michael.h.f.wilkinson

I really like the lot of them. I did a direct comparison between the SLV 5mm and the mighty Pentax XW5, which is the only pair that matched directly in terms of focal length, and the little SLV 5 held its own in all matters except FOV. It is comfortable, very sharp, very neutral in terms of colour (the old LVs had a slight brown cast, I seem to remember, especially the 7). Yes I prefer the XW, but that is only down to FOV. In more than one outreach event people were struggling to get good eye position with something like a 10mm Ortho. I lent them my 9mm SLV, and they were immediately impressed, both in terms of comfort and the tack sharp image. They immediately wanted to know the type, how much they cost, and where to buy one.

I have also always felt the 22 was best, but many people suggest the 17 is superior. I don't see that

Yours is even shorter, and therefore even harder to follow 😜

I quite happily mix Tele-Vue and Pentax, with some Vixen and the odd MaxVision thrown in for good measure. Since I got my parfocalizer rings, the Delos and XW EPs play very nicely together (except my Delos 14 mm which focuses a good deal further inwards). I might at some point replace my Nagler 12T4 with the ES 12mm 92 deg. The 12T4 is my least favourite Nagler. If the ES 12 works well, I might even replace the 17T4

There is a good train connection

Up here in the north we always say the distance from Amsterdam to Groningen seems to be much longer than from Groningen to Amsterdam . Whenever proposing a meeting with colleagues from the west of the country here in Groningen they look at you as if they have to travel to Hammerfest up by the North Cape It is a bit far to travel up and down for just an evening (only to find clouds have arrived, most likely)

Where in the Netherlands were you located again? If you are not too far away, you could try out the SLVs

I had a slow Newtonian with very good mirrors (1/10 lambda) and small central obstruction (23 % or so) and replaced that with my current main scope: the Celestron C8 with 35% CO. The latter definitely gives me more detail on planets, because although at the same exit pupil the contrast is a bit lower, the actual maximum magnification is higher, so more detail can be seen. At the same magnification, the C8 gives a distinctly brighter, crisper image. The lack of diffraction spikes gives another little advantage to the C8 (and the SN6 I now have for wide-field)

I have Vixen SLVs at 5, 9, and 15 mm focal length, mainly for my travel set-up and for outreach. They are a close match in terms of image quality for my Pentax XWs, and that is saying a lot. They only lack the XW's 70 deg FOV. They are ortho-like in quality, without the need to glue your eye to the lens at short focal lengths. I have looked through some Planetary EPs of different brandings (and the TS seem to be among the best of the lot), and at longer focal ratios they are pretty good, but in faster scopes they don't perform as well. I would certainly prefer an SLV over a TS Planetary.

I just reread the whole review, and it reminded me that a) I now have a 6" F/5 Schmidt-Newtonian b) A 3.5 mm EP would make sense for that focal length and focal ratio c) I have the XW5, 7 and 10 (with Delos 6 and 8 with parfocalizer rings "intercallated" in the series) d) I have nice piece of space in my EP case, just begging for a 3.5 mm EP. Oh dear.

Sounds interesting, but the weather forecast doesn't bode well here

I used to have a very sharp 6"F/8 Newtonian, and with that scope the brighter stars in M13 could just be made out as what I like to call "diamiond dust". In an 8 inch scope they are really obvious, so I am not surprised a 5.1" scope struggles a bit. Upping the magnification helps, as does waiting for darker nights than what summer provides this far north

And a hammer

Slight reprocess of my Gimp version, adding a bit more red

Had a go with the APM 80mm F/6 triplet, with TS 1x flattener, Optolong L-eNhance filter, and ASI183MC. I gathered 1 h and 51 minutes worth of 120 and 60 s subs (had to discard a few due to poor tracking). I added 30 bias , 25 darks at each exposure, and 30 flats and dark flats. Stacked and (very slight) gradients removed in APP. The first version shows the automatic stretch by APP, the second my manual tweaking in Gimp. It depends a bit on the monitor which I like best. Quite chuffed at how much detail can be captured despite the amount of background light so close to summer solstice

Cheers Paul, I stopped the lens down to F/2.8, but I think the Contax to EOS adapter may have a little play, which means the chip isn't entirely square on the optical axis. This complicates matters further.

Got 2 h 20 min worth of 5 minute subs on the Veil with the 85 mm F/1.4, ASI183MC and Optolong L-eNhance filter (no guiding). I think I might have missed focus by a little (possibly by nudging the lens by accident after focusing, I cannot lock focus on this lens yet) Not perfect, but still quite chuffed. Might use a Carl Zeiss Sonnar 135mm F/2.8 I have lying around as well

The original Vixen pucks have two screws to tighten: One at right angles to the dovetail and one under about 45 degrees. I first tighten the one at right angles, and then the secondary one. I have found that if the first is loosened, the other one won't turn and loosen, but locks. As a result, my telescopes (8" SCT, 80 mm triplet and 6" F/5 Schmidt Newton) have never slipped in any of my mounts, provided the second screw is also tightened.If you puck only has one screw, something is missing, I would say

There are various globular clusters well placed (M13, M92 in Hercules for example). I tried the North America Nebula and Pelican last night, I might go for the Veil, or M27 tonight

Lovely collection!

Got the scope out this morning for some solar work. Tracking was great because I had left the mount out from last night's DSO imaging, so polar alignment was much better than the usual "point north and pray" I usually do for solar. Seeing was also rather good, but unfortunately, not much in the way of detail could be discerned. Still, it is nice to get a batch of solar images again WL, grey scale: WL, pseudo colour: Ca-K, grey scale: Ca-K, pseudo colour: Ca-K, part inverted: Ca-K, part inverted + pseudo colour:

Just finished stacking 27 5 min subs of NGC 7000, taken with the ASI183MC with my new Optolong L-eNhance filter and Carl Zeiss Planar 85mm F/1.4 on the EQ3-2 mount. Stacked and processed entirely in Astro Pixel Processor, with darks, flats and bias frames. I stopped the lens down to F/2.8 for better star shapes in one of the corners, suggesting the lens might not be entirely square on the chip, probably due to the Contax/Yashica - Canon EOS adapter having a little play. I could easily get 5 minute subs without guiding at this short focal length. Star colours are bit weird, due probably due to the dual-band filter in use, and some red bloat is showing around stars. Still pretty chuffed at the new set-up. I might have a go at the Veil tonight.

Currently testing a new combination of my ASI183MC, with Optolong L-eNhance filter, and Carl Zeiss Planar 85 mm F/1.4 on the EQ3-2 mount. The Zeiss lens is my old Contax mount portrait lens for which I have an EOS adapter. I am currently capturing the North America Nebula at F/2.8 with 300 s unguided subs, which seems to be working smoothly. Very curious about the result.

Might want to use my own implementation of unsharp masking which prevents dark halos

Had a go at processing last night's data, and a bit more could be salvaged The latter is a much wider panorama than before, as I found some missing bits. I did some noise suppression followed by unsharp masking, and tweaks with curves to get out a bit more detail