michael.h.f.wilkinson

Very nice indeed. Very natural look

It is a matter of magnification. The larger the magnification, the more any rocking motion of the boat will disturb the view

I took a huge load of 60 s subs at ISO 800 on my Canon EOS 550D (modded). The Rosette is some 12 hours 21 minutes total exposure time. I was shooting at 384mm focal length, F/4.8. Darks, flats and dark-flats all applied.

Correct, I shoot RAW subs, and stack those in APP for DSOs and comets. For planets, moon and sun I shoot video (with planetary cameras), and stack with AS!

I should have added the M42 image was 7 h 11.5 m 30 s total exposure, the Rosette is a total of 12 h 21 min, both taken over several nights

I have had a lot of fun with my modded Canon 550D, which came up for a very good price second-hand. It is certainly a good investment as a starting camera for DSOs. This was one of my first longer efforts on M42, from Bortle 5 skies with just a CLS-CCD filter: With L-eXtreme filters, I captured the Rosette Nebula (both with an APM 80mm F/6 triplet and 0.8x reducer) I now also have a cooled mono camera (also second-hand), which is definitely more sensitive, but will not ditch the DSLR any time soon.

The L-eXtreme filter is really intended for narrow-band objects, i.e., emission nebulae and planetaries, not galaxies, and certainly not elliptical galaxies which lack H-II regions. This was obtained on the Rosette with teh L-eXtreme

Shot a 19-pane panorama with the Solar Spectrum 0.3 Å H-alpha filter, Baader TZ-4 4x telecentric lens, and ASI174MM behind the APM 80mm F/6 triplet (stopped down to 75mm) and Beloptik Tri-Band ERF filter. In hindsight, I should have not have used the full chip, and shot more panes, as the flats did not fully correct the shading problems over the full FOV, but AutoStitch did manage to make a decent panorama of the whole sun, although some blotchiness is still visible. Grey scale Pseudo-colour Part inverted Part inverted + pseudo-colour I also made a more detailed mosaic around the major ARs Grey scale Pseudo-colour Part inverted Part inverted + pseudo-colour Finally, I took a longer exposure image of the large prom in the north It felt good to be back in the saddle again

What with it being the King's birthday and bright sunshine, I finally got back to solar imaging with the APM 80mm F/6 triplet, and Beloptik tri-band ERF, allowing me to capture white light, Ca-K, and H-alpha (which I will post later), by inserting either the Lunt Herschel wedge, Lunt Ca-K module, or the Solar Spectrum filter in the rear. WL, grey scale WL, pseudo colour Ca-K, grey scale Ca-K, pseudo-colour Ca-K part inverted Ca-K, part inverted + pseudo-colour Note the ghostly proms visible in the latter. All are stacks of 200 out of 1000, shot with the ASI178MM

In my first scope the finder had just 5 degrees FOV, and that worked pretty well. That's more than 40 years ago, so I wasn't particularly experienced

There they can be useful, although I don't have anything on my 80 mm F/6, which gives me 5.75 degrees with the Vixen LVW 42 mm, and 5.3 with the Nagler 31T5.

I actually never use any form of a finder with wide-field instruments like 15x70 binoculars. In fact, my home-made finder scope for my C8 is a 14x70 RACI with about the same true FOV as my 16x80 binoculars. I just point at some bright reference star and star hop. I really wouldn't know how a telrad would work on a pair of binoculars other than much bigger ones mounted on a tripod.

I use a Benro MAD49A which works a treat with my Helios LightQuest 16x80 binoculars.

I can tell. I would rig it up with my ASI183MM-Pro (somewhat restricted FOV compared to yours). Before that I will install a Starizona Night Owl 0.4x reducer in my C8, which brings it down to F/4 and 16mm image circle (perfect for the 183MM). Not quite a RASA, but getting there

Wonderful image again Goran. Should I get a windfall, I might certainly invest in a RASA 8

M101 might be bright in terms of total magnitude, but its surface brightness is not very high at all. I rather like your result, I must say

The red colour is actually correct, as H-alpha dominates these nebulae. I use APP rather than DSS. APP is not free, but I much prefer it. It has a "calibrate star colours" tool which works well on most RGB data, I find. After that, I tend to increase saturation in GIMP a bit

Interesting report. I am a bit surprised at your struggles with 3C 273, as I picked that up from a suburban garden with a C8 on a good night. As it is a point source you can throw quite a bit of magnification at it without issue to get the sky background dark enough. I just keep wearing my glasses when observing

Just spotted this as well. Two smaller, brighter proms are just northwards, and a bright plage area shows on the eastern limb southwards, around the 3 o'clock position in my Coronado SolarMax-II 60 mm

I can well imagine the wonderful views. Sounds very much like my APM 80 mm F/6 triplet with the Nagler 31T5 "Panzerfaust", 15.5x magnification and 5.3 deg FOV. I tend to use it with a 2" Amici Prism, giving wonderful correct image views. Really ideal for wide-field sweeping. M31 from a camp site near Olly's place was just astounding

Impressive! Clearly better than my 50-100 mm F/1.8

Thanks! Temptation levels have just increased

What aperture did you use?

Very impressive image. I have been tempted by this lens, I must say, but I hadn't seen any astronomical results

What I do is stack the outcomes of different sessions separately, and create weight maps as well. I then give APP both the light-pollution corrected images plus weight maps, and select one to be the reference. APP adjusts the image scales of the others to that one. This is much faster than restacking all the data