Test Strip Exposure Intervals

[RalphLambrecht]

Thank you all so much for the advice. Dangerous subject as everyone has a slightly different method. My key learning is that standard intervals don't reflect the equivalent change in light. However, I am the sort of person who is prepared to sacrifice some technical accuracy for something that is easy to remember, so I think I will run with the Ilford technique to start with (2,4,8,16 and 32 seconds), which will give me 5 full stops, and adjust my technique as I gain experience.

good idea

 

[Bill Burk]

From the Bruce barnbaum book..that's where I learned it. A full sheet of paper and I can nail a print in usually 3 sheets. NO TEST STRIPS FOR ME EVER. seems really hard but I make great negatives and I know my route of approach that I'm looking for. Fancy machines and do dads ain't my thing no more. I know Michael Smith used a music timer in the darkroom
I'll put it anyone here...meet me and show me your prints and I'll show you mine... over been printing this way for close to 10 years now.
There are MANY PATHS ON THE ROAD..CHOOSE ONE AND LEARN IT WELL
IF YOU WANT WASTE YOUR TIME MAKING LITTLE TEST STRIPS PLEASE DO IT BUT IF YOU TRY THE WHOLE SHEET METHOD YOU MIGHT ACTUALLY GO TO THE NEXT LEVEL

Still not quite getting it. Your full sheet. It's one exposure?

 

[mshchem]

I use half stops - 2.8, 4, 5.6, 8, 11, 16, 22, 32, 45, 64 ... - if for no other reason than it is easy to remember.
I'm comfortable rounding things off to 3, 4, 6, 8, 11, 16, 22, 32, 45, 64.
I like to accomplish this by sequentially covering more and more of the strip. I accomplish that with the aid of this chart:
View attachment 215606

This is the way I've been doing it for 20 years. Foolproof. I have several pieces of hardboard (Masonite ) I have a couple little strip printers that I use with smaller prints. I have a f stop app on my cell phone too. The elegant F stop timer is not an option for my setups.

 

[Bill Burk]

I guess I could buy Bruce Barnbaum's book to see what he's saying. I've been threatening to do that for a while.

He's a contrarian so I wouldn't be surprised if his methods are unconventional.

Some of the things he says are opposite what I would say.

But I don't want to discredit or criticize him. I like the way he talks. I could listen to him for hours.

But I wouldn't say the same things he says.

Google let me see a few words of what he says.

He guesses the contrast based on the contact print. (OK I "know" the contrast because I aim for 2 1/2 and can tell from the negative if it's closer to 2 or 3... besides, if it's a really bad negative then I know it's going to be 1 or 5.)

He decides the exposure based on ... (then the Google preview cuts out). But I get it, he uses some logic to get close.

I don't know why I don't - I have the technology. But for the exposure... I just use a test strip.

 

[mshchem]

If all we did was shoot studio shots, like the folks did back in the day. Kept everything repeatable. It would be easy to calculate times based on the enlarger height. Problem with my work is I'm always cropping moving the beast up and down.
I will spend hours making a "perfect" print only to completely renovate it in a later session. I bet I waste 7 or 8 sheets of paper before I get a couple of prints that I like.
Test strip gets me in the ballpark then I start fiddling with my VCCE head.

 

[mooseontheloose]

Download and print a copy of the f-stop printing table that Ralph has so kindly provided. I photocopied a similar table from Tim Rudman's books and its the most used item I have in my darkroom. Going to f-stop printing from "time" (linear) intervals completely changed my success rate in the darkroom. After all, you shoot/base your in-camera exposures in stops, why not prints as well? Going 5-10-15-20 seconds (as I was first taught) means that the exposures are not equal, each subsequent exposure is less than half of the previous one. Where as printing in full (or half or third) stops, the consistency/exposure will be exactly the same between each strip. It also means that your dodging and burning will also be the same (based on stops) when making different size enlargements, as opposed to time values, which will change with each size.

Link 1
Link 2
Link 3

 

[M Carter]

What did you make the mask from.....cardboard.?
Thank You

Black poster board, pretty much "construction paper" or art paper in black. I expose a strip, mark the paper with a pen at one side of the mask, slide it over til the mark disappears.

 

[CMoore]

I see.....Thank You

 

[Doremus Scudder]

I guess I could buy Bruce Barnbaum's book to see what he's saying. I've been threatening to do that for a while.
He's a contrarian so I wouldn't be surprised if his methods are unconventional.
Some of the things he says are opposite what I would say.
But I don't want to discredit or criticize him. I like the way he talks. I could listen to him for hours.
But I wouldn't say the same things he says.
Google let me see a few words of what he says.
He guesses the contrast based on the contact print. (OK I "know" the contrast because I aim for 2 1/2 and can tell from the negative if it's closer to 2 or 3... besides, if it's a really bad negative then I know it's going to be 1 or 5.)
He decides the exposure based on ... (then the Google preview cuts out). But I get it, he uses some logic to get close.
I don't know why I don't - I have the technology. But for the exposure... I just use a test strip.

Bill,

(Off-topic a bit, but peripherally relevant I hope...) I, too, determine what contrast I want to start with from my proof. When exposing, I indicate a development time (N, N+ or N- whatever) and a target paper grade. My indication might look like this: N-1/3, meaning N-1 development, target grade 3. I'm right with the grade 85% of the time or thereabouts. However, I make "proper proofs" on about grade 2 of all my negs and evaluate them in order to really choose my starting contrast. If the print looks pretty good on the grade 2 proof, I'll start there. If it's too contrasty, I'll go lower; too flat, I'll go higher. For real extremes I know I have to start pretty far from center. This is exactly what Barnbaum does (Picker and others too). I then make a test strip on my chosen contrast grade and make an initial straight print. Like Barnbaum, I base my initial print exposure on the highlights (this is would be what's missing from your Google preview). If the blacks don't fall where they should, a change of contrast is in order. With VC paper, I'll just dial in what I think is the right amount of change. I'll make another test strip if the change is significant; if it's small, I'll guesstimate exposure and just make another print. If I'm working with graded paper, I'll always make another test strip. No sophisticated technology in my darkroom except the computer to log printing records. Just enlarger, color head and metronome.

FWIW, my basic printing card is a piece of 4-ply mat board, 16x20 inches, black on one side and white on the other (black side goes down, of course, white up so I can see the image). In this I have cut holes of various sizes and covered them with flaps of mat board (or the cardboard separators that come with sheet film) hinged with tape. I can easily choose an appropriate size of hole for burning that way just by flipping a flap.

Best,

Doremus

 

[wiltw]

Download and print a copy of the f-stop printing table that Ralph has so kindly provided. I photocopied a similar table from Tim Rudman's books and its the most used item I have in my darkroom. Going to f-stop printing from "time" (linear) intervals completely changed my success rate in the darkroom. After all, you shoot/base your in-camera exposures in stops, why not prints as well? Going 5-10-15-20 seconds (as I was first taught) means that the exposures are not equal, each subsequent exposure is less than half of the previous one. Where as printing in full (or half or third) stops, the consistency/exposure will be exactly the same between each strip. It also means that your dodging and burning will also be the same (based on stops) when making different size enlargements, as opposed to time values, which will change with each size.

Right. If full EV increments goes 5sec, 10sec, 20sec, 40sec, going in half EV increments yields

Sec Increment
5.....2
7.....3
10...4
14...6
20...8
28...12
40...16
56

 

[keithcraigs]

I'm going to reply here a few days late:
I use a 4x5 Jobo test strip maker. It allow me to get 4 test strips from an 8x10 and their big enough to actually see the differences in exposure and I can place it on my easel wherever I think it will work best. They're divided in 5ths. A 20 second exposure is 4, 8, 12, 16, 20. A 30 second exposure is 6, 12, 18, 24, 30 and so on. While most of my exposures are well under 20 seconds, I just used this on a 2 minute test strip and it came out as expected.

 

[removed account4]

hey OP
how dense is your film?
it could be 1/2 seconds 4 clicks or 10 seconds wide open ...

 

[RalphLambrecht]

Bill,

(Off-topic a bit, but peripherally relevant I hope...) I, too, determine what contrast I want to start with from my proof. When exposing, I indicate a development time (N, N+ or N- whatever) and a target paper grade. My indication might look like this: N-1/3, meaning N-1 development, target grade 3. I'm right with the grade 85% of the time or thereabouts. However, I make "proper proofs" on about grade 2 of all my negs and evaluate them in order to really choose my starting contrast. If the print looks pretty good on the grade 2 proof, I'll start there. If it's too contrasty, I'll go lower; too flat, I'll go higher. For real extremes I know I have to start pretty far from center. This is exactly what Barnbaum does (Picker and others too). I then make a test strip on my chosen contrast grade and make an initial straight print. Like Barnbaum, I base my initial print exposure on the highlights (this is would be what's missing from your Google preview). If the blacks don't fall where they should, a change of contrast is in order. With VC paper, I'll just dial in what I think is the right amount of change. I'll make another test strip if the change is significant; if it's small, I'll guesstimate exposure and just make another print. If I'm working with graded paper, I'll always make another test strip. No sophisticated technology in my darkroom except the computer to log printing records. Just enlarger, color head and metronome.

FWIW, my basic printing card is a piece of 4-ply mat board, 16x20 inches, black on one side and white on the other (black side goes down, of course, white up so I can see the image). In this I have cut holes of various sizes and covered them with flaps of mat board (or the cardboard separators that come with sheet film) hinged with tape. I can easily choose an appropriate size of hole for burning that way just by flipping a flap.

Best,

Doremus

to base exposure on highlights makes printing a hell of a lot easier.I must agree with Barnbaum and others 100% on this. Expose for the highlights and adjust contrast for shadows is my rule when printing.

 

[Kirth Gersen]

hey OP
how dense is your film?
it could be 1/2 seconds 4 clicks or 10 seconds wide open ...

I have no idea. I usually shoot HP5, Afga APX 100 or Pan F 50.

 

[Kirth Gersen]

A quick progress update.

I have produced about 6 different prints now (and used a ton of paper), slowly refining my skills. I have settled on 4,8,16,32 as my intervals, seeing no use for 2 seconds and so far only requiring one renewed strip for 64 secs.The process I am most comfortable with is to set the timer for 4, 4, 8, 16 secs steps, covering as I go.

I tend to shoot manually, and think in stops, so this really has been beneficial when it has come to dodging and burning, and have pinned up a version of the chart RalphLambrecht offered on my Darkroom wall. Very easy to think that a part of a photo needs to be lightened by 1/3rd of a stop, for example, and work it out from there.

Cutting out 4 strips seems to work most of the time, but on occasion I was fooled as it appeared that 32 secs would be the right exposure. I had in fact exposed at 32 secs on the part of the image which was very bright, so when I exposed the whole image at 32, everything else was pretty much black and unusable. Will be more careful where I am placing the test strip in future.

 

[removed account4]

I have no idea. I usually shoot HP5, Afga APX 100 or Pan F 50.

i guess you didn't understand my question ...oh well ..
good luck with your darkrooming !

 

[Bill Burk]

To improve where I place the test strip, after I get ready to go, I hold the strip behind my back and turn on the enlarger for a couple seconds so I can see where I'm aiming.