This sort of question is hugely dependent upon what sort of printing you do and what your expectations are.
If you are a shoot lots and knock out a print or two, then move on never to return - then no you probably don't need a fancy timer, counting will probably (just about) do
If you are a high end printer doing fine art or exhibition prints or similar then yes you will NEED one
Personally, I was more than a little skeptical about would an RH StopClock Pro be good value for money when my friends advised me to get one
Having bough one and used it a few times, I would say yes they are great value for money - expensive, yes but definitely worth it
Hint - have a look on e-bay for second hand RH equipment to see whether existing owners think their stuff was good value for money - about as common are common as bags of rocking horse manure
I use graylab 450's for most of my work, a simple timer that is repeatable is critical.
I only do percentage split printing, so once I find my base time I never touch the timer again, no need.
I do count like most here, but a metrodome would be of no use to me because AC DC is pumped so loud in my darkroom who would hear the silly thing.
So I get it now and should have a timer shortly. But one more question, after using a timer to standardize your exposure, how do you standardize processing in trays?
MattKing and Newt_on_Swings gave some good examples where consistency wasn't happening for what should have been routine darkroom work.
2F / 2F, great advice to throw in an ND filter.
I like my old Omega A.R.T. and try to keep it at 32 seconds. My third f/stop times from there are easy to remember 7-5-4-3 and I just count that many clicks while burning and dodging.
When I start out, I turn on my lamp and let it warm up a bit. I put a meter similar to Nicholas' under the brightest (shadow) spot and change my f/stop on the enlarging lens until it "nulls" at the point where my time should be 32 seconds.
To burn, I'll set the A.R.T. to 40 or 50 which is the next two third-stops up from there (nominal print time is still 32).
Even still, I sometimes have print-to-print variations that I blame on variations in brightness of the old fluorescent ring light source. I think it is funny that the Omega instruction booklet claims at great length how their large ring fluorescent tube is instant-on and provides more stable light output than competitor's grid lamps.
So the value of a timer is consistency - which will reduce frustration - which is priceless.
Assuming you have one of these light sources... I also assume your light is stable by one of these methods.
-With a grid lamp, I'd want to either have a compensating timer -or- a "Horowitz" stabilizer.
-With an incandescent lamp, I'd want to have a voltage regulator.
-A colorhead probably has a matching regulator.
-With my setup, if you believe the literature it's OK as-is.
But with my setup I'd want a compensating timer. For now I am settling on my old "null" meter and pledging to check before each print.
I live with the variation by making prints in "sets of three" - one for me, one for others, and one for mistake. One of the three can be wrecked and I still call the day a success.
For tray processing timing I use the CompnTemp. I have no relationship with the advertiser, but it is one of those landmark purchases that I have been very happy with.
You might want to do a dummy print and see how much the light output changes over your standard 32 second printing time. The light change over the printing time should be small when the lamp has warmed up but may be quite large if you are starting with a cold lamp.
Originally Posted by Bill Burk
For the most consistent results you might try turning the enlarger on and waiting until the meter reading stops climbing before making a print - that way you will always be working with a hot lamp.
Even an incandescent condenser head has a few minute stabilization time during which the light output rises by 0.03 stops or so - admittedly irrelevant for printing but interesting for the technoids among us.
Originally Posted by Nicholas Lindan
That's kind of what I (pledge to) do... after a bit of warmup, I adjust the aperture (around f/11 but I go off the detent) until the meter goes null and stays there... then I print.
I use an Omega CS-10 and it is at the edge of its range. I use a densitometer to evaluate the negative scale, but your enlarging meter (this is not a shill, I don't have relationship to advertiser) is on my short list as a good value.
Originally Posted by AlbertZeroK
I'd suggest you look into "factorial development" - essentially you time how long it takes for a particular tone to begin to emerge, and then develop the print for a total time that is 3, 4, 5 or 6 times that emergence time.
The factor you use (3, 4, 5 or 6) will depend on which paper and developer you are using, but will remain constant once you determine it.
You can arrive at the factor by working backwards - take fresh developer and prepare a print that, when developed for a time in the middle of the manufacturer's recommendations yields a good result. Then measure how long your chosen target tone takes to emerge. Divide the two times, and that will give you your factor.
Here is an APUG thread with more information:
Originally Posted by AlbertZeroK
You can look up the paper manufacture's recommendation for paper development.
You don't want to leave the paper developing in a tray too long, usually 1.5 minutes in Dektol 1:2 mixture. This would be for your average B&W print. Different papers react differently to exposure and development times, much like film does. There are some different printing methods and developers that use different starting points and dilution recommendations. It all comes down to what kind of prints you want to make. Your paper choice, developing chemical choices and how much or little you dilute your developers.
There are some great darkroom technique books available that can give you a good starting point. One series of books comes to mind, Saint Adams series books; The Camera, The Negative, and The Print.
Don't worry about making mistakes, sometimes those mistakes can lead to some great prints.