Some Idle thoughts - trying not to ignore the elephant in the room, my 45A
So, I bought a 45A nearly 6 months ago. For one reason or another, I haven't been able to our haven't had the inclination to load some film and fire it up.
I suppose a bit of this is due to the fact it's such an unknown quantity and I have a lot to learn.
Anyhow, I have a Rod Show coming up on Saturday and I have thoughts of just loading a few holders and leaving it in the bag and getting it out if I feel game, but I want to clear up a few things first.
- Bellows Extension and exposure compensation - To measure the bellows extension, is it correct in saying this is the measurement from the film plane to the lens board? Is this the correct way to measure the focal lenght? The lens I am using is a 210mm Caltar II - E. Also, how do I determine what infinity focus is? Is this 210mm from the film plane to the lens board? My plan is to use an Android app called Photo Tools to work out exposure compensation. Is there any caveats using apps like this?
- What is Accpeted practice with holders and dark slides? White is exposed, or is it black, or each to their own? (I'm just trying to start with good habits)
- To start with, I am planning on using an old 50mm F2 lens as a loupe. Is this going to be good enough to get going?
- While I am starting out, should I set all the movements at zero and worry about that later?
To start, yes, don't worry about movements. Just practice and play with using the camera as it's enough different from what you're used to you don't need ANOTHER complication.
210 mm from film plane to lens board is close enough to the infinity mark with your lens.
You can try that 50mm lens as loupe - if it works for you, it works. I'd look around for an inexpensive loupe like the Agfa ones they used to sell/give away for viewing slides as a starter.
I don't know that it matters which color for the dark slide you use for which, just be consistent.
For bellows extension, see the comment about infinity focus. As a handy rule of thumb, double the bellows extension, add two stops. If you increase the extension by 50%, add one stop. So if after focusing, you find that you have 315mm of bellows draw on your 210 lens, you would add one stop. If you have 263mm of extension, you'd add 1/2 stop. Another way to think about it is reproduction ratio - to hit 420 mm of extension with your 210mm lens, you're at 1:1 macro reproduction. On most people, a head-and-shoulders portrait would be less than 1/2 life size - probably in the range of 1/3-1/4 life size on 4x5, so you'd be in the range of adding between a half stop and a stop of exposure compensation, depending on how small their head was and how close you were focused. Back off to a half-length or full-length portrait and you're within the film's margin for error on exposure.
For bellows extension & exposure compensation, I use a very simple trick as described by John Cook - See under "A Fast Method to Calculate Bellows Extension Factor" - It helps to have a dress maker's tape sewn to the edge of your dark cloth, that way, you always have one to hand.
As for what side of the tab indicates the state of the film - That is the beginnings of a verrrry long thread. I use "white out, unexposed. Black out, exposed" and then add a sticky label on that side of the holder with a note of the exposure. Should I forget to flip the darkslide, the label acts as a reminder/backup. When the film is removed for processing, the label gets taken off, but the darkslide is returned with "Black out" and only flipped again when loaded with fresh film. So:
- White out = Loaded, unexposed.
- Black out, labelled = Exposed film
- Black out, no label = Unloaded.
- White out, labelled = Screwed up, do not use until checked in the dark.
Finally - Don't get hung up on technique, just get out there and have fun.
Welcome to the Wonderful World of Large Format! Seriously it's a wonderful world! I entered it about two years ago last month and haven't looked back since. Sure I had the same first faltering steps that you had as well and I'm sure many of us have had.
Don't be scared
Probably the best advise I heard from a trusted photographer and friend. As many have said, don't get too hung up on the niggly things, figure things out first, get some burner film practice loading and unloading the holders in the light with your eyes open, do that 100 times, then repeat it again with your eyes closed. I found these three videos very helpful as well: Part 1, Part 2, Part 3. Sure you'll make mistakes, but learn from them.
My very first 4x5 image, lots of things I could have done better for sure!
Practice, Practice, Practice. Figure out what works best for YOU, and stick to it, take notes, lots of notes. And have FUN!
My suggestion for exposure compensation for bellows extension is to get a small retractable tape measure. Do the math backwards from half F:stops marking the distance on the tape with a permanent marker. Then you don't have to remember anything as you measure from the lens board to the film plane. Since once you print from a larger negative you will be hooked and most likely add more lenses you can do the same for each focal length but use different color markers. Quick and easy you only have to think once. I attached my tape measure to my light meter strap .... compose, focus, take a reading, measure and adjust then trip the shutter and enjoy.
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I used a banged up old Canon FD 50/1.8 for a loupe when I started out - worked fine for me.
I use the Quickdisc for close-up stuff: http://www.salzgeber.at/disc/
Get out there ... and practice!
“Do your work, then step back. The only path to serenity.” - Lao Tzu
The extension factor is based on the square root of 2 = 1.414... You will lose a stop of light every time the extension is increased 1.4x. So, with a 210mm lens at 210mm x 1.4 ~ 294mm, you will need to compensate exposure by one stop. 210mm x 1.4 x 1.4 (= 210mm x 2) ~ 420mm or a 2-stop loss.
If you think about this in inches, it may be even easier. If 210mm is ~ 8" then 8 x 1.4 ~ 11, 8 x 1.4 x 1.4 ~ 16, etc. Notice the progression coincides with the f/stop progression, 8, 11, 16. If you have that progression memorized already, extension factors become easy to estimate.
If you ever expect to work with other large format photographers, use "black equals exposed" to avoid confusion, since that's conventional.
Originally Posted by hoffy
Here's a video from 1986 that provides useful basic information:
Thanks for the inputs people!
Am I a bit paranoid about using that thing? Yes, frankly I am. I did borrow a monorail a few years ago and shot 4 frames. It took me 2 hours to setup the first shot, so I am concerned I might make a nuisance of myself....that being said, if I don't shoot stuff I like with it, I'll never use it!
“You seek escape from pain. We seek the achievement of happiness. You exist for the sake of avoiding punishment. We exist for the sake of earning rewards. Threats will not make us function; fear is not our incentive. It is not death that we wish to avoid, but life that we wish to live.” - John Galt