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Zeiss 8x30B Oberkochen / 8x30 BGAT*P and 8x20 BGAT*P Dialyt's (1 Viewer)

james holdsworth

Consulting Biologist
I recently acquired three new Zeiss bins, at least new to me. Here is a brief review of all three....

Zeiss 8x30B Oberkochen - near mint, almost unmarked, this seems a late version [serial #935XXX] marked ''made in west germany'' and lug attachments on the body rather than the hinge.

Jewel-like build quality, absolutely beautiful fit and finish and appearance, tiny for a 8x30, nestles nicely in the palm of your hand.

The view is superb for an older porro. Wonderful sharpness, good contrast, fairly wide field, only a trace of warmth to the colour cast, great 3D view and sense of depth. Big sweetspot with very good edges. Transmission [as would be expected] isn't great, probably in the 75-80% range, but the image is gorgeous in most lighting conditions. Almost no CA. Immensely satisfying to look through, handle and look at - could very well become one of my all-time favourites.

I'm not likely to lug these jewels into the field much but they are very nice just sitting on a shelf over my desk, where I can look at their Zeiss-ness ;]

Zeiss 8x30 BGAT*P Dialyt - I have owned a non P of this model for awhile and dismissed the whole series as ''pretty average'' based on this non P. So, trading up to this P version was a revelation, as this model doesn't seem to get much love. This version seems a late issue as well, with coatings that have an FL-like magenta hue.

To me, the view is on par with my 7x42 BGAT*P - wonderfully sharp, contrasty with a huge sweetspot and very minimal edge softness, nice wide field and minimal distortion. Head-to-head, the 8x30 appeared a hair sharper and a tad more contrasty than the 7x42 - maybe due to newer coatings. Also appeared more colour neutral [coolish] than the slightly warm 7x42. Transmission seems very good, and would look to be close to 90%. Almost zero CA [a big problem for me], even at the edge of the field - equalling my FL and surpassing lots of other current alphas in this regard. Lower lateral colour than the FL. The P version is such a jump up from the non P that they hardly seem the same model.

I was in the market for a good 8x32 for fieldwork, and was looking at FL's but this 8x30 is so good I may just have found my answer.

Zeiss 8x20 BGAT*P Dialyt - I also owned a non P of this model and was completely underwhelmed with its performance - tons of distortion, tiny sweetspot, dim and pretty much undeserving of the Zeiss name. I kept it only for its collectability. The P version seems quite rare - I have only ever seen two for sale on the bay and elsewhere.

The P is loads better, although I must admit to hating most every compact I have ever tried. Much bigger sweetspot, flatter field, brighter and sharper - better in most every way. Still, this bin is a boutique version, and is most unlikely to find their way into the field for serious birding. Seems a great bin for the pocket, for travel or fishing or the like.

Anyway, thought I would share my thoughts on these three.....
 
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Pinewood

New York correspondent
United States
Hello James,

Do you have any idea of the date of manufacture of the 8x30B Porro? Some German binoculars, made around 1951 had trouble with aging Canadian Balsam, giving the view a warmish tone. My Leitz Binuxit, 8x30, of that year suffers from that. Another one, made in 1953, has no such problem.

The 8x30 BGAT has problems when aimed in the direction of the sun. Have you noticed the glare?

Happy bird watching,
Arthur Pinewood :hi:
 

james holdsworth

Consulting Biologist
Hello James,

Do you have any idea of the date of manufacture of the 8x30B Porro? Some German binoculars, made around 1951 had trouble with aging Canadian Balsam, giving the view a warmish tone. My Leitz Binuxit, 8x30, of that year suffers from that. Another one, made in 1953, has no such problem.

The 8x30 BGAT has problems when aimed in the direction of the sun. Have you noticed the glare?

Happy bird watching,
Arthur Pinewood :hi:


The porro I think is late run, maybe late 70's. I need to check with Gary or Henry about that. I think only the latest examples were labelled ''made in west germany.''

The 8x30 BGAT does suffer from a bit of washout on the lower edge of the FOV when viewing near the sun, but it is pretty unobtrusive. It should prove to be a very capable woodland birder, with my 10 FL used for open spaces and most distant viewing.
 

henry link

Well-known member
James,

The serial number on your 8x30B Porro suggests it may be one of the later 60º versions made between 1968 and 1978. As I recall the body is slightly different from the older 50º version. I believe the objective tubes are a little longer and the eyepiece housings a little shorter on the later model.

Yes, P coating made all the difference and I'm not surprised to hear that there's less lateral color in the old 8x30 BGAT*P than in the FL, since it used a cemented doublet objective. In my experience that kind of simple objective never causes the excessive lateral color seen in so many later roof prism designs from the 90's that use complex objectives with wide air spaces to achieve internal focus. IMO, ED glass in binoculars like the FL's has really only partially corrected a totally self-inflicted problem caused by that design choice.
 

Pinewood

New York correspondent
United States
The porro I think is late run, maybe late 70's. I need to check with Gary or Henry about that. I think only the latest examples were labelled ''made in west germany.''

The 8x30 BGAT does suffer from a bit of washout on the lower edge of the FOV when viewing near the sun, but it is pretty unobtrusive. It should prove to be a very capable woodland birder, with my 10 FL used for open spaces and most distant viewing.

Hello James,

The 8x30 and 10x sound like a good combination.

Happy bird watching,
Arthur Pinewood :scribe:
 

james holdsworth

Consulting Biologist
James,

The serial number on your 8x30B Porro suggests it may be one of the later 60º versions made between 1968 and 1978. As I recall the body is slightly different from the older 50º version. I believe the objective tubes are a little longer and the eyepiece housings a little shorter on the later model.

Yes, P coating made all the difference and I'm not surprised to hear that there's less lateral color in the old 8x30 BGAT*P than in the FL, since it used a cemented doublet objective. In my experience that kind of simple objective never causes the excessive lateral color seen in so many later roof prism designs from the 90's that use complex objectives with wide air spaces to achieve internal focus. IMO, ED glass in binoculars like the FL's has really only partially corrected a totally self-inflicted problem caused by that design choice.

Thanks Henry. I did compare my 8x30B porro to another B, lower serial # version labelled ''made in germany'' and mine did have a wider field. I'm not sure if either version is multi-coated though - looking at the oculars and objectives, some elements appear entirely uncoated, reflecting quite white light.
 

Troubador

Moderator
Staff member
Supporter
Hi James

What lovely acquisitions.

Does your 8x20 have a conventional focusing wheel or is it one with the 'telephone dial' focuser located concentrically around the logo/model name?


Lee
 

normjackson

Well-known member
James,
The serial number on your 8x30B Porro suggests it may be one of the later 60º versions made between 1968 and 1978. As I recall the body is slightly different from the older 50º version. I believe the objective tubes are a little longer and the eyepiece housings a little shorter on the later model.
Eyecandy here :
http://web.archive.org/web/20070805080453/http://binofan.home.att.net/z8x30b.htm

http://www.binocularsexplained.com/2012/01/carl-zeiss-west-german-binoculars-and.html
 

chartwell99

Well-known member
I have, at different times, owned all of these binoculars and agree with your comments. My 8 x 30B Oberkochen, unfortunately, suffered from a distinctly yellow image, probably due to the dreaded aging Canada balsam problem. It also suffered from a stiff focuser, which, thanks to its US lifetime transferable warranty, Zeiss willingly fixed with a thorough cleaning and lubrication.

The best of the bunch in my view (which I now regret selling) is the 8 x 30 P* Dialyt (marketed at the end of its run as the "Classic"). It was, sadly, overshadowed by its 10 x 40B P* Dialyt sibling, which I still own. The 10 x 40B is admittedly dated by its lack of close focus capability but not by its brilliant, wide field images or exceptional handling ease.
 

PHA

Well-known member
Hello James,

I agree with you about the 8x20 BGAT P*. Central focus. I had one for a few years. Mine (I understand all the P* made of this model) had only the P* but not the T*...
The built quality seemed very good but the optics were horrible!!! Exactly as you said, the so called sweet spot was very small and the view extremely unconfortable!! Was a pitty...I liked the size and the mechanical design. I trade it for other things, I don´t remember. Perhaps its collector`s value is high because it was made for a short time.

PHA
 

Troubador

Moderator
Staff member
Supporter
Hi James

Regarding compact pocket bins. I struggled with these and even had a Leica 8x20 BCA in my cars glove compartment for years that I never came to grips with.

However I can heartily recommend the current Victory Compact 8x20B. I have been able to use this extensively at home and on holiday. Its no substitute for a full size bin but its a fantastic stand-by near a window or in your pocket on the way to the shops. I have been full of my bigger purchases this year (FL 32 and HT 42) but the little Compact has established its own territory.

By the way it may superficially look like a Design Selection unit with its assymetric body but it is built very differently with a metal chassis and central dioptre adjustment.

Lee
 

Robert Wallace

Well-known member
Hello James

Congratulations on purchasing your Zeiss 8x30B porro. I obtained a pair a few years ago 510038 with the thin leather lanyard attached to the centre hinge. I was pleased to be able to replace the rubber eyecups as the previous owner had used them folded down.
They are a very elegant binocular which I use for my BTO Garden Birdwatch observations from the dining room window. I would say the optical quality of mine is about the same as my 10x40BGT dialyts (1985).
I guess my 8x30s are late 60s, Gary?
Did I read somewhere that the Nikon 8x30s (version before the 8x30 E11) were based on this design or did I imagine it?
 

james holdsworth

Consulting Biologist
The 8x30 Porro was manufactured in 1972.

Gary.


Thanks Gary. All the more impressive from a 40 year old bin!

Troub., my 8x20 Dialyt looks like a miniature version of the Classic series, at least the prism housing, and has a typical, top-end focusser. I have tried the Victory compact and it was the best [of that type] I have seen, although give me full-size every time.
 

Renze de Vries

Well-known member
James et al,

Thanks for posting this. Especially with respect to the Zeiss 8x30B porro every snippet of information is welcome.

The problem with this model is that Zeiss issued two types, differing in field of view. As not too many people have seen both types, it's not widely known that they differ in appearance as well. Henry is correct, the differences are in the objective tubes' lenght and the oculars' height and shape. Here's a picture of both types, with the 7.5 deg. (130/1000m) on the left.

Another issue is how to distinguish the two types by serial number and years of manufacturing. Over the years I have collected data of the 8x30B, mostly from eBay, and if I combine these data with the information supplied by Gary (and a couple of years ago by his collegue 'mak' (sorry 'mak' I lost our correspondence and so, your name)) we're able to draw some conclusions.

1. The serial numbers for the 6.5 deg. type (110/1000m) I've collected, go from 507535 to 798330. Now let's try to add years of manufacturing to these numbers. As it is highly probable that the low number matches the year the 8x30B was put to the market, 1958, and the high number corresponds with 1971 (source: Zeiss), we can draw the conclusion that the 6.5 deg. type was made from 1958 through 1971
2. The serial numbers for the 7.5 deg. type I've collected are in the range from 934319 to 1357121. As Gary has supplied us with the year of manufacturing for James' specimen (935xxx = 1972) and the high serial number can be dated (source: Zeiss) to 1975, the conclusion is that the 7.5 deg. type came in production in 1971 or 1972 while production was stopped in 1975.
3. This means that the manufacturing dates for the two types of Zeiss 8x30B porro, usually quoted from http://home.europa.com/~telscope/zeissbn2.txt (1958-1978 with the type change after 1968) must be incorrect. In the way that production of the first type must have been several years longer (1958-1971) and the second type several years shorter (1971/2-1975). It always puzzled me why the second type 8x30B has been so much rarer than the first type, but with these new figures I feel there's an explanation.
4. Note that there's a remarkable gap in my serial numbers between the last 6.5 deg. and the first 7.5 deg. type recorded: no serial numbers starting with 8. I think it's possible that Zeiss made a fresh start with their serial numbers for the 7.5 deg. type, i.e. from 900000 on.

Renze
 

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Renze de Vries

Well-known member
Zeiss 8x30 BGAT*P Dialyt - I have owned a non P of this model for awhile and dismissed the whole series as ''pretty average'' based on this non P. So, trading up to this P version was a revelation, as this model doesn't seem to get much love. This version seems a late issue as well, with coatings that have an FL-like magenta hue.

To me, the view is on par with my 7x42 BGAT*P - wonderfully sharp, contrasty with a huge sweetspot and very minimal edge softness, nice wide field and minimal distortion. Head-to-head, the 8x30 appeared a hair sharper and a tad more contrasty than the 7x42 - maybe due to newer coatings. Also appeared more colour neutral [coolish] than the slightly warm 7x42. Transmission seems very good, and would look to be close to 90%. Almost zero CA [a big problem for me], even at the edge of the field - equalling my FL and surpassing lots of other current alphas in this regard. Lower lateral colour than the FL. The P version is such a jump up from the non P that they hardly seem the same model.

I was in the market for a good 8x32 for fieldwork, and was looking at FL's but this 8x30 is so good I may just have found my answer.


James,

Well, an 8x30B T*P performing better than the large exit pupil 7x42 is a suprise, if not to say against all optical laws. But maybe you've found yourself a cherry?! A more appropriate comparison however would be to test the Dialyt against the Leica Trinovid 8x32 BA or BN. I think this hasn't been done regularly on BF, if at all, while it's well worth the effort since both models are still very usable and respected instruments.

Renze
 

John Dracon

John Dracon
James - If one likes to tinker, "breaking into" a West German Zeiss 8x30B porro binocular to clean the prisms is a revelation of its own kind. The craftsmanship is superb. The prism seats are so precise, that replacing them after cleaning (done with care of course) rarely affects collimation. The prisms themselves have a taper on the sides unlike most porro prisms.

Under the top and bottom lids you will find is a reusable neoprene gasket which is carefully formed to create an air tight seal. Neoprene, a synthetic rubber, was a DuPont invention in 1930, and seems to have great longevity.

Unfortunately, I've yet to find that particular Zeiss porro model which does not have a haze deposited on the prism faces, degrading the brightness of the image. But that is easily corrected with a clean micro weave cloth. Whether this is the result of contaminated air brought in via the bellows effect or some kind of gassification process relating to the neoprene gaskets or something else, I cannot say. The monoculars from that same design also show haze on the prisms.

Compared to other porro housings from other manufacturers, in terms of exterior and interior finishes, the Zeiss is tops. Now I'm going to venture an opinion and unquestionably provoke some controversy, viz., that Zeiss began abandoning the porro models (except for a few) in favor ot the roof models partially because of the the significant cost of casting the porro bodies. I'm not familiar with the process. It could be what is called the lost wax casting process. But it has to be labor intensive. The lens have to be mounted offset (objective to ocular), and the prism seats precisely cast, not to mention the top and bottom lid screw holes matching the fixed "nuts." Then both sides have to be hinged together with precision cast integral rings. I would like to see the jig(s) used in accomplishing that on a mass production basis.

Machining precision drawn tubes for roof prisms, both cutting and threading is a relatively easy process, but as we have seen, getting a focusing mechanism that is well timed and reliable and water proof, is another issue.

James, your Zeiss 8x30 B porros are real jewels and perfectly usable for a live time. Use the heck out of them.

John
 

james holdsworth

Consulting Biologist
Renze, John,

Based on the photo's, mine is the 7.5*

Maybe I'm just not looking hard enough, but a flashlight test shows the internals to be spotless and free of any hazing.

As to the 8x30 Dialyt being better optically than my 7x42 - well probably not in sum total. The 7 is brighter and a more pleasant, easier view - with less focus hunting. The 8 does seem a smidge sharper / more contrasty but [as mentioned] it may be newer coatings. My 7 is from about 1992 while the 8 is later - not really sure but it has the serial number 2482XXX in white paint on the focus knob and the bold Zeiss logo.
 

james holdsworth

Consulting Biologist
Here is a pic. of all three...pardon the quality as I re sized the photo well below what the system can take, I think.
 

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Troubador

Moderator
Staff member
Supporter
Here is a pic. of all three...pardon the quality as I re sized the photo well below what the system can take, I think.

James

Lovely pic and I realise now that I had somehow jumped to the conclusion that your 8x20 was a compact Z-folding model, not the 20mm little sister to your 8x30.

Despite my HT I am totally envious of your growing Dialyt family. Enjoy in good health.

Lee
 

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