focusing wide angle lenses

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I have been using my Linhof Technikardan 45S for over a year now and enjoying all it has to offer. I recently purchased a Schneider 72XL and as most, struggle with the ground glass focusing. after a particulary difficult low-light session, with movements that exacerbate the problem, I thought I might ask how others tackle this problem. I have almost come to dread having to use this lens, despite its excellent performance. no problems with my longer lenses, the 110XL and 210SA.

suggestions?

-- daniel taylor (lightsmythe@agalis.net), March 26, 2001

Answers

How? Just like you, with lots of difficulties! Wide angles require a certain (read: large) ammount of light. Otherwise it's striving and guessing. Taking off the center filter for composing (sorry, it's obvious). A loupe that can be used with an angle can help. Do you have a fresnel?

-- Paul Schilliger (pschilliger@smile.ch), March 26, 2001.

not having other cameras or access to different ground-glass types, I was curious about improvements to help facilitate focusing. I had to laugh, as my last series of low-light images had a Gitzo tripod leg sneaking into the bottom of the frame. in trying to catch the disappearing light, I could only focus in the center and hope for the best. it is a difficult proposition, making movements almost impossible, and frustrating with fleeting light. I use the Toyo 3.6x loupe.

-- daniel taylor (lightsmythe@agalis.net), March 26, 2001.

Daniel, I have the end of my Technika's flatbed extension on some slides too! Do I understand you use no fresnel screen? In that case, getting one would help a lot. It's a kind of an optical plastic device that you add on top of your GG. It diffuses the light towards the edges of your frame and makes the corners more visible. Another thing that has less effect but can be done in addition, is to change your standard GG for a Bosscreen. This is a sanwiched layer of paraffin between two sheets of glass. It diffuses the light more evenly on the entire frame than a standard GG would.

-- Paul Schilliger (pschilliger@smile.ch), March 26, 2001.

Hey, quit complaining! I use a 120mm lens with a maximum aperture of f/14 on my 8x10--slightly wider and 2.5 stops slower than your 72XL--and I've been using it for a series of shots in a dark interior space. It's mostly guesswork: I focus on something that looks like it may be 1/3 or so within the range of DOF, maybe apply a little movement based on intuition (bellows are too tightly packed to do much anyway), close down the aperture all the way, and hope for the best. It comes out OK surprisingly often. One thing that helps me is to focus as if I am using a rangefinder--that is swivel the camera around aiming the brightest central area on the GG at various points in the scene to determine their focus, then recomposing.

Obviously, w/ 4x5 an easy option is to shoot a Polaroid to check focus.

-- Chris Patti (cmpatti@aol.com), March 26, 2001.


I use the same lens as Chris, and it can be difficult. I don't use a fresnel. Be sure you are blocking out all extraneous light with the darkcloth. Stay under the darkcloth for a minute or so, so that your eyes can adjust. To check the corners and edges, realize that the arial image is being projected at quite a wide angle, so you can't see it if your eyes are parallel to the groundglass. You might need to tilt the loupe to catch the arial image.

-- David Goldfarb (dgoldfarb@barnard.edu), March 26, 2001.


Let's make it easy: if you are not sure about framing with your wide angle lens, get the 545 Ploaroid back and check the final framing. There is no better way to be sure if you are on the "good frame". If we are allready going to extreme and shooting with such a big film format, an extra gadget in the "big bag" will save a lot of grief. Are you with me people?...

-- Steven S. Miric (miric@sympatico.ca), March 26, 2001.

i do a lot of very low light view-camera work-- at night in dimly-lit urban areas where my light meter gives me an exposure value of below 1 in the brightest areas of my images (requiring exposures in the several-hour range). my trick is to bring a super bright flashlight and shine it on my subject while focussing. i use one of those black 5-D-cell mag lights that's about as bright as a car headlight-- it makes focussing much easier, and it doubles as a scarying looking protective device when groups of drug dealers saunter by... ~chris jordan

-- chris jordan (cjordan@yarmuth.com), March 26, 2001.

Are you using a fresnel lens?

Are you using an enhanced brightness screen?

Are you using a center filter?

-- Bob Salomon (bobsalomon@mindspring.com), March 26, 2001.


Daniel, a fresnel is a must with such wide angle lenses. If you live in the US contact 'Quality Camera Company' and ask about the Ebony Wide Angle Fresnel it will fit most other makes of 45 cameras. You've just got to use it to believe it. I use it with the 47XL and with just a little head movement you can see right into the corners even in low light situations. Its not too expensive either, I purchased mine from 'Robert White' for about 50. Good luck,

-- Trevor Crone (trevor.crone@uk.dreamcast.com), March 26, 2001.

I am using the standard Linhof ground-glass. no center filter and f5.6 viewing aperture. as I recall, the consensus was not all that positive about the gains from other viewing screens related to the costs. it sounds like a fresnel, much like what is included with my Hasselblad Flexbody for tilt viewing, would be valuable.

while I appreciate the Polaroid recommendation, the environment disallowed that luxury. lighting and subject transience presented overwhelming difficulties coupled with difficult focusing. there is good central focusing, but I am unable to see any image at the corners or enough to evaluate movements.

I have a project needing the 58XL, which I now hestitate to purchase, after experiencing these wide-angle difficulties. it might be easier though, since movements are unavailable.

-- daniel taylor (lightsmythe@agalis.net), March 26, 2001.



and I should say, that here in the studio with bright Oregon sunlight breaking through the storm clouds, I can easily compose and focus using a focusing cloth and acclimated eyeballs. just not the same as being in the heat of the moment, watching the light fade, subject moving, back tilt ala Keith Carter, almost imperceptible image on the ground-glass.

-- daniel taylor (lightsmythe@agalis.net), March 26, 2001.

Daniel,

Get a Maxwell focusing screen specific to your focal length. I don't have his Phone # handy but many of the posters know it.

-- Pat Raymore (patrick.f.raymore@kp.org), March 26, 2001.


Hi Daniel

Maybe you could improve your nightsight with vitamin A, for me it works! But if I have a very important shoot then I due it like this: 1. I look for the right place and view vor my 9kg tripod short bevor the sun goes down, 2. I put the camera on it and the right lens for example my f4,5 75 Nikon or my f 8 90mm Schneider and i setting everything up for the shoot with the last light of the sun and now I`m waiting `for the blue hour or the darkness and then I`m shooting. You loose an hour but you sleep very good after thad, because your sure everything is fine on the shoot! Other idea if the frame is not to far away you should take your strong car light to compose the frame and focus etc. Good light, to all!

-- Armin Seeholzer (armin.seeholzer@smile.ch), March 26, 2001.


You need a fresnel screen and probably a center filter.

-- Bob Salomon (bobsalomon@mindspring.com), March 26, 2001.

The 55mm 4.5 Apo grandagon to the 65mm lenses require the Accessory Wide Angle Focus Device. They can not be used properly without it on any Technika except the 2000.

-- Bob Salomon (bobsalomon@mindspring.com), March 26, 2001.


72 on a 4x5 isn't that wide. I routinely use the 110 on a 5x7 in low light, which is about the same angle. I have found that even when the light level is too low to photograph on Velvia, I can still see the subject. What helps me is (a) a good enclosing focussing cloth (BTZS) which almost totally eliminates unwanted light, (b) a good focussing screen (Boss), (c) a focussing lupe which can be pointed at an angle for the corners (Silvestri). To help focus, I place tiny flashlights (Photon Micro Light is great) on the ground. Occasionally I have found them to be of some help in the composition (ie determining cropping) as well.

-- Q.-Tuan Luong (qtl@ai.sri.com), March 26, 2001.

> 72 on a 4x5 isn't that wide

yes, just like my high-school gym coach used to yell at me 'come on Taylor, it's only 250 pounds'.

-- daniel taylor (lightsmythe@agalis.net), March 26, 2001.


i have a tk 45s and use the 72xl without problems. get a fresnel. i use the linhof one, although one that is designed specifically for wa use might be easier in the corners. i have started using the focus/metering bellows and find they help a lot. a btzs cloth would be a cheaper option. and definitely get a flashlight. i carry the brightest one i can fit in my case and they're not very expensive.

by the way, do you really use a 210 super angulon on a tk or is it a typo? or does sa stand for something else?

-- adam friedberg (asfberg@hotmail.com), March 26, 2001.


> do you really use a 210 super angulon on a tk or is it a typo

yes of course. it's my standard lens and quite wonderful.

-- daniel taylor (lightsmythe@agalis.net), March 26, 2001.


what's only 250 lbs.?

-- adam friedberg (asfberg@hotmail.com), March 26, 2001.

yeah, he made me curl a Gitzo 410 a thousand times, just warming up, one-handed. he used to wear a T-shirt that said 'real men don't curl Bogens'.

-- daniel taylor (lightsmythe@agalis.net), March 26, 2001.

now i see why you like that s.a.

-- adam friedberg (asfberg@hotmail.com), March 26, 2001.

truth be known, I am 5'10", 160 pounds, and couldn't lift 250 pounds with a fork lift. can barely curl a Bogen 3001 with both hands.

-- daniel taylor (lightsmythe@agalis.net), March 26, 2001.

I have/had similar problems with a sinar and nikkor 75 f4.5. A fresnel helps, but it needs to be removed (at least mine does)for fine focusing. Polaroids help, but don't cover the full 4x5 image area and (may) suffer from different reciprocity characteristics than the film i may be using.
What I have found:
The opacity of the focusing cloth is very important. For composition/framing polaroids and fresnels are great. Polaroids are also good for lighting and spotting detail issues. Polaroids are also excellent for checking DOF. Moving the camera along an axis (h or v) and checking focus (assuming that the distance of the object does not change much) Flash lights put into the scene (for large areas) or shown on the object (for smaller areas) Adding a stop or two when not sure.
This last item can an issue for me. I often prefer the subject to be in focus and the rest to fall out of focus and or I cannot afford to wait the extra 30, 60 or 120 minutes that stopping down will cost.

The idea of focusing whilst there is light and waiting for the darkness to fall or the correct opportunity seems like a wise move.

I should mention that I have only been shooting L/F for about 6 months, so my advice is founded in limited experience.

-- jdc (jdc@jdc-art.com), March 30, 2001.


Suggestion: zone focus! Schneider's d-o-f tables say that at f/16 and focused at 15', everything to 6.22' is in focus and at f/22 and focused at 10' everything to 4.36' is in focus. Even if you're real paranoid about sharpness, you can mark 15' focus on the camera, close down to f/22 and get everything to 6' in focus. If you need really close and far sharp, close it to f/32 focused at 10': 3.5'. See: http://www.schneideroptics.com/large/depth/72depth.htm

-- andy (buckwiet@yahoo.com), April 02, 2001.

Hi Daniel, I am new to large format and have only been using a 210mm lens with my TK45s. I just bought the Linhof super screen. It is a fresnel with a glass over it. I think that it is brighter than the Bosscreen, and if the fresnel lines don't bother you, i may be a good choice. I've tried the tilting 6x Silvestri lupe, but I can't get the tilting technique down. The Rodenstock 4x lupe appears brighter and may be a good match for the Super Screen. Good Luck.

-- Bill Henick (dhen1922@aol.com), April 02, 2001.

bill,

you don't need to tilt the loupe with a 210. the tilting feature is for wide angle lenses. re. the superscreen: although a good general purpose combined screen/fresnel, i no longer use it with my linhof as the long sides are unsupported and tend to sag. this will happen with any plastic screen. some put matchsticks in for support but this wasn't a good solution for me. a real glass screen with fresnel has proved more accurate and reliable. watch for bowing in your screen.

as for dof tables, they are more suggestions than anything else.

-- adam friedberg (asfberg@hotmail.com), April 02, 2001.


In addition to what has been said, I wonder if anyone is using the Linhof baloon focussing hood and loupe. This could be a good accessory for wide angles.

-- Paul Schilliger (pschilliger@smile.ch), April 03, 2001.

The Linhof Focus/Meter Bellows works for wide angles just fine. But you do need to use the fresnel lens with either it or the Reflex Hood.

-- Bob Salomon (bobsalomon@mindspring.com), April 03, 2001.

If possible, such as when shooting interior spaces, have an assistant hold a small flashlight at your desired focus distance shining directly into the lens. Under a 7x loupe, you should be able to get accurate focus. Or place the light carefully if there's no assistant.

I use this technique without any special groundglass, and it's quick and reliable. The darker the room, the easier it is to do.

-- Don Wong (wongx017@tc.umn.edu), April 04, 2001.


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