michael.h.f.wilkinson

That is lovely! I must give that area a go with the 6" Schmidt-Newton one of these days

A 102mm ED doublet should provide a very nice, reasonably portably scope, with a nice wide FOV. I myself have an APM 80mm F/6 triplet, both for imaging and wide-field viewing. For planets, I would guess the little 127 mm Maksutov will give the 4" ED doublet a very serious run for its money. Those 5" Maks punch well above their weight for planetary viewing and imaging. I would certainly not ditch that Mak.

The right-hand lower row seems to have the slightly higher contrast in the Cassini division. However, this is a comparison on the stacked images. I consistently got better results after stacking when switching to the 1.3x Barlow, using the same telescope, on the same night, while seeing stayed the same.

I have found I get a bit more detail going for 5x pixel size than 4x pixel size. Seeing wasn't great, but at F/10 on my 2.4 micron pixel camera I got this: whereas using a 1.3x Siebert Optics tele-centric Barlow (similar optics to PowerMate), at roughly 5x pixel size I get this: The Cassini division is much more clearly seen in this case. Siebert Optics makes a series of tele-centric Barlows at a range of magnifications. They can be found here: https://www.siebertoptics.com/SiebertOptics-barlows.html (scroll a bit further down the page to find the tele-centrics)

I still have my Nagler 22T4 and 31T5. I don't see them going anywhere soon. Brilliant EPs. I did sell my 17T4 and 12T4, and replaced them with the ES 92 deg counterparts. I always felt the 12T4 was ever so slightly less crisp than the others, so when an ES 12mm 92 deg came up I snapped it up and found it had an edge over the 12T4 both in sharpness and in FOV. A little later an ES 17 mm 92 deg came up, so I added that. I cannot say the ES 17mm 92 deg is clearly sharper than the Nagler 17T4, it just has a wider FOV.

It is possible to image planets with a DSLR if it has a 1:1 uncompressed crop video option. However, I would always go for a proper planetary camera. I have used several ZWO cameras for planets, in particular the ASI120MC, ASI224MC and the ASI183MC. The latter also allows imaging large sections of lunar surface, and can be used for DSOs as well (although the cooled version is better for that. Jupiter with the C8 and ASI224MC Saturn in bad seeing (ASI183MC using small ROI + C8) Large chunk of moon (ASI183MC + C8) Leo Triplet in Meade SN6 6" F/5 Schmidt-Newton + ASI183MC

Hi Magnus, I use a Solar Spectrum 0.3 Å H-alpha filter with Baader TZ-4 4x tele-centric lens, combined with an ERF (Beloptik Tri-band)

I always use a 2" diagonal, except on very rare occasions when I need to travel light. In my C8, the extra FOV offered is too big to ignore, in my little APM 80 mm F/6 triplet the huge FOV offered is amazing fun. In the case of dielectric diagonals, there is an added bonus with 1.25" EPs of slightly better image quality due to a larger truly optically flat area.

Very nice set of disks!

I had the TMB Paragon 40mm and that listed a "true" AFOV of 68 deg (as measured from the effective field stop, i.e. how much of the sky do you actually see), and an "apparent" AFOV of 69 deg (the angle of the image you see looking through the scope). This means the Paragon has negligible distortion and can as such be named orthoscopic (as it said on the barrel). I sold the EP because it got little use after I got the Nagler 31 mm T5, but I must say I regretted the sale, and got the Vixen LVW 42mm when one came up secondhand. The LVW has a true AFOV of 65 deg, and an apparent AFOV of 72, showing much more pincushion distortion. Great EP, nonetheless.

Nice results for such conditions. My attempt last night was scuppered by clouds and approaching rain, alas

I use my 80 mm F/6 triplet for most of my solar imaging. In this case I used a Beloptik Tri-Band ERF (no longer made, but also not essential for Ca-K), and a Lunt B1800s Ca-K module (18mm free aperture which is overkill, but also future proof, straight through rather than as diagonal), and an ASI178MM camera.

Got a load of H-alpha data as well, three days running now. Grey scale: Pseudo-colour: Part inverted: Part inverted + pseudo-colour: There seems to be some flaring going on in one of the ARs on the eastern side of the disk. I took some longer SER files of that region: 12:58:51 local time: 12:59:40 13:06:40 It does not perhaps look like a lot, but at the eyepiece it was really brighter than the surroundings

The sun is showing some nice activity these last few days, and I have had time to image it as well. I love the way the two bands of ARs show up so clearly, in particular in Ca-K. WL: Ca-K, grey scale: Ca-K, pseudo-colour: Ca-K, part inverted: Ca-K, part inverted + pseudo-colour: H-alpha coming up shortly

Nice crisp disk

Had a stab at imaging Saturn for the first time in quite a while. It was still less than 20 deg above the horizon, but I hope my ADC would counter the worst of the problems. Seeing turned out to be very choppy indeed, with heat radiating off the hills to my south-east. I had set up the Celestron C8 long before starting to image, so any thermal problems were definitely external. I used a small ROI on my ASI183MC to image, and after faffing around with the ADC took two sets of 10,000 frame SER files: one at prime focus, one with my Siebert Optics 1.3x tele-centric Barlow. I stacked 20% of the data using AS!3, and sharpened with Registax, with some final tweaks in GIMP. The result are below. F/10, no Barlow: F/13, Siebert Optics 1.3x Tele-Centric Barlow The latter shows the Cassini division is much clearer in the second image, so I think I will be using the Siebert Barlow more often. Jupiter rose above a nearby house as I was about to finish, but the view was truly attrocious, so packed in the stuff (had to get up at 7:30 for an early morning cycle through the hills here with my son).

All set for some planetary imaging. All I need now is for Saturn to rise above the trees.

Great stuff. Very crisp images

Really lovely results

Here are the H-alpha results of today. Pretty steady seeing, I must say. Ended up stacking 50% of each of the 1000-frame SER files. Grey scale: Pseudo-colour: Part inverted: Part inverted + pseudo colour: A very small strand of detached material can be seen on the 9 o'clock position, but not as clearly as in Ca-K, oddly. I also grabbed a 4000 frame SER file of the activity in the lower right of the disk. Grey scale: Pseudo-colour: Rather pleased with the overall results.

Sunny again in southern France, so more solar data grabbed. WL: Ca-K, grey scale: Ca-K, pseudo-colour: Ca-K, part inverted: Ca-K, part inverted + pseudo-colour: Some big proms visible, with what looks like a detached prom at the 9 o'clock position. H-alpha data to follow

Absolutely lovely

Shot a longer SER file in H-alpha (4000 frames rather than 1000) to see how much detail I could extract from one of the more active areas. Grey scale: Pseudo-colour: Part inverted: Part inverted + pseudo-colour:

After the usual Wl and Ca-K disks, I grabbed a series of 1000-frame SER files for a 15-pane, full disk H-alpha mosaic. Seeing was a bit up and down, which meant I re-shot a few before I was content. I stacked 25% of each in AS!3, sharpened in ImPPG, and stitched in MS-ICE. Final postprocessing in GIMP. Grey scale: Pseudo-colour: Part inverted: Part inverted + pseudo-colour:

Got the rig out in the sun again, and landed a decent set of WL and Ca-K disks. Seeing wasn't too bad, once the thin cloud that plagued me earlier in the day had dissipated White light: Ca-K, grey scale: Ca-K, pseudo-colour: Ca-K, part inverted: Ca-K, part inverted + pseudo-colour: Will post H-alpha results shortly