ORWO N75 Plus 400 35mm Film Test
I got some ORWO N75 Plus 400 film yesterday. There are some threads on this film out there. I will mention that it is an inexpensive 35mm negative movie film with rotary process and still photography characteristics unknown to myself.
The first test shown here is a test of film speed. This is a test relative to fresh Tri-X. Both films were exposed with a Wejex Daylight sensitometer and processed together about 30 minutes after exposure. Processed in Jobo CPP2 6 min at 24C in T-max developer one-shot. Films read with a calibrated Tobias TCX transmission densitometer.
The speed of each film was determined and Tri-X was defined as "400" to see where the ORWO falls relative to that. A 'minimum gradient' film speed test was done, rather than a '0.1 fixed value' test to avoid having to create a series of curves for each film.
The results are in the following graph.
The ORWO is a fast film but it is just slightly slower than Tri-X. In terms of error of this method, I'm using a standard deviation of 0.3 DIN units per the paper by Nelson on W-Speed.
So that gives Tri-X a range of 27.3 to 26.7 DIN and ORWO a range of 26.7 to 26.1, so they almost overlap.
I'll say they are very close. Based on this I'll meter them the same.
This was not a development test pre say, but I can see that the ORWO does not respond as well as Tri-X to Tmax developer. I'll probably use a time that is 25% greater than my time for Tri-X.
SPECS: ORWO emulsion number N62-1, Roll 1711 25d, Box speed 400 daylight, 250 Tung.
Thanks for performing these tests. I look forward to seeing some images from this film.
Well done IC-racer!! Thank you! You are right! ORWO needs more developing time. It's Dmax is only 1.3. Even more than 25%. I'm looking forward to try slower ORWO film. I hope very soon.
I interpret fog level as an indicator of how long film as been sitting around before I buy it. My Tri-x (100ft) came from a refrigerator at a local dealer a few weeks ago and the ORWO came in the mail the day before the test. Results are as follows:
Film base plus fog:
Tri-x = 0.33
ORWO = 0.41
Just to be fair, ic-racer, Kodak is Kodak and TRI-X is one of the best films ever made. Under no circumstances I can't except those two films to be direct competitors. I haven't use fresh ORWO in more than 18 years and I'm looking forward to try their new emulsions.
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Although that Tri-X was fried a little (gamma was around 0.9) that ORWO looks like it has a straighter curve. I'm keeping an open mind. All I know is that ORWO wants to be your 35mm film supplier and Kodak, well I don't know that they want...
Originally Posted by gorbas
Here is a curve for OWRO N75 processed a little longer to more closely match the slope of the Tri-X. In this case the films were processed individually, but the other conditions were held reasonably constant.
The two film curves look very similar. Speed is very close.
Last edited by ic-racer; 11-24-2011 at 11:41 PM. Click to view previous post history.
Great to see some data, (especially since I have a roll of the stuff on order.) how is the grain?
I still live just beyond the fringe in Stittsville
At 6 minutes the grain is very similar on both test strips. With 8 min on the ORWO the grain is slightly more pronounced than the TriX at 6 minutes.
Originally Posted by cmacd123
I did my first film run with new ORWO UN-54 developed in Agfa Rodinal 1:50.
Also, there are few more pictures on my Flickr