BlueGumby
26-06-2023, 07:45 PM
Hello fellow amateur astronomers, I am at odds with my health.... so
D180 F8-R30 Objective, Back Plate, Front Mounting Ring with dew shield, machined lens cap and brand new Large Format 2.5" Moonlite Focuser with manual focus 10:1, two iStar style adapters (M100x1.5), two x 2.5" spacers and 1-1/4" and 2" compression rings.
Here is my iStar D180, F8 R30 anastigmat refractor project. This is going to make someone a wonderful instrument suitable for planets or deep space with a full 180mm aperture. The R30 designation indicates that the chromatic aberration correction is equal to or better than a classic achromat with 30% longer focal length (ie.better than 180 x F8 x 1.3 = 1872mm, or F10.4).
The objective is of a high quality and was purchased directly from iStar Optical in Arizona, USA in 2020. This was one of their prototype D180/R30 objectives and is a heavier build than the production unit at 7.9Kg with mounting cell.
The lens is excellent optically and I have a copy of the iStar test results which can be provided on request. Ales Krivanek, the iStar CEO had this to say..
"We do have that one last unit 180 F8 R30 in stock. it is heavy but we have just tested it and the image quality is very good. it is a great lens optically........."
also....
"Regarding the lens design, we use heavy flint to achieve the R30 level of correction. We do not share exact glass types or the actual design. We are the only ones in the industry offering these cross-over anastigmats and our design is a trade secret."
"All R30 doublets are made with short flints and special, more expensive crowns than any classic Achromat."
".......R30 anastigmatic doublets offer a substantially smaller spot size, greatly improved resolution and amount of chromatic aberration comparable to a classic system of 1.30 x longer focal length....."
The telescope tube design is for a riveted sheet metal construction with machined solid aluminium back plate and front mounting ring. The back plate has an M100x1.5 female thread to take a MoonLite-iStar style focuser adapter, and the front mounting ring has three tapped holes to take M5 bolts through the objective mounting cell. Tapped holes in the lens cell allow three adjustment screws to bear up against the mounting ring.
I have completed the dew shield using this design and have tooling for assembling the main tube, however I have not had the main tube profiles laser cut. All SolidWorks models and drawings will be provided including profiles, DXFs and PDFs. I am happy to provide some of these on request and prior to sale.
The purchaser may choose to connect the back plate and front mounting ring in a simpler manner by using a rolled aluminium tube ID=231 and Length=1090. Thickness say 2.5mm.
Extensive construction notes and photos here:-
https://istarscopeclub.proboards.com/thread/723/istar-180-r30-build-oz
Included in sale........
iStar D180 F8-R30 Objective in mounting cell
Aluminium lens cap for same, painted white with brass handle.
Machined aluminium backplate (M100x1.5 female thread)
Machined aluminium front mounting ring (tapped for objective cell)
Sheet aluminium dew shield
Various sealed pop rivets for main tube assembly
Finderscope mounting bracket x 2
Finderscope mounting bracket curved backing plate x 2 (fits inside flange of backplate)
Ø 235 tube mounting rings x 2
Losmandy Dovetail, length 14"
Large Format 2.5" Moonlite Focuser with manual focus and 10:1 (heavy duty tri-knob reduction unit)
iStar style adapters (M100x1.5 male) x 2 (only one needed, includes a spare)
2.5" spacer x 2
1-1/4" compression ring
2" compression ring.
Assembly tooling for assembling the sheet metal tubes. (see link to project above)
This has cost me around $5000 plus $2000 worth of 5-axis machining, asking $4500
Pickup preferred from Frankston South.
thanks for looking!
...will consider trade/part trade for bullion coins
Graham
D180 F8-R30 Objective, Back Plate, Front Mounting Ring with dew shield, machined lens cap and brand new Large Format 2.5" Moonlite Focuser with manual focus 10:1, two iStar style adapters (M100x1.5), two x 2.5" spacers and 1-1/4" and 2" compression rings.
Here is my iStar D180, F8 R30 anastigmat refractor project. This is going to make someone a wonderful instrument suitable for planets or deep space with a full 180mm aperture. The R30 designation indicates that the chromatic aberration correction is equal to or better than a classic achromat with 30% longer focal length (ie.better than 180 x F8 x 1.3 = 1872mm, or F10.4).
The objective is of a high quality and was purchased directly from iStar Optical in Arizona, USA in 2020. This was one of their prototype D180/R30 objectives and is a heavier build than the production unit at 7.9Kg with mounting cell.
The lens is excellent optically and I have a copy of the iStar test results which can be provided on request. Ales Krivanek, the iStar CEO had this to say..
"We do have that one last unit 180 F8 R30 in stock. it is heavy but we have just tested it and the image quality is very good. it is a great lens optically........."
also....
"Regarding the lens design, we use heavy flint to achieve the R30 level of correction. We do not share exact glass types or the actual design. We are the only ones in the industry offering these cross-over anastigmats and our design is a trade secret."
"All R30 doublets are made with short flints and special, more expensive crowns than any classic Achromat."
".......R30 anastigmatic doublets offer a substantially smaller spot size, greatly improved resolution and amount of chromatic aberration comparable to a classic system of 1.30 x longer focal length....."
The telescope tube design is for a riveted sheet metal construction with machined solid aluminium back plate and front mounting ring. The back plate has an M100x1.5 female thread to take a MoonLite-iStar style focuser adapter, and the front mounting ring has three tapped holes to take M5 bolts through the objective mounting cell. Tapped holes in the lens cell allow three adjustment screws to bear up against the mounting ring.
I have completed the dew shield using this design and have tooling for assembling the main tube, however I have not had the main tube profiles laser cut. All SolidWorks models and drawings will be provided including profiles, DXFs and PDFs. I am happy to provide some of these on request and prior to sale.
The purchaser may choose to connect the back plate and front mounting ring in a simpler manner by using a rolled aluminium tube ID=231 and Length=1090. Thickness say 2.5mm.
Extensive construction notes and photos here:-
https://istarscopeclub.proboards.com/thread/723/istar-180-r30-build-oz
Included in sale........
iStar D180 F8-R30 Objective in mounting cell
Aluminium lens cap for same, painted white with brass handle.
Machined aluminium backplate (M100x1.5 female thread)
Machined aluminium front mounting ring (tapped for objective cell)
Sheet aluminium dew shield
Various sealed pop rivets for main tube assembly
Finderscope mounting bracket x 2
Finderscope mounting bracket curved backing plate x 2 (fits inside flange of backplate)
Ø 235 tube mounting rings x 2
Losmandy Dovetail, length 14"
Large Format 2.5" Moonlite Focuser with manual focus and 10:1 (heavy duty tri-knob reduction unit)
iStar style adapters (M100x1.5 male) x 2 (only one needed, includes a spare)
2.5" spacer x 2
1-1/4" compression ring
2" compression ring.
Assembly tooling for assembling the sheet metal tubes. (see link to project above)
This has cost me around $5000 plus $2000 worth of 5-axis machining, asking $4500
Pickup preferred from Frankston South.
thanks for looking!
...will consider trade/part trade for bullion coins
Graham