jetstream

Just now, Ships and Stars said:

Thanks, all of this makes sense above. I suppose you could have a highly accurate encoder, but the overall system is only as strong as the weakest link(s), so a few small wobbles here and there with a leg flexing or a base settling into the ground can add up I suppose. 

It stands to reason a three star align would resolve or reduce error effectively, but not sure why manufacturers (that I'm aware of) don't offer it? Presumably it wouldn't be difficult to add a third alignment point, so perhaps it's a case of diminishing returns? I do note there are some tricks in the back of the synscan manual I've yet to try, that could be something to do this summer when the stars are ou, but too bright for most DSOs.

Question- what accuracy does you 20" Synscan give?

My 2 dobs both easily find any object in .8deg TFOV and after using the "re align on object" (sort of a 3rd point) the accuracy is down to at least a quarter degree. What I do is re align on an easy object near my target and then the accuracy carries through to the target.

1 hour ago, Ships and Stars said:

I do now! 

lol!

Well, they provide enough accuracy- actually more accuracy than typical mounting systems do...IMHO. By mount I also mean what the SCOPE SITS ON.

This is a crucial factor with both tripods and dobs. If the scope moves even a small amount and the encoder does not- wham, off target. Most think tripods are stable and they can be laterally. One little push down on a leg skews things in all directions. A dob on grass is not so stable either.

Then there is mount backlash... this is why we have to take it up by going up and to the right... but- the backlash remains and reveals itself in inaccuracy.

To recap- to improve on 10,000 step encoders everything else has to be perfect, zero scope movement without the encoders following. A mentor explained this to me. A typical dob has excellent encoder tracking- ie the encoder moves with the scope. I had pursued the thought of 40,000 step encoders before a lesson in enlightenment changed my mind and I now try to maximize other things in my control.

A third alignment point is also a huge advantage which used properly mitigates unwanted mount movement to some extent. ie a stable base. Of course these are just my current thoughts, probably wrong

57 minutes ago, Beardy30 said:

😂sorry missed that .. get it now ...I’m Not a dob fan but certainly know they have a loyal following And great scopes of choice for the right person 

lol!

To each his own but I had a less than stable mount before- great for the 90mm frac, not so good with 120mm f7.5's. Actually almost unuseable.

Whatever you get I would make sure its stable. Good luck and have fun with your choice!

8 minutes ago, Ships and Stars said:

Good point!

Do you wonder why I use 10,000 step encoders?

1 minute ago, Ships and Stars said:

I've heard others comment here or on CN a rough level will suffice for the synscan, but I like to get it as close as possible assuming it does indeed have an effect on pointing accuracy.

One of the reasons the TSA120 is not used much is the mount-its VG but set up is challenging. Levelling the mount and then finishing "up and to the right" is a pain. It is nowhere near as accurate as the SC. I hear Nexus DSC are VG too.

I replaced the SW GPS (member Rainmakers suggestion) with one made in WPG, Man- I don't have to input anything. Once set up to track planets, the AZ EQ6 is amazingly accurate for this.

On 10/04/2020 at 04:08, Ships and Stars said:

I was wondering if it was faster to align and more accurate in people's experience than the Synscan system on SW dobsonians? Primarily if I was able to increase accuracy once aligned on an object by pressing a button for a 'secondary' realign to correct for any initial error?

I'm curious why my AZ EQ6 needs to be leveled with the bubble with Synscan but my Sky Commander DSC could care less about being level? the SC can be accurate to 1/10 deg with 10,000 step encoders. I can easily get .25 deg in use with the 24" dob.

Limited experience with mounts but mentors told me to get one over capacity to the scope used -thanks @Stu

This can get expensive and my longish refractor sure enjoys this mount.-AZ EQ6

Actually this mount is almost as stable as my dobson.....stability is of paramount importance IMHO. Thanks to @Moonshane for nudging me in the direction of dobsonians.

31 minutes ago, scarp15 said:

Hope I've sold it to you.

Yup!

Now do I get a set of dedicated astro binos + smaller IS Canons or astro binos + replace my revered Pentax or get the 10x42 Canon IS?

Thoughts Iain?

1 hour ago, Littleguy80 said:

I’d be interested to hear if anyone else has made the choice to reduce FOV to get better quality views. Is there an ideal middle ground? 

The fastest, cheapest way to sort things out is to copy other experienced observers IMHO. I did this but just HAD lol! to go keep trying more and more eyepieces out.

I'll always have a 20mmish hyperwide and something around 13mm too. Supplementing the orthos wth Delos class eyepieces is a vg thing to do. Only my very best, few orthos go deeper than my Delos.

I shant ever be without orthos however, I just like them.

The 30mm ES 82 is adequate but lacking compared to the 21E/20mm APM IMHO but so is the 42mm LVW. So far I havn't found long fl eyepieces in the same class as the Ethos.

26 minutes ago, John said:

I've given up worrying about there being eyepieces out there that are slightly better at this or that now than the ones I have. I think its possible to get a bit obsessive about that rather than fully enjoying what you do have

Thats because you have figured out the best eyepieces to use now IMHO

5 minutes ago, Ships and Stars said:

Helios Apollo

Excellent innovation!

How good are the Helios Apollos?

9 minutes ago, Ships and Stars said:

PS I don't think you can go wrong with Pentax binoculars from what I've read, I came really close to buying the 20x60 Pentax before the Helios 15x70s popped up for a good price. 

I bought my Pentax after looking through a hunting buddies, I no longer hunt but that glass was so good... At the time the Pentax (about 20 yrs ago) were around $700.00. The Swaro, Leica were about $2000.00.

So I was in the store in Winnipeg looking through them all. It went like this- $700...$2000, $700...$2000 etc. The more expensive binos were superb- but the Pentax also pleased my eye...

For me good glass causes a reaction every time I look through it and those Pentax did for 19 yrs or so. The suffered many crashes until the last one finished them off.

I would bet money the Canon IS wouldn't survive even one of the minor crashes, but I could be wrong. I don't know Steve but his advice would be appreciated.

The nebula... for me stability is absolutely crucial to see faint objects regardless of the optic. Even 10x50 filtered should show the mentioned nebs but we better be steady with the binos...IMHO.

1 hour ago, sarahsmiffy said:

will I be able to see nebulae and galaxies.

Do you have ideas about how dark your skies are? how many stars can you see?

I ask this because a portable scope will not only give good views from home but open up the possibility to take it to dark skies.

There is no question that a 150mm or 200mm SW dob is a top choice for you, however some of us truly like the diminutive Heritage 130 mini dob. I would make sure you could carry the first 2 with ease...

It is hard to beat a 200mm f6 SW dob- it you can move it around. The 150mm is right up there too IMHO.

3 minutes ago, Ships and Stars said:

Part of the allure with binoculars is being able to scan the sky quickly with both eyes

Thanks S&S- I too want binoculars for portability and also for quick sessions under changing skies like last night. The sky clear for just a little while so I went out before bed for a bit. I had Pentax 8x42 for many years until a drop on the rocks finished them off. There were superbly sharp and with a great depth of focus, the glass in these were right up there. BUT lol! they too left me lacking on the sky and suffered CA to some extent on Jupiter etc.

I have no desire for tripods and even the monopod mount might be enough of a hassle to make me pass on it.

Quandary- I need some new binos- preferably IS, for the boat, trekking and birdwatching (& animals) but I don't need the super expensive 10x42 Canon IS for this, a smaller pair would meet 90% of my needs. I did want IS for the sky but if the views aren't what I want...

Another thing- good binos like Swaro,Zeiss, Leica, Pentax etc will last a lifetime if cared for whereas I'm not so sure about the Canon IS...

Can you easily see galaxies in your binos when propped against the hood or a tree or something? I wonder if the Angelfish (SH2-264) and Barnards Loop are do able with filters?

A friend gave me an old set of 10x50 binoculars to try out on the sky so last night a quick session was had. I sure am wobbly with them! Much better in the lawnchair or laying on the ground for stability.

These shakes made my target confirmation sketchy... I tried M81/M82/ NGC 2403 and M51. I'll give about 70% confidence on NGC 2403 and maybe 60% on M81/M82. I just might have seen a very small faint glow ball where M51 should be... who knows lol!

A couple of thoughts:

some say M81/M82 are just visible naked eye- in my opinion this is an extremely optimistic thought and after using the binos it just re affirms this- I've been trying for 7 years to see them naked eye with no luck and under reasonable skies.

second, no matter how good small binocular views can get I don't think they will ever come close to the ultra portable H130 which I can set up in under a minute. This might come down to stability?

I'd like to hear from binocular observers regarding expectations, before I buy some IS Canons...

3 hours ago, domstar said:

During a double star session last night I found myself face to face with the Eskimo Nebula at 150x magnification in my 4 inch refractor. I'd like to know if it is possible to see the central star in this nebula with my equipment. With averted vision the core was unexpectedly bright with a point of light in the middle. I'm not very experienced with planetary nebular and I was surprised to see it brighter in the middle. Could it have been the central star? Am I kidding myself? (probably). Is the Eskimo usually brighter in the middle?

Thanks for any thoughts.

Congrats!

Yes the Eskimo is 2 toned (at least) and you have touched on this. Repeated observing under good skies and using high mag reveals much in the Eskimo. I get more detail out of it with no filter.

Excellent observing Domstar.

50 minutes ago, PeterW said:

try hand holding a 12x and the wobbles will reduce what detail you can see. With IS you can get a perfectly steady view holding them with one hand… showing off.

Great info Peter, yesterday a buddy gave me an old set of binos to use and get me in the game. I'm looking at trading some astro stuff in on the Canon 10x42L, we'll see. I used to always have binos, usually cheaper ones laying around but not now. My Pentax were good in the daytime but were lacking at night.

Lawnchair observing is gonna take a step up over here soon I hope.

5 minutes ago, JTEC said:

Here’s how I use the monopod with my Nikons. It’s a Manfrotto.  You get a lot of stability.  Not that I wouldn’t like some IS bins as well ...

Excellent!

I've never seen a monopod before and now understand how it will add rock solid stability. Hmmm, maybe a pair of small IS for the boat, trekking and conventionals with monopod for the stars.

Great images JTEC, thank you.

1 minute ago, osbourne one-nil said:

I had a pair of 10x30 which I loved but after 10 years some of the lubrication seemed to be leaking onto the prisms. I opted for the 12x36 as their replacement because Argos had a good deal on at the time and from what I read, the price/performance combination was good. It is! Had I not just got the Leicas I probably would have gone for the 10x42 Canons but I think for the sort of price they are, I'd want perfection and it seems like they're not perfect. They're very very good, but some seemingly silly things like uncomfortable eye cups and their weight (which isn't a silly thing) kept gnawing away at me. 

I wonder which IS is needed, I see II's, III's and then other systems. I'm kind of reluctant to get the most expensive ones as they might see hard use, well actually they will. Theres button push ones and ones on all the time I think etc.

I too wonder about the IS price and if a smaller pair might be all I need.

16 hours ago, Ciaran Meier said:

The other half does a bit of sewing (quite a bit actually) and I'm pretty certain she's got some heavy duty canvas fabric tucked away somewhere.  If I"m well behaved  I could convince her to put together a decent sized tailored light proof shroud.  Perhaps incorporate a bit of ventilation as well.   I'll drop a wee hint tomorrow 😀. 

Cheers and keep safe

Ciaran. 

Ciaran, it might be useful to explore the terms "contrast" and also the concept of Suiters "wobbly stack" (preservation of the arriving image, through the scope).

Contrast is the fixed difference between the sky brightness and the objects brightness. This points out that sky conditions (darkness) are the only the thing in our control re contrast. This includes local light intrusion etc.

Then there is the scope and features of its use ie scatter control, flocking (stray light) and magnification used etc.

Lots of info out there on all this and stray light control for your dob is a worthwhile endeavour IMHO.

15 minutes ago, osbourne one-nil said:

They're not as expensive so they can't be as good! In reality, I just really like the field of view the 8x42s give me and with no mechanical interference, I find the view to have a real "wow" factor with the image essential perfect. The Canons are great, truly remarkable, but I'm always aware that there's a little bit of something going on behind the scenes. Of course, when looking through the Leicas I'm always aware that they don't have image stabilisation, so I'm just looking to provide them with a little bit myself. 

I've not actually tried the Canons on Andromeda yet, but on M81 and M82, you can definitely make them out. They're there....tiny, but there and this is where I am starting to really appreciate binocular astronomy because it makes me feel like a kid again when the thrill was just in actually seeing something and trying to comprehend what it was, without worrying about tracking or making sure you're getting every little bit of detail. I'm hooked!

You have excellent binoculars

I know what you mean about some optics grabbing the attention. I want a pair of IS binos for the boat, wild life observing and the sky. I seem to have a hard time getting rock steady views free hand.

On the other hand I really like top views. Question- which Canon IS version should I buy? I have zero experience and zero knowledge re IS

ps- I tried Leica and Zeiss binos out in a store onetime.... and ran out before I bought a pair lol! they were both stunning, better than my good Pentax.

7 hours ago, osbourne one-nil said:

I really like the IS feature on my 12x36s but I wish they were optically as pleasing as my 8x42s.

I'm looking for binoculars and was wanting to try Canon IS- how are they on the stars and objects like M31/M81/M82?

In what way are they not as good as the Leica?

I had a VG pair of old Pentax but they broke unfortunately so in the market now.

4 hours ago, JOC said:

Used to be excellent South, in the last year 5 spotlights have appeared about 1/4 mile away, still pretty good higher up.  Excellent East (over the estuary and then open ocean), West light pollution in distance, North Light pollution at distance and factory lights just beyond hedge - Polaris often awkward behind trees.  Whole garden ringed by trees, extra tall detached house central on plot limits views to about 2 directions in any chosen location.  Unless I want to lug everything 200m over un-made ground to the middle of the field where I can have a 360 degree view.

Sounds vg, the ocean must be nice! I always try to observe south for some reason, actually SE to SW. You know, maybe try your filter out to see if it works and if underwhelming Astronomik and TV make excellent OIII- expensive yes but they work. Using a top OIII can mitigate light intrusion to some extent and Sag is so full of great objects.

Markarians Chain is easily do able with your scope in Virgo and so much more.

Synscan... the DCS's need a few procedures to help alignment- first you need a really solid, stable piece of ground- if the base moves around or wobbles no good. Second use a narrow FOV eyepiece after finding the alignment stars with the widefield. I forget if my AZ EQ6 has a 3 star align, if yours does I would use it.

Give it a try even in the moonlight to see if accuracy improves- the DSC can have a personality.

Hows the Morpheus on the moon?

ps-there are DSC (sysnscan tricks) more later off to work on the waterline.

34 minutes ago, JOC said:

someone of my limited callibre.

You are not of limited calibre at all JOC- getting good views is a process at least it is for me. Having an open find can be very useful in all this I find.

So the constellations... in their full extent they can be boggling and frustrating to identify. I break them down a bit- take Leo, for example- a bright 3 star triangle with the point on the left- forget the rest for now. Try finding main stars in less than dark skies- just after dusk- and the main ones reveal themselves.

Some are huge like Cygnus and Aquila others more compact like Delphinius.

Leo is large in whole but the triangle is smaller.

So JOC we must all forget our limitations, realize where were at and explore! In my case galaxies need work, been at it 7 years now lol! startin to get better finally.

Hows your south view?