Ratlet

I've got one of those multi target finder.  I think mine was a generic one from ebay for a pistol.  They work pretty well and are very robust.  Perhaps a little too bright, but still works well, although I'm not sure what the diameter of the outer circle corresponds to.

Looking at the price of the quickfinder shoe makes me glad that I've got a 3D printer for doing my own small parts.  Maybe I need to start going astro prints on ebay lol.

The high school returned!  Have to say they did a great design for it.  Fantastic planning by the pupils.  Took us longer to put the felt on than it did to raise the building.  The doors were a separate unit so they couldn't go squint and because it straddled the join it sort of locks the structure together.

Not the post man, but the local high school just delivered this lot.

Entered a raffle last year for a 6x10 summer house and won! Not bad for £50.

Built by the third year pupils and the construction is better quality than most commercial units I've seen.

The missus says I can use it for astronomy stuff.  Not a roll off roof, but with the dob I'm better of dumping it outside.

Going to get it outfitted with power an a wood burner and have a nice wee warm room for myself.  Need to rejig the garden, but a pier will be going in too and I'll have a nice wee setup.

1 hour ago, John_D said:

My TAL 2M that I bought off Ebay recently cost £90 which I thought was cheap. The plywood cases would probably cost more that that if you bought them new.

( Yes it cost me £40 in fuel to go and get it but using man-maths I'm rounding that down to "about £100 all in"  )

 

You need to subtract the cost of the case from the telescope then so basically you got the scope for free!

10 minutes ago, Mr Spock said:

What I'm expecting is a low MTF due to large central obstruction similar to an SCT. It's f4. My 12" f5 is exceptional on planets, but, has a small central obstruction. 

What a poor MTF does is make things like Jupiter's belts 'fade' compared to an apo for example. It doesn't change the resolving power, so it will, if it has good optics, see fine detail. 

That ties in with what I observed (or rather didn't) with the 130PDS (also has an oversized secondary) on planetary.

5 minutes ago, powerlord said:

maybe worth using a Bahtinov ? bit of card and a knife is all you need to make one right for the lens:

https://skeye.rocks/tools/mask/

usually printing and cutting one out is an option, but with a 135 it'd be pretty fiddly I reckon.

Prob needs 3d printing. do you have access to a 3d printer ?

You did well to get a takumur135 for 15 quid. I got one a few years ago which had sticky blades cheap.. took it apart to clean the blades, and it's never properly worked since - nearly went mad putting it back together..but still not right.

stu

I might give that a try.  The trick as @alacant mentioned is that in focus the Takumars only focus blue and green so you need to get in focus and then back out slightly.  Usually they are well behaved and can produce decent results, although in this case I missed the mark on both images (although I'm still quite happy with them as they captured some nice parts of the sky).

I'm going to go for some CA free shenanigans next though and use the 130PDS without a coma corrector.  The 533C is small enough a sensor that the coma is pretty well controlled without a corrector.  Just need to decide what to image.  Got a bahtinov mask for that thankfully.

1 hour ago, wookie1965 said:

3-8mm SVBony zoom £55

It's a bargain at twice the price!

42 minutes ago, alacant said:

Even so, excellent images.

Don't forget that the four element Takumars focus only the green and blue to the same point, leaving red as an unfocused halo. The best method for focusing is by zooming in on a mid brightness white star. Focus to infinitty or where you see the sharpest image, then move away from a tiny amount until the red halo just disappears; a compromise, but one which will give pinpoint true-colour stars.

The crescent: Close. Maybe even a little too much:

The veil: perhaps needs a little more 'compromise'.

Cheers and HTH.

Aye, usually that's the method I aim for, unfortunately I must have knocked it off focus for the Veil (first imaged).  Spotted the issue when I slewed onto the Crescent but I think I took it just a nip too far.  I usually find processing responds better to a hint of blue/green than a small red halo.  The photometric calibration usually gets rid of it completely.

Managed to get out and do some imaging with the 135mm Takumar SMC stopped down with a ring to F5.6 ish, Altair 533c, and SVBONY 220 dual band filter.  Fluffed my focus for the first round on the veil, but got it pretty much as good as possible for the crescent.  27 minutes of data where processing was stacked and stretched with tiny tweak to the saturation and some green noise removal (all done in Siril), @vlaiv would be proud I think.  If I were good at processing I could probably get more out of it.

I think though it shows the potential of a cheap bit of vintage glass (and not missing your focus).  This lens cost £15 on ebay...

Got the imaging rig out for the first decent session of the year.  Focus wasn't great, but good enough for fb on the veil and crescent with the 135mm.

Set up the 130pds for visual and set up in the west side of the garden for Jupiter and Saturn, both looking very good.  Sneak peak at pleiades to wrap up.

16mm ovl wide field eyepiece.  The eyepiece that taught me that my low standards have limits. 

1 hour ago, lawsio said:

Thank you for sending me down the most interesting Google rabbit hole I've been down in a while!

Is it a good scope or a bad scope that let's you see things that don't even exist, do we think?

Averted imagination 

Wish I could get a look at it.  Thinking that it in combination with a Starfield 102 might be pretty tasty.  How have you found it with a bit more time?

It will probably do in a pinch for planetary.  I used the 130pds for a year with its oversized secondary and whilst it wasn't great out of the box a contrast booster filter helped massively and might help in your case.  Since it's not what it is for it's not much of an issue, but a stacked yellow and moonglow filter did the trick for me and might do for you in a pinch if you found the seeing warranted a quick peek.

What's your thoughts around the eyepiece position?  I only tried mine on an EQ mount a couple times before giving up due to the eyepiece ending up at weird positions requiring rotating the scope and contortions to get my eyeball to the eyepiece.

Will be interested to see how you get on with the coma corrector.  Is it the Stellalyra one with the 75mm back focus and 1.1 X magnification?

16 minutes ago, bosun21 said:

As far as I know the template for the platform wedges is what determines the working latitude for the platform. I don’t see how it can affect the actual length of the platform.

The design of the platforms is largely determined by the scope COG (centre of gravity) and the latitude.  You are projecting a cone that passes through the centre of gravity of the scope (base + ota) and the latitude from the ground.  As the latitude decreases the pivot point position moves further away from the COG.  In a VNS platform the segments are basically the circular sections of the cone projected into a vertical section (to give an ellipse).

Taking a look at a design for a 10" Stellalyra (because I'm building one and have the COG and feet measurements) and designing for 28 degrees latitude, we can see that the Southen Pivot Point would be 850mm from the COG, which once turned into a platform would probably end up being over one meter long!  Not ideal...

The alternative would be to simply take another circle through the cone that is closer to the COG and make southern sections from this.

I'm in the process of designing one myself for 57°.  Is the issue that the platform would become very long?  It it possible for you to replace the south pivot with sectors instead to keep the length down?

My rampant geekery collided and I missed the first few hours of darkness because I was running a d&d session.

Managed to get out about half ten.  I'm not convinced on the Starsense on the honor 20.  More often than not it fails to find stars and I don't think it's sky quality since I could naked eyeball Andromeda!  Will try and find my daughter's iPhone and try that.

Anyway, Andromeda got the 30mm launched at it in the Dob.  Made a point to look at M110 whilst I was there.  Got the owl cluster which looked suitably owly (hopefully it's not the cosmic owl).  Caroline's rose got the 30mm but didn't make much of it till I put the 17.5mm on it, when it definitely looked rose like.  Also used this on the blue snowball nebula and it definitely looked blue.

Jupiter remained behind the trees but broke out the X2 binoculars for a bit of a tour.  I'd love to get these fired up at a more southern latitude.  They're brilliant.  Great on the double cluster and give a good effort on Andromeda.  Best thing for these is m45 though as it looks like a mini big dipper.

Called it earlier than I would like as it was cold and I've sprained my wrist.  It hurts to do simple things like putting my hand in my pocket and adjusting the tension on the dob was agony.  I sprained it when I literally touched my mattress picking up my phone (somehow) and the wife has started calling me 'mattress toucher' which frankly sounds worse than my wrist hurts!

4 hours ago, Zermelo said:

Vulcans are known to be stronger than the average human

You've not seen the arm he uses to lift the Dob.

I use a sack barrow to move my 10" dob about.  I think I moved it in two parts about two times before I found it too much work and swapped to snack barrow.  Easier to move the whole unit with the barrow than either part on their own.

That's an incredible amount of detail for such short exposure.  Great job.  Nebula colours look reminiscent of a dual band filter.

33 minutes ago, wheresthetorch? said:

Well, they're on @Ratlet!  Hoping to test them tonight at the weather looks clear. 

Hope they work for you!  I loved mine on the dob, though I used a digital inclinometer for inclination.  Like goto should be.

This is basically the conundrum I'm in at the moment.  A 4" Scope would be a nice compliment to the 10" Dob, however I could also do with something that would be flight compatible as we tend to go on holiday to the med / gran canaria and there is plenty extra this would let me see from my 57 degrees latitude.  I think unfortunately the Tak is outside my budget (and I'm not a fan of the aesthetics) and the AP definitely is outside of my budget!  Would be nice if the Starfield 102 could be broken down small enough.

I think in terms of 'realistic chance of me getting one' I'll need to look at a 90mm and hold out for a used Megrez 90.  Or remove the mirror cell from the 130 pds, throw the rube in my case and take the primary/secondary on as carry on lol.

Really good session last night.  Not much new observed as I wanted to make the most of the summer constellations.  Starsense was being an absolute mare on the pixel 6, first time I tried it, but fortunately it was slightly better behaved on the Honor 20 so I swapped to that.  I spent some time a couple days ago to work on the balance of the Dob with the dew shield and everything else on it.  Took a bit of getting used to using the weight to help with the balance at different inclinations, but doing fin adjustments on target was infinitely easier and more pleasant than previously.  Probably not best practice, but there is something intensely satisfying about nudging a dob with your eyebrow.  It'll be more satisfying once I get an EQ platform built and don't have to nudge at all.

M13, M92 and M71 provided some nice globular viewing.  They are all quite different in structure and density so it was a nice little tour.  M71 appeared quite elongated, more of an ellipse than a sphere.  I took in Albireo and Almaak for a bit out colourful double viewing.  M27 looked quite spectacular, helped massively by averted vision.  Not required but I'm starting to notice colour in stars a lot easier, especially the orange/red ones and noticed a couple to the edge of the FOV with my 12mm around M27 and focusing on these helped bring out the detail in the nebula.  More detail on DSO with the 10" Vs 5" Newtonian, but the difference in globulars is the big draw for me.

I've been trying for The Veil for a couple of months now but with my high latitude and summer nights, it has not been forthcoming.  Swung round to 52 Cyg with the 30mm Superview and still couldn't see it.  Until I could.  Running about 45 degrees there was a something there, not bright but a definite difference in texture.  I had the imaging rig setup in the shed so pull out the SV220 7nm Dual band filter and dropped it in.  Suddenly it was everywhere!  The Witches Broom extended well through the FOV and had the appearance of high clouds.  There was a distinct radial lighting to the broom itself which was surprising.  The more central areas were also apparent although I couldn't pick out much detail, panning across you could easily see the difference in brightness.  I panned up to the Eastern Veil and was greeted with a nice door handle shape nebulosity that had the similar cloudyness to it although the 'lighting' wasn't as impressive as the broom.  I'm going to need to whip out the 130PDS for it next time to get a wide FOV.  It should be able to squeeze both in with the 30mm.  

With the filter in I went back down to M27 and swapped to the 12mm BST.  The contrast was greatly improved as you'd expect but where as previously the nebula was spherical there was now a clear horizontal elongation to it, the filter helping to highlight some of the subtler nebulosity in wings.

I swear at some point I'll use that filter for imaging, but so far it's doing too good a job as an OIII filter!

Saturn  had cleared one of the trees (about 20 degrees is my limit) but I could see it through the branches so decided to give it a shot.  Having removed the filter the focus was out so I was greeted with about 5 out of focus Saturn's which gave me a minor panic.  Turns out Saturn had not quite cleared the branches and there was some diffraction through the leaves.  Getting her in focus though and I got quite a pleasant view of our ringed neighbour.  Despite the tree it was in the sweet spot between houses so there wasn't a huge amount of turbulence in the atmosphere.  I stuck with the 12mm and whilst there wasn't a huge amount of detail I could make out a subtle band of cloud that ran parallel with the rings.  It gave the impression that the rings were passing in front of the planet.  I'm looking forward to the next few years when the planet gets out of the ruddy weeds.  If only some of the constellations would join it!

1 hour ago, powerlord said:

Yeh I would say, you need a surprisingly large amount of ply to make drawers and stuff, and the results do tend to look a bit 'look what I made in woodwork class mum'. But they are sturdy, and the benefit is that you can customize the sizes, etc to be precisely what you want.

40w will be pretty mental. I had to do quite a bit of work to ensure the smoke gets sucked out with my 10w.. with a 40w you'll need some serious exhuasting.

Going to pick up an enclosure for it as well.  Fortunately the missus is very much on board with the maker movement.  So long as it does the job, she's happy.  Mostly it's stuff made from 3-5mm ply for small crafting items.

With the 3D printer I've noticed that there are some things which it does well but there are plenty of others that some thin wood and some glue wood do a better job off.

Primarily I want it for some wood working projects I've got planned.  Going to build an EQ Platform and a better base for my dob.  I don't want to use the laser for cutting the wood but I think it could do a good job for inlays and engraving on it.

Good to see you're still getting use out of it.

The missus gets lots of stuff online that is made from laser cut plywood. boxes/shelves/models/etc so she is in favour of getting one.

We're thinking about getting one of the fancy 40W diode units that have just been released.  Looks like it will cut up to a reasonable thickness of ply (3/4in) without it taking forever and burning the wood up too much.

I like the sound of the co2 units but there isn't an option for feed through on the cheaper ones.