F stop timer

[Pawlowski6132]

Does anyone use one of these? I'd be curious to know how you use it.

Thanx

[Peter De Smidt]

I use an f-stop professional by RH Designs.

First, I make an educated guess about what overall contrast the print should have. Second, I use the timers' test strip function. You can have it space the steps by whatever increments you like. 1/12th stop, 1/6th stop, 1/3 stop... In general, with lower contrast it's better to uses bigger steps than with high contrast. Third, I now make a print at the exposure that the test strip indicated would give the best overall highlight exposure. Process, wash a bit, dry, evaluate. If the contrast is off by a bit, I adjust. (I use a settings on my De Vere color head to change contrast. I tested so that I can change contrast while keeping Print Value VIII constant.) Fourth, I may make minor changes to exposure, and then I work out a pattern of burning in areas. It's easy to program the time to give a base exposure and up to 10 separate burning steps. These are entered as fractions of an f-stop. E.g. I can specify that I want to burn down the sky by 1/2 stop more exposure than the main exposure. If I change my main exposure, all the burning steps will be recalculated to the required amount of more exposure.

This timer is the best piece of darkroom kit that I've ever acquired.

[banjo]

you can make your own !!
http://www.darkroomagic.com/DarkroomMagic/Darkroom.html

[jeroldharter]

Ditto Peter's comments.

[Bill Burk]

I marked my timer in 1/3 f/stop increments. It serves me well. But I only recently realized that it is suitable for work in a single grade (for example Grade 2) but as you move up grades, the increments cause greater change. So something more sophisticated is required (if you are going to use random Grades of paper).

[kev curry]

As Peter said; plus the timer mentioned has two separate programmable channels that make split grade printing easy. The timer has made my D/R experience more controlled and enjoyable, but I'm also aware that some master printers use nothing but a simple metronome and I'm beginning to understand its benefits over any timer.

[bigdog]

I'd be curious to know how you use it.

I use it essentially the same as any other enlarger timer. Except, that it is more intuitive to look at a test print and determine that it needs another half stop, than that it needs X more seconds. Also, test strips made in f stop incriments have been a revelation.

[Richard Rankin]

I used to own one in Australia, and felt it was one of the most valuable pieces of equipment I had ever purchased. If I ever have the money to do a decent darkroom again, that will be my first purchase.

Richard

[polyglot]

a spot of devil's advocacy (http://www.brodie-tyrrell.org/fstoptimer/)

[Bill Burk]

In general, with lower contrast it's better to uses bigger steps than with high contrast..

Funny, I just re-read this and it is quite an understatement.

I'd say it is a fatal flaw in f/stop timer logic.

If there could be a timer that marks time in terms of noticeable tone change and this time would vary depending on paper grade -- now that would be awesome.

Meanwhile, I will stick to 1/3 stop and Grade 2.

[Cor]

Funny, I just re-read this and it is quite an understatement.

I'd say it is a fatal flaw in f/stop timer logic.

If there could be a timer that marks time in terms of noticeable tone change and this time would vary depending on paper grade -- now that would be awesome.

Meanwhile, I will stick to 1/3 stop and Grade 2.

I fail to see the fatal flaw, a lower grade (say grade 1) by definition a longer contrast range than a higher grade (4), so it takes more stops (time units) to go from white to black. If your f stop timer can handle it (mine cannot, it's "only" 1/4 stop steps) you would use 1/12 steps at Grade 5 and perhaps 1/3 steps at Grade 0, what is the problem?

Best,

Cor

[GeorgesGiralt]

Hello Bill,
I own and use a marvelous piece of gear : the Analyser Pro from RH Designs.
It does just that. It knows the sensitivity and contrast range of the paper you put on your easel, and it shows you, on a grey scale, what gray tones you will get when committing a print. whatever grade you choose... you can figure what your print will look like on different papers without actually printing it...
Not cheap but pays for itself in less time than you thought it will...
If you're short on money don't try one !
P.S. Gene Nocon, the one who devised F stop printing and was a hell of a printer has just passed away. RIP.

[David Aimone]

I love mine. The only "new" piece of equipment in my new darkroom and it is worth every penny!

[Bill Burk]

what is the problem?


No real problem, just have to mentally shift into lower gear on steeper grades.

Sorry to hear of Gene Nocon's passing, I just saw his video.

I work on Grade 2 most of the time and when I saw the video I thought how lucky I was to have always used his concept of the f/stop time series.

But I was caught off-guard when doing a stylized Grade 4 print and a 1/3 f/stop burn took my sky from stark white to moody storm.

[blevblev]

I use an RH Design f-stop timer as well. The authors of "Way Beyond Monochrome" suggest that you should make prints in a kind of flip side of the axiom used when making negatives - "expose for the shadows and develop for the highlights." That is, "expose for the highlights and control the shadows with contrast." So, make a test strip and ignore everything except the highlights. Pick the exposure time/f stop that gives correct highlights. Then make a test print and evaluate the shadows. Change the contrast to control the shadows. Just as changing negative development time will only minimally change the shadow ares in a negative, changing print contrast will only minimally change the highlight areas of the print. After that, dodge and burn if necessary.

The F-Stop timer particularly makes your test strips more meaningful. Then after you determine the exposure you want from the test strip, you simply start with the base exposure of the test strip, and press the up button the number of times that corresponds to the number of sections of the strip that matches the exposure you want. In other words, if your test strip shows that the 5th strip is the exposure you want, you start with the base exposure, and hit the up button 5 times. This will give you the exposure of the 5th strip.