Lukehurst-Nichol classic dobsonian modifications

[Piero]

Very happy with it! Wish the sky were clear, but as we all know, when we buy astro equipment, it's cloudy! Argh!

The telescope was collected from David Lukehurst at noon and then we travelled back to Cambridge. 

John Nichol primary mirror: 37mm thickness, Suprax. Hilux coated. Optics 1/8 PV wavefront  1/27 wave RMS. Strehl .95. Secondary mirror: 62mm MA.

Here a few photos:

 

 

 

 

 

[Stu]

Looks gorgeous Piero, will provide you with many happy nights I'm sure.

Go away clouds!

[Pig]

 Very nice indeed Piero 😀 

 

Edited June 23, 2019 by Pig

[John]

Lovely scope Piero - congratulations

[FenlandPaul]

Love it! It looks gorgeous, Piero! You’re going to have a lot of fun with that - although I suspect not until Thursday at the earliest!!! 

[laudropb]

Lovely looking scope Piero. Looking forward to hearing how it performs.

[estwing]

Very nice...and one of John's mirrors, excellent. 

[Sunshine]

Well isn't that a beautiful looking dob, and optics to boot too! i'm sure you're itching to get her outside and get a retina full of nebulae with that beauty, congratulation!

[jetstream]

Congrats Piero!

[Floater]

Wow! A beauty! 😊

[Trikeflyer]

Stunning.  You must be delighted. That's a keeper for sure!

Can't wait to hear how it performs.

Steve

[jetstream]

20 hours ago, Piero said:

John Nichol primary mirror: 37mm thickness, Suprax. Hilux coated. Optics 1/8 PV wavefront  1/27 wave RMS. Strehl .95. Secondary mirror: 62mm MA.

Excellent specs and from a maker that I believe his numbers. This scope will punch way above its weight Piero and be good on everything-its at f6 correct?

Is the 30 UFF substantially better than the ES 30 82?

[Mark at Beaufort]

Yet another fantastic looking Dob. The specification looks excellent. So I am looking forward to info on 'first light'.

[Ally8446]

Beautiful work. David doing what he does best. Congratulations. 

[fiestazetecmk2]

Nice looks superb. 

[Piero]

2 hours ago, jetstream said:

Excellent specs and from a maker that I believe his numbers. This scope will punch way above its weight Piero and be good on everything-its at f6 correct?

Is the 30 UFF substantially better than the ES 30 82?

Thank you, Gerry.

The structure is reasonably solid, but I can lift both the rocker and mirror box by myself (separately of course). The wheel-handles make movement dead easy which is great for moving the telescope around the garden.

Yes, it is a F6 (F5.94 to be more accurate) and 1813mm focal length. Altitude bearings are 15 inch diameter, with a good friction. The focuser is the Moonlite CR2 that was installed in my other dobson (which now has its standard focuser).

In my opinion the ES30 82 is a real bargain. I prefer the APM 30mm UFF for a few other reasons such as eyecup, weight, and size. Optically, the APM is better at the edge but its AFOV is smaller. The FOV is just a bit larger than the Lunt 20 HDC.

[Littleguy80]

Congrats Piero. Great looking scope. Looking forward to hearing your impressions of it as you get to know it  

[jetstream]

39 minutes ago, Piero said:

Yes, it is a F6 (F5.94 to be more accurate) and 1813mm focal length

Thanks Piero, I might try the 30 UFF someday.

Your new telescope will be so similar to my 15" in performance...this is a great focal length and your f ratio allows for some great exit pupils and mags for DSO, and with VG EP's. Your 24 Pan will be good, along with your others but I really wish there was a 25mm EP with performance above Nagler/ES.

A 25mm Lunt HDC would be the ticket! (IMHO).

ps- forgot to say-( and you know this lol!) this scope will be more forgiving for lunar/planetary than my f4.8- very nice choice Piero!

Edited June 24, 2019 by jetstream

[Piero]

58 minutes ago, jetstream said:

Thanks Piero, I might try the 30 UFF someday.

Your new telescope will be so similar to my 15" in performance...this is a great focal length and your f ratio allows for some great exit pupils and mags for DSO, and with VG EP's. Your 24 Pan will be good, along with your others but I really wish there was a 25mm EP with performance above Nagler/ES.

A 25mm Lunt HDC would be the ticket! (IMHO).

ps- forgot to say-( and you know this lol!) this scope will be more forgiving for lunar/planetary than my f4.8- very nice choice Piero!

 

Thank you, Sir!   

I did the maths before ordering. It should be a good trade-off between performance and portability. The table below is w/o VIP barlow. I look forward to seeing when that brilliant device kicks in!

Anyway, I only plan to use the above eps with this telescope, therefore no 1.25" eps. The 30mm and 20mm will likely have some competition. I'm quite curious to see how I feel the 100 deg with this telescope. I do like my Lunt 20mm, but so far I have not been trilled by the 100 deg bug. Actually, I could be just happy with the APM, Docter (now called "Noblex"...), and ZZ.

Have you got a CC with your new dob? If so, I would be very curious to know how you get on with it. 

Edited June 24, 2019 by Piero

[jetstream]

1 hour ago, Piero said:

Have you got a CC with your new dob?

No not yet, for some reason I'm reluctant, but I probably will try a Paracorr 2. I'm not sure I want that extra glass in the way on those nebs/galaxies... Taking the CO into account the effective f ratio is about f5 so with narrower planetary EP's the coma is less concerning and with any scope I obs in the center of the field.

In theory however, controlling the coma should increase contrast across the FOV-that is unless the extra glass diminishes or eliminates the benefit ie Suiters wobbly stack.

Thoughts?

[scarp15]

Very elegant and articulate looking scope Piero. The 'blond' natural finish is interesting, I am accustomed to seeing pictures of David Lukehurst commissions coated in black lacquer, what coating has been applied? Going to be very interesting to follow yours's and Gerry's reports.

[Piero]

2 hours ago, jetstream said:

No not yet, for some reason I'm reluctant, but I probably will try a Paracorr 2. I'm not sure I want that extra glass in the way on those nebs/galaxies... Taking the CO into account the effective f ratio is about f5 so with narrower planetary EP's the coma is less concerning and with any scope I obs in the center of the field.

In theory however, controlling the coma should increase contrast across the FOV-that is unless the extra glass diminishes or eliminates the benefit ie Suiters wobbly stack.

Thoughts?

Well, I've been thinking about a coma corrector for almost 1 year. As far as I can see each choice has advantages and disadvantages. The safest route I would choose is the SIP. The parcorr2 requires inward travel I think. Apart from that it is optimised with TV EPs. Not sure about the settings for the Lunt, docter and ZZ. This can be a pain. It will correct the view off axis, but my feeling is that it will cause some loss on axis. This is what I saw with my previous TV powermate when used with the Docter/Noblex.

We can talk in more detail if you like.

[Piero]

52 minutes ago, scarp15 said:

Very elegant and articulate looking scope Piero. The 'blond' natural finish is interesting, I am accustomed to seeing pictures of David Lukehurst commissions coated in black lacquer, what coating has been applied? Going to be very interesting to follow yours's and Gerry's reports.

Thank you, Iain. I'm a great fan of natural wood finish. David applied a protective layer of course.

The coating is Hilux, applied by Orion Optics.

[Piero]

This evening I tested how the telescope holds collimation with my Glatter's tools. 

The secondary mirror was slightly off but it was recentred in a couple of seconds. The primary was also adjusted quickly. I pointed the telescope at different angles with the laser on in order to check any alignment changes. Nothing. I therefore moved the telescope from 90 deg to 0 deg altitude a few times. The reflection of circle on the primary mirror didn't change position on the tublug. Very glad that the Glatter's sling was installed.

[jetstream]

20 minutes ago, Piero said:

Very glad that the Glatter's sling was installed.

Yes.

A must to reduce distortion including "potato chipping".