Sensitometer For B&W Film?

[LFLarry]

Hi, I have been reading the Kodak Basic Photographic Sensitometery Workbook and I would like to find a sensitometer that I can use with B&W film. I looked on eBay and it seems all I can find are ones rated for x-ray film. I may be missing something obvious, so I wanted to ask the group here for some advice. Basically, I would like to find a model that can do B&W film. Any help/tips are appreciated.

Thanks

Larry

[Daniel Casper Lohenstein]

Gossen Mastersix/Ultra Pro + Profiflex.

[Tony Lakin]

Error in post

[ic-racer]

I tested green LED, blue LED, incandescent and xenon tube sensitometers for their ability to detect different film speeds and different percent gamma change with development change and all sensitometers gave the same normalized results. So, depending on your use, any of the 4 types could work.

[LFLarry]

Thanks for the info.

I was under the impression that I would either need to correct for the daylight-balanced B&W film when using the X-Ray (green or blue) light units or get a proper sensitometer.

Any idea why the X-Ray units also work on panchromatic film too?




I tested green LED, blue LED, incandescent and xenon tube sensitometers for their ability to detect different film speeds and different percent gamma change with development change and all sensitometers gave the same normalized results. So, depending on your use, any of the 4 types could work.

[LFLarry]

Hey Daniel, thanks. I did a search on eBay using the info you provided and I am not seeing anything at this time.



Gossen Mastersix/Ultra Pro + Profiflex.

[Peter De Smidt]

A MacBeth, X-rite or Cosar densitometer should work fine. If you're doing alt processes, one that has a UV option is useful. A color one works fine, but you don't need one for general bw work. I've owned and used all of the ones mentioned, and they've worked fine for film speed/development testing.

[Mark Sampson]

I'm a bit confused here. A Sensitometer is a calibrated device which exposes a density step wedge onto film. They are not common and are generally used by the film manufacturer. One use is to make the step wedge "control strips" sold by Kodak (and perhaps other makers).
A Densitometer is used to read densities on a processed piece of film and is standard equipment in a photo lab to measure process control, and also used by careful photographers to calibrate their exposure and development. Which are you looking for?
-And per Mr. Lohenstein's advice, Gossen often called their products by different names in the USA and in Europe.

[ic-racer]

I tested green LED, blue LED, incandescent and xenon tube sensitometers for their ability to detect different film speeds and different percent gamma change with development change and all sensitometers gave the same normalized results. So, depending on your use, any of the 4 types could work.

https://www.photrio.com/forum/threads/the-great-sensitometer-shootout.95837/page-3#post-2173619

https://www.photrio.com/forum/threads/the-great-sensitometer-shootout.95837/page-3#post-2173622

https://www.photrio.com/forum/threads/the-great-sensitometer-shootout.95837/page-3#post-2003147

[Daniel Casper Lohenstein]

Hey Daniel, thanks. I did a search on eBay using the info you provided and I am not seeing anything at this time.

E.g.

https://www.ebay.ch/itm/Gossen-Mastersix-Belichtungsmesser-Studiomesser-Photo-Meter/401880146763?hash=item5d91ec634b:g:X80AAOSwK7xdd-YD

https://www.ebay.ch/itm/Gossen-Mess-Sonde-fur-Lunasix-3-Lunalite-Lunasix-F-Multisix-Messonde/312940349088?hash=item48dcb2c6a0:g:hegAAOSwPsBeGcS9

https://www.ebay.ch/itm/Gossen-Mastersix-outfit-32554-1/352836336640?hash=item5226af3c00:g:LlwAAOSwoBFdt2xO

Manual, see: https://www.cameramanuals.org/flashes_meters/gossen_ultra_pro.pdf , page 30

https://grossformatfotografie.de/attachment/5823-d2x4481-jpg/ and https://grossformatfotografie.de/attachment/5824-d2x4484-jpg/

A real light meter is more versatile than a densitometer. You can use it in other situations, too. It also works without the flexible fiber attachment - just put a little sleeve in front of the light meter, that blocks stray light and keeps the light meter at a constant distance from the measuring point, that's all. The Mastersix / Ultra pro has a dedicated photometry mode with zero density calibration. This is very useful. The light meter measures very accurately, to two decimal places, just like a dedicated densitometer.


Regards

[Daniel Casper Lohenstein]

You guys should read his original post again. He is not looking for a densitometer to read film density. He is looking for a sensitometer to expose film density. Completely different machine and purpose.

Does he produce black and white films and does he have to measure any densities daily to ensure a consistent production?

That is rather unlikely, IMHO. That's why I assumed that he meant a densitometer rather than a sensitometer. Sorry.

Furthermore, the term "sensitometer" contains the word "meter", which refers to an activity of "measuring". I don't see that exposing grayscales on a piece of film involves "measuring".

But: if you buy a sensitometer (sensitoexposer), just send me some normally exposed gray scales on my favorite film ... You could provide us all with it.

[Tin Can]

Good video Greg


You guys should read his original post again. He is not looking for a densitometer to read film density. He is looking for a sensitometer to expose film density. Completely different machine and purpose.

I use a Tobias Wejex I-W that uses a small incandescent bulb with nd and 80A filters to convert it to daylight. About a 1/2 second exposure time. There is one on eBay right now for $200, but you just missed one for $5. I show mine in this video:

https://youtu.be/VNbyShwYi6c

[ic-racer]

That is a great Wejex, thank you for showing the insides, now I want one. I have a small collection of sensitometers including the older "Black Box" Wejex, but I don't have that one. I'll have to keep my eyes open for one.

[ic-racer]

Does he produce black and white films and does he have to measure any densities daily to ensure a consistent production?

That is rather unlikely, IMHO. That's why I assumed that he meant a densitometer rather than a sensitometer. Sorry.

Furthermore, the term "sensitometer" contains the word "meter", which refers to an activity of "measuring". I don't see that exposing grayscales on a piece of film involves "measuring".

But: if you buy a sensitometer (sensitoexposer), just send me some normally exposed gray scales on my favorite film ... You could provide us all with it.

To use the sensitometer a calibrated step wedge is paced in contact with the film. Yes, without that part, the machine is useless.

[Daniel Casper Lohenstein]

To use the sensitometer a calibrated step wedge is paced in contact with the film. Yes, without that part, the machine is useless.

I've been thinking. I'm not a native English speaker. Everything takes a little longer with me.

in the german large format forum a user has the idea to use a contact copy box with a flash. so he can control the iso, by power.

he uses darkslides with holes to expose the stouffer card. so he has 3 different iso per step.

i myself would like to use the enlarger for the contact copy. that should be enough. but with which exposure time?

[ic-racer]

I've been thinking. I'm not a native English speaker. Everything takes a little longer with me.

in the german large format forum a user has the idea to use a contact copy box with a flash. so he can control the iso, by power.

he uses darkslides with holes to expose the stouffer card. so he has 3 different iso per step.

i myself would like to use the enlarger for the contact copy. that should be enough. but with which exposure time?

Enlarger exposure time can be problematic because many enlarger timers don't go below 1 second. Making a sensitometer is not that hard, but make very sure of two things. 1) The field on which the step wedge is placed is PERFECTLY EVENLY illuminated and 2) The level of illumination will not change from year to year, month to month or day to day.

[bnxvs]

You guys should read his original post again. He is not looking for a densitometer to read film density. He is looking for a sensitometer to expose film density. Completely different machine and purpose.

I use a Tobias Wejex I-W that uses a small incandescent bulb with nd and 80A filters to convert it to daylight. About a 1/2 second exposure time. There is one on eBay right now for $200, but you just missed one for $5. I show mine in this video:

https://youtu.be/VNbyShwYi6c
+100!


I just wrote about it yesterday ... https://www.largeformatphotography.info/forum/showthread.php?52865-Stouffer-s-4x5-step-wedge-for-exposing-negative&p=1536887&viewfull=1#post1536887
If the topic author is interested (DIY), I can give more detailed descriptions of the device and place the sketch and photos.

[Bill Kumpf]

Phil Davis in his book "Beyond the Zone System" 4th Ed describes adapting a Pentax Spotmeter to use as a densitometer. It is a good read on film testing.

[eli]

Use a colour analyzer like the Beseler PM2a, which can read black and white negatives and colour negatives and slides (back in the days of Cibachrome, etc) and allow you to use your colour head instead of contrast filters.

It's dead simple, and if you are doing critical b&w shots, (are no they all) shoot a good grey card with your first frames and maybe again when lighting conditions swing in extremes, with whatever filter you're using, in place.

Using a colour analyzer like the PM2a can put you within a second or three of your correct enlarger settings.

I have also used simple light meters, such as the Minolta III flash unit, with a darkroom metering attachment, the grey body, Gossen Luna Pro SBC (U.S. version) and the Gossen Luna Pro F, both with the same Gossen darkroom enlarger attachment and they both work fine.

For B&W printmaking, pretty much any good, low light, ambient meter should do the trick, so long as you are using a relatively small meter aperture for reading the negative, which allows you to read from different areas of the image.

And, yes, having a digital timer, does make a difference in fine tuning enlarger time, however, you can always slide a fractional ND filter into the filter drawer or above the negative, as needed.

IMO.

Good luck.

[Bill Burk]

Great video Greg!

Daniel, an enlarger will work fine and Greg's right. You want about a half second exposure. (Avoids reciprocity failure issues). How much light? Don't overthink. Just do trial and error. You need one step under 0.10 density to check film speed. Give more or less exposure until developed test has 19, 20 or 21 steps (of a 21 step Stouffer scale) to measure.

ic-racer's "sensitometer shootout" was an eye-opener for me. Any sensitometer will help you develop film for consistent contrast.