jetstream

7 minutes ago, JOC said:

LOL, like that's an intuitive name pairing!!  I would love to be able to go out and identify all the constellations by eye.  I have bought a classically hand held constellation map / planisphere for this location.  Maybe I should get outside on starry nights and just familiarise myself with what's what.

Great idea!

I did the same- and still do- lawnchair observing can rule here lol! The constellations are actually the "map" of the sky and I observe them every time out. Can you make out Leo?

5 minutes ago, JOC said:

I haven't, but I am sure I saw Cygnus out the other night - the big W - yes?  If so it's not beyond the realms of possibility that knowing that I could find it.

Johns right and its great to hear youre out exploring the sky. M15, the Swan nebula is a showcase object in Sagittarius and is one of the best, easiest nebula to see in the sky. It might be worth marking this one down to try out when its good to view.

Seeing as you are sky cruising Cass maybe try out the Pacman nebula, NGC 281 once the moon is gone and with your OIII. It might be pretty hard to see first time out but will tell much about your sky and filter.

In Cass I never miss viewing "ET" a fantastic goto asterism! I love this one.

Its hard to best a good 200p dob... the central obstruction at over 30% starts to become an issue which can compound other things optics wise such as slight miscollimation.

4 minutes ago, JOC said:

All the Morpheii have the ability to seat into a 2" focusser.  Novice question, is this just for convenience or is there any advantage to seating them into a 2" focusser - I guess they are possibly more stable, but I can't see how it can affect the view if the final barrel is only 1.25"

Some scopes can benefit from this focus point wise, and the option is great to have IMHO.

Off topic JOC- have you seen the Swan nebula?

On 04/04/2020 at 07:01, cloudsweeper said:

Thanks everyone for suggestions and encouragement.  Keener than ever to put the Dob into action now!

Great scope!

I have had issues with the Rigels baseplates too- in the cold the adhesive tape comes off. I now use 100% silicone adhesive and let it sit for 24hrs to cure. Not one of my bases -4- come off now.

On 03/04/2020 at 16:31, Louis D said:

That's wild.  I've never heard of a solid tube Newt flexing.

The area under and around the focuser flexes- a buddy with a VX14 made a plate to stiffen it up. Its all made worse by the need to run an extension adapter (I use the excellent Baader Clicklock instead) which has the EP weight up really high.

My Astrosystems is extremely solid, even with 2 Docter UWA in the Binotron 27s- very hvy. even this combo held collimation until about 1/2 racked out.

I measured the flex with a dial indicator lol!  Thats a long time ago now, sure glad I ran through all this- it was a great learning experience.

7 hours ago, Don Pensack said:

Just got an updated list from Baader in Germany.  They haven't updated their site yet.

They say:

4.5mm--358g

6.5mm--326g

9mm--328g

12.5mm--315g

14mm--363g

17.5mm--305g.

That is very close to JOC's weights.  Excellent.

Thanks Don, good to know and I'm pleased with their weight. Also good info on the Vixen SSW- I wonder how they work at f4.1 with the PCII?

21 hours ago, JOC said:

Both!!  

Yeah, I know lol!

Glad to hear these are a bit lighter now- I wonder what the chances of me getting light ones are over here. Actually the 12.5mm and 9mm would be very good additions to the arsenal.

Baaders newest coatings are very good as is there polish IMHO. My 10 BCO go a bit deeper than the deep Delos, which is actually really something. Not all my orthos do, only the best ones. Curious where these Morphs sit is this regard.

Btw JOC, any scope with 2 or 3 "trusses"  (single tubes) just might not like hvy eyepieces.....these Morphs wont stress out the collimation.

Yes, the Delos is out for the H130 as is the hvy Doc used for testing focuser twist.

just in...

Just now, Louis D said:

Are they twisting the truss poles somehow?

no. First off I'm fussy on some things, mind you I do get vg views- its a process IMHO.

My OOUK VX10 Al tube will flex, so this is the issue here. I can't binoview with this scope. Very hvy eyepieces will also decollimate this scope.

The 15" is rock solid but the Moonlight will flex about 2/3 racked out with a simulated binoviewer weight. Same goes for the 24"- focuser sag.

However, colleagues tell me the new Feathertouch is worse...

The 15"/24" will not decollimate with hvy eyepieces but I wouldn't want to try a 2" Powermate with an Ethos in it

It is well worth checking focuser alignment and also sag IMHO.

1 hour ago, JOC said:

I'm pleased that my weights for the 9mm and the 14mm are very close to those quoted by Louis D above

5 hours ago, Louis D said:

According to my scale, my 9mm Morpheus weighs 327g without caps, and my 14mm Morpheus weighs 361g without caps.

Perfect!

Thanks for this- it all matters to maximize views. In other scopes too... secondary decollimation can be common and I test all my dobs. Doing this allows 761x on the moon with the 15" and as much mag as I can merge with the binos but only up to 2/3 racked out.

All the numbers agree- Manish at Agena and both of you.

The 9mm or 12.5mm Morph will work in the H130- many of us think 12 oz is max.

Question now is which one lol!

3 minutes ago, Don Pensack said:

12.5mm is 345g.

Did you measure it Don? Out of curiosity how much astig shows in the Vixen SSW? I'm looking at those as well but...

5 minutes ago, Louis D said:

As I recall, the caps might weigh 1g or 2g taken together.  Some don't even register, so must be less than 1g.

Agena lists the 12.5mm at 11 oz -no caps- 1.2 oz less than Baader. If its 11oz it will work for sure- confirmation is nice before I blow a bunch of money lol!

4 minutes ago, Louis D said:

According to my scale, my 9mm Morpheus weighs 327g without caps, and my 14mm Morpheus weighs 361g without caps.

Thanks Louis, perfect- can I ask what the end caps weigh? then I can figure out the 12.5mm weight.

Its a toss up between the 12.5mm and 9mm for the galaxies in this scope, the 12.5mm wins on M42. My 12.5 mm Tak ortho while extremely sharp falls short on DSO and I have no reason why and I quit trying to figure this stuff out.

The recent posts about Morpheus eyepieces got me thinking.

First I "need" a bit lower mag for the Paracorred dobs for bright galaxies and second the super Heritage 130 is waiting for an eyepiece to maximize views of the same (and M42).

The 13mm Nagler is often quoted as a goto eyepiece for the H130 but my 16T5 while vg gets edged out in contrast by the 18mm BCO and others. So I think I'll scratch the 13mm off the list.

These scopes-H130s- can give such good views it never ceases to amaze me and are worthy of fine eye glass. But as we all know heavy eyepieces, escp long ones will decollimate the secondary.

The 24 ES 68 is fine at 329 (listed) grams.

So can anyone with the 12.5mm and 9mm weigh them without the end caps on? I think these will work with the H130 at the published weights but I need to know for sure before ordering.

A 14mm will work out well with the 15" /PCII in particular, equivalent to a un CC 12.5mm- yeah I'm fussy...

18 hours ago, russ.will said:

the Bresser 8" Dobsonian will soon be inbound.

Your f6 200mm could really use the 20mm for unfiltered views of M42 and for so many galaxies IMHO. You have the 32mm Panaview in the works so a much needed tight, high transmission OIII would be a great asset. The only ones I would currently buy are the new Astronomik or new Televue (made by them). I have the new Televue OIII and it is a bit better than a superb, older copy of the Lumicon.

The 12.5mm Morph or the 13mm 100 APM could also be an asset IMHO.

The 20mm HDC I have is a rival for the 21E, for filtered neb contrast in fast scopes it edges the 21E out. Using the Paracorr II the 21E is perfect to the edge, the 20mm HDC  has a very small amount of astig at the very edge of the FS.

I use the 20mm HDC almost exclusively... and is essentially parfocal with the 21E.

There are many many good choices out there now that are not green and black

21 minutes ago, Ships and Stars said:

BTW, I'd love to try the ES 25mm 100deg EP some time, but it will be a while

"Occasionally however, there have been a few moments in my astronomy career when a ten second look tells you all you need to know. This was one such moment.  In short, I had bought a problem.  "

https://www.cloudynights.com/articles/cat/user-reviews/explore-scientific-25mm-100-degree-eyepiece-r2813

https://www.cloudynights.com/articles/cat/user-reviews/the-baader-planetarium-morpheus-r3003

29 minutes ago, Louis D said:

Um, not necessarily so.  If it is so large that its energy is too spread out to detect, you're just not going to see it.  Try detecting the North American nebula in a very large Dob at high power.  If you swing the Dob rapidly enough across it, you might just detect the brightness change as you sweep past the edges, but that's about it.  It's generally easier to detect or even "see" it with wider field instruments at lower powers.

The object you describe is large already, meaning extra mag is not needed and is best viewed with a 5mm-6mm exit pupil, regardless of mag. The issue you describe can be attributed to "seeing" through the nebula, a common issue in large telescopes. I observe this easily in my 15" and 24" dob, but again the narrow TFOV means seeing through the object happens.

29 minutes ago, Louis D said:

A low-contrast object is more easily detected if it is larger.

This says it all- NGC 7000 is "large" already. Somewhere I have a formula for object size in arc min at different mags in the eyepiece but I don't use it, all this is easy if a few things are accepted.

The true advantage to large scopes (fast btw) is the fact that they give "image scale" (size in EP) at a good eye illumination (exit pupil). An example of this is the Jelly fish nebula IC 443- easy direct vision in my 24" because the focal length gives great image scale and at an eye illumination that works well with filters -4.5mm-6mm.

Same goes for the "Little Veil" SH2-91.

So yeah, all this does work and illustrates the importance of exit pupil and object size.

48 minutes ago, JOC said:

is understood and common sense suggests that this has to be the case.

Then your all set to go.

Clark

"Optimum Magnified Visual Angle

A low-contrast object is more easily detected if it is larger. For an extended object such as a galaxy viewed in a telescope, magnification does not change the contrast with the background, because both the sky's and the object's surface brightnesses are affected equally"

I can make it simpler than this-your 31mm Baader gives 5.16mm exit pupil and is perfect for diffuse nebula like the Veil, Monkyhead, Rosette, Eagle, Swan neb. etc...and the list is long.

If you can temporarily assume that a 2mm exit pupil is good for many galaxies then your super 12.5mm Morpheus puts you in the strike zone.

Object size in the eyepiece is a defining parameter, eventhough there is a range.

Clark and Blackwell have VG info on detection.

https://clarkvision.com/visastro/omva1/index.html

No real need to go to the trouble understanding this but its interesting.

What are your thoughts now about eye illumination (exit pupil)?

On 30/03/2020 at 09:24, JOC said:

I've largely now discounted mirror size - I realise now that is really only important for gathering more light needed to see more distant objects. 

JOC, I'm no expert and didn't want to disagree with you on a lot at once. The easiest thing to do is just "follow" the advice, but if your like me a deep understanding of something is almost mandatory.

@Ricochet is right. But, I'll describe something else that many discount, but what a few believe later.

1 hour ago, Ricochet said:

No. Each object has an ideal exit pupil size. Increasing the aperture allows you to view the object at a larger magnification while keeping the exit pupil size the same. The horse head requires a large (4-5mm) exit pupil and a good level of magnification, hence why you need a large scope to observe it. With a smaller scope you have to choose between getting the right exit pupil or the right magnification, and so you will struggle to see it. 

This is correct but I might add that the "ideal" exit pupil is an individual thing, however each object has a "typical" range.

INCREASING APERTURE DOES NOT MAKE DSO EASIER TO SEE BY ITSELF.

After you follow the path of realization on this, objects will "fall" into the eyepiece, limited by your sky.

JOC are you onboard to explore this fact?

Just now, JOC said:

Not so far - in fact it's been largely unexperimented with due to it being for 'larger objects' and I haven't had much success chasing these at all (i swear blind that damn veil is a figment of the imagination - mind you at the other end of the scale so is E and F in the trapezium - though apparently they might show with slightly less magnification from what folks have shared with me over the last few days) so I've tended to stick with what I know I can find.

JOC, you will see at least one dust lane with the 31mm Baader.

You can easily see the Veil with a high transmission tight OIII from your home-using the 31mm.

I might humbly add that M31 is one of the largest objects (in EP) in the sky to observe.

7 minutes ago, JOC said:

I have a list of favourite objects if anyone wants to include them.

Very interesting that all your objects listed can take high mag (low exit pupil), knowing this allows suggestions for other, fainter observable objects if members would like to pursue it.

Have you tried your 31mm Baader on M31?

3 minutes ago, JOC said:

As a novice it is good to have things explained in terms of things that I Immediately comprehend

Well, if exit pupil is not directly used then a list of f ratios and mag ranges needed for nebula viewing might be an asset.

Inadvertently, optimum exit pupil will be stumbled upon and then reflected in the eyepiece of choice by the individual. If an understanding of eye illumination can be had the sky really opens up IMHO and much quicker.

Using S&S image I'll relate (if its ok) whats possible with basic equipment using eye illumination as a component of the observation.

Of course this is completely off topic ^^- but I'll say this- the eyepiece class that the Morpheus sits in is high.