Ratlet

Good question.  I just got a go-to and I'm still making my mind up about it.   I'm going to cast my vote for the goto as I have been using it more.  I do enjoy and miss the star charts though.

Some adapters for my vintage lens obsession and a giant spirit level thing so I can hopefully optimise levelling my mounts.

Supposed to have been a 49mm to 48mm Stepdown in there but I couldn't see it.  Unfortunately I opened the packet at work and the bins got emptied before I realised!

This is the first time I've ever seen an image from a camera and telescope that looks like what I see through a telescope!

Of course you used a Mak 🤣 it's been 6 months since I sold mine so I'm due finding my monthly post that makes me regret selling it.

As Rod Stewart once said "I wish that I knew what I know now, when I was younger"

Sorry to revive this old thread, but someone shared these in another thread.  Their magnificent!  How did you take them?

Comment deleted as I didn't read the question properly 😳

11 hours ago, Pixies said:

Had a quick pootle around Cancer last night. the first clear night here for ages, it seemed. Seeing was average but transparency was pretty poor; the sky looking pale and washed out.

Still - haven't had the dob out for a while and had some new (to me) eyepieces to try out.

 

Σ 1245 - easy split at x40 - both yellow but one much brighter. 

Tegmine (Zeta Cnc) - the tighter pair were elongated at x150 but at x240 were occasionally notched but the seeing wasn't good enough for anything better.

Σ 1291 (57 Cnc) - Obviously notched at x240, but seeing too poor to split

Σ 1298 (66 Cnc) - Nice easy split.  Quite a difference in brightness but nothing too tricky.

M67 - Used this to compare the new Delos 12mm to my old Vixen LVW 13mm. The former framed it better and gave a more immersive view, but the LVW was so much more comfortable to use!

 

Also - Iota Cnc - Very easy split with lovely looking larger gold and smaller cool blue. One of these 4 - see this really nice image and past post by  @orion25:

 

How on earth did you take those?!  They're fantastic.  Are they images? 

Fantastic.

This would make a good birthday present for someone if you were feeling a bit cheeky.  Show them the light of a star on the day they were born.

Probably need to get a new eyepiece/scope to make the experience truly magical for them...

Just did the exact same as you.  The 16mm Nirvana is what I got.  Very happy with my purchase.  I found it had great star colour and was really sharp on axis.  Bit ropey towards the edge but nothing major.  That was in an F5 scope.

It didn't feel like much going up from 60 to 82, but coming down you miss the fov.  

I've been using the first version (pdf) when I get in to check things when I spot an unplanned double but book 2 I think will be better for dedicated double work as a newbie as I can move about easily hunting them down.  I think.

I'm probably going to buy the 1st version at the star of the month.  I think they will be very much complimentary rather than one being an upgrade over the other.

7 minutes ago, Mr Spock said:

On the other hand people see what isn't there due to expectation bias...

This will be my last post. I can see more and more SGL turning into another forum where there are constant disagreements and highly opinionated views. There have been several threads like this recently. Not very SGL in my view.

That will be a great loss to the forum.  You've done loads to help further my enjoyment of the hobby and understanding of how to squeeze every last drop from the limited dark skies we get.  I'm sure there is a slew of others who feel the same way.

I understand your feeling though.  I've always found the discussions here to be more relaxed and sociable than other forums and is a large part of why this is the forum I mostly post on.

6 minutes ago, Stu said:

Have a look at lower powers and see what you see. It seems like it may be an eye sensitivity thing. In terms of physics they are there, but it seems some see them, some don’t. I don’t believe it is the scope making the difference (assuming standard 3 or 4 vane spiders)

I'll need to have a proper look.  I try to ignore them, I seem to recall that they were less like what you'd see with a diffraction spike like in an image and more like a solid band.  They're definitely from the vanes, but they done taper as they get away from the planet (as far as I can remember)

Cheers lads, I understand the concept I was more wondering about Mr Spock not getting them on Jupiter with his wider array of newts.  I assumed it was normal to get them but if he's not it made me question if I have an issue.

Fun fact:

If you want some fancy thinned lenses but don't want to spend big fish on the premium, ask your optician to put in polycarbonate lenses (safety spec glass)

It's as thin as some of the thinnest lenses but can be got for free of the NHS.  No coatings on them unfortunately, but good for the price.

I did this for years as I combined being broke with my innate Scottish grippyness.  -8.5 in each eye so my lenses are beefy.

On 14/02/2023 at 23:07, Mr Spock said:

With Newtonians, I've had a 4.5", 8", two 10" and a 12" and none of them have shown diffraction spikes coming off Jupiter.

I forgot about this, but I get some farily pronounced diffraction spikes on Jupiter with my 130PDS.  Is that likely to be something to do with my eyepiece selection or could it be my spider isn't quite straight with the tube?

1 hour ago, Louis D said:

Thanks for the feedback.  I'm an engineer who enjoys finding solutions to problems.  The problem here is how to get the best performance out of fast achromatic refractors.  There have been expensive solutions in the past (the Aries Chromacor), but I was intrigued by the possibility of simply improving rather than correcting the view.

I've been using my retired 14mm Pentax XL in a Parks GS 2x shorty Barlow for the testing at about 57x.  I place the object slightly off center to allow for more drift time on my undriven alt-az mount.  I then grab two filters, one in each hand, carefully by their edges (they're all in a shallow box nearby to avoid them disappearing into the lawn).  Next, I return to the eyepiece and move each eyepiece in and out of the exiting light cone using a variation on the blink comparator method to look for changes.  I sometimes move one, then the other, then both at the same time, into the light cone.  I even alternate which one is stationary while moving the other one in and out to observe what changes occur when stacking to better understand what each filter is doing.  This method only works with small objects like planets and stars since I can only see a small portion of the FOV while pulled back so far from the eyepiece to fit one, and sometimes two, filters in between my eye and the eyepiece.

I chose the Pentax XL because it has a smooth top with a rubber guard, so I wouldn't have snagging issues or eye lens scratching issues.  It also has no chromatic aberration issues of its own, so I wouldn't have to sort eyepiece chromatism from scope chromatism.  Lastly, since it was retired by my 14mm Morpheus, I wouldn't be too upset if something were to happen to it.

Grabbing the filters without putting fingerprints on them is difficult, but practice makes perfect.

Overall, I've been really surprised and enlightened by my discoveries.  I can't recall anyone else systematically comparing various filters on an achromat to narrow in on what works well and what doesn't.  There's been lots of work done in the area of figuring out which filters work best on which objects, but they always seem to assume the scope doesn't have strong chromatism of its own to sort through as well.

Often, folks write off fast achromats for planetary usage, but I've found that with the proper filtering, they can put up quite sharp and pleasing images if you can ignore the color cast.

Surprisingly, I've found my brain performs a white balance on pale yellow and yellow-green images over time such that they seem color cast free.

There's also the fun of playing with my toys in a new way.  As a kid, I used to combine my toys in new and unusual ways such as racing my Hot Wheels cars down tracks through long Lincoln Log cabins built over the track.  I was amused by the change in sound as they went through the cabin and how they disappeared and reappeared.  So, I'm always looking for new ways to combine things in ways that haven't been done before.

I had written off my Newtonian for planetary until you dropped the hot tip about using the m&sg filter with a cheap yellow.  I'm seriously considering just leaving it on my svbony zoom and altering my shadowfoam in the case.  Absolutely changed the game in terms of what I can see.  It's the difference between looking at a lightbulb and a photo.

Safe to say your engineering approach to this has me convinced!

16 minutes ago, Littleguy80 said:

In my 130mm newt, the 12mm BST was always my favourite 

I agree.  It's a fantastic focal length for the scope. My 8mm is languishing unloved since Christmas as the 12mm frames lots of objects nicely and gets good contrast on DSO.

I'm really enjoying this.  It's interesting to see empirical analysis of the filter combined with testing at the eyepiece.

Not sure how you manage to change filters so much without getting finger prints on them.  I struggle at the best of times (to the point I designed special filter cases).

Forgive the use of a stock image, but I'm working nights. 

Couple times I've been out recently where high hazy cloudy have made DSO observing a challenge and doubles rescued me.  For some reason Cor Caroli was the one that convinced mem

I've referred to the pdf a couple times and it felt like theft because it was a really good resource and intuitive too.  Nice little blurb on the doubles and handy star charts too.

Ordered black and white spiral bound.

I'll need to do some math and work out how big a circle I need to I can sort out various eyepiece fov.

Thanks for the great resource @Ags

Those are some fantastic animations!

I use a 130pds newt on an alt az mount and attempted to use it on my GEM28 eq mount.  The eyepiece ends up all over the place.  It's not much fun.  From my experience you'll find it better to go for something alt-az like (dob or legit alt-az mount and normal Newtonian).

You'll see oodles even if you go for a smaller aperture so that's always an option.  I'm massively biased, but my 130pds is awesome.  Nice views of lots of objects.

4 minutes ago, Marvin Jenkins said:

Nice to know us B3 dwellers have just enough eye sight to do it.

Observational astronomy is on the decline, we all know that. It is not a result of AP becoming more popular but just that you need to be driven and dedicated.

Most of all you need dark skies. #jetstream has them but at a cost in life style most country dwellers would run from. I personally would love to have that darkness.

#jet stream, what do you think the Bortle limit would be? I saw repeat nebulosity around the running man with a 5” newt in B3 skies.

Am I seeing things as I think at that aperture you are B1 or better. Just want to say that I am a completely worn wreck at 50 but my eyesight is crazy good. Often I go places with friends and say look at that, and then I spend sixty seconds working out what they are doing.🤣

Marv

 

I'm bortle 4-5 in my location.  Facing south it is more bortle 4 according the online stuff.

We are prone to a haze though which absolutely destroys most DSO observing and altitudes (Orion is not much above 25° at best).  Nights like that are why I have ordered a double star book!

27 minutes ago, jetstream said:

You also managed a portion of the lower loop in m42 IMHO👍

I thought THAT was dew on the eyepiece.  I think that the second image might have been some nebulosity on the far side of m42? but here's the full sketc and I think I did get the running man after all?

I am hink I might have seen it.  I struggle massively to link what I see through my 130pds with what a photo looks like.

This is what I sketched a while back.  The blob at North might be the running man?

32 minutes ago, LaurenceT said:

Can you all please stop posting stuff about 135mm prime lenses. It's probably my favourite focal length lens for "ordinary" photography and astro. I've had several of these over the years but sold them all on, and now I'm looking for yet another one thanks to you😄

This is actually the third 135mm I've bought.  One was Pentax mount which I didn't get an adapter for and the other was a cheap Chinon which I couldn't adjust the infinity focus on.

I've probably spent about £200 on 6 lenses from 135mm to 300mm focal length over the last year.  2 of them were gambles (the 135mm) as there was nothin online about their quality, but cost £20 total and may turn out to be good.  I think in terms of bang for buck though I'm doing okay, but I'm absolutely going to bring the rest of you down with me!

33 minutes ago, alacant said:

Hi

Yeah, they really are underrated. Excellent shot. Just imagine what 10 lots of 10 minutes would look like😀
To help with the stars, leave the internal diaphragm wide open and fit a e.g. 49 to 30 step down ring to control the aperture.

There's loadsa detail to dig out. Even in the .jpg.

Cheers

 

Cheers bud,

I usually use Stepdown rings (I have a lot) as a preference but I leave them outside with the mount.  I should have checked, since the one size I don't have is 49mm which I need for this lens!  I've ordered some in at any rate.

I was quite surprised at the amount of detail it pulled out for only 10 minutes.  I didnt attempt to do too much to it since there is nebulosity everywhere in it and I hadn't got the time to begin to approach it for a more serious attempt.

The F3.5 seems to not be anywhere as popular as the F2.5 for imaging, but I think it gives very respectable performance for 1/3rd the cost! (This one was an absolute steal at only £15 versus the £150+ for the F2.5).

I'm not sure whether it is the lens or the filter or both, but I'm very impressed with the levels of chromatic aberration.

I've had issues with lenses not reaching focus without some tweaking (adjustable m42 adapter on order) but this had some room at infinity without anything.  Again that might be down to the filter shifting the focus slightly.