Hi Greg, really fantastic that you are producing these videos. I watched all 3 videos you have published so far and they are very well done. Great job!! Looking forward to watching the rest in this series.
Larry
Originally Posted by Greg Davis
Hi Greg, really fantastic that you are producing these videos. I watched all 3 videos you have published so far and they are very well done. Great job!! Looking forward to watching the rest in this series.
Larry
Very helpful for sure. Thank you!
Hi, I want to make sure I am clear on a point that you made in the first link below.
Are you saying that the blue and green LED sensitometers that are readily available today which were designed for Radiographic work I believe are sufficient for testing B&W 35mm roll films for the range of sensitometry tests as outlined in Kodak's "Basic Photographic Sensitometry Workbook"?
If you want to test film for speed and developing time, I use a densitometer, NOT a sensitometer.
Hi Luis, I understand and agree with you. I am talking about using a sensitometer for creating a characteristic curve, determining D-min/D-max, Contrast Index, and exposure latitude. Basically, all the sensitometry "stuff". I have a solid process already in place with my densitometer only where I can accurately determine the EI rating for any film and developer combo as well as the associated development times for N, N+, N-, etc.
My goal with the sensitometer in conjunction with the densitometer is to really compare same films in different developers and various films in the same developer to ultimately meet my personal creative vision.
While the exposure part can be done with an enlarger and electronic timer, a sensitometer just makes that part of the process fast, painless, and easy with 35mm roll film. I also think it is more consistent than using an enlarger too.
I don't know of any consumer-grade sensitometers being made today. When I worked for Eastman Kodak, my division designed, built, and sold a few of the Model 1-B sensitometer. It was used to characterize aerial camera and duplicating films, and create control strips for the various specialized processes used. I believe we supplied a few 1-Bs to other Kodak divisions, as well as the U.S. government. It was also about the size of a home washer-drier combo, and the price must have been quite substantial (as in if you have to ask...). Of course if you're a manufacturer selling hundreds of million dollars worth of quality product, you'd need something like that. Oddly enough, my first assignment at EK, in 1984, was to make photographs of that machine for an upgraded instruction manual.
I'll guess that any of the various home-made devices mentioned above will serve your purposes quite well.
I have no idea if these are worth buying, but there are 50 FS
I think they were used for Mammogram X-Ray which was the last of the analog uses in NA
https://www.ebay.com/sch/i.html?_fro...R+SENSITOMETER
2022
2022
New video in the series, Contrast Index: https://youtu.be/TwTymRBedz4
The blue and green X-ray sensitometers will be useful for comparing different films, but may not be full spectrum enough for contrast index, accurate film speed, etc. And they may not have a means of measuring illuminance. There are three EG&G units on ebay right now that are 5500K flash units and discussed in IC-racers threads on Photrio. They may need work on the electronics though.
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