View Full Version : 4x5 wide angle lens primer?

MIke Sherck
15-Apr-2010, 12:47
I've always been a longer-than-normal lens sort of guy but lately I've gotten an itch to try shorter focal lengths. I'm currently making a wide-angle bellows for my old Zone VI 4x5 and am interested in lenses from 90mm and shorter, particularly in the 75mm range. Would a 75mm lens for 4x5 need a center filter? At what point would a wide lens for 4x5 need one? Finally, while I don't find f/8 or f/9 to be an issue with 300mm, 355mm and 420mm lenses on 4x5 or 8x10, I understand that the effects of small apertures are more pronounced at shorter focal lengths (dimmer image on the ground glass.) Do you find 90mm f/8 to be unworkable? How about 75mm f/8?



Jack Dahlgren
15-Apr-2010, 13:00
Use of a center filter depends on your tolerance for light fall-off and how close you are the the edge of the center filter. I use 90mm without a center filter but I'm usually outside and a perfectly even illumination is not that important to me.

The wider the lens the worse the fall-off becomes.

It all depends what you consider tolerable and the trade-offs you are willing to make.

f/8 is workable. But larger apertures help with finding focus. Wide angles are harder to focus because DOF is larger so f/5.6 or f/4 will help narrow down your point of focus.
Also helpful indoors or dim conditions.

If f/8 were unworkable then they wouldn't sell very well would they?

I don't have anything shorter than 90mm so I can't comment on 75mm.

15-Apr-2010, 13:05
A question from one who is technically impaired. What is a center filter?

Eric Woodbury
15-Apr-2010, 13:21
Bob, In most lenses, light falls off, decreases from center, at a rate of "cosine to the fourth". This is minor until you get into wide angle lenses and then it creates the appearance of a bright center and dark perimeter. With some subjects and in BW, this can be hidden or made non-distracting, but if you want it even, then you use a center filter that is the opposite of fading off at the edge, it is darker in the center and becomes more transparent at the edges. This counteracts the falloff, but costs you a couple of stops in lens speed and several hundred dollars. And different lenses use different filters ... sometimes. Keep the wallet open.

15-Apr-2010, 14:10
Generally people tend not to use CFs on 90mm on 4x5, I think they really start to be used from 65mm downwards, but it will all depend on what you're shooting. Falloff is more visible in areas of even tone like clear skies. I had a 65mm f/8 and in general landscape use (i.e. stopped well down) the falloff wasn't a problem - you could actually use it to your favour in some cases. I did try to avoid using it against a clear sky though. The other thing to consider is if you're scanning then its pretty trivial to correct in photoshop if you have no choice.

The f/8 issue can depend a lot on your ground glass, fresnel and length of lens. I dare say an f/8 lens on a snazzy bright ground glass can look brighter than an f/5.6 lens on a dull old glass. For me using a fresnel was like night and day on a 65mm lens.

A 90mm f/8 is a lot brighter on the glass than a 65mm f/8, and a lot easier to compose with because there's less falloff and falloff is always more severe when the lens is wide open for focussing.

Another thing to consider is the wider you go the less you have to tilt, to get front-to-back focus for example. This means it can be quite hard to do prescisely on a camera without geared tilt because even the slightest slip or if you don't tighten a knob fully it can throw the focus. And also means if you knock anything out of a zero position when the camera is in transit even a tiny amount which you don't notice it can give you problems.

If you're new to wideangles the most obvious thing to suggest is not to go too balls-deep at first, go with a 90 or 110mm to start with, it may end up being all you ever need.

15-Apr-2010, 14:45
If you are doing the digital workflow then compensating for the lack of a center filter should be possible. I remember seeing an older C program that could do it- there may be more modern Photoshop plug-ins and such by now. Center filters aren't cheap so it's a good thing to investigate and save a little money.

Joshua Dunn
15-Apr-2010, 14:58

I use center filters on 90mm and below but I am a techno-tard. A lot of this is a matter of taste but to me light fall of is not just a lack of exposure but a loss of information. This will be exaggerated with any movements you use. Like a lot of things you just need to try it and see how you feel about it. If you don’t know someone who has a 75mmish lens with a center filter than maybe rent one. The ideal trial would be for you to photograph a subject that is typical of what you plan to shoot with a wide lens on 4x5 with and without a center filter and see what you think.


15-Apr-2010, 18:23
Bob, In most lenses, light falls off, decreases from center, at a rate of "cosine to the fourth". This is minor until you get into wide angle lenses and then it creates the appearance of a bright center and dark perimeter. With some subjects and in BW, this can be hidden or made non-distracting, but if you want it even, then you use a center filter that is the opposite of fading off at the edge, it is darker in the center and becomes more transparent at the edges. This counteracts the falloff, but costs you a couple of stops in lens speed and several hundred dollars. And different lenses use different filters ... sometimes. Keep the wallet open.


Thanks for the very clear explanation, very appreciated.

MIke Sherck
15-Apr-2010, 18:25
I see some background would have been helpful. Sorry for missing that!

My widest lens to date is my Fuji 125mm; before that, it was an Ektar 127mm. I tried someone else's 90mm Angulon once and the camera barely came to infinity focus with the regular bellows, so that's why I'm making the wide angle bellows. To date I don't do digital. Most of my photography is B&W and I print in my darkroom but my local color lab no longer makes wet color prints from 4x5 and I'm more than a little unhappy about having to pay $25 for a scan for each negative, plus then a print. We'll see what happens next with color, but that's not really part of the wide-angle experiment.

Maybe I should look for an old 90mm Angulon or something similarly inexpensive, just to see the difference from my 125mm? Or would that be too close to make much difference? Then, there's a 75mm f/8 Super Angulon on Ebay which might end up affordable... I know that the Angulon won't give me much in the way of movements but generations before me have lived with that and I probably can, too. :)


15-Apr-2010, 19:07
FWIW, I have a 90mm f8 Super Angulon... an older one which are cheap at Keh. I used to own a 90mm Caltar f6.8 (relabeled Grandagon). I DO find the SA f8 to be considerably more difficult to focus. If I were buying again I would definitely buy the Gradagon instead, or the Caltar version of it which I am sure is just as good. I will probably sell my 90 SA and buy a faster 90 at some point in the future... shows how saving a bit can be more expensive in the long run.

I've never used a center filter with a 90mm. I suppose I might for transparency film or architecture which I don't shoot enough to worry about.

Doremus Scudder
16-Apr-2010, 02:26

There are a couple of things that haven't been mentioned yet that you should probably take into consideration before buying.

First, the center filter issue. If you make optical enlargements (i.e., use an enlarger), then correcting for light fall-off at the printing stage is pretty easy (edge burning, etc.). Ditto for digital. If, however, you have a lab do your work, or really want to make straight prints and not deal with the manipulations, then a center filter would likely be worthwhile for 75mm and shorter focal lengths. However, you should make that decision after you have purchased and used the lens for a while. You may find that it's not worth it. If you want to use other filters and a center filter, you often need to step up to larger (and more expensive) filters to avoid vignetting. A center filter, contrast filter and a polarizer together will almost certainly vignette.

Coverage changes with different lenses/apertures. You need to consider what kind of movements you are likely to be doing. The fact you are making your own wide-angle bellows leads me to believe that you will be using camera movements. A 90mm Angulon (i.e., not "Super-") barely covers 4x5. No movements are really available. In the designs with more coverage, you will find that the f/8 lenses generally have less coverage than their f/5.6 or f/6.8 counterparts: A Super Angulon f/5.6 covers quite a bit more than the f/8, for instance. Also, different brands have slightly different coverage specs. I get by with an f/8 in 90mm, but an f/5.6 75mm gets used to the edge of the image circle more often than I like...

Size considerations: Size of the lens is generally in inverse proportion to the coverage. Bigger lenses cover more, smaller, more portable lenses cover less. It's a trade-off. If you are going to do a lot of backpacking, maybe the smaller f/8 would be worth the loss of coverage. The new XL wide lenses can be huge. Traditional wide designs are smaller but there is still a hefty size difference with aperture. Also, the shorter the lens, the smaller it will be. My f/5.6 75mm is almost exactly the same size as my f/8 90mm Super Angulon.

Recessed lensboards can help with movements, but you need to make sure you can work the lens controls and that the lens is small enough to fit in the recess. Some lenses with bigger front elements can pose a problem, making it difficult to set shutter and aperture, etc. My 90mm f/8 Super Angulon just barely fits in a Technika recessed board. I use the end of the cable release to set aperture and shutter. An f/5.6 probably would not fit in a recessed board, and I would then not be able to take advantage of the greater coverage, at least on my wooden field cameras.

Screen brightness is affected by a number of other issues besides maximum aperture. For wider lenses, the light fall-off will darken corners appreciably (2 stops or so on a 65mm). The center will be bright, but the edges often difficult to deal with. This is compounded if you have a Fresnel lens that is optimized for longer focal lengths. Many don't know that the Fresnel works best with just one focal length and that the ones mostly available are designed for "normal" focal lengths in the 135-200mm range. A Fresnel designed for wider lenses will help a lot, but then not do so well with the longer focal lengths. A good dark cloth helps a lot with wider lenses. With my Wista factory Fresnel, I only rarely use a dark cloth for outdoor photography with normal to long lenses, but pull it out almost always for anything that needs the 90mm or wider. Fortunately, the increased DoF with wider lenses compensates for the difficulty in focusing the relatively dimmer image. Stopping down to f/22 or so will give you a lot of DoF; the same applies to using movements.

Lastly, I own 75mm and 65mm lenses, but find that 90+% of my "wide angle" work gets done with the 90mm. The 135mm focal length is by far my most used lens, but I consider that "normal." If you don't have a specific need for a 75mm or shorter in mind already, you should probably start with a 90mm. An f/8 version of a Super Angulon, Nikkor SW, etc. provides enough coverage for most situations, can be had relatively inexpensively on the used market. You may find that wide enough.

Hope this helps,

Doremus Scudder

16-Apr-2010, 06:44
I'll probably be repeating some of what Doremus has written, but sometimes a variety of explanations is a good thing.

There are several issues when using very short lenses.

1. Coverage and lens design. The Super Angulon was the first double-reversed-telephoto design to emerge, and it expanded coverage far beyond what was possible with the Dagor wide-field lenses that preceded it (including the Angulon). It works by providing two reversed-telephoto (i.e. retrofocus) wide-angle lenses in opposition to each other around the shutter. The Nikkor-SW, Fuji SWD, and Rodenstock Grandagon are similar designs. The Super Angulon six-element f/8 version provides 95 degrees of coverage, and the 8-element f/5.6 version provides 105 degrees of coverage. So, the shorter the lens, the more valuable is the f/5.6 version. The XL versions are still current and pretty expensive, but they provide up to 120 degrees of coverage. If you go as short at 47, you'll need the XL version to cover 4x5 (the f/5.6 version covers 6x9 officially but will -just- cover 6x12). The 65/8 will just cover 4x5, but with no movements. The 5.6 version is more generous at that focal length. I don't have a 75, but I would expect the f/8 to provide a little movement space. From 90 on, the f/8 versions are fine.

But there are some shutter issues, too. Some of the early 90/8 Super Angulons were fitted into a Compur 00 shutter, and this is considered somewhat fragile. Many of the 47mm lenses you see will be in a 00 shutter, as will the 65/8 and 75/8 versions, but those lenses don't stress the shutter body as much. But the 00 shutters require pencil-points for fingers, plus a good strong set of bifocals--they are tiny. And they do not have press-focus.

2. Center filters. I have not used them, but I have bought a 49mm filter originally designed for the 65/8 but that will fit the 47/5.6 (though it vignettes it a bit). I'll probably save buying a purpose-built center filter for 47 for when I finally break down and get an XL version of that lens. The Super Angulon's design presents a round aperture even at the edges, so its falloff isn't as bad as a more conventional design, but you still have the cosine effect as the light strikes the film at a shallower angle. With transparency film, it is a problem--you can't bring up the dark corners if there is nothing there. With negative materials, though, it's far easier to correct.

Here's a link to a photo I made on Velvia using the 65/5.6 without a center filter. Velvia exaggerates it to its extreme, of course. The format is 6x12, but it will give you an idea of what to expect:

Fort Niagara with 65/5.6 Super Angulon (http://www.rickdenney.com/images/south_redoubt_ft_niagra_scan0017lr.jpg)

3. Ground glass. This is a big, big issue. The falloff probably affects what you can see on the ground glass more than anything. Without a Fresnel, you can use a tilting loupe--with it tilted so that it is pointed to the rear exit pupil of the lens. Forget using a reflex viewing hood or anything like that. Even with a tilting loupe, an extreme wide is a little troublesome to manage. This is where a 5.6 lens is a little easier to use because of its brighter image for focusing. But you'll still need to see the image stopped down to check depth of field. An (expensive) alternative is to get a Maxwell screen, which GREATLY aids in viewing when using wide-angle lenses. And for purpose-built wide-angle cameras, Maxwell also makes a screen specifically designed for ultra-wides. I use his regular screen without issue, along with a Silvestri tilting loupe.

Do not expect to get away with a conventional Fresnel. My Sinar Fresnel would should doubled and ghosted images in the corners with very short lenses, making it unusable.

4. Movements. Remember that the shorter the lens, the less the tilt and swing is needed to adjust the focus plane. An example illustrates the point: Say you want to photograph leaves on the ground. You might tilt the lens down to adjust the focus plane to run along the ground. With, say, an 8" lens and a camera height of 48 inches, you'll need a 9.5-degree downward tilt. With a 3" (75mm) lens in the same spot, you'll need a downward tilt of only 3.5 degrees. You'll need a finer touch on those movements, and with slight adjustments, you might find yourself fighting the edge of the detent, if your camera has one.

And accuracy is also an issue. A small misalignment that might have no noticeable effect with a longer lens might move your focus plane in noticeable ways with a really short lens. Really short lenses will test your camera beyond just what you can make focus at infinity.

5. Shadows. With very short lenses, and the sun behind you, you'll have to pay attention to keeping your shadow out of the picture. In many cases I have had to lay on the ground. Often, when using an extreme wide, you won't necessarily check all parts of the image on the ground glass, and will be surprised to discover your shadow or the camera's shadow when you process the film. You have to put that on your image checklist.

6. Self-portraits. Of the camera, that is. The lens board will be pushed way back into the camera, especially with a field camera, and if you can't drop the bed out of the way (or use a shorter rail), you'll have to crop a bit of self-portrait off the image. 75mm might be at the extreme of most field cameras. Even with monorail cameras, this can be a problem. I had to use an alternative 12" rail when I use my Cambo/Calumet and anything shorter than 90, and that camera would not focus 47 even with bag bellows. That's why I switched to a Sinar F/F2, which can handle very short lenses without too many issues, and without rendering the camera inconvenient or unusable for longer lenses.

Using long lenses presents a different set of challenges, of course, that are just as demanding. But, as a wide-angle freak myself, I've had to deal with these issues, and that's what I'm passing along in response to your question. Only you can decide if it's worth it; for me, it's a must.

Rick "who has 47/5.6, 65/5.6, 65/8, 90/5.6, and 121/8 Super Angulons" Denney