John

About 1 degree from Messier 13 (the globular cluster) lies the galaxy NGC 6207. That gives an interesting sense of scale when you get both in the same field of view🙂

The Altair 102ED F/11 does come "binoviewer ready" with a removable section of the tube to allow for the additional inward focus movement that binoviewers provide.

Using binoviewers might be a way to further bridge the planetary performance gap between 102mm and your current 10 inch dob, if you find they suit you. 

The F/11 approach will need a much sturdier mount than the AZ-4 though and may undermine some of your ease of use / portability objectives in going for a 4 inch refractor.

An F/11 4 inch would rule out the AZ-4 - it just would not cope with the forces that the long tube exerts.

6 minutes ago, Mr Spock said:

East is cloudy, west is clear. I have the Tak out.

Jupiter - wow - it's all kicking off. GRS is dead centre and a lovely pale salmon colour. There's a transit shadow off to the left (refractor view) and oodles of detail in the belts with a couple of festoons.

Why do people keep saying the Jupiter season is over? Looks pretty lively to me!

Great stuff !!!

Fog-bound here after an otherwise fine day 🤨

Moon just about visible shining dimly though the murk. 

If you are not keen on a 50 degree AFoV the 4mm TOE will not help much at 52 degrees.

I owned one for a while and found it very good but not exceptional.

Others will differ from my findings though - that's the way of things 🙂

1 minute ago, Stu said:

……you remove the mirror cover 🤬🤬🤣🤣

I spent about ten minutes trying to find the Moon unsuccessfully before I realised! 🤪🤪

Still got my dob L plates!

We all do this stuff from time to time !

A couple of nights back I had the Tak 100 setup and after a gap in the session I popped back out again to have a look at M42. I could not get anything in focus which confounded me because I'd been having lovely views of Jupiter an hour before. 

What I forgot was that I bought the eyepiece in when I came in for a break and forgot to take it back out again. So I was staring into an empty diagonal barrel in the dark wondering why I could only see vague lights where before had been sharp and sparkling stars - dohhhh !!!! 🙄

When I had the Meade Lightbridge 12 inch truss I'm sure I recall leaving the mirror cover in place more than once !

4 hours ago, Mr Spock said:

I've got a 6mm SLV to fit in mine somewhere 

It will earn it's keep I'm sure. I found it excellent when I tried one and compared it with the Baader Genuine Ortho 6mm. 

19 minutes ago, JeremyS said:

Interesting to hear that John, considering I thought you had a Nagler 31. Looking for something lighter/less bulky?

I have the Nagler 31 and the Ethos 21 and they are both heavy beasts. As well as the weight, I'm motivated by curiosity - I've read a lot about the 30mm UFF variants over the past couple of years.

11 minutes ago, Moonlit Night said:

50 degree field of view doesn’t really work with an un-driven mount.

I find my 2-4mm nagler zoom works fine for me with my un-driven alt-azimuth mounts but it's not an approach that everybody would enjoy, I appreciate.

On the eyepiece choice, I'd go for a 4mm as well. I find 225x and more very often in use with my refractors. I tend to prefer 1mm or less increments in the short focal lengths to increase the choices at high powers.

On 15/02/2024 at 08:46, Saganite said:

I sold my 30mm Pentax XW  last summer for a Stellalyra 30mm UFF and have no regrets.

That is interesting to hear Steve. I've been considering those two recently. I'm swayed towards the 30mm UFF now despite my admiration for the build and optical quality of Pentax XW's generally.

Hmmm ....... 🤔

4 hours ago, Louis D said:

A bit off-topic, but does anyone recall a 30mm to 32mm Plossl/Plossl-like comparison ever being done?  I've always wondered how much better the Vixen SLV, Tele Vue and Brandon are than the budget Plossl lines, Celestron Omni, GSO, Vixen NPL, etc.  I'd also be interested how they compare to the vintage Clave, 5 element Meade 4000 from Kowa, etc.  The Brandon in particular costs more the 30mm UFF, so it had better do something spectacularly well.

This is more limited that I think you are looking for but I compared the Vixen NPL 30mm with the Baader Classic 32mm plossl a while back:

Baader Classic 32mm Plossl meets Vixen 30mm NPL Plossl - Member Equipment Reviews - Stargazers Lounge

On a side note, I can hardly believe that nearly 11 years have elapsed since I did that comparison 😬

Not mine of course but currently for sale in Germany and a snip at 295,000 Euros - a 14 inch / 365mm F/12 Lzos triplet. Interesting that the objective bears Thomas M Back's initials and seems to date from 2002 according to the test report.

When I want to use a 2 inch diagonal in my Tak FC100-DL I use an Astro Physics Maxbright, which is really a superb item 🙂

Most of the time I use a Baader T2 Zeiss prism though and stick to 1.25 inch format eyepieces.

With smaller to medium apertures I reckon the challenge will be to see some signs of a deformity to the primary star airy disk at approximately the correct position angle. 

Rather like I managed to get with Dubhe a couple of years back. No split, just vague indications of a "bump" at one point in the primary star airy disk.

I wonder if this 3-8mm zoom will come out under other brandings ?

The UFF eyepieces seem to be available under a plethora of brands now and at a range of prices too.

This well known and detailed comparison of diagonals places the Takahashi 2 inch mirror more or less on par with the 1.25 inch Tele Vue Everbright so probably little or nothing to gain except for the facility to accept 2 inch eyepieces should to wish to do so at some point:

Mirror vs. Dielectric vs. Prism Diagonal Comparison - Articles - Articles - Articles - Cloudy Nights

9 minutes ago, JTEC said:

.....we are slipping into a creeping acceptance of the mediocre and rebranding it as good.....

 

Sadly very true IMHO and not just in astronomy 😔

With a limit of £150 the Svbony 3-8 zoom is all I can currently offer up for this thread I'm afraid 🙄

If I was allowed used prices (all of my eyepieces but 2 were purchased used) then a couple more might just squeeze in.

I recently parted with a set of 4 Astro Hutech HD orthos (4mm, 5mm, 6mm and 7mm) which I think retail at around £89 apiece, considerably less 2nd hand though. They were excellent performers within the usual abbe ortho constraints of a 40 degree AFoV, small eye lenses and eye relief around 80% of the focal length. The Svbony zoom seemed to match their performance though while offering more comfort.

There are plenty of very good sub-£150 eyepieces about these days though so the thread should have no trouble generating a good list of candidates 🙂

The Baader Classic Ortho 18mm and 10mm are pretty darn good for their cost that's for sure. I don't currently have those though.

Here is a relatively recent thread from the CN forum regarding Newton Rings visible in a Tak FC76DS objective. They look almost identical to yours:

Takahashi FC76DS Newton rings - Refractors - Cloudy Nights

The 4th post in the thread mentions a discussion on this topic with an optical technician at Takahashi Europe who provided reassurance that they are not in any way untoward.

One of the least effective UHC filters that I tried was the Explore Scientific. I don't know what it's band pass looks like but the Astronomik UHC and even my elderly Meade 4000 Narrowband made a much more obvious difference to the contrast and extent of the nebulae I tried them on.

I was slightly surprised by this. Most of the other Explore Scientific stuff that I've used has been pretty decent. And they do supply the filter in a very impressive and somewhat over-large decorated and foam filled box as well as the nice little plastic case. Perhaps they should have spent some of their packaging budget on a more effective filter ?

32 minutes ago, Naughty Neal said:

.....suffering a very heavy cold which is proving hard to shake , still suffering sinus and asthma issues due to it's  effects....

 

  

Sorry to hear that but I've had something similar. In my case I lost my voice for 3 days and I'm still speaking in a whispering croak 🙄

Nice to see some starlight this evening though. Made me feel a bit more human again !

Before the forecast cloud cover obliterates things I had a look at Eta Geminorum (Propus) inspired by @Nik271's report here:

https://stargazerslounge.com/topic/418615-eta-geminorum-a-gem-in-gemini/

I was pleased to see the fainter secondary star on the outer edge of the faint diffraction ring around the primary star and the colours matched Nik's description. I found 225x and upwards was required to clearly make out the secondary star to the W of the primary.

I'm not sure that I've split this one before - it's probably a new one for me, which is very nice 🙂

1 hour ago, Peter Drew said:

Newton rings are a very sensitive indication of how well the lens is held and centred.  It's one of the first things I look for when assessing one, I would be very pleased with one like yours.     🙂

I've seen them with some Vixen doublets and a TAL doublet that I had but not in Tak FC100 doublets. I put that down to the air space being a touch wider in the FC100 objective design.

I agree that they are not a negative thing to see but just wonder why they are present in just one example of that particular scope 🤔

First stargazing / space tourism for ages here for various reasons. 

Jupiter looks lovely despite the red spot hiding around it's other side. The 4 Galilean moons are strung out nicely to the west of the planet. Ganymede stands out as the largest of the four at 180x magnification.

Rigel split neatly and cleanly.

I don't think the clearish skies are going to last though but something is better than nothing 🙂

13 minutes ago, mikeDnight said:

It sounds like your FC100 has won your heart, which I fully understand. DC's are great scopes, and there would always be that niggling question of whether a replacement would be as good? 

I think the niggling question is why they are showing.

I've never seen newtons rings showing on the objective of a TAK FC100 before, and lets face it, there have been enough pictures of them on the forum over the past 5-6 years or so !