World's best 75mm?

Hi all, I intend to invest in the upcoming Fotoman 6x9 camera. I know, I know, it is medium format, BUT, like the

ridiculously expensive Alpa series it uses large format lenses. That is why I'm asking you guys about this. I think my

first lens will be a 75mm lens. It will be a good allround focal length. I have been looking at the Rodenstock 75mm

f/4.5 Grandagon-N which seems like a very nice lens. But I would like to know from you guys, which, in your very

subjective opinion, is the world'sbest large format 75mm lens? I know that Fuji and Schneider manufacture 75mm

lenses as well, and Nikkor used to. So, and we're not talking value for money here, which is the very best 75mm

lens?

I hate to say it but I doubt that anyone can give you a definitive answer. Any modern 75mm lens from any of the following will do the job - Schneider, Rodenstock, Fuji, Nikon. If you plan on using it with a 6x9 then size and weight is probably more important - I've had some excellent results (on 6x12) with a Rodenstock 75mm f6.8 lens - nice and light and with a sensible filter thread (I think it was a 58mm). The benefits of a lens with a wider maximum aperture like the Nikon or Rodenstock 75mm f4.5 might be overkill as these come into their own when focussing on a ground glass screen - I have assumed that you plan on using the viewfinder with the Fotoman? I have been fortunate and have used a 75mm from Schneider (f5.6) and Rodenstock (f6.8) and currently use a Nikon (f4.5). Can't tell the difference in image quality between any of them - they are all stunning lenses!

The current Rodenstock 75mm f4.5.

You should check the product specifications and compare MTF, distortion and color curves so you can see which

performs best for what you will be shooting. However Paul made a partially correct statement:

" The benefits of a lens with a wider maximum aperture like the Nikon or Rodenstock 75mm f4.5 might be overkill as

these come into their own when focussing on a ground glass screen"

 

Not exactly. Yes they are brighter on the groundglass but the faster lens from a manufacturer covers a larger circle of

illumination. This has several benefits:

 

1: You may want to go to a larger format in the future so the lens will still cover.

2: A larger circle means more movements are possible.

3: A larger circle means that the fall off inherent in wide angle lenses occurs further from the center of the image thus

reducing the need for a center filter for some people.

4: The faster lens is usually a better performer overall and more highly corrected.

 

The slower lens has a couple of benefits also.

 

It is smaller and lighter and cheaper.

 

Currently, and for the past several years, Rodenstock only makes the 75mm in a 4.5 version and it uses a very common

filter size, 67mm.

Thank you for your quick reactions. About what I intend to use it for, I will be using it for a variety of subjects. Sometimes on a tripod, sometimes handheld. I am going for the new small Fotoman because I can't afford the Alpa outfit, and I really want a very compact system. I could even imagine using it as a street camera, with ISO 400 B/W film. So I have considered that maybe instead of a 75mm I should get a 55mm and a 90mm or 100mm for different applications. I know Rodenstocks 55mm is supposed to be a fantastic lens. Oh yes, and primarily I would be using the viewfinder, I don't think I want to bother with a ground glass screen. If and when I do, I'll get a nice field camera. Looking forward to your input.

Bob has made some valid points, but, if the lens is only being used on 6x9 then I think the benefits are wasted - the Fotoman does not allow for movements so a large image circle is not needed, likewise the fall-off mentioned would not impact on a 6x9 frame and so negate the need for a centre filter. I am still of the opinion that the more highly corrected faster lens would only exhibit an improvement if the lens was used on a larger format with movements applied. For a medium format viewfinder/point and shoot camera I reckon the slower lenses would be a better and cheaper choice? Just my two cents/pennies :)

A bit of a hasty rethink!! I've just realised that you are talking about the new 6x9 from Fotoman! This camera will allow the use of a shift adapter making the use of a lens with a larger image circle preferable - disregard my advice and listen to Bob!

I think that the difference in coverage between the 75 mm f4.5 and f6.8 Grandagon-N lenses is insignificant for 6x9 cm. For a paper Rodenstock brochure that lists both lenses, back when the f6.8 was still made, on 6x9 with the f4.5 rise/shift of 59/49 mm is possible in landscape orientation. With the f6.8 lens, rise/shift of 55/45 mm is possible. With both lenses the amount of rise/shift possible with 6x9 is generous, and the difference is only 4 mm -- very small. Since you will sometimes use the camera handheld, my inclination would be to get the lighter lens, i.e., the f6.8. Unfortunately the brochure doesn't give the weights, so I don't know how large the weight difference is.

 

It is a common idea that lenses with larger coverages have more even illumination. From the optical principles that control illumination, there isn't any reason to believe this. Both of the the f4.5 and f6.8 lenses use the design of tilting pupils to improve illumination over the cosine to the fourth performance of the typical lens. The paper brochure has graphs of relative light fall-off for both of the 75 mm Grandagon-N lenses. The graphs clearly show that both do better than cosine to the fourth by f11. It is a difficult to compare the graphs since the scales are different, but the curves appear to be quite similar. Perhaps the f4.5 version has a very slight edge in evenness of illumination.

 

I think Paul has the answer -- almost all modern LF lenses are excellent. He is a unusual case of having used several of the focal length that you are asking about, and so answered from experience rather than speculation. There are unique lenses in each manufacturer's ine that don't have counterparts, but 75 mm isn't such a case. (If you want incredible coverage, there is Schneider's 72 mm Super-Angulon-XL, with an image circle of 226 mm, vs 195 mm for the 75 mm f4.5 Grandagon-N, 187 mm for the f6.8, but this lens is plain excessive for 6x9 cm.)

"It is a common idea that lenses with larger coverages have more even illumination. From the optical principles that control

illumination, there isn't any reason to believe this. "

 

I did not say it was more even. I said that the circle was larger on the faster lens. That means that the fall off is further

from the center on the faster lens.

 

Essentially fall off starts becoming a problem after the first 70% of the field of coverage. So larger circles of illumination

help to minimize the need for a CF but they do not eliminate the need for the CF.

"which, in your very subjective opinion,"

 

"I think that the difference in coverage between the 75 mm f4.5 and f6.8 Grandagon-N lenses is insignificant for 6x9 cm

 

In other words you have not actually used the two lenses in question?

Bob, re the coverage: I am going by Rodenstock's published figures -- is that too subjective? From the

Rodentstock brochure, the rise/shifts possible with the two lenses for 6x9 cm are around 2 inches (59/49 mm

rise/shift for f4.5, 55/45 mm for the f6.8) and only differ by 4 mm. I wanted to point out what the coverage

difference actually was. More coverage is better, but with plenty of coverage, the small gain of 4 mm may not

be worth the weight cost on a lens that will be used on a handheld camera. The original poster can make his

own decision. The decision might be different for a 4x5 photographer doing architecture -- they might value

every bit of coverage, plus they will be viewing through the lens.

 

You are reasserting the statement that I questioned: "I did not say it was more even. I said that the circle was

larger on the faster lens. That means that the fall off is further from the center on the faster lens."

Neither optical theory nor the graphs of relative light fall-off in the paper Rodenstock Product Information

brochure on the Apo-Grandagon and Grandagon-N support the idea that a lens with more coverage has a larger area

without falloff. (And how does that idea differ from saying that the illumination is more even?) (Of course,

different optical designs have different light falloff, so a Grandagon-N and a Sironar of the same focal length

will have different falloff performance.)

 

From the graphs in the Rodenstock brochure, at 70% radius for the 75 mm f4.5 Grandagon-N, which is 70.8 mm

(because the graph is for the lens focused slightly closer than infinity), the illumination is 37% of the center

illumination. The same mm radius for the f6.8 version, which is 73% radius in the units of the graph, the

illumination is 34% of the center illumination. So as well as I can measure these small graphs, the f4.5 model

at its 70% radius mm has better illumination than the f6.8 model at the same mm radius (its 73% radius) by

one-tenth of a stop.

Some photographers believe the classic Zeiss Biogon 75mm to be the finest lens made in that focal length for larger formats. They can be

found from time to time, and they usually cost thousands of dollars. They have a reputation for extreme sharpness and lack of distortion,

as do all Biogons. These lenses did not cover 4x5 that well, providing very little excess movements for that format, they were large and

heavy with a huge front element. I believe they were originally designed for military aerial photography and adapted (mounted in a shutter)

by many for general LF work.

 

Ken Rockwell has a brief opinion on this lens which you might find interesting: http://www.kenrockwell.com/tech/zeiss75biogon.htm

 

And there are lots of interesting comments archived on this lens on the Large Format Photography site.

 

However, I would agree with the others. The Rodenstock Grandagon 75 f/4.5 is an outstanding lens. I've had one for several years and it's a

very fine lens for general 4x5 photography with ample movements. And for your applications...the 6x9 format...any of the modern 75mm LF

lenses from Nikkor, Schneider or Fuji would be excellent.

Michael, the fall off is after the first 70% of the circle of illumination. That means that the lens with more coverage will have

a larger area that does not need the CF filter.

take my word if u came across Biogon 75 Grab it. but if your looking to have a quick solution Grandagon-N 75mm f/4.5 is the best choice, if u want to be Double sure buy one from Linhof or Sinar.

 

and dont take Ken's words or any others who never even seen a biogon 75 from close. I have both and both are master pieces of optic design. biogon outperforms in many aspects (mine is the last series so it has coating that earlier versions dont) the wieght is 1430gr with caps and it actually doesnt weigh a Ton cuz people easily accept Distagon 4/40 CFE which is 1130gr and it only covers 6x6 on hassy and the length is 15cm which again compared to 4/40 12.5cm its nothing for a 4x5" lens but Grandagon-n 75 4.5 weighs only 440gr and thats a Kilo difference to Biogon 75. for 6x9 there is a very nice option, Biogon 53mm it has all the benefits of Biogon design BUT its designed for 6x9 its smaller lighter & very robust the barrel is solid as a rock. GoodLuck