f/stop timer

CMoore · Feb 16, 2019

I must not know (Very Possible) what that means.
But i hear it discussed "all the time".....member XYZ is looking to buy an f/stop timer.
Isn't every timer an f/stop timer.?
3-6-12-24-48 seconds.?
Or simply watching a Clock/Timer and move the cardboard at each appropriate f/stop.?
Then just split the difference from there 24-48 =36 =31=27 or 28 or 27.5 if you are into that.?
Or does an f/stop timer just count 1-2-3-4-5-6.....and assign whatever time you want to each digit.?
1=3...2=6...3=12...etc etc
Does the f/stop timer just refine the process and make it more "versatile".?
Thank You

Pieter12 · Feb 16, 2019

CMoore said:
I must not know (Very Possible) what that means.
But i hear it discussed "all the time".....member XYZ is looking to buy an f/stop timer.
Isn't every timer an f/stop timer.?
3-6-12-24-48 seconds.?
Or simply watching a Clock/Timer and move the cardboard at each appropriate f/stop.?
Then just split the difference from there 24-48 =36 =31=27 or 28 or 27.5 if you are into that.?
Or does an f/stop timer just count 1-2-3-4-5-6.....and assign whatever time you want to each digit.?
1=3...2=6...3=12...etc etc
Does the f/stop timer just refine the process and make it more "versatile".?
Thank You

For me, being able to change the time in f-stop intervals without calculating lets me adjust exposures, burning and dodging as I would judge in-camera. Thus, I can look at a print and see that I want it to be 1/2 stop lighter, etc. Plus, f-stop intervals are constant at any size enlargement.

Doremus Scudder · Feb 16, 2019

CMoore,

Your assessment is fundamentally correct. F-stop timers seem useful for those that like to think in terms of stops/fractions of a stop to make exposure changes.

I find juggling the f-stop numbers a bit unwieldy in the darkroom as well. I just use percentages. I've been doing it for so long that I know how much a 10%/20%/30% change in exposure will affect the look of a print. I use it when scaling up and down (e.g., burning/dodging as a percent of the base exposure). I make my test strips in 30% increments. It's a lot easier to remember than the numbers for third-stops.

I try to stay low-tech. My old time is set on 99 seconds and I count my exposures with the aid of the built-in metronome. I can watch what I'm doing all the time. Percentages give me the advantages f-stop timing without the number crunching.

Best,

Doremus

fiddle · Feb 16, 2019

I guess thats the point of an f-stop timer. Dont have to crunch numbers, let the timer do that for you, all you have to concern yourself with is stops, half stops, etc.

CMoore · Feb 16, 2019

fiddle said:
I guess thats the point of an f-stop timer. Dont have to crunch numbers, let the timer do that for you, all you have to concern yourself with is stops, half stops, etc.

Right. Any timer COULD be, but the dedicated unit does it "better" and "easier".
Thanks for the info. I can understand Why a person would want one...makes sense.
Thank You

awty · Feb 16, 2019

If you use 3 6 12 etc you are working in 1 stop intervals, when you work your exposure time you generally work to 1/3 or 1/4 stops. So to use a normal timer you must adjust the timer for each exposure of the test strip. Say 2. 2 , 2.6, 3.3, 4.2, 5.4 etc. To get 3rd stop intervals.
With an f stop timer it works that out for you.
If you work to say 3 secs intervals you start by doubling the light and then decreasing with every exposure. You may end up with the same base time , but it is easier and more accurate to work to f stops especially if you do complicated dodge and burns.
I use to adjust my timer to a fstop chart, now I have a fstop timer it does the mental arithmetic for me.
Also the more modern timers can store different programs to run in sequence if you are doing multiple prints as well as adjust for dry down and different filters etc.
if you are serious about printing its a good idea to work to fstops, like your camera, now so you get use to it, harder to change when use to working in seconds for a long time.....well at least all those I know who work in secs seem to dispel using fstops.

RalphLambrecht · Feb 16, 2019

CMoore said:
I must not know (Very Possible) what that means.
But i hear it discussed "all the time".....member XYZ is looking to buy an f/stop timer.
Isn't every timer an f/stop timer.?
3-6-12-24-48 seconds.?
Or simply watching a Clock/Timer and move the cardboard at each appropriate f/stop.?
Then just split the difference from there 24-48 =36 =31=27 or 28 or 27.5 if you are into that.?
Or does an f/stop timer just count 1-2-3-4-5-6.....and assign whatever time you want to each digit.?
1=3...2=6...3=12...etc etc
Does the f/stop timer just refine the process and make it more "versatile".?
Thank You

you are right but a 'real' f/stop timer can be set to increase logarithmically rather than just using linear increases.

mshchem · Feb 16, 2019

It takes me looking at finished prints, sometimes going back and starting over days later . I have a chart on the wall that shows 1/3, 1/2, etc. And I have an app on my phone. I use closed loop light sources that have photocells with controller timer combination.

All this stuff is very cool. I remember getting my first real enlarger timer. Lot's better than counting 1 Mississippi, 2 Mississippi ,3 etc.

Deleted member 88956 · Feb 16, 2019

mshchem said:
... I remember getting my first real enlarger timer. Lot's better than counting 1 Mississippi, 2 Mississippi ,3 etc.

Yeah, but I had found that with some practice when augmented by a good Porto, I could tweak how long I pronounced Mississippi essentially giving me f/stop control. Only after too many augmentations did i lose control of that process.

mshchem · Feb 17, 2019

Witold said:
Yeah, but I had found that with some practice when augmented by a good Porto, I could tweak how long I pronounced Mississippi essentially giving me f/stop control. Only after too many augmentations did i lose control of that process.

RalphLambrecht · Feb 17, 2019

Witold said:
Yeah, but I had found that with some practice when augmented by a good Porto, I could tweak how long I pronounced Mississippi essentially giving me f/stop control. Only after too many augmentations did i lose control of that process.

if you eat a lot of carrots, you can improve your vision; drinking a lot of wine and you can double it; but drink a lot of vodka and you can see things that are not even there.so, why eat carrots?

RalphLambrecht · Feb 17, 2019

CMoore said:
I must not know (Very Possible) what that means.
But i hear it discussed "all the time".....member XYZ is looking to buy an f/stop timer.
Isn't every timer an f/stop timer.?
3-6-12-24-48 seconds.?
Or simply watching a Clock/Timer and move the cardboard at each appropriate f/stop.?
Then just split the difference from there 24-48 =36 =31=27 or 28 or 27.5 if you are into that.?
Or does an f/stop timer just count 1-2-3-4-5-6.....and assign whatever time you want to each digit.?
1=3...2=6...3=12...etc etc
Does the f/stop timer just refine the process and make it more "versatile".?
Thank You

any timer and the attached list can be an f/stop timer

MattKing · Feb 17, 2019

If you need something to help you conveniently remember a progression of half stops of exposure time, then this progression might seem familiar:
2.8, 4, 5.6, 8, 11, 16, 22, 32, 45, 64, 90, 128 ... (all in seconds).

Deleted member 88956 · Feb 17, 2019

RalphLambrecht said:
if you eat a lot of carrots, you can improve your vision; drinking a lot of wine and you can double it; but drink a lot of vodka and you can see things that are not even there.so, why eat carrots?

Appears to be so true, after too many Porto augmentations I started making images I never knew I actually shot.

CMoore · Feb 17, 2019

RalphLambrecht said:
any timer and the attached list can be an f/stop timer

MattKing said:
If you need something to help you conveniently remember a progression of half stops of exposure time, then this progression might seem familiar:
2.8, 4, 5.6, 8, 11, 16, 22, 32, 45, 64, 90, 128 ... (all in seconds).

Very interesting and clever.....Thank You

Doremus Scudder · Feb 17, 2019

MattKing said:
If you need something to help you conveniently remember a progression of half stops of exposure time, then this progression might seem familiar:
2.8, 4, 5.6, 8, 11, 16, 22, 32, 45, 64, 90, 128 ... (all in seconds).

I don't know about the rest of you, but I have problems accurately counting 2.8 or 5.6 seconds... I basically do what Matt suggests, though, just rounding the numbers a bit:

3, 4, 6, 8, 11, 16, 22...

Actually, I don't like print exposure times much shorter than 15 seconds, so one could just start at 11:

11, 16, 22, 32, 45... Note, however, that this is in a progression where every number is roughly the product of the square root of 2 and the previous value, about a 40% increase every time.

Often, I need test strips in finer gradations, so I'll make a strip at approx. 30% intervals (each number is 1.3 x the previous one):

10, 13, 17, 22, 28, 37, 48... (I count 10, 3, 4, 5, 6, 9, 11...)

Or in roughly 25% intervals, where each number is roughly 1.25 x the previous:

10, 13, 16, 20, 25, 32, 40, 50... (I count 10, 3, 3, 4, 5, 7, 8, 10...)

Same idea, but I still think that using percentages instead of f-stop numbers (which are unwieldy because they're based on the square root of 2), is more flexible. I can't figure third-stop intervals in my head quickly...

Best,

Doremus

MattKing · Feb 17, 2019

Doremus Scudder said:
I don't know about the rest of you, but I have problems accurately counting 2.8 or 5.6 seconds... I basically do what Matt suggests, though, just rounding the numbers a bit:

3, 4, 6, 8, 11, 16, 22...

Actually, I don't like print exposure times much shorter than 15 seconds, so one could just start at 11:

I usually start at 6 anyways .
And by the way, if you are in the habit of using a single exposure, and progressively covering more and more of your paper, you can use this progression:

c41 · Feb 17, 2019

I have a printed chart on the wall by the enlarger and just multiply or divide accordingly to adjust. (I have an electronic timer so I can do 1/10ths of seconds.)
I can see the appeal of the f stop timer - I hate maths - but my printing is simple and I dodge/burn 'by eye'.
But now I see Ralph's handy chart above, I'll print that and add to the wallpaper - thanks.

Here is the chart I use to date - (courtesy of retailer that sells f stop timers)

Stops - Seconds - Enlarger Adjustments.pdf

tezzasmall · Feb 18, 2019

Gosh!!! All these numbers bouncing around is giving me a headache!

Good luck to those that are able to do it 'manually' with a number chart on the wall.

I loved maths at school, but I am so glad to of gotten an RH f-stop timer to do it all for me. It is so easy compared to doing it 'manually' and it was definitely well worth the money paid!!!

Terry S

David Brown · Feb 18, 2019

I had graduated from mechanical Time-o-Lights to a fairly sofisticated electronic timer, an Omega CT40. About 12 years ago I took a workshop with Les McLean (old APUGers remember him?) and he was demonstrating the new RH fstop timer. I thought it was cool,but didn’t “need it”. Then, as fate would have it, the Omega died a sudden electronic death. I splurged fof the RH and have never looked back. It is a wonderful device.

Tom Kershaw · Feb 19, 2019

tezzasmall said:
Gosh!!! All these numbers bouncing around is giving me a headache!

Good luck to those that are able to do it 'manually' with a number chart on the wall.

I loved maths at school, but I am so glad to of gotten an RH f-stop timer to do it all for me. It is so easy compared to doing it 'manually' and it was definitely well worth the money paid!!!

Terry S

I realised recently that now I mostly use an RH Designs F-stop timer (set to 1/12th stops), I've forgotten how to do some of the manual calculations, although I have a chart in 1/8th stops on the wall.

Tom

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