F stop printing

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mshchem

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For small increments, like 1/12 stop, there isn't much if any difference between a linear progression and a logarithmic progression. The smaller the stop increment the more linear the progression - the basis of differential calculus, really.

A 1/12 stop 5-strip test would start out at a 6% step and finish at a 7% step: 10 seconds, 10.6 seconds, 11.2 seconds, 11.9 seconds, 12.6 seconds. Without an f-Stop timer one might as well set the timer to 0.6 seconds (or 6% of the base exposure (though 5% / 10% are easier on the grey matter)) and be done with it.

A 1/12 of a stop change in print exposure is roughly equivalent to a 1/6 of a zone / stop change in negative exposure (midtones, regular development, #2 paper). Control over exposure can be far more precise when printing than when shooting. Printing can deliver what the Zone System only promises.

Did you (a few years back) sell a f stop overlay for the Gralab timers? That seems like the first time I recall seeing a f stop timer for printing.
My method seems to be make a lot of test prints. I use a Metrolux II timer for my cold light enlargers, this works nice but alas no f stop function, I have a phone app, my problem is I don't always know if a print is X fstops light or dark.
 

MattKing

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Did you (a few years back) sell a f stop overlay for the Gralab timers?

There is a template in the Support Files section of Nicholas' Darkroom Automations website.
 

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RalphLambrecht

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Mr Lambrect:

Did this modification help much? I have been just using a regular timer and 5 second intervals for my first "test strip" for a long time. When I learned the "close time" I then shortened my interval. My gray lab was broken after a long while and I just worked by intuition, it worked OK

it helped me understanding f/stop timing.
 

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pentaxuser

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Ralph, I do hope that lenshustle will look at your link and begin to re-think his attitude to fstop timing

pentaxuser
 

RalphLambrecht

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Ralph, I do hope that lenshustle will look at your link and begin to re-think his attitude to fstop timing

pentaxuser
I do too.I was in the fortunate situation to have started with f/stop timing and needed no convincing.
 

Nicholas Lindan

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But no illustrated introduction to those who are new to the subject (hint, hint).

Ralph has already done a wonderful job of this in Beyond Monochrome. Anything I did would just be a poor imitation of Ralph's book.

After reading Ralph's work is there any aspect that remains cryptic?

Much of my writing comes out sounding like an engineering textbook. Spend a lifetime writing engineering documents and look what happens to you - crippled for life.
 

MattKing

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Ralph has already done a wonderful job of this in Beyond Monochrome. Anything I did would just be a poor imitation of Ralph's book.

After reading Ralph's work is there any aspect that remains cryptic?

Much of my writing comes out sounding like an engineering textbook. Spend a lifetime writing engineering documents and look what happens to you - crippled for life.

Thanks, and I understand.
And thanks to Ralph for sharing!
I have and rely on the first version of his book, and recommend either version to everyone who asks.
But its nice to be able to refer people to a web resource as well.
Perhaps Ralph and his co-author would allow you to use a credited copy of the excerpt he uploaded on your site.
 

cliveh

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If you are doing f-stop printing, are you ignoring depth of focus?
 

MattKing

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If you are doing f-stop printing, are you ignoring depth of focus?

They have nothing to do with each other.
Depth of focus is a function of the efficiency of the negative holder and the lens aperture used.
f/stop printing relates to exposure times (not lens aperture).
 

albada

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If you are doing f-stop printing, are you ignoring depth of focus?

The names "f-stop printing" or "f-stop timing" are poor because they imply that the lens-aperture is being changed, causing confusion.
That's why I would prefer that it be called "stop-based timing" or "geometric timing".
 

Pieter12

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I don’t see much difference between stop an f-stop timing. But I do think the reference should be to timing rather than printing, since it is the time that is being changed in f-stop increments.
 

cliveh

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I seem to have mis-understood f/stop timing, so why give it this name if you are not changing f/stops?
 

MattKing

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I seem to have mis-understood f/stop timing, so why give it this name if you are not changing f/stops?

Because:
1) the logarithmic progression of exposure times matches how the paper actually behaves; and
2) the common sequence of aperture f/stops happens to mirror almost exactly the sequence of 1/2 stop progressions of exposure times: 8, 11, 16, 22, 32, 45, 64, 90, 128 seconds etc.
So if you are working without a fancy f-stop timer, you can still easily make 1/2 stop adjustments.
And remember, f/stop actually means stop factors, which apply to both apertures and times.
 

albada

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I seem to have mis-understood f/stop timing, so why give it this name if you are not changing f/stops?

That is why "f/stop timing" is a bad name. Most photographers are not engineers, and to them it sounds like we're changing the aperture. Misleading.
I used "stops" for time in my timer/controller for LEDs, abbreviated as "st" as the time "4.0st" illustrates below:

CtlStops.jpg


But when one selects and changes time, the controller also displays seconds:

CtlStopsSec.jpg


For me, this is clear. It cannot be confused with f/stops (aperture) on the lens.

The LED-brightnesses on the top row of the display for red/green/blue are also in stops (10=max, 9=half bright, 8=quarter, ...). The steps in test strips (via the Strip button) progress in stops, not seconds. With everything in stops, it's easy to interchange settings, such as dimming the LEDs and exposing longer to compensate. Yesterday, Ralph Lambrecht posted a chapter from his book, Way Beyond Monochrome, detailing additional advantages of stop-based timing.
 

Pieter12

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That is why "f/stop timing" is a bad name. Most photographers are not engineers, and to them it sounds like we're changing the aperture. Misleading.
I used "stops" for time in my timer/controller for LEDs, abbreviated as "st" as the time "4.0st" illustrates below:

View attachment 317030

But when one selects and changes time, the controller also displays seconds:

View attachment 317031

For me, this is clear. It cannot be confused with f/stops (aperture) on the lens.

The LED-brightnesses on the top row of the display for red/green/blue are also in stops (10=max, 9=half bright, 8=quarter, ...). The steps in test strips (via the Strip button) progress in stops, not seconds. With everything in stops, it's easy to interchange settings, such as dimming the LEDs and exposing longer to compensate. Yesterday, Ralph Lambrecht posted a chapter from his book, Way Beyond Monochrome, detailing additional advantages of stop-based timing.

Once you start using the method, you surely wouldn’t be confusing time and aperture. It is only those who don’t know what is involved who are unclear.
 

Sirius Glass

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Once you start using the method, you surely wouldn’t be confusing time and aperture. It is only those who don’t know what is involved who are unclear.

I agree, even as an engineer, it was not enough to only read about it, I had to work through it several times with one or two prints. Then the light went on, no paper fogged here, I understood it. When you were first taught about logarithms in Algebra II your teacher probably gave the same lesson every day for a week. Each day the light popped on in a few more students. A month later everyone in the class was using logarithms as thought they were as easy as counting with natural numbers [1, 2, 3, 4, ...].
 
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mshchem

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I use an app or a chart. An f stop timer is probably one of the better investments a printer could make, that and a lab book for records.
 

mshchem

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Thanks, and I understand.
And thanks to Ralph for sharing!
I have and rely on the first version of his book, and recommend either version to everyone who asks.
But its nice to be able to refer people to a web resource as well.
Perhaps Ralph and his co-author would allow you to use a credited copy of the excerpt he uploaded on your site.

I have both editions. Great!!
 

RalphLambrecht

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Thanks, and I understand.
And thanks to Ralph for sharing!
I have and rely on the first version of his book, and recommend either version to everyone who asks.
But its nice to be able to refer people to a web resource as well.
Perhaps Ralph and his co-author would allow you to use a credited copy of the excerpt he uploaded on your site.

I would
 

Sirius Glass

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I use an app or a chart. An f stop timer is probably one of the better investments a printer could make, that and a lab book for records.


I have a digital enlarger timer that works in seconds and seconds and tenths, so I do not know how an f/stop label will help me. I will stick to a chart.
 
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