John

58 minutes ago, Carl Au said:

..Entirely different subject, I don't suppose you know why there is a grey hand sign over my profile picture do you?

I don't but the forum software just just been upgraded (about an hour ago) and hovering over that hand gives me the message that you "joined recently" so I guess it is a new feature ?

8 minutes ago, Carl Au said:

Yes that's the one

Ok - that's not the same as the one I was talking about but it is a very good accessory to have with the Baader Zoom. 

I use the Baader 2.25x Q-Turret barlow. Mostly with a 7.2mm - 21.5mm zoom to give a high power zoom eyepiece (9.5mm - 3.2mm). This combination works pretty well. I don't tend to use barlows / telextenders / Powermate's with my other eyepieces now though, just with the zoom.

The Baader 2.25x does seem a nice optic. They kept the body work simple though. No compression ring fitting, just a set screw.

Just exploring some of the nice crater chains close to the terminator before the Moon goes behind our house.

Fascinating features. This one is in the walled plain of Deslandres, to the south of the Rupes Recta:

2 minutes ago, Mark at Beaufort said:

Well done John. I set up the 12 inch dob plus all the eyepiece a few hours ago to view moon, mars and uranus. Forecast total clear skies no cloud all night plus the early hours. I had to deliver something to my son (out for 10 minutes) in that time it poured down with everything getting totally wet. You would not believe the mess.

Sorry to hear that Mark.

I have a scope cover on standby but it looks OK at the moment here.

Uranus is just 1.4 degrees from Mars so easy to find tonight - just go "down" a bit from Mars. Both easily fitting into the field of view of my 9x50 finder and I can just about fit the pair in the same field with the 12 inch dob if I use the 31mm Nagler. Uranus disk looks bluer tonight than last time I observed it. Perhaps that is the proximity of the bright Moon having an effect ?

Got to have a break for supper now. Fingers crossed for more of this later 🤞

Clearish night forecast tonight and it does indeed look that way

As my 12 inch dob cools down I've been catching some early views of Mars and the Moon with a 7.2mm - 21.5mm zoom eyepiece so that I can adjust the magnification to suit.

The seeing seems steady currently. Mars 8.6 arc second disk clearly defined at 221x with some dark areas showing across the southern hemisphere of the planet.

The Moon's phase is really nice just now. The Rupes Recta (Straight Wall) and the Birt craters are very close to the terminator with strong shadows strongly emphasizing the rugged folds and clefts in the lunar landscape. The Apollo 15 landing site in the Lunar Apennines is also really well placed and illuminated. The sinuous form of the Hadley Rillle can be traced as it wriggles through the foothills and crosses the plain in front of Mount Hadley which Scott and Irwin explored in the Lunar Roving Vehicle.

The Lunar Alpine Valley is very nicely presented as well. The illumination looks suitable for spotting that elusive rille that runs down the valley floor perhaps ?

Hopefully this will continue for a few hours yet to make up for the past 10 days or so of unremitting cloud cover here !

If it stays clear, as well as the usual Orion favourites and some Leo galaxies I'd like to try and see that supernova in NGC 4414 while it still has some brightness in it:

https://stargazerslounge.com/topic/369912-supernova-2021j-in-ngc-4414/?tab=comments#comment-4023877

That's a very thorough and analytical approach 

I have a spreadsheet set up with my scope specs loaded and can then plug in any other eyepieces that I am thinking about to get the basic figures on what they deliver in terms of magnification and true field of view. One snag with that approach is that the specs supplied by the manufacturers are sometimes wide of the mark, occasionally well wide

What they actually deliver in terms of image sharpness across the field of view, field flatness or otherwise, eye relief accessibility, ergonomics, etc, etc seems to be a more qualitative business for which there seems to be no alternative but to try them out and see how they fare

I was very lucky that FLO kindly provided me with a regular stream of eyepieces on loan to try out and report back on

I hope you reach a satisfying conclusion in the not to distant future

By the way, I have recently owned one of the Extra Flat 27mm eyepieces. Mine was branded "Orion" but it was the same as the other clones of this eyepiece. The AFoV did seem to be around 53 degrees as stated. The eyepiece was nice to use in a 90mm mak-cassegrain and 70mm F/6.8 refractor but even in the latter the stars in the outer part of the field were looking astigmatic and I was not keen on the eyepiece in my F/5.3 12 inch dobsonian at all really. But for what it cost me (used) the eyepiece was well made and good to use in the slower scopes.

Clear sky forecast tonight so I may have a chance of this one

I've done a bit of imaging using a phone held over the eyepiece and found, as Stu says, that the positioning of the phone camera over the eyepiece lens is really critical to the results. A tiny movement or tilt and the image is skewed or over exposed, out of focus or all three !

I now use a low cost phone holder which helps keep the "sweet spot" positioning. I find that I use the "zoom" feature on the phone camera combined with a zoom eyepiece which together give some room for framing and increasing  or decreasing the image scale. The phone software actually does quite a good job of getting a decent exposure and sharp focus if you can get things lined up and keep them there.

5 hours ago, Voyager 3 said:

Did you try with your tak John ?

Hello,

I'm not sure that I have actually tried with the Tak 100 since I posted that report. Cancer will be getting more favourably placed for me over the next month so I will remember to give it a try next time that I have that scope out

It should make a fine challenge if the seeing is good.

4 hours ago, neil phillips said:

I am certainly no expert. But suspect its exactly the same achromatic lens as the SW 90/900 ?  just with the usual extra feild curvature and extra CA. Nothing in that report suggests comparable CA to the 90/900 just comparable  sharpness and contrast ( with a smaller sweet spot ) no doubt. I personally am buying the 90/900. But realize some may want a more portable refractor

I think you are probably correct.

I have a Celestron branded (same as the SW) 90/1000 (F/11.1) optical tube which also looks exactly the same but longer. Same objective cell, dew cap design and same focuser design. The F/11.1 version would be too much for the AZ-Pronto though. The F/7.3 version might be OK though - maybe thats why they introduced the shorter tube version, to give lighter mounts a chance ?

Tegmine is a fun challenge with smaller scopes:

It looks lovely - congratulations !

I find this a great online resource for data on double stars:

https://www.stelledoppie.it/index2.php?section=1

I think I would be trying to remove the fork part of the mount and replacing that with a post with a robust pan / tilt head mounted on it. The binocular mounting bracket would then go on top of that.

If you have an old photo tripod the central post and pan / tilt head can usually be removed and you might find that would then fit into the socket where the fork mount head had been ?

I agree that is a Skywatcher or Celestron branded EQ5 mount.

William Optics do have an alt-azimuth mount with their branding on it (the EZ Touch) and an equatorial mount (the EQ35) but the one in those links is not one of those.

It seems an interesting idea, to me, to carefully capture and process photons that have travelled many light years to reach here and then to add an optical effect created by unncessary hardware added a metre or so away from the imaging chip

But, I'm not an imager, so what do I know

I'm not sure that dobsonians are suited to observatories.

A roll-off shed where the whole shed moves is probably a better idea:

https://stargazerslounge.com/topic/273274-roll-off-dob-shed/

Anything with walls more than a couple of feet high is going to impede the way that the dobsonian mount works. The dob works best when it is out in the open.

I came across this simple list of 100 double stars which might help you identify some suitable future targets:

doublestarlist.pdf

2 minutes ago, jock1958 said:

For the foreseeable it looks like I'll be keeping the Skytee 2 until @Dek Rowan Astro comes up with a smaller version of the AZ100 with slo mo's....pretty please 😉

I really do believe that there is still a niche for something in between the Skytee II / Ercole class mounts and the £1K plus AZ100 / DM6 / APM Maxload class. Initially I thought the AZ100 might be it but that was not to be as it turned out. I think Rowan might have thoughts about a smaller / less expensive mount but I'm sure that the AZ100 development is keeping them pretty much fully occupied currently.

1 hour ago, jcj380 said:

Question - How much load can a typical Giro-style mount handle  before a counterweight is necessary?  Thanks.

In terms of weight, the Giro Ercole quite a lot, if balanced correctly 

My 12 inch dob is at least as quick to set up as my refractors are on their alt azimuth mounts.  I can only move the whole thing a short distance in once piece but as the tube and altitude bearings just lift off the mount base, it is very quick and easy to move it in 2 sections.

The large altitude bearings also make great carry handles !

47 minutes ago, mikeDnight said:

I've owned a Gibraltar mount on a beautiful walnut tripod. It looked great but it wasn't a good fork. The mount wasn't solid enough and it was difficult to balance my scope. The altitude axis was difficult to lock, and when changing to heavy eyepieces, the fork struggled to hold position. The best fork I've ever owned was a Hercules Helix (below), sadly nolonger in production, but it would carry a hefty 5" or 6" refractor without breaking into a sweat. I wish I hadn't sold it, but like many others, I'm not immune from making stupid decisions.

I agree with Mike's assessment of the Gibraltar mount. I owned one for a while and found that it simply did not perform as well as it looked. One of the few Tele Vue products that I've been disappointed in. It worked OK with my F/6.5 Vixen 102mm ED refractor but was not really happy with the ED120 on board.

I've also owned one of the Hercules mounts that Mike pictures above. It was better than the Gibraltar but again I was not really happy with it when the ED120 and a later 127mm F/9.4 achromat was mounted on it.

My current alt az mounts are a Giro Ercole, a Skytee II (with ADM clamps) and the superb T-Rex.

The Giro mounts can handle heavy scopes fine but balance seems to be key to getting smooth motions from the axis with them so some sort of counterweight is worth having on even with a lightish OTA just to keep that very smooth tracking. My Tak FC100-DL (below on the Ercole) weighs less than 4kg but even with that a small counterweight improves the azimuth motion.

The Skytee II, despite having a lesser quality of finish overall, seems to manage very well without a counterweight even with an 7kg refractor on board such as my ED120.

Wow !!!!

So that is what the hobby is all about ?

I was beginning to forget with all the clouds I've had here for the past couple of weeks

Thanks for posting a great report

Some of the TAL 150 K's had the 3 curved vane design and some the 4 straight vanes.

The rear end of the scope seems consistent and distinctive though: