I posted one of the Kodak classic ones a few weeks ago here on Apug. Asked a lot less than the one listed on ebay. If interested pm me.
I have had great success with brand new DeltaTrak Auto-Cal Digital Pocket Probes. I have two of them (~$37 USD) and they're easy to come by. The read out is immediate and with an accuracy of + or - 1 degree Fahrenheit, they're perfect for C41 and E6.
While this may be true for BW it is not true for color. Note Kodak's temperature requirements for their various color processes. They are quite restrictive if one wants good results.
Originally Posted by BMbikerider
A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.
~Antoine de Saint-Exupery
I use both a Kodak Process thermometer and a Paterson Color thermometer available from B&H for about $25. They match at the temperatures needed for color work, so I usually use the Paterson just in case I drop it, it is easily replaced.
The issue though isn't that your thermometer is within ⅛℉, it's that it's consistent. For example most glass thermometers have a fluid and a scale, the fluid expands as it's temperature raises, and contracts as it's temperature drops, the scale is then marked so that when the temperature is a certain point, the scale reads that point. If your scale says 100℉ and it's actually 100.5℉ that is okay, as long as the next time it reads 100℉ the temperature is actually 100.5℉. Your work flow will adapt to any shifts caused by the thermometer being a little off. Where it gets difficult, is if the next time you look at your thermometer and it says 100℉ it's actually 99.5℉ Because it's not consistent, your work flow can't adapt for any shifts, because the shifts are not consistent. Glass thermometers tend to always read the same, if they are off +.5℉ when new, then when you drop it and break it it will still be off +.5℉. The mechanical dial type were notorious for reading differently, some would read differently for different readings, some simply drifted as they aged. Digital ones can also drift as they age, the glass ones tended to remain accurate, but tended to get dropped after a while and break.
Originally Posted by Gerald C Koch
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I'll +1 the suggestion for the Paterson Color Thermometer sold by B&H here:
Claimed accuracy is +/- 0.14 C. If you've ever used a slide-rule, then you can estimate tenths of degrees C with the scale on this thermometer.
I had a Kodak one up until about two weeks ago. I got done using it, went to put it back into the 1 liter graduate that I typically stored it in and it slipped out of my hand and fell about 4" inches into the graduate and cracked.
Originally Posted by Greg Davis
I will never waste my money on one of those again, my cheaper dial ones all read the same as the fragile Kodak one anyway, just as fast and just as accurate...
"I'm the freak that shoots film. God bless the freaks!" ~ Mainecoonmaniac ~
Keep in mind that some of the bi-metal dial thermometers have an adjustment nut on the backside of the dial casing. These can be very handy if you are standardized on a specific reference thermometer in your work. Or as you can imagine, they can also be a royal pain in the butt if they unknowingly fall out of calibration while being banged around.
The large dial Weston thermometers have these adjustment nuts. I found that mine would need to be checked and adjusted frequently enough that I just made it a regular part of my development routine. Eventually I got tired of that extra step, so I calibrated my inexpensive glass Kodak Darkroom Thermometer to 68F/20C* against my reference and now use that. It never goes out of calibration. But I do need to be more careful.
* 68F/20C on my reference thermometer registers as 69.6F/20.9C on my Kodak instrument.
Last edited by Ken Nadvornick; 10-15-2012 at 06:14 PM. Click to view previous post history.
"When making a portrait, my approach is quite the same as when I am portraying a rock. I do not wish to impose my personality upon the sitter, but, keeping myself open to receive reactions from his own special ego, record this with nothing added: except of course when I am working professionally, when money enters in,—then for a price, I become a liar..."
— Edward Weston, Daybooks, Vol. II, February 2, 1932
I bought a $10 digital cooking thermometer at Walmart, and have processed over E-6 100 rolls in the last 1.5 years using the Kodak, Tetenal, and Arista kits, with no problems. This, combined with a $3 styrofoam cooler with water overflow holes punched in the top has served me well for temp control.
As a side note, I suggest the Tetenal E-6 kit from Freestyle Photo, it gives much better results than the Arista. (Kodak kits being long gone...)
Thermometer for Color Processing?
I bought and own two of those inexpensive digital thermometers. They disagree by more then three degrees, at least at black and white temperatures. The better one agrees to within less than 1/2 degree (about .3-.4) with my glass Patterson color thermometer, so I use that one.
Originally Posted by pukalo
Some of those are good but you must verify as some are also pretty far off.