4x5 wide angle lens for 6x9greenspun.com : LUSENET : Large format photography : One Thread
Could someone explain if I use a 90mm wide angle lens like a Angulon for 4x5 to shoot 6x9 ,will it look more or less the same as a normal 90-100mm standard lens for 6x9(since I am just using the center portion of the lens)
-- Robert Choi (Audia6@connect.ab.ca), June 13, 1999
hi i hope i've understood your question correctly. the answer should be yes. after all, 90mm is 90mm and regardless of whether it's a WA from 4X5 or a normal for 6X9, it will produce the 'same' image. the wide angle design will give you more coverage/movements than a normal design lens. but i'm curious as to why you would go this route. do you need such extreme movements (100% or so extra coverage) for some particular reason? in fact, i wonder if your bellows/camera movements would even allow you to take advantage of that extra coverage. or am i missing the point of your question? dj
-- N Dhananjay (firstname.lastname@example.org), June 13, 1999.
I am afraid I have to disagree with the previous contributor. Strictly speaking the kind of image you get isn't in direct connection to focal length, the image angle has a lot more to do with it , so two lenses a normal and wideangle will give a different image. However this is just academic and the difference will be hardly noticeble and again only when comparing the two images. Most 6x9 cameras will allow usage up to 65mm and some brands would provide special features where movements are allowed even though limited if at all possible. An Angulon lens is NOT a "real" wideangle lens! As opposed to a super angulon a angulon has a image angle which is almost the same as a modern normal lens. The angulons are very small an will fit a 6x9 camera but focusing with them will prove very difficult on a ground glass. Linhof has always had special extra "Bright" lenses for the purpose, I'll suggest you to get more informations about this kind of lenses (Zeiss for Linhof, for example). In general, look at the various arrays of lenses for 6x9 or 6x7 technikas. However, how about using a 4x5 camera with a rollfilm for 6x7 or 6x9? It will be easier, cheaper and open to the occasional use with cut film! Your angulon 90 will just about cover the format but the possibilities will be greater. Most people would advice to stay away from angulons but they are allright.Super angulons or grandangons(surely the 5.6 or 4,5), although much better lenses, will prove,in general, to be to large to fit the lens board of some 6x7 or 6x9 cameras. Anyway to get back to the original point; a focal lenght, loosely speaking, is simply the distance between lens and projected image when focussed at a given (in general infinity) distance. This gives you no further information about how much of the photographed scene will be on your film, since this is a feature of the image angle. I do not intend to stirr up the usual fuss that goes on forever but, clearly, an angulon and a super angulon of the same focal length give origin to two complitely different images! So your angulon will look similar to a standard lens because of its image angle and its focal length. Lots of nice shootings anyway, and, if I may, can I suggest you all to check out the site of the WFPA (World Field Photographers Association) at http://www.johndesq.com you'll find interesting! Greetings
-- andrea milano (email@example.com), June 14, 1999.
hi andrea i'm afraid i didn't quite follow. i respect your wishes for not starting a prolonged debate and only add this to aid my (and perhaps others') understanding. i've always understood what gets on the film is a function of the format of the film and the focal length. so angle of view determines what the film sees, while angle of coverage determines what the lens sees. in other words, you can draw lines from the corners of the film area through the lens and out and that tells you what part of the scene before you ends up on the film. now while ange of coverage determines how much movement you get (i.e., how much you can reposition the film to choose a part of what the lens sees), i do not understand how it affects what gets on the film. i'm not sying there are no differences between lenses (stuff like resolution, flare etc) but i spent some time thinking about it and i can't for the life of me understand how two lenses of the same focal length looking ta the same scene can put different things on the film (assuming all movements are zeroed etc). i would really appreciate your time in explaining this to me. and you're right about the angulon not being a true WA. i overlooked that. thanks for the correction. dj
-- N Dhananjay (firstname.lastname@example.org), June 14, 1999.
Guys thanks for your response ! I guess I should state the reason behind the question to make it more relevant for discussion.
I intend to start off using 2x3 film on a 2x3 crown or century graphic or a 4x5 crown or super graphic.If I am going to get more or less the same result on an angulon or a 90mm lens for 4x5 work to use on 2x3 film then I don't need to buy a 100mm lens just for 2x3 work.The 90mm lens can be used in the future to shoot 4x5.
Having said that,I would doubt if using angulon on a 2x3 will yield as good a result as say a 101kodak ektar ,not to mention a 100 apo-symmar.
-- Robert Choi (Audia6@connect.ab.ca), June 14, 1999.
Hallo there! Well! When it comes down to a straightforward question.........you get a straightforward opinion if not an answer. There is hardly any "real" difference, in terms of image, between shooting with a 90mm angulon or a normal 100mm or thereabouts. So buy the first which can be used (the angulon covers the 4"x5" really just about!) for all formats. Concerning the objections of DJ to my simply formulated answer I can quote a few facts as I understand them, again, I am a photographer and a photography teacher but my knowledge of the technical nitty-gritty might just be incomplete. I apply or try to apply what I believe to be the art of logic to most things and therefore make some conclusions which, at times, might be un-true due to lack of knowledge. However, here it is.
Rodenstock (just chose this brand for illustration purposes) produces and has produced a wide range of lenses with similar focal length but with different "field angles" for example the cheap wideangle Geronar WA as opposed to the serious and senior Grandangon.Let's take a 90mm focal length.
They both have a focal length of 90mm which means that they focus infinity at a flange distance of 90mm, however, the "field angle" of the first is one of 850 while the second is a considerably larger 1050. This must mean that two lenses of identical focal length (Yes, they will be focussing infinity or any other given distance at the same flange distance!) giwe a wider or narrower rappresentation of the reality on your film. If not so, what does the difference in "field angle" mean? You might argue that the image circle has something to do with it and it does, but it works,in general both ways. More comes in, more goes out. When comparing longer lenses difference will be even more macroscopic but I leave this to the personal research of those who like this sort of things. Honestly DJ, Go to a shop or contact a friend and mount two similar lenses on your camera , have a look and you will see what I mean. You will also tell me that the differences won't be huge, and they won't be indeed, nevertheless,the original point was :"Is it the same to take a picture with two different (in design) lenses of similar focal length, and my opinion is that it is not. Again, I might mistake.........I am more of camera guy(Andrea is in Italy a gentleman's name) rather than being a tech-wiz.
Love and peace
-- andrea milano (email@example.com), June 15, 1999.
I think Andrea is confusing two concepts, often called 'angle of view' and 'angle of coverage'.
The angle of view is defined by the focal length of the lens, and the format. This is, roughly speaking, what appears on the film. A 90mm lens on 6x9 (centimetre) film will give the same picture, in terms of perspective, on the film as any other lens of that focal length on the same film. The two lenses may be of different quality. And one may not cover the film format: a 90mm lens that is made for 35mm format won't cover 6x9.
Which brings us to the angle of coverage. This is defined by the particular model of lens. It might be expressed as an angle, or as the diameter of a circle, or as a film size. To cover 35mm film, the circle diameter should be at least 43mm. 6x9 negatives need 108mm, and 5x4 film needs 160mm. The required angle is alpha, where tan (alpha/2) = semi-diameter / focal-length. So the minimum angles to cover these formats are 26 degrees, 62 degrees and 84 degrees.
I hope that has clarified matters.
-- Alan Gibson (Alan.Gibson@technologist.com), June 15, 1999.