DanielOB
Member
- Joined
- Sep 30, 2007
- Messages
- 139
- Format
- 35mm
A long time, since Zeiss put on the internet “Top Secret”, I am looking to find some useful “test” for their macro lens ZF, just because of Cosina Japan involvement. All lens presentations are just digital shooting of the bricks and personal investment defence. People get that lens just with a hope to earn respect of other photogs. No useful comments on the lens. I got frustrated and blamed Zeiss all the time, on this forum, for lack of “photographic” data about the lens, finding that they just cannot improve over Nikkor 2.8/55 Micro AIS.
Finaly I took on myself to investigate that Germany/Japan coleboration.
So how lens manufacturing looks like?
1. Carl Zeiss designed the lens, means determined glass composition, production process (casting or grinding), glass dimensions, tolerances, and curvatures radii, glass grinding roughness, glass coating, focusing barrel material, machining roughness and tolerances, coating kind and process (e.g. anodizing or chrome), grease kind and maker, … Nothing is left to manufacturer to decide. All of these are recorded into technical documentation and handed to manufacturer.
2. When inspections of parts comes Zeiss is second to none. They make their own machinery for that purpose and so they know very well how to incorporate inspection accuracy of produced parts into design documentation.
3. When manufacturer receive the technical documentation they have to check what they need more than they already own to produce the lens and to assembly the same. This do not go through “believe me…”. The next step is shopping for missed machinery. Also some existing machines are replaced with Zeiss brand if Zeiss is concerned with its reliability. Simple all manufacturing lines are set the same way as it would in Germany.
4. People are trained to use new machines, they are also informed what Zeiss standard is and that they have to meet it.
5. There are parts of production where use of machines are not acceptable expensive and of low reliability, Example is looks of coating, small dents on focusing barrel, … In this case visual inspections is a must. Japanese people today are of highest industry culture and of highest reliability in the world, as is known to me.
Now I gave up, and headed to New York City into B&H. I got a new Zeiss F2/100 mm ZF for my Nikon F6.
6. My lens came with inspection or test certificate sheet filled by hand writing with a ball-pen.
- the lens serial number
- optical quality
- aperture
- cleanliness, optic
- cleanliness, barrel
- packing
Followed by signature of worker.
Cosina designed and made lenses in past on their own. They are not “pinpin” as many Nikon lenses are, simple because it was not intended to be (“pinpin” is Japanese word for being the best). Cosina has no reputation, experience nor history in design and making lenses, so and price was accordingly. In case of ZF lenses nothing is left to Cosina, except to pay bills for electricity, phone, … So why then and Nikon did not hand to Cosina to make F6 cameras? Too many machinery Cosina has to get to be able to produce and inspect it. Nikon already had many of them (from digital cameras lines) and so to Nikon is less expensive to make it themself, and even not so such high production volume is expected. The next reason is coincidence with all F-Nikons tradition.
I can conclude that should not be concern but advantage of “ZF made in Japan”. Is it Cosina or anyone else no difference. Manufacturer have to produce what Zeiss ask, period (however “made in China” is different for so many reasons).
And how about picture for you guys. No picture, for internet just cannot reproduce photograph even and close (scanner quality, its properties,…), than 72 dpi, …, to be able to judge about the lens.
I can say that I have extremely strict and rigorous standard for what is good lens to me.
To evaluate should this Zeiss lens slide into my photo bag among Leicas or not I have my list to check it
(the number is prop. importance 1 through 5 as highest importance degree)
OTICAL PROPERTIES
4 - Large max opening (for small DOF)
5 - Good blur all around (at low and high contrast edge, green area, in front and behind the focus plane
4 - Good acutance (“sharpness”)
4 - Good contrast reproduction at center and corners
5 - Good at max opening (F-number)
4 - Uniform MTF distribution between 5-10-20-40 lpm at all useful lens openings
5 - Rendering of finest texture and nuances, in shade and highlight (nuancing)
4 - No edge distortion
3 - No flare in the worst condition
4 - Flat field
5 - Lens elements made of glass (no plastic elements)
5 - Portrait lens (80 mm and like) eliminating small face imperfections
4 - Number of elements reasonable high (not too many)
4 - Good at close (say 1:8 reproduction ratio) as at far
MECHANICAL PROPERTIES
5 - Manufacturers reputation and history
5 - No play in focusing barrel
4 - Design elegance
4 - Focusing barrel with good resistance to turn, at all weather conditions
2 - No special filter size or mount
3 - Reasonable small and light
4 - Good sealing against dust penetration into optical assembly
3 - Grip for the finger on the turning barrel “sticky”
5 - No oil goes onto diaphragm blades
5 - Long life design and manufacturing
3 - All marks engraved rather than good paint
4 - Half stop aperture
4 - Long turning of the focusing barrel rather than short
5 - Metal rather than plastic design
Leica Apo-Macro-Elmarit 2.8/100 mm is one of the finest lens Leica ever made. Comparing this ZF lens to above Leica lens I can say they are not identical at the first view and NO VISIBLE DIFFERENCES in the photographs. I found F2 on ZF very useful especially with this long focal length to produce very nice blur (bokeh), one of the property of photography.
Zeiss F2/100 mm ZF pass nearly all criterions from above and could get overall score around the same as Leica Apo-Macro-Elmarit 2.8/100 mm. Real value of the ZF lens is not less than $5500 (ZF being F2 and Leica ($4000) being F2.8), but we pay only $1700 with Leica Uva filter 67 mm, plus tax fee.
Diaphragm shows irregular polygon rather than circle. I knew that “something is wrong” with diaphragm but it was not clear to me what. Before I paid for the lens I inspected it and had a look at diaphragm. When I saw what is the matter I smiled. I have the same thing on my Apo-Rodagon enlarging lens from Rodenstock, and never noticed any problem so far. So it was not a problem to me.
There is only one think I do not like. It is lens cover, but it is not on the lens quality list (above) so no big deal to me.
Note that all above is for the lens I talk about ONLY. You guys figure out for other ZF lenses you need for which I cannot say just any word.
This is my “sorry” to Zeiss for all my postings against that lens in past.
This is somehow long to read but the lens deserve and more.
Daniel OB
www.Leica-R.com
Finaly I took on myself to investigate that Germany/Japan coleboration.
So how lens manufacturing looks like?
1. Carl Zeiss designed the lens, means determined glass composition, production process (casting or grinding), glass dimensions, tolerances, and curvatures radii, glass grinding roughness, glass coating, focusing barrel material, machining roughness and tolerances, coating kind and process (e.g. anodizing or chrome), grease kind and maker, … Nothing is left to manufacturer to decide. All of these are recorded into technical documentation and handed to manufacturer.
2. When inspections of parts comes Zeiss is second to none. They make their own machinery for that purpose and so they know very well how to incorporate inspection accuracy of produced parts into design documentation.
3. When manufacturer receive the technical documentation they have to check what they need more than they already own to produce the lens and to assembly the same. This do not go through “believe me…”. The next step is shopping for missed machinery. Also some existing machines are replaced with Zeiss brand if Zeiss is concerned with its reliability. Simple all manufacturing lines are set the same way as it would in Germany.
4. People are trained to use new machines, they are also informed what Zeiss standard is and that they have to meet it.
5. There are parts of production where use of machines are not acceptable expensive and of low reliability, Example is looks of coating, small dents on focusing barrel, … In this case visual inspections is a must. Japanese people today are of highest industry culture and of highest reliability in the world, as is known to me.
Now I gave up, and headed to New York City into B&H. I got a new Zeiss F2/100 mm ZF for my Nikon F6.
6. My lens came with inspection or test certificate sheet filled by hand writing with a ball-pen.
- the lens serial number
- optical quality
- aperture
- cleanliness, optic
- cleanliness, barrel
- packing
Followed by signature of worker.
Cosina designed and made lenses in past on their own. They are not “pinpin” as many Nikon lenses are, simple because it was not intended to be (“pinpin” is Japanese word for being the best). Cosina has no reputation, experience nor history in design and making lenses, so and price was accordingly. In case of ZF lenses nothing is left to Cosina, except to pay bills for electricity, phone, … So why then and Nikon did not hand to Cosina to make F6 cameras? Too many machinery Cosina has to get to be able to produce and inspect it. Nikon already had many of them (from digital cameras lines) and so to Nikon is less expensive to make it themself, and even not so such high production volume is expected. The next reason is coincidence with all F-Nikons tradition.
I can conclude that should not be concern but advantage of “ZF made in Japan”. Is it Cosina or anyone else no difference. Manufacturer have to produce what Zeiss ask, period (however “made in China” is different for so many reasons).
And how about picture for you guys. No picture, for internet just cannot reproduce photograph even and close (scanner quality, its properties,…), than 72 dpi, …, to be able to judge about the lens.
I can say that I have extremely strict and rigorous standard for what is good lens to me.
To evaluate should this Zeiss lens slide into my photo bag among Leicas or not I have my list to check it
(the number is prop. importance 1 through 5 as highest importance degree)
OTICAL PROPERTIES
4 - Large max opening (for small DOF)
5 - Good blur all around (at low and high contrast edge, green area, in front and behind the focus plane
4 - Good acutance (“sharpness”)
4 - Good contrast reproduction at center and corners
5 - Good at max opening (F-number)
4 - Uniform MTF distribution between 5-10-20-40 lpm at all useful lens openings
5 - Rendering of finest texture and nuances, in shade and highlight (nuancing)
4 - No edge distortion
3 - No flare in the worst condition
4 - Flat field
5 - Lens elements made of glass (no plastic elements)
5 - Portrait lens (80 mm and like) eliminating small face imperfections
4 - Number of elements reasonable high (not too many)
4 - Good at close (say 1:8 reproduction ratio) as at far
MECHANICAL PROPERTIES
5 - Manufacturers reputation and history
5 - No play in focusing barrel
4 - Design elegance
4 - Focusing barrel with good resistance to turn, at all weather conditions
2 - No special filter size or mount
3 - Reasonable small and light
4 - Good sealing against dust penetration into optical assembly
3 - Grip for the finger on the turning barrel “sticky”
5 - No oil goes onto diaphragm blades
5 - Long life design and manufacturing
3 - All marks engraved rather than good paint
4 - Half stop aperture
4 - Long turning of the focusing barrel rather than short
5 - Metal rather than plastic design
Leica Apo-Macro-Elmarit 2.8/100 mm is one of the finest lens Leica ever made. Comparing this ZF lens to above Leica lens I can say they are not identical at the first view and NO VISIBLE DIFFERENCES in the photographs. I found F2 on ZF very useful especially with this long focal length to produce very nice blur (bokeh), one of the property of photography.
Zeiss F2/100 mm ZF pass nearly all criterions from above and could get overall score around the same as Leica Apo-Macro-Elmarit 2.8/100 mm. Real value of the ZF lens is not less than $5500 (ZF being F2 and Leica ($4000) being F2.8), but we pay only $1700 with Leica Uva filter 67 mm, plus tax fee.
Diaphragm shows irregular polygon rather than circle. I knew that “something is wrong” with diaphragm but it was not clear to me what. Before I paid for the lens I inspected it and had a look at diaphragm. When I saw what is the matter I smiled. I have the same thing on my Apo-Rodagon enlarging lens from Rodenstock, and never noticed any problem so far. So it was not a problem to me.
There is only one think I do not like. It is lens cover, but it is not on the lens quality list (above) so no big deal to me.
Note that all above is for the lens I talk about ONLY. You guys figure out for other ZF lenses you need for which I cannot say just any word.
This is my “sorry” to Zeiss for all my postings against that lens in past.
This is somehow long to read but the lens deserve and more.
Daniel OB
www.Leica-R.com
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