Ratlet

Bit of a mixed bag tonight.  First clear night (proper clear) in a month and, Brucey Bonus, no moon!

Wanted to test out the svbony 7nm dual band filter and the takumar 135mm f3.5 I picked up for £15.  Got outside to realise I don't have any suitable step down rings so had to aperture blade it to down 2 stops.  Also quickly had to gaffer tape up a few shield as it was sopping wet out.

Started off well, but something went very wrong early into the session.  Mount just seemed to give up tracking.  Looked back through the subs and lo I only had 10minutes of data.  Gave it a perfunctory stretch and colour calibration and this is what I got.

Not delighted with the amount of data, but thought the image turned out well consider there isn't really much to it.  No sign of halos from the filter but will need to do some testing.  Pretty impressed with the takumar 135mm.  Obviously not as quick as the samyang, but for a fraction of the price I won't complain!

My 32mm svbony sv131 plossl is the bees knees.  I use mine with a 130pds and it is generally pleasingly sharp for most of the FOV.  

I use it instead of a finder scope.  Once I get close with the Rigel I use the plossl to get the last bit to target.  It's got shed loads of eyerelief so I can leave my glasses on when I check charts against the eyepiece.  If I don't wear glasses I find my eye gets too close to the eyepiece and I start getting blackouts.

Strain wave being newer is also largely an unknown in terms of how well it's going to cope on the mass market.  It also makes sense to continue with the older lines until the technology is proven obsolete, especially if people are still buying them.

I think Ioptron have done a certain amount of bet hedging with their line up as they introduced some which only have one strainwave drive where as most companies have introduced versions that have 2.  Ioptron have also tended to introduce 2 of every mount as they will often have one with/without encoders.

I don't agree about Apple and ZWO having a singler product.  Both these companies thrive because they have monopolistic ecosystems.  Itunes, the Ipad, the Iphone...  Heck, Apple even got the cables!  I could just as easily bring up Huawei which had a massive range of products and required government legislation to prevent their meteoric rise.

Meanwhile I'm sat here like Oliver twist wishing for more!

On 11/02/2023 at 09:46, ollypenrice said:

Glad you like it, Rodd. The crop was a deliberate choice to bring the colourful part to full screen without a zoom. I do like a challenge, so here's a slightly wider view  ...

Still a bit cramped? Let me see, what do we have in stock at the moment?    This might do it, though I'll have to give you a discount since I can't run to the full rectangle...

Olly

 

 

 

 

Might want to clean your sensor mate.  Loads of dust there!

Stunning pictures.  It's incredible that most of that is nothing with the diary bits still being mostly nothing, only not quite as much nothing.

Just asked it why is astronomical sketching such fun.  Not sure if it copied it wholesale from somewhere else, but seems reasonable to me:

"Astronomical sketching is a unique and enjoyable activity that combines elements of art and science. When you sketch the night sky, you are capturing the beauty of the stars and celestial objects in a way that a photograph cannot replicate. Sketching by hand allows you to capture the delicate details of a star cluster, the faint wisps of a distant galaxy, or the intricate patterns of a nebula, and to add your own personal interpretation to the scene.

Additionally, astronomical sketching allows you to develop a deeper understanding of the objects you are observing. Through the process of sketching, you become more aware of the size, shape, and relative positions of celestial objects, and you begin to see patterns and relationships that you may not have noticed before.

Finally, astronomical sketching can be a peaceful and meditative activity, as you spend time outdoors under the night sky, observing the beauty of the universe around you. Whether you are sketching solo or with friends, it can be a wonderful opportunity to connect with nature and to slow down and appreciate the world around you.

Overall, astronomical sketching is fun because it combines the creativity of art with the wonder of the night sky, and it allows you to capture and interpret the beauty of the universe in your own unique way."

Welcome. Cracking image of orion

17 minutes ago, Stu said:

You are right, of course, Paul. To be fair I have written on a number of occasions, to the point of being boring perhaps, about the giant slaying abilities of the humble Heritage 130 and 150p scopes, particularly where resolution is concerned eg splitting Zeta Herc more clearly than an FL102S.

In the four inch camp I would put the arguments of convenience, consistency, stability of image and that hard to define aesthetic quality to the views.

If I had to bet on a particular night which scope would give the best planetary views regardless of seeing, the 4” is likely to be the one. They don’t require heavy mounts, are quick to cool, pretty bomb proof in terms of collimation and capable of anything from 3 or 4 degree widefields to well over x200 planetary, lunar and solar views. I think it’s the versatility and convenience which make them so appealing, as much as anything else.

But yes, it should be made clear that they cannot defy the laws of physics, however much we think they can.

To be fair to the 130pds, it mounts really well on an azgti (I find it more stable than the az5) and if you get the collimation good you can easily get above x200.

I do find that without filters on planets it can be a bit washed out, but I spent more on flocking my scope than for the yellow and moon glow that sorted that out.

The key is though the collimation which can be a bit of a mare, especially with the 130pds because the screws have a habit of cutting into the aluminium on the back of the secondary which gives it a preference of sorts to where it wants to collimate.  This can be fixed by putting a bit of plastic from a milk bottle between the screws and the aluminium though.  Just hope it doesn't lose it.

Over on cloudy nights they call the 130pds the 'apo killer'.  But comparing scopes of different types is a bit like comparing tools.  Yes, you can use an adjustable spanner to drive in nails, but a hammer is better.

They know who they are..

Sorry to jump in, but in terms of light gathering how would a 4" compare to the 130pds?  Would the lack of secondary put them on a par?

I also have a 130pds and have been pondering an upgrade path and was wondering abou possibly seeing what the buzz about refractors is about.  My only concern is the 130pds does such a good job on DSO for visual.  That and John Dobson whispering sweet nothings In my ear...

2 minutes ago, JeremyS said:

On the other handle, Dave, at least you can spend the next few evenings admiring them 😊

And when you do get them out to test them you enter the observer's paradox where you look through them for 5 minutes and 4 hours passes.

Turned up surprisingly quick.  SV220.  SVBony's 7nm dual band filter.  Not heard a massive amount about it so a complete unknown in terms of performance.  We shall see how it performs.  Worth a punt for £140.  Debating ordering a 49mm to 48mm ring so I can front mount it to a lens.

Ridiculously shiny.

EDIT:  Just had a look in the box and there was a chart of the band pass of the filter.  Not sure if it is useful to anyone (or accurate) but hey ho.

From inside the house it looked clear so I scampered out hoping to get a quick bit of observing done.  Unfortunately there's this really thing high cloud about and even m42 looked garbage.  Mars was about the only viable target but the seeing was rather good so managed to screw the zoom up to 3mm with the baargain contrast booster.

Some nice surface features showing.  Need to try and get a sketch in before it gets too small.

In all seriousness though, the photogrpahing a ruler thing is amazing when you are starting out.  It would be a lot of work, but if a retailer had it for their eyepieces for a couple of scopes (say a fast newt and a mak) it would make comparing eyepieces a dawdle.

1 hour ago, StevieDvd said:

I think you have a typo surely the Optolong Armadeddun.

I'm guessing it'll be the imaging conditions that cause the halos and not the filter with that one 🧚‍♂️

33 minutes ago, StevieDvd said:

It'll probably happen on one of the few clear nights we have.

And I guarantee one of the last messages out of Shropshire before a 1.5km wide lump of primordial Nickel and Iron smashes into the countryside and unleashes forces on the planet that haven't been seen since the dinosaurs will be a  Facebook post: "Just seen a bright fireball in the sky, is it the comet?  It didn't look green."

55 minutes ago, Mr Spock said:

Excuse poor phone photo, but, If you want sharp to the edge with minimal distortion, try an LVW 22mm. If you can find one... 

Not sure if we can trust this.  The ruler is not even made of wood!

Really nice images

29 minutes ago, Matthew Star said:

Interessting.

For Lunar I use 2 polar filters, 1 at the end of my diagonal and 1 on the EP, just with one or two turns, so not screwing it on completely for every EP by switching..

I leave the EP unlocked, so by turning the EP I can determine the brightness.

That really helps for me

That's a great idea.

I wonder if you rotated the binoviewer 90° would the edge sharpness effect you observed also be rotated, like maybe the significant decrease is an artifact of the binoviewer rather than the eyepiece.

Hmmm.

I printed out a 1.25" to 2" filter adapter a while back.  It uses clips to hold the filter in place. It's very secure.  Might be a better alternative than threads.

https://www.thingiverse.com/thing:4009041

Double post

Sky was looking pretty clear tonight, some interloping high wispy clouds but generally better than I’ve had for a while.  Suspected it might.  I’ve probably had more observing when Clearoutside has said it’s red because of high clouds than at any other time.

Given I had my recently acquired Nirvana 16mm (x40) to test I was going to make the most of it.  Given the moon was full I resolved to still do some testing/observing and also see how I got on with the AZ-Gti.  I would observe till the goto broke or I did.

M42 looked pretty good.  The sky was ferociously bright though.  The UHC filter helped somewhat although I noted that I with it I could only observe 3 stars in the Trapezium.  It just ceased to be with the filter in.

I had a look at M47 but between the moon and the elevation it was underwhelming.  I did however note KQ Puppis in the FOV.  The colour was fantastic.  Very pleasing orange colour.  I should probably have tested a different eyepiece on it, but the intensity was enough for me to stop and take it in.  Not done that before for a mere star!

I did a quick pit stop at the Rosette Nebula (no nebulosity) and stopped at the Esikmo Nebula.  It’s bright enough that with the UHC filter it was worth it.  Sporadically got some more of the nebulosity but not ideal conditions.  Thinking that tonight might be a night for clusters I tried the Beehive but it was too close to the moon and aside from the brightest stars there wasn’t much going on.

I decided to go north and stopped by chance on Cor Caroli  Delighted that I did.  I don’t often do doubles, but this one was really nice in the 16mm.  Nice separation and a definite orange colour on the secondary.  How good was it?  So good that I stopped writing this so I could order a copy of @Ags exceptional 'Discovering Double Stars' so I can find more.

I hopped along a few more DSO but couldn’t really see anything so decided to go to Polaris to check out the goto accuracy.  Sure enough it was largely within the FOV of the eyepiece.  Oddly I could see a fair white dot beside Polaris.  I’d split it before but needed 4-8mm.  There is no way that the Nirvana could split it at 16mm?  I dropped the 8mm Starguider in (x81) and sure enough, and with more effort than the Nirvana, there it was.  It was trying to hide behind a diffraction spike, but it was a split.  I can see why @Mr Spock likes these eyepieces.  Double splitting monsters!

This was also the point that I realised why people like the 82 field of view.  When I went down to Starguider with its 60 degree FOV it felt a lot more cramped.  I swapped back and forth a few times but the sensation was there.  Hmmm. I see a slippery slope just ahead…

I continued hopping my way around and got a good glimpse of the Double Cluster. (First time I’ve found it through the scope), M34, The Pleiades and finally Mars and despite having left the house 5 minutes ago to setup, somehow 2 hours had passed and I couldn’t feel my toes.

All in all, whilst the conditions weren’t great I had a good night.  The Nirvana is a great eyepiece.  It’s not flat out to the edge at F5, but time will tell if that’s an issues for me, but the wide FOV is very nice to observe with and the colours of the stars really pop.  It feels like it is very sharp on axis and is great at splitting, although I think my collimation is just better than when I started and I’m getting better at observing so the splitting efficiency is probably a combination of all these factors.

Stars of the show this evening is the AZ-Gti which nailed every target more or less on the head (or nudging distance away) and the double stars which looked amazing despite the moon.

3 minutes ago, chubster1302 said:

The one I'm "hopefully" about to buy for myself. Does that count 🤔 

Might not win too many votes from the general public, but if the hobby bites you then yes it will be, certainly the most important in the history of your wallet.

Sorry, re reading what I wrote isn't massively clear.  It's just trying to get the point that with astro imaging you are more trying to use techniques and processing to get the best possible image, possibly even if that can take hours of work.  With EAA your are viewing live as the images are stacked in realtime so your options are limited in how much processing can be carried out.  The 'good enough' was a tad flippant, but really it's as good as possible within the confines of stacking live.