What lens are you missing?

[GPS]

Calm down Bruce. If I insulted people (you?) in my first phrase show where did I do so. If not why are you so upset?
If for you bag bellows doesn't mean freedom of movements that normal bellows cannot give for the given lens, it's fine. It means you don't need bag bellows. Yet you wanted to have freedom from it... hmm.
If you want to have "freedom from having the weight of the mechanism to make changing possible" buy the Arca Swiss. The mechanism to change bellows weighs about 1 g and is as big as a small button battery... You won't get greater freedom in this in any other camera.
Once again, if you want to have freedom from owning bag bellows and carrying it around it's fine with me. To buy this freedom by carrying a much heavier lens, less optically good - if it is fine with you, I couldn't care less. Logical it is not. Just say to an optical constructor that you need a retro-focus LF lens because that 1g button on the standard frame is too much for you to carry - notice his reaction then but don't be angry with him after his answer, for goodness sake...

When it comes to the retro-focus lens optical design notice the fact that it is the rear positive lens element that makes the front negative wide angle assembly being a retro-focus design (by extending the back focal length). Without it it would just be a true wide angle lens.

Now have a good day and forget the idea of "insulting ideas" - nobody can insult an idea, fortunately... Ideas would otherwise be pissed off and wouldn't come to us, would they?? ;-))

[GPS]

But the difference between a retrofocus lens and a "normal" lens is the positive rear cell. Symmetrical wide angle lenses can have negative front elements too, which improve illumination across the field. THAT was first described by Rusinov/Roosinov in 1946. Reverse telephoto lenses (AKA retrofocus) have been around since 1929, the Angenieux Retrofocus lens was merely the first one to be widely used for photography.

Don't criticise others for not understanding if you don't understand what they are referring to.

Personally, I wouldn't mind a new series of small compact wide angle lenses with matched center filters - either Angulon or double-Gauss design.

Thanks a lot Ole, you made my day...

[Bruce Watson]

But the difference between a retrofocus lens and a "normal" lens is the positive rear cell. Symmetrical wide angle lenses can have negative front elements too, which improve illumination across the field. THAT was first described by Rusinov/Roosinov in 1946. Reverse telephoto lenses (AKA retrofocus) have been around since 1929, the Angenieux Retrofocus lens was merely the first one to be widely used for photography.

Don't criticize others for not understanding if you don't understand what they are referring to.

Amazing. What is it today? Since you insist:

Rudolf Kingslake, one of the acknowledged greats of lens design, disagrees with you. According to Kingslake in A History of the Photographic Lens "The combination of a large negative lens in front of an ordinary lens constitutes a Reversed Telephoto objective." Kinglake is on my side here. Sorry.

Kingslake goes on to say "It should be remarked that the large negative element in front of a wide-angle lens of this type has the effect of increasing the illumination at the outer parts of the image." What more needs said?

The Angenieux Retrofocus lenses were the first ones widely used for still photography (as I said in an earlier post). The earliest actual retrofocus production lens I can find is a 1931 cine lens from Taylor, Taylor, and Hobson (TTH later became Cooke IIRC). But cine lenses aren't as relevant to this forum as the still camera lenses, which is why I cited the more relevant Angenieux work.

[Bruce Watson]

When it comes to the retro-focus lens optical design notice the fact that it is the rear positive lens element that makes the front negative wide angle assembly being a retro-focus design (by extending the back focal length). Without it it would just be a true wide angle lens.

Kingslake disagrees. I'll take his side.

[Arthur Nichols]

The lens that I am missing is the one that has made me a recognized and affluent artist

[Ole Tjugen]

...
Rudolf Kingslake, one of the acknowledged greats of lens design, disagrees with you. According to Kingslake in A History of the Photographic Lens "The combination of a large negative lens in front of an ordinary lens constitutes a Reversed Telephoto objective." Kinglake is on my side here. Sorry.
...

Funny - I used the same book to find my references!

But you ought to read the whole book, where you would find just about everything in my post.

A reversed telephoto lens has a negative group in front of a positive group, just the opposite of a telephoto lens which has a positive group in front of a negative group. But the large negative lens having the effect of evening out the illumination is mentioned under "III. The Biogon Type" (p. 150), see also "field flattener, p. 45. The chapter entitle "The Advantages of Symmetry", ch. 4.I, is also relevant to this discussion.

My page numbers refer to the edition printed by Academic Press.

[Gene McCluney]

I am a fan of the Fujinon compact lenses. What I would really like is for Fujinon to produce a 900mm lens in the compact range. They are relatively small, great image circle, suitable for 4x5 to ULF, great performers, and inexpensive – and I’m not a big fan of telephotos.

But the question would be: would you have enough bellows to "use" a 900mm on a field camera? Particularly a prime and not a telephoto.

[GPS]

Kingslake disagrees. I'll take his side.

By all means, do so. Just - as someone very correctly said - read the whole book...

[Dave_B]

It may be my imagination but it seems to me that the usually congenial nature of this forum has recently been replaced with a lot of generally unpleasant behavior. When even kindly old souls like Jim Galli get attacked (on another thread), something is definitely out of whack. It must the economy.....

[GPS]

...
For instance I myself find there is a dearth of really long lenses on the market. I am a fan of the Fujinon compact lenses. What I would really like is for Fujinon to produce a 900mm lens in the compact range. They are relatively small, great image circle, suitable for 4x5 to ULF, great performers, and inexpensive – and I’m not a big fan of telephotos.

It would be great if others would nominate what lenses they would like to see from our manufacturers, with image circles, specifications, etc. Lenses that you would really like to have in your lens arsenal?

Having said that the 900mm Fujinon C would probably not be too much of compact I have to say that I agree with you. Me too I would love to have the long non true tele lenses. The super long Dagors series comes to my mind. I even know how to go around the long bellows problem but what I dislike is the lack of shutters in these lenses. I scorn Packard shutters, obviously. That only stops me from going after the super long lenses...