Quote Originally Posted by Photo Engineer View Post
Henning;

Sorry to hear about your illness. I hope that you are back up to par.
Thanks Ron, not quite yet, but it is getting better.


Quote Originally Posted by Photo Engineer View Post
Try here: http://www.kodak.com/global/en/profe...4024/e4024.pdf page 6

and here: http://www.kodak.com/global/en/profe...4046/e4046.pdf page 5

You see the response of the Ektachrome falling off at 20 c/mm falling below 100 whereas the Ektar remains at about 100 at this same point. The projected red response at 100 c/mm is not very good.
Well, of course we know the data from the tech. pubs. very well.

And that is one result of our work in testing films, sensors and lenses for more than 20 years now:
The technical data published by the manufacturers is of limited informative value for real life photography, because the laboratory test methods have some significant differences compared to normal shooting conditions photographers use in their normal daily photography.

That is why we use test methods which are closely related to normal photography: Normal cameras and lenses, tripods and lower object contrast (1:4; not 1:1000).

We've found that this is not an Kodak related issue, but true for all manufacturers. Sometimes the data from the data sheets leads to too high expectations (we've experienced this especially with some Agfa films in the past), but sometimes the official data is even a bit too conservative (example: some Fuji CN films).

So from this experience (we probably have the biggest private test archiv worldwide with over 5000 test results) our recommendation is:
Test your films by shooting it under the conditions they are used by the photographer.

Quote Originally Posted by Photo Engineer View Post
I again stress that contrast can confound measurements.

PE
Of course, that's right.
That is one reason why we measure the object contrast of the test subject by two different methods before a test is started.
And we always say at which object contrast our tests were done.
Sharpness and resolution are dependant on object contrast. Lot's of people don't consider this.

Best regards,
Henning