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automatic filmspeed (still film)



Aha, here's where my still photography background may help explain.

Kodak Gold Max (EI 800) and Kodak PJM Ektapress "multispeed" (EI 640) 35mm 
still color neg films are just very good color negative films.  The 
"multispeed" labels come from the marketing departments taking advantage of 
the wide latitude of negative films.  I've read that they both use those 
nifty Kodak T-grains in all layers. 

They have the same broad latitude that most color neg films do, which is 
quite a few stops over and maybe a stop or so under, depending on how much 
of your shadows you don't mind loosing.

The DIR (developer inhibited reduction or some other screwy thing) couplers 
used in many modern color negative films makes them very resistant to over 
exposure problems.  These DIR couplers tend to reduce the effects of the 
developer in areas that have already been developed, extending the dynamic 
range of the film.  They also tend reduce grain a bit when this happens.  
Ask a chemist if this interests you, I'm not an expert here. 

Of course the density continues to build with exposure, leading to longer 
print times. There certainly is no magic that alters the whole neg's 
density so that scenes shot at different speeds will print identically.

Over-exposure (shooting these films at EI 400, 200, 100, etc.) is, as usual,
 little or no problem.  In fact one will often see a desired increase in 
contrast and color saturation at a stop over.

No changes (push/pull) in C-41 processing are used.

With under exposure (EI 1000, 3200, shooting daylight film unfiltered under 
tungsten at rated EI, etc.) you can expect the usual results depending on 
scene contrast.  Of course one can push the film with the usual results.

For a good review of PJM see an article by Ctein in a recent issue of 
"Photo Techniques" magazine. Popular Photography reviewed the Kodak 800 
recently as well.

The promotion by Kodak of Gold 800 as an all around film for snapshooters 
came about because Kodak finally realized that the biggest loss of 
sharpness faced by amateurs is camera-movement blur and lack of depth of 
field caused when using slower film, and not the grain from a faster film 
which is invisible at drugstore print sizes.  In other words, Kodak finally 
realized (after years of making good fast color neg film) that 
snap-shooters will get better results, even in fairly good light, with 
faster film.  Kodak also realized that one needs to be a rather proficient 
photographer to take advantage of (and to notice) the improved image 
potential of the slower films that they have recommended for decades to 
everyone. 

In other words the 800 film is not magic; it just has grain quite 
acceptable for daylight snapshots and offers great advantages in crummy 
light.  In the past few years the differences in grain between different 
speeds of still color neg films has become very small, and color saturation 
with fast film has gotten very close to slow film.  The biggest differences 
between the different speed still color neg films now is price and almost 
invisible differences in MTF curves (sharpness).  All the film makers are 
happy to send out technical data booklets which list RMS grain values which 
will confirm all this.  Agfa has a lot at www.agfa.com and so does Kodak 
and probably Fuji and Konica, too.

>From my experiments the PJM requires different color balancing than 
ordinary amateur color neg films, and therefore may look crummy if not 
printed at a pro lab that has the right printing "channels," as they are 
called in still photo land.  I have not tried the Kodak 800.  I use the 
Fuji Super-G Plus 800 (professional) because the lab I use balances for it 
fairly consistently.

The new APS "Amateur Photo System" or "Advanced Photo System" or Advantix 
(Kodak) or Smart Film (Fuji) is a re-packaging of film and an added 
transparent magnetic layer.  It was developed primarily to increase profits 
for manufacturers of new cameras, film and processing equipment through 
sales of new equipment and very importantly, increases in reprint orders.  
Reprints are a big profit section for the still photo biz.

Advantages of the APS are simplified film loading and (you guessed it) 
simplified print-to-negative matching for reprint ordering.

Disadvantages are smaller film size (somewhere between standard 35mm still 
and disc/110), higher cost, limited availability of film, film types and 
local processing.  

The processed film is stored its original cassette, protecting it from 
fingers and dust but not scratches.  It also makes it a pain to file. 

APS follows 126, 110, and disc cameras for the many of the same reasons.  

Unfortunately many of the potential advantages of APS of being able to 
record specifics of the scene (light value, color temperature, flash on/off,
 distance) on the magnetics of the film are not implemented in current 
cameras.  Even worse, the cameras that have the most to benefit by those 
attempts to use that data to extract a good print later are of course the 
cheapest cameras least likely ever to incorporate those features.  I 
suspect that those features will die on the vine much like the audio CD's 
capacity to store all sorts of ancillary data (like librettos and titles) 
that never were used or standardized. 

Of course for professional motion picture applications a clear magnetic 
overcoat has all sorts of interesting possibilies for logging and....

My 2 cents worth,
Ken Rockwell
(Tektronix by day) 
Hollywood

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