Some Idle thoughts - trying not to ignore the elephant in the room, my 45A

hoffy · Mar 11, 2015

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?

Cheers

TheFlyingCamera · Mar 11, 2015

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.

paul_c5x4 · Mar 11, 2015

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.

Axle · Mar 11, 2015

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!

jeffreyg · Mar 11, 2015

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.

http://www.jeffreyglasser.com/

Jerevan · Mar 11, 2015

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!

smieglitz · Mar 11, 2015

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.

Sal Santamaura · Mar 11, 2015

hoffy said:
...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)...

If you ever expect to work with other large format photographers, use "black equals exposed" to avoid confusion, since that's conventional.

Here's a video from 1986 that provides useful basic information:

https://www.youtube.com/watch?feature=player_embedded&v=nOtxvNaYC1s

hoffy · Mar 11, 2015

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!

Cheers

pbromaghin · Mar 11, 2015

GO FOR IT!

cliveh · Mar 11, 2015

smieglitz said:
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.

Do you ever find the light has changed while you are working this out?

gone · Mar 11, 2015

I've used SLR lenses for loupes too. They work great!

SMBooth · Mar 11, 2015

Download an app called RECIPROCITY TIMER. Works a treat when needing to find bellow factor and reciprocity.

smieglitz · Mar 11, 2015

cliveh said:
Do you ever find the light has changed while you are working this out?

No.

hoffy · Mar 11, 2015

smieglitz said:
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.

Interesting! I checked this against the app that I downloaded and it appears that when taking into account rounding, the values correspond.* It appears that they would be using the same formula in their app

*Close - in the app, a Bellows extension of 297mm would equate to a 1 stop difference. I can only assume that they have used more decimal places then the simple 1.4

smieglitz · Mar 12, 2015

Knowing the f/stop sequence is very handy when it comes to exposure. The extension factor is one example. Another is the placement of lights in a studio. If you wish to make a (point source) light half as bright, just move it out to the next number in the sequence. For example, if you have a light at 4' from the subject, it will be half as intense at 5.6' from the subject. Move it to 8' and it is 2 stops less intense. At 11', 3 stops less intense and so on. (A quick look at the exposure dial or table of an old manual electronic flash unit will indicate the same relationship.)

It doesn't matter what unit of distance you use. From 4' to 5.6' is a one-stop loss and from 4m to 5.6m is a one-stop loss. 4" to 5.6" is also a one-stop loss. Knowing this facilitates placing lights of equal intensity at different distances to achieve specific lighting ratios.

polyglot · Mar 12, 2015

It's a rod show, not a portrait of the Queen. Park yourself in front of a cool car and spend the half-hour to setup if you feel like it, 'cos the car isn't going to get bored; the only drawback will be people who have questions about your camera. This is your big chance to both get some shots you're confident will work (no movements - should work just as well as your medium format) and to get familiar with movements and observe their effect. One suggestion I would make is to get low near the front corner of a car, use front rise to keep the car straight (maybe) but definitely use swings to get just the side or the front of the car in focus. Take a straight shot with lots of DOF then take a bunch more with all sorts of swing experiments. Also try using movements to minimise DOF, e.g. to isolate a hood ornament.

In terms of bellows compensation, IMHO it's easier to go by magnification than futzing around with extension because it doesn't matter what the lens' focal length is and it doesn't matter if the lens is tele or a bit retrofocus (not that your 210 will be). The formula for this approach is:

C = (1+M)2

where C is the linear compensation factor and M is the magnification (e.g. 0 at infinity, 1 at life-size, etc). For 4x5", don't bother with doing the bellows compensation for any (in-focus) subject area larger than about a metre across because that's only 1/3 of a stop compensation (M=0.125). Say you make a copy of an 8x10" page, that's M=0.5 and C=2.25, which means you need about 1.2 stops of extra light.

How do you measure M? You guess it. Look at your scene, guess the size of the region in-focus and divide by 5". Good enough as long as you're within about 30%. If you're ultra-fussy, you could stick a ruler in the scene but ain't nobody got time for that.

For my film holders, black=exposed. I think that is the more-common approach but obviously there are freaks who do the opposite and We Don't Talk To Them Obviously it only matters if you ever have to interact with someone else's equipment or vice-versa; just be consistent.

SMBooth · Mar 12, 2015

Let be a bit more practical, Hoffy has a 210mm lens, the bellows of a Toyo 45 goes out to say 330-350, even cranked out all the way its one stop. Nothing to work out.

smieglitz · Mar 12, 2015

SMBooth said:
Let be a bit more practical, Hoffy has a 210mm lens, the bellows of a Toyo 45 goes out to say 330-350, even cranked out all the way its one stop. Nothing to work out.

Oh, you're no fun. But, good point.

smieglitz · Mar 12, 2015

polyglot said:
but obviously there are freaks who do the opposite and We Don't Talk To Them

+1

msage · Mar 12, 2015

hoffy said:
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!

Cheers

Before you go out, unpack, setup, compose, meter, set the aperture and shutter speed. Stop and pack up the camera. Repeat, repeat, repeat, maybe ten times. Then go out and expose film!
I did this early on in my career and when ever I get a new view camera. I can do this faster then some with a 35mm cameras.

White=unexposed
black=exposed or empty

Have fun!

Jim Rice · Mar 12, 2015

Traditionally, dark slides are white=unexposed/black=exposed. I always found this counter-intuitive so decided to fix it for once and all and began using the opposite sides. Soon, I had no idea which holders had been exposed and which hadn't so re-loaded everything in the traditional scheme. Thankfully I never did spring for that many holders.

M Carter · Mar 12, 2015

I shot a lot of 4x5 product and found the cheap plastic loupes to be fine, and you can stuff 'em in your pocket. A lens seems awfully bulky for that job!

The real key for focus is to have great isolation via your dark cloth. Sometimes you really have to pull it tight around your head if the sun is on you.

I'd take your camera out in the yard and just play with focusing and movements for an hour or so, you'll hit your stride in no time.

Dr Croubie · Mar 12, 2015

polyglot said:
For my film holders, black=exposed. I think that is the more-common approach but obviously there are freaks who do the opposite and We Don't Talk To Them

When I started 4x5", I didn't even think to ask anyone else, or figure out what was 'standard practice'. I just picked one the made sense and stuck with it. So for me Black is unshot, White has seen the light. I've also got Green and Red stickers respectively on my darkslides (for go / no go). Whatever you pick, just stick with it, and don't mix up your holders with anyone else's.

For reciprocity, I've never bothered with that. But then I only ever really shoot landscapes, where almost every single one is at infinity. It's only 2 stops at 1:1 macro, so unless you're shooting chrome headshots, don't worry about it.

Sounds like we need an AFDUG outing where we can all play LF. Now that I've handed up my summer semester assignments I'm pretty much free for a few weeks until Semester 1 projects start (I've got a shiteload of 8x10 Foma100/FP4/TMX film cheap off fleabay to play with too). Oh yeah, and who wants a 45A lensboard with #0 hole? (came with a lens I bought)

hoffy · Mar 12, 2015

Damn. Apart from Tomorrow, I'm booked solid each weekend until the kids go back for term 2

Some Idle thoughts - trying not to ignore the elephant in the room, my 45A

Membership Council

Privacy & Transparency

Privacy & Transparency