vineyard

Thanks John.  Yes would concur with that shape & hue based on a short stint w the old 102M at about 200x.  Its fair blowing though and I was only on alt-az so may try again tomorrow with an EQ mount.  Esp as FLO delivered a Baader contrast booster filter (I guess a shipment came in the country?) and it looks v promising w that filter.  Cheers!

Wow that's a great capture!  I wonder if EKOS can show detail to that level as Stellarium in terms of FOV & objects...

Tbh that looks pretty good to my eyes - thank you for sharing the .tif as well - something to while away cloudy days with

I think if you scroll down a bit on this link it should show you the latest stable release updates w links? https://edu.kde.org/kstars/ - good luck!

I'm quite happy with my Evoguide50ED with a Skywatcher Evo Field Flattener.  Works really well & is much cheaper than a Redcat.  Some basic quick images here.  (Have also figured out a way to use 1.25" filters with it subsequent to this post).

.

This should work for what you're looking to do I think?  https://www.teleskop-express.de/shop/product_info.php/language/en/info/p8315_TS-Guidemount---ultra-compact-Vixen-GP-level-dual-mount.html

Lovely sketches.  Did the polarising filters experiment work?

2 hours ago, MercianDabbler said:

I'm curious... why the new diagonal?

The current one uses a single set screw to hold the EP (or PM or BV) and itself also threads into the visual back via one set screw.  And that gives me the hee-bee-gee-bees because the grip isn't strong enough to stop either rotating.  Nothing's fallen out yet but I really don't want to take the chance.  So am switching to new visual back & diagonal that each have compression bands for a proper grip (the fine focus on the visual back is an added bonus).  Cheers!

Here's my Vixen 102M earlier this evening (before the fluffy stuff moved in).  An old scope, on an old WO/AOK EZtouch, on an old Berlebach Report 2042 (at a bargain price on eBay!).  And why not - it all works.

Took a peek at the moon - it is so restful, and then Jupiter - just resplendent with moons scattered across and bands on the surface - and then Saturn - Cassini division and a blurry portion on the disk (?).

Want to continue to tweak the Vixen a bit - a Telrad (being searched for), a new visual back adapter to allow for fine-focus (awaited from FLO), and a new 1.25" diagonal w compression bands (awaited in the post tomorrow from another SGLer), and I think it will be done.  (Well, then a stop-spreader for the tripod and a little EP tray...its never done is it).

Stay safe all.

The wisps of the nebulosity are so rich. 👍🏾

I think its brilliant that you can remember what day of the week it was that you bought it - says it all about how important buying a scope should be: a memorable occasion  

It does look naked without the dew shield though!

For polar alignment, I've given up trying to remember how those dials work.  Instead I use a free app on my iPhone called PS Align.  It shows me where on a clock face Polaris should be for my location & time.  And then I just look through the polar scope and try & get Polaris roughly there.  For visual I find that's good enough & things stay where they are meant to be when it tracks.  But I have a dec motor so that does make tweaking things a bit easy in all 4 directions if the alignment is too far off.

I'll defer to others w greater EP knowledge, but if you have 6mm & 24mm then maybe something in the middle?  I really like the way a 12mm works in mine. but I reckon a good 18mm would be pretty decent too?

Cheers

(PS re pointing, I think I'm going to go with a Telrad)

Great Q. I'll defer to other more experienced SGLers, esp as I've never used a Dob so I don't know what BVs on a Dob are like from a practical perspective.

I like them on my fracs.  Definitely more immersive, and overall restful.  I've noticed less floaters at high power if I use both eyes vs just one eye - don't know why that would be?  The moon is pretty amazing in BVs, and you do feel as if you're floating in space.

From what I can tell, the general lower power EP is perhaps for two reasons (a) quite often you need to put a GPC in there that has a magnifying effect, and/or (b) the BV's do dim the view as the light is split so perhaps they larger exit pupil of longer EPs offsets that?  (But I could well be misunderstanding).

One Q I've often puzzled over though is the clear aperture of diagonals for BV'ing.  V often they get marketed as having, eg, 30+mm clear aperture.  For slower scopes I guess that makes sense.  But for a fast scope, I think the image size by the time its gets to the end of the OTA (where the focuser is) will v often be <1.25" anyway, so what difference would it make to have larger clear aperture?  For example, on my little 72ED which is f6 432mm f/l and 330mm OTA length.  By my calculations, the image size will be 17mm by the time it gets to the end of the OTA (ie, even before factoring in any racking out) so there's not much point in having a larger diagonal - I won't see more FOV.  Or am I getting that wrong?

I have no idea whether would still be the case w Dobs though.

Cheers

I just clicked on the linked image of @retret66's rig. 😮

I think that's the best M31 I can remember seeing.  The warmth & variety of the colours - its positively inviting & exceptionally restful on the eyes. 👏🏾

51 minutes ago, F15Rules said:

I note you're a relatively recent member of SGL so you may not have seen some of the other interesting stuff about all things Vixen in previous threads?

Here's a link to a thread I started back in 2018 about Vixen gear..not just scopes, but mounts etc as well:

Hi Dave, yes you're right, I only joined late last year after my astro-bug was rekindled after decades during the summer.  I'm actually quite glad it was re-kindled then & not now b/c (a) it's been invaluable to staying sane in lockdown earlier in the year, and (b) I really wouldn't want to be trying to assemble kit under today's demand-supply imbalance.

So, being a newbie, I had missed that wonderful thread on old Vixens 👏🏾 They really are beautiful to look at, as well as through, aren't they.  I'll try and post a couple of photos to that in the next few days.

That is v interesting on the GPDX.  I sometimes toy with the idea of a dual rig for visual (a wide-field and a 4" side-by-side) and I think the SP mount might hit its limit at that, but perhaps a GPDX...

Great to hear about the fine focus via the EP adapter too - just need that adapter to come w some clear skies now (that's what FLO always pack them with right?).

@John I remember Telescope House on Farringdon Rd, and used to similarly drool!

@Stu I ended up going in the opposite direction from you.  I had a GP2 for a short while which I modded w some belts to make it go-to.  Unfortunately it didn't quite have the load capacity for my imaging rig so - after much deliberation & a certain amount of regret-foretold - I sold it to part-fund an HEQ5Pro.  Can't really complain b/c the HEQ5Pro does its job really well but even so.  I noticed in Dave's Show-your-Vixen thread that you have a Sphinx: how has that shaped up for you?

Cheers all - looking fwd to some fine dark winter nights!

45 minutes ago, David J H said:

I've had my 102M for about 25 years, with a Super Polaris mount. All that is needed to convert the original Vizen fittings to accept 1.25" eyepieces is this adapter;

https://www.firstlightoptics.com/adapters/baader_1.25-36.4_adptr_2408195.html

However, the original 0.965" eyepieces that were supplied (20mm, 12.5mm, and 5mm) still work quite well. Observing Mars with the 5mm in the last couple of weeks has worked really well.

 

That's the adapter I've pressed "go" on at FLO earlier in the week so that is v good to hear!  I like the compression ring on it (the set-screw on my current 1.25" is starting to become quite unreliable), and also that its got 5mm of fine focus travel.  So I'm hoping that that will effectively also synthesise a nice two-speed focuser - the single wheel for coarse focus, and the EP adapter for fine 🤞🏾

5 hours ago, nfotis said:

Regarding dispersion of planetary observation views, wouldn't an ADC help with this? (I suppose that we are speaking about atmospheric dispersion, right?)

Hi, yes that's right.  I guess an ADC would - I don't have one & have never used one, so I couldn't compare with-and-without.  But tbh, it didn't bother me at all on Mars, and is pretty much non-existent to my eyes on stars.  I'll see once M42 is up whether I can make out any dispersion on that.  If not, no need for an ADC for me (which means astro-budget can stay dry for other things ).

Cheers.

19 minutes ago, dweller25 said:

Yes the setting circles on the Vixen SP don’t work as they should.

I added a small locking screw to mine by drilling through the setting circle and tapping a thread.

But even then they were not very accurate to be honest.

Ah, thanks - I suppose I'm glad it's not just me being daft but that's a pity.  Star-hopping w a Telrad it is then!  Cheers.

45 minutes ago, JeremyS said:

Not tried that, Vin. I use that side to attach a counterweight arm:

 

That's a good idea.  I'd like to occasionally have a little wide-field there at the same time, and would prefer to not be reliant on a single point of failure.  But cannot for the life of me figure out Beat Kohler managed to fit that saddle on like that!

Hello,

I'm v much a newbie on mount tweaks, and so had two Qs pls on these mounts.

1.  On the Vixen SP, the setting circles are meant to rotate right?  There don't seem to be any set screws - a tiny allen bolt on one & nothing on the other.  So right now the setting circles don't rotate so I can't use them.  Is it that they need to be lubricated or am I doing something really daft?

2.  On the EZtouch (or I guess also on Ayo2) does anyone know whether this saddle can be taken off and replaced?  The other side of the mount can be, but on this side I can't see any screws or anything - does that mean that side is stuck w that saddle (I'd ideally like to replace it with a clamping one, or at least one with two screws)?

Thank you!

Vin

Thanks both Olly @ollypenrice & Adrian @Adreneline.  Yes I noticed those striations too (reminded me a bit of stretch marks on skin!).  Definitely re more data, and ok will look at subs too.  And will tinker w ArcinhStretch & see what happens (I definitely want to explore what PixelMath allows a bit more - sadly no Photoshop).  The star-swapping sounds cool too - have not used Starnet yet.  Lots of cloudy days & nights had, so this gives me stuff to play with.

Cheers both!

Vin

Hello,

Here are a couple of images from my first spin with the new flattener for the Evo50 last week.  No filters (that's the biggest design fault w this - no natural place for a 1.25" filter vs the Starizona one, although I intend to test one way to see if it might work).  I've cropped it a bit (probably taken about 5-10% off on each side) b/c there is vignetting which causes some edge effects in stacking (see separate thread for that).  60lights of 60s, unguided, d, f & df applied.  All stacking & processing done in Pixinsight.  A little bit of star reduction in both images (& both downsampled for size).

All feedback on the processing v welcome pls (I know the camera - ASI294MCPro - has too big pixels for this little scope based on astronomy.tools, leading to under-sampling & a bit of softness; but I'm also pretty clumsy so feedback is the only way to improve!).

Overall I'm quite happy with this wee flattened scope (even with the cropped FOV) - if the filter adaptation works, then that'll be gravy.

Stay safe,

Vin

3 hours ago, ollypenrice said:

What I'd do first is measure the level of vignetting without flats applied. Take sample ADU values from the background sky in the corners and in the middle (which you won't be able to do in this image 😁). This will tell you the true level of uncorrected vignetting. Actually I guess you could just measure it using the flats, in linear form. That should work if the flats are correct but a sub of fairly 'empty' sky would be best. In my most vignetted rig I have a 23% fall-off corner-to-centre. This sounds catastrophic but flats do correct it. That will tell you the level of vignetting you're dealing with.

My experience of ABE is that it will not work on galaxy images. Galaxies have faint outer glows, sometimes scarcely visible in the image, and ABE will measure the sky within these glows and conclude that it's too bright due to some kind of gradient. It will then pull down the background where that outer galaxy glow was, and create a dark ring around the galaxy. When using DBE keep well away from the galaxy and look on the web for very deep images which will reveal where the faintest glow will be on your own image. Keep the markers away from there as well.

Olly

Hi Olly, I did a quick look at a couple of flat FITS and the drop off from centre to corner is about 18%.  Thanks re that on ABE vs DBE - I do notice ABE galaxy images as having a dark ring around them, this explains it.  I had done a quick DSS+ABE stab at the Perseus Double Cluster image I took with this rig and it was comparatively a lot less weird than this galaxy one, so I wonder if that also helps explain that.  I'm going run that Perseus image through PI instead of DSS and let's see what emerges.

Will use that tip for DBE galaxies as well!

Thanks again!

You're quite right, the ASI294MC is only APS-C sized so I am a bit surprised as well to see so much vignetting (haven't seen reports of that w the Starizona).  Its interesting to see the left hand side is a straight edge between the vignetted corners, but the right hand side if a curved one.  The halo/tone effects are more pronounced on the left hand side so I wonder if that's connected. Could there be some tilt in the system (which could also explain the slight curvature in the far top right and bottom left corners)?  Will check if I made any newbie errors when I break the system down!

I'm v much an enthusiast like you - more energy than skill at this point, but as long as that's accompanied w curiosity it's all good

Hi @happy-kathere are two images.  Both stacked in DSS w/o any calibration - the first is DBE, the second is ABE.

Its a good idea re trying it w/o the flattener - I will try and do that next time I'm using this for wide-field AP (I will also try it with an ASI178 chip size).

Cheers!

[EDIT: the DBE one does suggest edge effects form vignetting given the way there are straight lines from top left curved vignetted corner to bottom left?]