vineyard

A lovely read of a what was clearly a v happy first light - congrats, you're on your way to becoming an addict.  Nice use of polarising filter.  Wait till you BV in HA...

Doh, I'm an idiot @vlaiv you're quite right was getting my radius & diameters mixed up.  Hmm an APS-C DSLR would help but only up to 28.2mm.  Maybe I'll eyeball it w projection if its still bigger than that (just want to get a rough sense).  Cheers!

Yowsa @pete_l that's quite disconcerting that they don't know that about their own kit?!

Thanks @vlaiv - I have a 294MCPro which I think has a diagonal of 23.1mm so if there's no vignetting on that, that will mean an image circle of at least 46.2mm which would be enough for me to know whether rigging something for 2" / T2 would be worth it or whether I should leave it as 1.25".  Let's see!  Cheers.

2 minutes ago, vlaiv said:

You can always attach a camera and look at the flat as well.

That will tell you where vignetting starts.

That's interesting.  How could I calculate the image circle size in mm from that?  I guess if I know the sensor dimensions, then I can see the proportion of the central horizontal that is not vignetted and use that to guesstimate the image circle diameter?

Thanks @vlaiv - I'll measure it via the projection method!  Cheers

Hello,

I decided to test out on the moon last night some old kit that has been lying unused for quite a while - ETX125 & various EPs.  Didn't have much time so this was not systematic (just wanted to see if stuff still worked).

The motor on the fork mount was reporting problems - slewed for a bit but then did nothing  & the DEC motor also didn't seem to be doing anything.  Will have to open them up to see.  Probably not fixable w my skills.

But, just undid the clutches manually & pointed it at the moon.  & tbh I was really surprised w the optics (this is an old one w Made in USA optics).  Looked v sharp and ofc not a hint of colour.  Tested out a range of old EPs (small kit clear-out coming up, so had to make sure they all worked).  The one that surprised me the most was an old Circle T Erfle 20mm (exactly the one pictured here) - the combination was really stunning for its clarity & sharpness.

I'm now going to have to defork the ETX and put it side-by-side w an old CZ Telementor 2 w CZJ orthos to compare.

Will also do a side by side of the ETX w a Vixen 102M to compare.

Going purely from memory of previous sessions, I suspect the ETX should outperform the 102M, but I really can't call the TM2 v ETX125 in advance.  ETX ought to have the advantage of resolution, but CZ TM2 optics were pretty d*%n good.  Will report back, but any guesses in advance?

Cheers,

Vin

Hello,

Is there a formula that can be used to calculate how big an image circle a particular scope would show?  Or is the best way just to focus on a distant terrestrial object and let it fall on a piece of paper w bullseye style circles of different diameters?

Thank you!

Vin

Those are gorgeous - esp the Rosette & if that's without a field flattener that must be at least a 2/3 crop?  The SW flattener plays well w the Evo50.  I did used to get weird stacking artefacts when using DSS on my Evo50 images, but APP was better.

EDIT: my bad I got mixed up between the OP's images (which are w the EvoFF) and another poster's comment on not using a flattener.  Lovely images @tompato!

Hello,

Title is pretty much self-explanatory I guess.  Was just looking at Moravian website & saw they have expanded their CMOS range a bit since the C1 first came out.  But I can't seem to find many reviews of their cameras out in the wild (maybe I'm not googling well enough).  Are there any SGLers who've used their C1X or C3 CMOS cameras who can share feedback?

Cheers,

Vin

Thanks @vlaiv that is v helpful re the calculations - yes definitely some form of filter to be used.  And a good idea re the variable polarising filter.  May end up w two different Hoya filters depending on whether imaging or visual.  Will need to do the calcs carefully once the mirror is finished - sadly classes have been shut down (understandably) since the lockdowns.  Hopefully will begin again at some stage this year.  Cheers!

Its worth checking out solarchatforum on this.  Yes it has been done by some of the folks on there & is pretty interesting.  I'm part way through ATM classes, making a 6" newtonian.  Mirror is almost done but not yet coated etc, so whenever the classes resume, I'm definitely pivoting the rest of my ATM to an uncoated primary mirror and truss tubes for the body.  Should be a v nice WL scope, perhaps even adaptable for CaK w a PM (depending on coated or uncoated secondary I suspect) but I'm by no means an expert on that - solarchat v v helpful (mountains of expertise & folks are happy to share their insights).

I guess someone has to be the first to post.  1 April itself - felt a fool setting up given how cloudy it was but GONG was showing a lot of activity.  In the end only had enough cloudless time to get 180 images (!) but seeing must have been good b/c could easily stack the best 50% & still stay high on the quality curve in AS!3.

Software: FC --> AS!3 --> ImPPG --> GIMP

Added a bit of GIMPification which I think improves it a bit & also inverted image just for kicks.

Thanks @happy-kat - its a TV102iis (f/8.6) but with a 0.79x reducer/flattener added.  My spacing isn't quite right & there is probably some tilt, but this was me just tinkering w mono-style processing (using Pixelmaths to combine different filters in different proportions) - I'll probably keep playing with saturation just to see what happens, but all told I'm thinking more about a switch to mono now.

Hello,

Here's 17h20 of M81 & M82 from February, taken with a range of filters (UHC, CLSCCD, 6nmHA, L1) with an ASI294MCPro.  I am so rusty on processing DSOs that I'm sure this processing could be way better, but hey ho.

Cheers,

Vin

Lovely false colour image @astroavani.  That's interesting re the McIntosh et al analysis (do you have a link?) - from what I've seen from some curves, it does seem this cycle is picking up faster with more activity than the normal expectation, which could be in line w their analysis.  How extreme do they think it will get (I think there were 2 CMEs yesterday eg?)

I think the first one, although perhaps I'd make the stars a bit brighter to add more geometric contrast to the v different texture of the nebulosity?

Adding an image of Tycho from the same session.  Again not the bes, but sharing b/c looking at it made me notice the difference between Tycho & its neighbouring craters.  At first I thought oh I wonder if the Tycho impact was in a really old much larger prior crater region given how smooth the surroundings are.  And then looking at the Kaguya Lunar Atlas (which also has some good lunar geology explanations) it turned out that yes it was an impact in such an older zone, but that likely what happened is that the molten flows from the force of the Tycho impact flooded the neighbouring craters and that's why they have such smooth eroded features (since of course there isn't much erosion on the moon...doh 😂)

(PS - I also at first thought the line of craterlets at 9 o'clock was an artefact, but it actually exists running along Tycho U & Heinsius Q towards Wurzelbauer: https://quickmap.lroc.asu.edu/)

And here are a quick couple of other images from same session.

I was just having a quick play-around w a setup in the evening, so this was not a proper imaging session.  Here are 3 images of Clavius (STF7" f/10) - the first w an ASI178MMcool, and then the other two with an ASI290MM attached to a 2.5xPM (f/25!).  The second image is binned 1x1, the last image binned 2x2.  I didn't really spend too much time on fine focus (which at f/25 is a must I guess!).  But v pleasantly surprised by the PM images - was expecting them to be total mush.  The 2x2 binning really makes a big difference.

Cheers

Quick update.  Was emailing Jasem on something else, & asked about the SMPro.  They are just starting the production samples!  And so hope to be able to go to full production soon.  😃 Cannot wait!

Hi Mike, thanks for this.  GHS is great - cannot wait to try out v2.  I just tried to add the update repository and got this error msg "You have specified an unsupported update repository protocol".  It may be b/c I'm still on 1.8.8-6 not the latest version (1.8.8-8?) as my MacBook OS doesn't support the latest Pixinsight (it's too old!).

Cheers

Hello,

Here's IC417.  I can't quite figure out why its called the Spider Nebula (don't really see it myself).  16.5hrs of data - about 7h w double-stacked UHC & CLS CCD filters, another c 7h w 6nm HA, and c 3 hrs of luminance.  All done with an ASI294MCPro (I know, an OSC camera!).  I actually quite enjoyed the process - it's made me think about mono much more.

JPG'd for size, the closer crop is star-reduced to try and let the nebulosity show a bit more.  So many stars in that part of the sky!

Cheers,

Vin

You've made me put this on top of the list for my next NV opportunity now!🙏🏾