f Stop Timer

[Lee L]

Lee-

thanks for the clarification. I don't recall seeing that in my hard copy when I bought the timer, which was about 2 years ago. I did not read the owners manual online prior to purchasing - I bought the unit purely on multiple word-of-mouth recommendations from folks here on APUG. That said, I still think they should be available from the OEM, when I'm paying north of $400 for something new in the box, items that are required to make it function should all be in the box.

Steve,

I certainly understand the frustration of getting a great new tool and having some unexpected work to do to get it going.

Since I already had two IEC adapter cords ready when my timer arrived, I put the RH Designs supplied IEC female plug on a small power strip I had on hand, replacing the standard US male AC plug. That gave me a "safelight" power strip coming out of the Stop Clock that I could plug a collection of safelights into, and switch off or on with the timer, or switch off independently. This could have also gotten your enlarger going quickly without modifying your enlarger plug, or could have given the timer control of two enlargers without having to switch plugs. If you do something like that, I'd recommend either a switched enlarger cord or the AC wall plug in-line switches that you can find at every hardware and discount store.

Sorry if I've taken this too far off topic.

Lee

 

[TheFlyingCamera]

No problem. I'm not used to thinking in terms of electrical appliances; it took a serious case of guts for me to hack the plug off the Beseler power supply and re-wire it for the timer. I never would have thought of doing it the way you did. Oh well, goes to show we all have different experience levels and comfort levels with these things. It's one of those cases where an assumption was made somewhere along the line that everyone buying the timer would be equally comfortable with wiring devices. I'm getting better at it- I've installed a programmable thermostat, rheostat light switches, and a few overhead light fixtures now, and I still have all my fingers, toes, and the same amount of un-barbecued hair I had before (factoring out natural male pattern baldness). None of the above is a huge accomplishment, but for someone not used to doing such, it's something.

-Scott

 

[Lee L]

-Scott

Oops! Sorry about the name mix up Scott. I really knew better. I was just in the middle of sending an email asking advice from a friend who does publicity photo work for musicians and a couple of venues in NYC. His name is Steve and my feeble brain missed the switch from that email to my reply here.

Lee

 

[dslater]

I have a couple of questions/issues with f/stop printing times. I have done this in the past using a conventional timer. However, it is my understanding that because the light source has a ramp up time to full intensity, a series of short exposures are not the same a one long exposure for the total time. What do you do about this? In my case, I now use a metronome timer which doesn't lend itself well to f/stop timing for test strips.
The other thing is that all the tables I have found give total exposure times. However, for making a test strip, these tables aren't very useful. For making a test strip, what you really need is a table of deltas - i.e. how much time to add for the next strip as you progressively cover the paper. For example going in 1/3 stop increments:

start with 2 seconds then - covering a strip after each step:

0.2, 0.3, 0.3, 0.3, 0.4, 0.4, 0.5, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.4, 1.6
2.2, 2.5, 2.8, 3.2, 3.6, 4.0, 4.5, 5.0, 5.7, 6.3, 7.1, 8.0, 9.0, 10.1,11.3,12.7,14.3

the top row are the deltas, the bottom the total exposure time. These numbers have been rounded to 1 decimal place.

Dan

 

[Curt]

I got a quick reply from RH, they recommend a model that's $500.00. And I was saving for a Cooke lens set!

I wanted to use it with my two Aristo Cold light heads and one Beseler Halogen. Maybe I need to junk it all and just go to ULF and contact printing. I don't know about the rest of you but I have to save up for months to get items I need. I was hoping it was going to be around $200.00. Oh well!

 

[jeroldharter]

It is expensive but still worth it. The Darkroom Innovations timer advertised on this site is much cheaper. Should work just as well and you don't lose on the exchange rate.

 

[dslater]

I got a quick reply from RH, they recommend a model that's $500.00. And I was saving for a Cooke lens set!

I wanted to use it with my two Aristo Cold light heads and one Beseler Halogen. Maybe I need to junk it all and just go to ULF and contact printing. I don't know about the rest of you but I have to save up for months to get items I need. I was hoping it was going to be around $200.00. Oh well!

Curt,
As a compromise, try this - make your initial test strip the usual way. Then, once you start making work prints, think if terms of f-stop times - i.e. when you are judging a work print, instead of thinking about how many seconds more or less exposure it needs, think in terms of how many f-stops more or less exposure it needs, then look at one of the tables to find out how to change your exposure time. This is how I work with my metronome.

Dan

 

[Ray Heath]

I have a couple of questions/issues with f/stop printing times. I have done this in the past using a conventional timer. However, it is my understanding that because the light source has a ramp up time to full intensity, a series of short exposures are not the same a one long exposure for the total time. What do you do about this? In my case, I now use a metronome timer which doesn't lend itself well to f/stop timing for test strips.
The other thing is that all the tables I have found give total exposure times. However, for making a test strip, these tables aren't very useful. For making a test strip, what you really need is a table of deltas - i.e. how much time to add for the next strip as you progressively cover the paper. For example going in 1/3 stop increments:

start with 2 seconds then - covering a strip after each step:

0.2, 0.3, 0.3, 0.3, 0.4, 0.4, 0.5, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.4, 1.6
2.2, 2.5, 2.8, 3.2, 3.6, 4.0, 4.5, 5.0, 5.7, 6.3, 7.1, 8.0, 9.0, 10.1,11.3,12.7,14.3

the top row are the deltas, the bottom the total exposure time. These numbers have been rounded to 1 decimal place.

Dan

why make it so complicated, it doesn't need to be high tech

i even doubt the need for so called f stop printing

 

[Curt]

It is expensive but still worth it. The Darkroom Innovations timer advertised on this site is much cheaper. Should work just as well and you don't lose on the exchange rate.

I just emailed Darkroom Innovations, I found out a long time ago that going cheap is not worth the effort. I will figure out which is best and get the one that's worth the effort.

Thanks Jerold and others,
Curt

 

[RH Designs]

when I'm paying north of $400 for something new in the box, items that are required to make it function should all be in the box.

Hi Scott

I do take your point, but I've not been able to find a source for these adaptors here in the UK (probably because they can't legally be used here). A link to IEC is on our FAQ pages and I normally include the info with packages shipped to the US - my apologies if I omitted it in your case.

Kind regards
Richard

 

[Nicholas Lindan]

I even doubt the need for so called f stop printing

The question is "Do you want it?" - not if you need it.

 

[Nicholas Lindan]

I just emailed Darkroom Automation, I found out a long time ago that going cheap is not worth the effort.

Cheap it is not ...

Wood case finished with 3 coats of Waterlox Marine Varnish
16Ga. steel front panel
50,000,000 operation rating on the key switches
10,000,000 operation rating on the relay
Lexan front panel overlay
UL/VDE approved components
Screw machine gold sockets
105C rated capacitors, extra long life
AMP Diamond Grip connectors
Calibrated AMP tooling
Epoxy-Glass circuit boards
State of the art RISC microprocessor
Structured software design, C language
& more

... reasonably priced it is.

 

[TheFlyingCamera]

Hi Scott

I do take your point, but I've not been able to find a source for these adaptors here in the UK (probably because they can't legally be used here). A link to IEC is on our FAQ pages and I normally include the info with packages shipped to the US - my apologies if I omitted it in your case.

Kind regards
Richard

Richard - it's more a quibble than a major source of upset- I still love the timer and I'll keep on using it. Now that I know, if/when I upgrade my enlarger, I'll know I don't need to chop off the plug!

 

[TheFlyingCamera]

why make it so complicated, it doesn't need to be high tech

i even doubt the need for so called f stop printing

While I agree with the sentiment as relating to all those tables and charts for factoring exposure manually, I totally disagree with the "why f-stop printing" comment. I didn't get it originally, because I was used to printing the old-fashioned way - set 10 seconds, etc. Once I tried using one, it made all the difference in the world. I can't say anything about the Darkroom Innovations timer as I haven't used one, but from my experience with the RH Designs timer, it has made a quantum improvement in my printing - my prints are more accurate and more repeatable, and I waste substantially less paper printing a new unknown negative than I would if I used a traditional timer. This is in part due to the densitometric probe that comes with my timer. It lets me analyze the negative for base time and for contrast range. Tremendous tool, and worth every penny.

 

[Curt]

I just got an email and I can say that it makes sense. The Darkroom Automation timer can be used with my Aristo heads, I have one for 6x6, two for 4x5, a 5x7 and an 8x10, the latter two are not being used presently. I also converted the Beseler Color head from 83 volt and feedback electronics to a 120 volt halogen bulb, this head has the three knobs on the front to mechanically control the filters. I have calibrated the filters and I since I don't do color it's now perfect and the bulb or lamp is available. Sometimes I want to use the cold light but most often I will be using the Beseler.