My stupid lens question.

[Ole Tjugen]

There are two basic concepts which I can't see have been defined in this thread:

"Angle of View" depends on the focal length of the lens and the size of the film. All 100mm lenses will give the same AoV on a 4x5" film - provided that they have enough coverage that they can actually give an image all the way across the film. And that brings us to:

"Angle of Coverage" depends only on the lens construction (and the f-stop). It defines the total angle where the lens will give a good definition on film, regardless of the film format. Common lens types have different AoC: Telephoto lenses can have around 30 degrees, Tessars typically a little less than 60 degrees, Plasmats up to 70, and true wide angle lenses around 100 degrees. Sometimes more, sometimes less.

[Nick_3536]

"That sounds like marketing talk to me"

Why? It's a quote from a book. The author isn't selling lenses.

No but it sounds like he is explaining how the lens companies label things.

So what's your point, that there's no such thing as a wide angle lens because different people have different ideas as to what constitutes an acceptable image circle? Or that there's no such thing as a wide angle lens because the angle of view varies with the film format? Or that Stroebel doesn't know what he's talking about?

My point is a wide angle lens depends on what you do with it. Not on it's coverage. Assuming the lens covers the format then any excess coverage isn't part of the question.

A wide angle lens has a wider view.

[Ole Tjugen]

...I've read "multiply your favourite 35mm lens by 3 and that's the focal length you need for 4x5"

I use a 35mm as my "normal" lens ... so that seems to indicate a 105mm. But then this issue of coverage and movement comes up ...

That "multiplication factor" should be taken with a pinch of salt.
First of all, the aspect ratios are very different between the narrow 35mm frame and the more square 4x5". Second, the "normal" focal length is often defined as "equal to the film diagonal", which means that 35mm has a "normal focal length" of 43mm, not 50mm. 4x5" film is about 153mm, which is about what many consider as "normal" - at least the lens manufacturers seem to favor that length. 150/43 is about 3.5, not 3.

By using that number you end up with a focal length of around 120mm to get about the same as a 35mm lens on 35mm film. A 100mm lens will give something similar to 28mm on 35mm, which I'm sure you will agree is a whole lot wider!

In the 120mm range there are a lot of lenses which will cover 4x5" with room for movements, and moving the upper limit to 135mm really expands the possibilities.

[Brian Ellis]

No but it sounds like he is explaining how the lens companies label things.



My point is a wide angle lens depends on what you do with it. Not on it's coverage. Assuming the lens covers the format then any excess coverage isn't part of the question.

A wide angle lens has a wider view.

[e. a. smith]

Wow ... thanks for all the responses ...

I'm not REALLY stupid but .....

I checked out the link to the lens chart and don't understand some of the specs ... references to movements for portrait being one of them ... I take it that a lens is not just a lens in terms of movement ... that some sorts of photography require more movement than other types ... but why the diferent specs for portrait movement

The OTHER thing I'm stumbling with is bellows extension in longer lenses. I've owned 6 Mamiyas with focusing bellows and the bellows is contracted for distance focus and expanded for closer focus ... much like adding extension tubes in 35mm .... but several posters mentioned needing longer bellows extensions to focus longer lenses . That seems to me to be backwards ... what am not understanding here ...

Several posters suggested knowing my camera and the type of photography I intend using it for would help with lens recomendations .... I have been given a Linhof Color 45s by one of my customers and an Omega D5 Variable by another ... plus three great Schnieder EL lenses ...

This camera is strictly for me ... any commercial work I do now is digital ... I want to do B+W studio portraits and figure studies ... so I need X-sync ... and I want to do outdoor work that would not be landscapes as much as isolating elements in a scene ...

My 35 kit is normally 24 ... 35... and either85, 90 or 105 depending upon camera brand.
I seldom use "normal" lenses ...

From what I've read in the posts I'm thinking 120-125 and a 210. Would a shorter lens that converts to 300-315 be a good idea? I assume that any softness in the converted lens would be compensated for by neg size and I use 600 WS Photogenics
so smaller aperature shouldn't be a problem.

I guess as soon as I get lenses I'll invest in the recommended books.

Again ... thanks for all the great input.

E.A. Smith
Chaffeys Lock Ontario Canada

[Ole Tjugen]

To begin from the top:

"Portrait" and "landscape" are not only possible subjects, but also names for vertical and horizontal orientation respectively. Since portraits are often printed with the vertical side a little longer than the horizontal, this is called "portrait orientation". Since the image area of the film is not square, there is a little difference in how much movements can be applied in horizontal and vertical orientation.

Unlike most lenses for smaller formats, LF lenses do not have a fixed "flange focal distance". On a 35mm camera it's easy - a 25mm lens, a 50mm lens and a 100mm lens are all attached to the camera at the same point, and will focus at infinity with the focus mechanism turned all the way in.
LF lenses are a lot simpler - there is no fixed distance at all! So with a 90mm lens you need to extend the lens enough to put the lens node at 90mm from the film plane to focus at infinity; with a 150mm lens you need 150mm, and so on. If you want to use a lens with longer focal length than 400mm on the Linhof Color, you will need a telephoto lens. That does not merely mean "long focal length"; it really means that the node is somewhere outside the lens itself - right out in open air in front of the lens. That again means that the mounting flange is quite far behind the node, so you need less bellows length.

Most shutters made after WWII have X-sync. Don't worry about that unless you want to shoot antiques.

A "shorter lens that converts to 300-315" would be a 180mm f:5.6 Symmar. That converts to a 315mm f:12 by removing the front cell. However it requires quite a bit more extension than 315mm to focus that thing at infinity! Taking portraits with that on the 40cm bellows of the Linhof could well be difficult. Apart from that little "niggle", I'm a great fan of convertible lenses in general and Symmars in particular.

Having done quite a bit of portrait photography earlier (admittedly with MF), I wouldn't like to be sitting for a portrait with a photographer who blasts off a strong enough flash to expose at f:32. If you are sure you have enough light, I recommend you test them out from the "receiving end" too.

[e. a. smith]

Ole ....

Thanks so much ... I think I'm starting to grasp this a bit .... maybe I AM stupid ... I should have figured out that landscape and portrait reffered to the film orientation ...

And that's a good point about flashes ... I normally shoot studio stuff at f-8 so I assumed that a converable lens at f-12 would be about a stop less light ... I hadn't considered closing down for sharpness. My bellows extends to about 13 inches ... would that let me focus a 300+ convertable lens at say 10-12 feet? I sort of like the idea of one lens doing two jobs ...

Thanks

E. A. Smith

[Ole Tjugen]

A 300mm converted lens won't even focus at infinity with 13 inches of bellows, much less 10-12 feet!

The document HERE shows the necessary extension with converted Symmars - other convertibles are very, very similar. To focus a 315mm f:12 rear half of a 180 Symmar at 3m (10 feet), you need 48cm bellows extension...

I like "dual-purpose" lenses myself, and use 180, 210, 240 and 300mm convertible SYmmar lenses. I have even used a 120mm Angulon as "convertible", when I found I needed a 200mm lens and only had short lenses at hand!

[Carsten Wolff]

You could of course just try it out stopped down.... But I agree with Ole, Kirk and Mark and others. You're likely to be unhappy with the coverage. I'd sell the 100mm Zeiss Tessar and use the money to perhaps get a later model 90mm Angulon (non Super- if you want to save weight and money) This a harmless looking, but fine lens (with reasonable, but not spectacular extra cover). Any other modern 90mm will do, too and have more coverage, (but also weigh a fair bit more; Congo being the exception perhaps).
Then get above mentioned 135 Symmar, or Symmar-S and if you still have money left, any 200, 210mm, or thereabouts (e.g. a Kodak Ektar) and you're set! 300, esp. convertible doesn't sound as if it's gonna work either; you'll be fine with the above spread anyway.

[Alan Davenport]

"The 150mm Super Symmar XL has far more coverage than normal lenses of the same focal length.

I love these threads where everyone argues about the definitions of technical terms; they almost invariably end with the responders arguing semantics instead of responding to the original question.

I don't know who wrote the book (quoted earlier) but there's another -- "normal lens" -- which is of course defined by the film format and has no focal length until defined by the film. It appears the book's author incorrectly used "normal lens" to refer to some type of lens construction.

It's probably more appropriate to refer to lenses as short, long or normal lenses, rather than using terms such as wide angle, which term can obviously be applied in various ways, not all of them technically correct.

e.a., the 100mm Tessar was probably made for use with medium formats, like 2¼x3¼. It might possibly (just barely) cover 4x5 when stopped down, but it may not allow any movements and might be soft in the corners. A recessed board won't improve the lens coverage issue; all a recessed board does is reduce the amount that the bellows has to be compressed with short lenses.

You can buy a 90mm f/8 Super Angulon for around $300 these days, which will be sharp to the corners and offer lots of movements. A 90mm lens, on 4x5 film, is sort of equivalent to a 28 on 35mm film, or even a 24, depending on who you talk to; comparing lenses on formats with different aspect ratios is at best imprecise.