John

Assuming that you keep the same eyepiece in the scope, if you have the moon in sharp focus, you would only need to make a very small adjustment to get sharp focus on something further away such as a planet or star.

16 minutes ago, Chaz2b said:

.... I meant the scopes not the mounts. Do I take it they are identical scopes then with different mounts?

 

chaz

I think so Chaz.

A shortage of outward travel is easier to solve than a shortage of inward travel.

My DL focuser seems to have ample travel for a very wide range of eyepieces - does the ES 14mm have a particularly extreme focal point ?

1 minute ago, Stu said:

Big difference between Bortle 5 and Bortle 7 or 8 John as I’m sure you know. Even in a decent sized scope, galaxies are very tricky from my skies which are 7, and 8 would be trickier still. I tend to focus on globular and open clusters from here for that reason.

I have occasionally done outreach under bortle 7-8 skies. It is hard work showing folks galaxies I agree, even the bright ones (galaxies, not folks).

I've used Hermes dozens of times over the past few years with 100% success, even with international deliveries.

I'm not expecting much to be "normal" currently even if website info is optimistic. 

Split them into a number of zip files ?

My typical sky is Bortle 5 but I seem to do OK on actually finding galaxies. Seeing details in them, spiral arms etc is another matter though. That is limited here except on a really good night.

Still, I'm lucky that I can have a good galaxy hunting night from my patio. Many folks have to take their scope somewhere dark to do that.

20 minutes ago, Waddensky said:

I noticed this too, but I also noticed the comet is a bit larger than M82. It's quite possible the surface brightness of C/2019 Y4 is lower because the total brightness is spread out over a larger area.

I felt that the comet was less extensive than M82 but my sky is not that transparent tonight.

You could well be right about mag 8 being an integrated figure while the surface brightness of the comet is less.

Good one - sounds like your conditions were much better than mine tonight. Every time I've observed it with my 12 inch dob, even under the best conditions, the B star has glimmered faintly out through the glare that surrounds Sirius A. Not at all like observing a "conventional" double star (eg: Rigel) although the separation between A & B is about the same as Rigel and its companion.

I've found 265x - 318x the optimum magnification for seeing this. Pentax XW 5mm or Ethos 6mm. My 1st ever sighting of it (about 4 years back) was with the same scope and a 6mm Baader Genuine Ortho eyepiece.

I have spotted Sirius B a couple of times with my 130mm triplet refractor but it is more obvious (though still hard and not consistently seen) with the 12 inch dob.

You have done very well to get it with your 8 inch dob IMHO

I've just viewed the comment with my Tak 100mm refractor. Fairly strightforward to find as you say. I though M82 was brighter than the comet though, despite the comet being billed currently at mag 8.0 and M82 at Mag 8.4.

Well done if you have got it !

Here is my sketch of Sirius A and B made around a year ago with my 12 inch dob. Its position angle has changed a little in the past year but not a great deal:

The B star (the Pup) trails behind Sirus A as it drifts across an un-driven field of view.

Just had a look with my Tak 100mm refractor.

Fairly easy to find but I still feel that it is a bit dimmer than M82 (mag  8.4) despite the claimed mag 8.0 for the comet

Looks like the view you might expect to get from a spacecraft approaching the moon Mike - nice one

Very nice Dave

Here are a couple that I snapped before supper.

1 hour ago, Paul73 said:

Interesting John. If it was a choice between Delos and Ethos, it would be Ethos all the way. But is the APM a match for the Delos quality wise? I’d rather sacrifice a bit of fov for better quality.

Paul

I have not made that comparison but I think it would be close given what I've read about the APM / Lunt 100's.

Don's points about coma are worth considering though. With my dob being F/5.3 it's not such an issue. F/4 and 100 degree eyepieces without coma correction might not be such a good match.

With the schmidt-newtonian scopes the difference is the mount. The LXD75 is a more capable mount than the LXD55.

As it's out, I might as well point a camera at it. Takahashi FC-100DL:

In the dob I'd go 100 degrees.

I have the 14 Delos and it's really nice but with my 12 inch dob the 13mm Ethos is the way I go every time.

Just now, Barry-W-Fenner said:

Ursa Major is in a bit of an awkward position for me currently. I am almost directly underneath it. Trying to adjust the dob pointing towards the zenith is doing my back in 🙂 

 

 

That's where the term "the dob hole" comes from.

It's a term that can also be applied to your bank balance if you get a bad case of aperture fever and go for something much bigger !

7 minutes ago, Second Time Around said:

Thanks, John, but I obviously didn't explain myself well.  It was the Celestron and Olivons that Louis was referring to that I'm talking about.

I can confirm that a Dioptrx fits my Baader zoom, preferably with an O ring.

 

 

Actually I didn't read your post carefully enough - you did say that of course

I think this is one of the eyepieces that Louis was referring to by the way:

https://www.ebay.co.uk/itm/Celestron-1-25-Regal-M2-8-24mm-eyepiece-with-case-Boxed-Fully-multi-coated/162688568329?hash=item25e0fe8c09:g:juIAAOSwzHNZy2gr

I've not used one myself by Louis is always positive about them.

No problem. Well done for getting the cell off and at least blowing the worst off.

57 minutes ago, Second Time Around said:

Many thanks, Louis!

Do these zooms take a Dioptrx? I see there's a photographic thread, is it between 41 and 44mm?  If it's the same as the M43 on my Baader zoom a Dioptrx will fit, although an O ring or elastic band on the thread will help.

These posts on the Cloudynights forum cover that. It looks like it is possible, with some care:

https://www.cloudynights.com/topic/573621-new-baader-mark-iv-8-24mm-zoom-eyepiece/?p=8816705

There are some photos from Don Pensack (Starman1) further down that thread.

2 hours ago, banjaxed said:

I was replying to your first message when you posted this one. It is not the collimatable type as it does not have those screws.

Ok. I think the dew shield still slides off the objective cell but you will need to find a way to remove the whole objective cell from the scope tube to get to the rear of the objective lens.

Once the dew shield is removed, the objective sell should look like this:

There are 3 screws around the objective cell with nuts on the inside which I think hold the cell onto the tube - the trick is how to undo these without beeing able to get at the nuts. I don't think the objective cell in these threads onto the tube, which would make things easier.

If you really have to (not really recommended) remove the objective, the objective retaining ring around the front end of the objective cell will need to be loosened and removed and the lens elements gently taken out. If you can avoid having to do that though, I would. It is a delicate business.

Great stuff again Mark

I had good fun one night a couple of years back just seeing how many of the galaxies shown in the "bowl" of Ursa Major in the S&T Pocket Sky atlas I could pick up with my 12 inch dob - there are quite a lot !

I think these 100 degree eyepieces are really nice for this task - you can get by with just a couple of focal lengths for a whole session of galaxy hunting !

If it is the collimatable type, the objective end should look like the 2nd photo below: