Pixies

Galaxy season in Spring

20 minutes ago, Gfamily said:

It's a bank holiday isn't it? 

Not up in Scotland ! 😢

That reminds me! I better book out a 'meeting' in the work calendar for tomorrow afternoon!

6 minutes ago, Stu said:

Unless of course you would only say me, then it’s you and me.

eg ‘it looks like it’s just me at this party’, ‘it looks like it’s just you and me at this party’. In this case ‘you and I’ would be wrong.

Don't get me started on the Doors' "Touch Me"

Now, I'm going to love you
'Til the heavens stop the rain
I'm going to love you
'Til the stars fall from the sky
For you and I

I love the song, but that line makes me wince.

On 19/08/2022 at 20:13, JeremyS said:

Getting ready for action 

You just need a nice 3.7mm Ethos to go with them!

2 hours ago, Stu said:

 

Might be worth trying a towel over the head to avoid this? Could help, as the light is presumably coming from surrounding glare/LP?

yep - sorry, replied to Zermelo's post before reading yours.

38 minutes ago, Zermelo said:

I've noticed something like this with my 24mm UFF. Filters give a kind of reflection - though I'd not thought it to be of my own eye. It does not appear in the UFF without a filter, and does not show in any other eyepiece I have, filtered or not.

 

I'll need to try it next time with a hood over my head and focuser. I assume it's from local light pollution.

I'll be going to Astocamp, too. I've not seen cajen2's new van, but it won't be as rusty as mine!

6 minutes ago, vlaiv said:

In this particular case - it is the same as AS!3 uses special debayering algorithm - bayer drizzle that restores original resolution even from OSC sensor.

So formula works for both mono and OSC.

So as this camera has 2um pixels, I'd be best with an f8 scope for planetary?

My options are an F6 200mm newt or an F10 105mm achro. Perhaps I'll need to rethink and get something with 2.5um or 3um pixels (F10 or F6 with x2 barlow)?

On 10/08/2022 at 16:25, vlaiv said:

That really depends on pixel size.

There is no difference between average seeing conditions and best possible seeing conditions. You choose F/ratio to match pixel size for "perfect" conditions. Point of lucky imaging technique is to try to capture those short moments of "perfect" seeing, so you want sampling rate to be matched to what the scope is capable without worrying about seeing part.

In any case - here is formula

F/ratio = pixel size * 2 / wavelength_ of_light

(here pixel size and wavelength of light is in same units, and for regular imaging 500nm is often used so wavelength is 0.5um)

For regular imaging (not narrow band filters) above simplifies to

F/ratio = pixel size * 4

If you have camera like ASI178 with 2.4um pixel size, then optimum F/ratio is 2.4 * 4 = F/9.6

For 3.75 (ASI224, ASI120 and alike) you get 3.75 * 4 = F/15

For F/20 you would need 5um pixel size, and I'm not sure if I know camera with that pixel size to be honest (closest that I've heard of is 5.2um).

 

Sorry to jump in. 

@vlaiv, does the above apply to a mono camera only? What about OSC?

You see, I was thinking about a ASI678MC for EEVA/EAA with an F5 400mm scope. But if I wanted to use it for planetary, what focal ratio would I need (assuming a different scope with larger aperture)

I saw the Veil a few nights ago for the first time. Using an 8" dob with a couple of wide-angle 2" EPs. One was 40mm 72deg (2.36deg FOV) and the other a 28mm 82deg (1.8deg FOV).  I could only get the west or east parts separately, not both together.

It was clearer with an Oiii filter, the east part especially. Once I had seen them with the filter, I could just make them out without, since I knew what I was looking for. This is a Bortle-6 sky.

Well - I'm saying 2 on the night. As I don't want to be left out!

Saw the Veil properly for the first time tonight! 🥳

Have been playing with some of the big 2" EPs that I picked up this week. I found a Baader 2" Oiii filter in the treasure box too!

I used the SWAN 40mm 72° and the Nirvana 28mm 82°. Both showed the veil without filter but with it, the view was quite impressive. The exit pupils were 6.7mm and 4.7mm respectively, which is good for the filter, I guess. The skies were brightening with the rising moon  and the neighbour's lights were on, so I was hardly fully dark adapted. The contrast appeared better in the Nirvana, which is a nicer eyepiece all together. I tried the Celestron Axiom LX 19mm 82°, but the contrast was poorer.

At some points however, I was having problems with the view through the filtered Nirvana. I eventually realised that I was seeing the reflection of my eye being thrown back at me by the mirrored surface of the filter!

Yep - agree about north level alignment. I usually start with Polaris as the first star, then 2 more roughly at right angles. At the moment that's Alpheratz and then Altair. So you've aligned on N, E and S. After that, it's great.

Check your mount/tripod interface though. There should be no flex! What tripod are you using?

7 minutes ago, Franklin said:

Never knew Vixen made a 2" Diagonal, but they must have because I now have one.

 

Oooo!

Is that a single thumb screw or does it have a compression ring?

Here goes....

I saw an advert in local facebook - someone was selling what hey thought was photography gear that they had inherited, but not sure of the value. It was mainly astro stuff though, and some people were taking the mick with offers. I contacted him, not because I wanted it - there was no way I could afford it - but to tell him what they were and how much they were worth!

He thanked me, then kindly offered it to me for a price I could not refuse! It arrived today:

Yes - that's a TeleVue Ethos.

I think that's an off-axis guider?

Well. That's the weather ruined for a few months!

30 minutes ago, spacegalaxy said:

Thanks for the answer, but I was looking at 120x magnification for Juipter and Saturn, so is it okay for that?

It's not the best scope for planetary viewing, but it's more than capable of showing Saturn's rings, plus Jupiter with cloud belts and moons. 120x is a bit high for that scope, in my opinion. You will get chromatic aberration and a lot of vibration. I usually stick to 80x max (100x at a push). Others may disagree.

1 hour ago, MercianDabbler said:

Spent the afternoon, err... keeping warm... in the shade of the shed yesterday playing with my lathe to make the remaining five replacement bolts for my SP tripod...

A 40mm length of B&Q's finest M8 studding, an M8 wing nut and a threaded bush (about 8mm thick) made from 1/2 inch steel bar drilled and tapped M8.

All done... no more fumbling around for an Allen key in the dark  

I still wound't call an SP and 102mm scope 'grab and go' but it's now less hassle and more likely to get out.

Now... any suggestions for how to make the original sheet metal 'spider' less annoying? - mine seems to have a penchant for detaching the arms at inopportune moments. It's probably upside down too but that was a previous change to reduce the frequency of it falling apart.

You need to get the triangular tray. It helps with stability too.

1 hour ago, Priesters said:

Barnard’s E (142)?

Wot Priesters said (B142 and B143)

The OP said it was a HERITAGE 150p.

The OTA without dob base is 3.5kg - according to Telescop-Express Which should be no problem for the AZ5

But that tripod that comes with the AZ5 has a payload capacity of 3.5kg (according to some sites). The AZ5 is 2.3kg, so the OTA and mount are 5.8kg together! The  OP doesn't say which tripod they use with the mount.

The grub screw will adjust the load on the worm gear. Too tight, and the slo-mo will be tight, too loose and you will have backlash. It shouldn't affect the action of the clutch.

With the clutch loose, you should be able to rotate around the Az axis easily, although it's not so loose it will spin around our anything like that. It does sound like it's quite tight. This means the clutch has a lot of friction to act against, which is why you have to tighten it a lot to get the slo-mo to work.

Try loosening the clutch and spend a while just rotating the mount around the Az axis. See if that loosens it off a little.

Hi all 

As C mentioned, I'm the other one going. This'll also be my second.

Looking forward to meeting everyone. 

Cloudy here tonight. Brief views of some brighter stars. However, saving myself for the rest of the week which looks like it's going to be clear.

Until 12th! Cloudy at the peak or Perseids meteor shower! 🙄

Just sayin':

3 minutes ago, Franklin said:

One will turn up some day. I'm on the hunt for a LVW 17mm to complete the set.

You and me both!