Posts Made By: Kevin Barker

Simon
I have seen a pair of the latest version. I have not looked through them though.

I think the T* coatings are very good in fact they are a big breakthrough over earlier Zeiss coatings.

I have also read on a cloudy nights review by Markus Ludes a few years ago that the older versions has semi apochromatic air spaced objectives. The newer version also have air spaced objecttives and have eyepieces with longer eye relief and slightly inferior colour correction.

So my guess is the latest will be significantly brighter have a nicer eye relief and they will suffer from slightly more chromatic aberration when compered to earlier versions.

having said that I bet the views are superb and how could a 15 X pair have an issue with colour correction??

Just a thought!!

I bet they are lovely, I wish I had insisted on a look through them. I trialed the 7X50 T* a few years back and they were wonderful especially when using them in daylight. The T* is a much better coating than the coating in my 1970's 7X50B.

Kevin Barker

David, Michael

I once asked and received an answer from A Dr Wimmer a Zeiss employee on this exact question. I have long since lost his reply.

The answer I recall was about 500 APQ's in total

140 were APQ 130/1000, 80 were APQ 100/640, I am sure he quoted these numbers.

The number of APQ 150/1500 was either 40 or 80 ?? Most likely 40.

The number of APQ 100/1000 was either 200 or 250?? most probably the 200 number.

One or two other APQ's were also fabricated from memory although I cannot recall if they were 110/750, 110/840 but he did not mention 80/500 size. He mentioned a APQ 200/1600 designed

He also mentioned one or two prototypes 100/1000 that were AQ and AP designs were made possibly when the APQ's were being designed. Triplet AQ had ZK2, KzF2 and Bak2 glass, and doublet AP semi apo with KzF2 and BK7 glass and an apo with CaF2 and BaK2 glass.

APQ's were designed with two variants BaK2/CaF2/K11 and ZK2/CaF2/ZK2. I believe the first is the only one fabricated. ??Who knows, perhaps some of the early APQ's were the other design.

I also had an APQ 100/1000 which was uncoated and truly wonderful. A perfect telescope. I sold it to fund it's big brother 130/1000 which is also a GEM.

best wishes

Kevin Barker
Auckland, New Zealand

Another view of the "Barkonian"
OTA is 18 cm X18 cm X73 cm. It has a mass of 4.5 kg approx.

50 mm eliptical Secondary is mounted on a 40 mm stalk of timber. Antares helical finder. lens is a 127/830

Works great I pushed it to 133 X last night on the moon and the images are very crisp.

Oddly CA seems quite low.

It is designed to be grab and go. The edge of the white Optical Box Assembly acts as a good finder.

Kevin barker

Another view of the "Barkonian"
OTA is 18 cm X18 cm X73 cm. It has a mass of 4.5 kg approx.

50 mm eliptical Secondary is mounted on a 40 mm stalk of timber. Antares helical finder. lens is a 127/830

Works great I pushed it to 133 X last night on the moon and the images are very crisp.

Oddly CA seems quite low.
Design follows the KISS principle "Keep It Simple Stupid"

It is designed to be grab and go. The edge of the white Optical Box Assembly acts as a finder.

Kevin Barker

A few finishing touches

Phil
I look forward to looking through this scope.

The 130X to split Antares sounds promising. Another good test is Gamma Centauri in good seeing.t should be a peanut in this lens if the spherical figure is good enough.

I am glad you were able to sort out the Newton's rings scenario. I read somewhere (possibly Cloudy nights) that earlier versions of the 127/1200 has a rubber ring between the crown and flint elements.
In theory a 5 inch f 9.4 is similar to a 6 inch f-12 if you crunch the numbers. The 6 inch f-12 you mention was the one you wrote about on CN which I owned. It was too big for my Zeiss 1b mount but I remember the open cluster images were outstanding.

I reckon 5 inches of aperture is optimum in New Zealand conditions.

Kevin

The attached Jpeg shows the secondary arrangement and the objective, note the tooth picks!!!

Secondary Stalk arrangement and objective.

Thanks Jon
I had some old red oil based paint lying around.

the white is to prevent folks walking into it.

That has happened to me before at a star party

Kevin

Dark Sky, latitude 36 South...seeing exquisite!!!
The jewel box NGC 4755, perfect seeing, nagler 13 mm T6, Zeiss APQ 130/1000.

Lovely!!! I have shown folks who are new to stargazing and they usually saw ...wow!!!

Kevin B