GB variant seems to be 1x 128GB eMMC + 1x 128GB M.2 SSD, so if you're thinking of upgrading storage at any stage you're better to buy the 128GB variant and leave the M.2 slot free. Otherwise you're wasting the 128GB SSD.

Hi Ian, I was looking into this today, and while it's not 100% gospel (no specs whatsoever on the MeLE website), it actually looks like it runs on 12V, not 5V. Cuiv the Lazy Geek just bought a cable to convert from DC jack to USB C male and it didn't blow up; also, an Amazon listing shows: Interestingly the same Amazon listing says: I'm using the Pegasus Pocket Powerbox Advanced so the equivalent USB C male - 2.1mm DC jack female is also available for €6. I'm thinking of pushing the button on this.

A pre-loved ST80 in pristine condition 🙂 ! Seriously, it's been my most used scope this year, partly because it's so serviceable at short notice, and partly because the weather hasn't given many opportunities to image with a bigger rig. I also just recently bought a 2nd hand NEQ6 and so far am enjoying it very much.

That's very good - I'd hate to show my first attempt at Orion! Probably wobble if you're touching the camera to take a shot. Given the angles you're dealing with, the tiniest of shakes will show. Eradicate that and you can start to think about polar alignment to get good tracking. You would like to be able to get 10-20s of exposure time before stars start to trail.

Yes, I noticed. It may be showing that a shorter exposure/lower gain might be appropriate as quite a few stars are saturated at that level.

Thanks Vlaiv, Yes, I have that selected. Still no sign. I'll keep reading and trying - I don't want to hog your time! I can get FWHM in the seeing profile. Also in pixels, although I've plate-solved and set the plate scale. This is how my radii are set. Oops! I'm on 3.2 so maybe it's worth the risk?? @alacant thanks for that link. I have Siril installed so will take a look.

This is puzzling me now - when I load a fits file I can alt+click, or do multi-aperture photometry, but the measurements table doesn't contain FWHM. I can see in the Aperture Photometry Settings a list of fits file header keywords to include in the measurements table and FWHM is not one of them. I don't see any way to ask APP to include FWHM in the fits header, so maybe this is why it's not appearing in the table??? Also, AstroImageJ seems to approximate a FWHM based on user-defined constants (i.e. the 13/19/26 radii above, and/or the FWHM factor pf 1.4). Do you have a different way of calculating FWHM?

Yes I'm inclined to agree. I've spent quite a bit of time adjusting back distance etc. to try to get round stars with the C8 and haven't succeeded so far. Was considering trading up to an EdgeHD, or possibly using the Starizona flattener which gets good reviews. For much the same cost of upgrading, the EHD may be the better solution.

@vlaiv, great, thanks for that answer, I think I understand now. There is a benefit in a second setup with a longer focal length. The question now is whether the C8 XLT is up to the job optically. I need more experiments!

@powerlord that's a nice Triangulum! Is it the non-Edge HD 9.25, and what flattener/reducer are you using?

@vlaiv, OK, I got you. The larger aperture of the C8 (200mm) gives a smaller Dawes limit of 0.67". So if seeing supports this, or this binned x2 to 1.34", it can provide better detail than the Esprit, design limitations apart. Sorry, my confusion. I misremembered one of your previous posts relating FWHM to seeing by a factor of 1.6. I've checked my image stats in APP for my most recent session, and I got FWHM between 2.5 and 3.0 consistently, with average guiding RMS from Phd2 log viewer of 0.6" over 2hrs 15mins. Can you tell me where the relationship below comes from? Thanks!

I'm trying to get my head around the relationships between pixel size, focal length and seeing, and trying to understand whether there is a benefit in having a second imaging setup with a longer focal length. I can just about follow other conversations on this topic, so my logic may be completely out - looking for corrections and suggestions. My current main imaging setup is ASI1600MM Pro on an Esprit 80/400, NEQ6 (or HEQ5) guiding at ~0.6-0.8". HFR on good nights is 2.6 which implies seeing of 1.6". I also have a C8 SCT @ 2032mm f/10 or 1280mm f/6.3 with a flattener/reducer. Intuitively, there seems to be a logic that says that the two rigs can work together, with the overall wide-ish field being captured by the Esprit, and narrow-field detail being added by the C8. Think, as an example, capturing Orion with the Esprit, and getting close-in detail of the trapezium with the C8 at shorter exposures. But I'm wondering if (given the seeing) the two setups are actually equivalent and the C8 will give no benefit whatsoever. As it is, the optical quality of the Esprit is much better than the C8, so unless there's a tangible benefit that would warrant investment in the C8 setup, I may be better off not going down that road. Pixel scale for the Esprit/1600MM setup is 1.9". This is pretty much spot on given the seeing of down to 1.6", and the guiding is well within this limit. Pixel scale for the C8/1600MM with 0.63x reducer is 0.61" which is way oversampled. If I understand this correctly, I get no additional detail with any pixel scale below the seeing (obviously without using AO); I would need to bin 2x2 or even 3x3 to sample correctly, which will improve capture speed but not resolution. Even changing to a different camera with larger pixels still hits the same limit - the pixel scale needs to be >1.6" to capture detail un-binned, and that puts it right back into the Esprit resolution territory. The only difference is that the C8 has a much narrower FOV than the Esprit, but I can achieve that at the same resolution and with better image quality by cropping an Esprit image. What am I missing here?

First night imaging in a few weeks, thanks to the weather. This is 45x60s each of RG&B, processed in APP and touched up in Gimp. Equipment was Esprit 80, NEQ6, ASI1600MM Pro. I think the Esprit and my filters need a dusting down, as the flats didn't quite work.

For the 72EDF, a 50mm guide scope will be ideal. Best to fix it securely to the scope rings with its own dovetail rail, but tbh firmly screwed into the finder shoe may well do until you have some experience. I use the Altair Starwave 50mm with a ZWO ASI290MM Mini on a 80mm main scope and it works a treat. It comes with a non-rotating helical focuser but as @rl says above, you only focus it once. Focus isn't as critical on the guide scope as it is on the imaging scope. The TS Optics 50mm Deluxe seems to be exactly the same scope. https://www.teleskop-express.de/shop/product_info.php/info/p11100 If you're using the Meade for imaging, there is a strong argument for using an OAG but imo they are an absolute pain to get set up. You can also use the Starwave firmly attached, but you are likely to suffer if there is mirror flop.

Very nice Adam, and interesting as it may be a project for me over Christmas with a very similar setup. Are those two frames stitched together in landscape format? That's a good idea.

13.8V unloaded is spot on. When load is applied on some supplies the voltage will drop. As long as it stays above 12V everything should work fine. Highest load, obviously, will be drawn when everything is on, especially when your mount is slewing on both axes (slewing to target or parking). My setup is similar to yours with a HEQ5, ASI1600, focuser, filter wheel, 2x dew straps etc. Total power draw rarely goes above 3A, but I had a 10A power block that couldn't maintain voltage above 12V. Very strange things started to happen - so much so that now I consider that those real head-scratcher problems are very likely to be power-related. I now use a Nevada Radio 30A supply, and it's rock-solid. There's a single cable from there to a Pegasus Astro Pocket Powerbox Advance which distributes power to mount, camera and dew straps. Your Mini PC is an added complication and I believe they can draw a lot of current.

The forums have been suggesting that to Mabula for years, but nothing's happened. I'm used to it now, and almost understand the logic that you don't need to save your settings if you save your iterations. The one that gets me though is the Gong - makes me jump out of my skin every time if I forget to turn it off. Just as well it's so good at doing the important stuff, but usability issues like that really do get to people

Yes, I know what you mean, but I think I looked through the Esprit once shortly after it arrived, and haven't done so since. NINA runs the mount, the autofocus routine, and the capture sequence while I sit inside and watch the telly!

I'd recommend the Primalucelabs Sesto Senso. I have one on my Esprit 80 and it's fantastic.

Beautiful image Richard. I saw and enjoyed the early draft version but the extra data does make a difference. A friendly subject nicely presented, and good choice of composition too!

Can't comment on the WO but I have the Esprit 80 and it's a joy to use. Agree with the comment about the mounting foot - I've removed it and fitted Primaluce Labs tube rings. They're a bit tight, and a bit expensive, but they do the job.

That's superb Richard, both capturing and processing. I don't know how you managed 15 hours, I don't think I've seen stars since July! Well worth the effort.

No problem 🙂 ! More exposure time can be longer subs or more subs at 60s. Guiding does make things easier though and gives you more options. Be careful, I sense you've started down that slippery slope....

The Astro processing Tool (APT) Canon matrix lists 1600 as the best ISO for 70D. https://astrophotography.app/EOS.php I don't think a low ISO will clip the blacks, it just won't gather as much light so you'll need more exposure time.