Science V practice

[stuart grundy]

G'day,
I am a real newbie, today I registered with the LFP forum. In way of introduction: I was a press photographer here in Australia. I worked the national newspapers. A Rollie man in the first part followed by Nikon. I recently retired and have had this penchant for large format. I now own a Sinar in 4x5, I have read "In and out of focus" and similar texts explaining the science behind camera movements. I (think) I understand the fundamentals but I have great difficulty in putting the science into practice.

My question is really looking for a practical assignment that will put a real life spin on what I have read. I don't appear to see on the ground glass the image variations that are explained in the text - is there a simple test I can try to help me see what I am supposed to see? I have 65mm and a 300mm lens' for the Sinar. I'm not sure where to from here.

Hoping for some assistance/guidance.

[Jeff Conrad]

I've seldom seen a conflict between science and practice, but it's important to look at the science most relevant to your situation. Like you, I don't see the differences described in The INs and OUTs of FOCUS, either on a groundglass or in a final image. This isn't to say that Merklinger got it wrong, but recall that he illustrated his points with huge enlargements, far larger than I'd ever consider. His approach well might apply to surveillance or forensic photography, where the ability to identify every possible object in the image may be the most important consideration. But for me, it's generally inapplicable.

I think his book Focusing the View Camera, at least the basic parts that discuss the effects of tilt, focus, and f-number on DoF, is far more useful. His diagrams are also very helpful in visualizing what happens with tilt and swing; prior to his articles in Shutterbug, Photo Techniques, and View Camera in the 1990s, I don't think very many people (aside, perhaps, from Linhof and Sinar) had a clue as to what was really involved. Both the book (in PDF) and the diagrams are available on his web site. Beyond the basics, I think he makes things a bit more complicated than they need be. He sometimes gets dinged for this, but I think we're eternally in his debt for sorting out a few things most of us probably would not have sorted out on our own, as well as setting us straight on a few things we knew that just weren't so.

Of course, the Sinar tilt calculators also do a pretty reasonable job, but it doesn't hurt to have a basic idea of what's going on.

I've looked at some of the science in great detail (see my paper Depth of Field in Depth if you really must know), and largely concluded that, in the field, I hardly ever need worry about most of it. And accordingly, I don't.

[Paul Fitzgerald]

Stuart,
"My question is really looking for a practical assignment that will put a real life spin on what I have read."

Look on ebay for the original instructions for a GraphicView camera, the instant explanation, very easy to read.

You can put a cube on a table and set-up to see only the front face, now square up everything with movements. Now raise the camera to see the face and top, again square up everything with movements. Now shift to the right to see face, top and side, again square up everything with movements.

For extra credit you can set-up a row of equal object (film canisters) and using movements get everything in focus wide open. To make yourself crazy, make them all the same size with movements.

Have fun with it.

[stuart grundy]

Jeff,
Many thanks for your response. I think an excursion into the real world would prove to you that science is fallible unlike math which is not. "I've seldom seen a conflict between science and practice, but it's important to look at the science most relevant to your situation." My enquiry was how to test the "movement" theories which I have had difficulty doing. Not whether there is any need for them in the field. Simply, they are there to be used, for that reason only I would like to manage them.
Have a nice day.

Paul,
Thank you, that's exactly what I had in mind - having fun.

[Ole Tjugen]

I think part of your difficulties lie in the focal lengths you have started with: The 65mm is very short, and it can be difficult enough to see anything at al, let alone the subtle differences you are looking for here. conversely the 300mm is rather long, and unless you have a huge old "boat anchor" of a f.4.5 lens, the smaller aperture can also make it difficult to see...

I suggest you invest in a good older 150mm to 210mm lens of reasonable aperture - no slower than f:5.6 - with plenty of coverage. Among the best of these old lenses (for the price) are the old convertible Schneider Symmars. A 150mm f:5.6 / 265mm f.12 can be had for very little money, often less than the value of the shutter it comes in. it provides ample coverage for playing with shift and swings, and is bright enough that you can actually see the difference. A 180mm or 210mm might be even better (due to even more coverage), but these are slightly less ubiquitous and you might have to pay what the lens is actually worth.

[Bruce Watson]

I think part of your difficulties lie in the focal lengths you have started with: The 65mm is very short, and it can be difficult enough to see anything at al, let alone the subtle differences you are looking for here. conversely the 300mm is rather long, and unless you have a huge old "boat anchor" of a f.4.5 lens, the smaller aperture can also make it difficult to see...

I suggest you invest in a good older 150mm to 210mm lens of reasonable aperture - no slower than f:5.6 - with plenty of coverage.

+1.

It's far easier to learn movements when you can see what's going on. And it's far easier to see what's going on with a "normal" lens.

Most of us coming from smaller formats immediately eschew the whole concept of a normal lens. We didn't use them in smaller formats, so why would we use them in LF? What we don't know coming in is that LF isn't just a bigger version of small format. Much of what we learned in small formats doesn't translate directly to LF. And one of those things is lens choice.

Nearly everyone who uses LF ends up sooner or later with a "normal" lens. They are plentiful and comparatively cheap on the used market. And if you don't like the one you pick you can always resell it, so not to worry.

My personal favorite is a Rodenstock APO-Sironar-S 150mm f/5.6. I highly recommend it, but also stress that it's not the only lens that will do. There are many new and especially used lenses out there that will work well for you.

Once you've got a normal lens, take it and the camera (film optional) outside and play with it. Pick out some compositions and try them. Near-far compositions are fun and will graphically illustrate how to use front tilt (for example). Focus on the far (using the focusing knob) and tilt for the near. A couple of iterations is usually all it takes. You'll see how it works on the ground glass even without a loupe. But you'll want a loupe to help you fine tune and nail the focus and movements. And you'll likely be interested and amazed at how little tilt it takes to bring everything into focus.

This stuff isn't intuitively obvious to the casual observer. You have to do it to understand it, and practice makes perfect. IOW, the more you shoot the better you get. Really.

Good luck with it and welcome to the club.

[David Watts]

Stuart, as someone who has only 15 months experience with LF, I agree with the replies you have received. I spent several evenings with my 4x5 on the tripod focused on the mess on my desk watching items go in and out of focus, or the perspective alter or the shift effect. I agree with the 150 Symmar f5.6 as a good first lens to work with. There are also a number of Australian LFPF members at present and there may be someone living near you who can help. Good luck.

[Paul Fitzgerald]

Stuart,

For a full degree do all the above WITHOUT moving the camera, movements only.

The front movements change the plane of focus only, the rear movements change the perspective and focus. You can taper the top edges to the vanishing point OR keep them parallel with the rear tilt. Use the rear swing to change the side's edges in similar fashion. Rear movements change the magnification across the film, perspective distortion.

[stuart grundy]

Many thanks to all for your helpful comments. It looks like I am in the market for a "Normal" lens. As an aside what are your views on "Bright screens", do they really help when focussing?

[Bruce Watson]

Many thanks to all for your helpful comments. It looks like I am in the market for a "Normal" lens. As an aside what are your views on "Bright screens", do they really help when focussing?

They do. More light makes it easier to see, particularly to see small detail. And if you can see it, you can focus on it. It also allows your eyes' pupils to close down some which works similarly to a camera lens -- the smaller aperture decreases the effects of (some) aberrations, and gives your eye somewhat greater depth of focus. All good things.