Re: 3D slides & high contrast, slide duplication

[P3D Don Chaps <dchaps@xxxxxxx>]

On Sat, 7 Sep 1996, P3D Dr. George A. Themelis wrote:

> Don Chaps writes:
> 
> >I think the reason that color slide film is used widely 
> >professionally even with its disadvantages of higher contrast and 
> >limited exposure range is because the color balance is fixed and 
> >not subject to interpretation by an unknown third party.
> 
> This sounds as if the slide film has an *inherent* disadvantage of 
> high contrast and limited exposure range, compared to print film.
>
I'd look at it more as a characteristic than a disadvantage. Negative 
film has a longer range because they can do little tricks like add that 
orange mask. But the downside is that for normal pix some person who's 
daydreaming about his or her lunch break is determining the color 
balance. 
	Have you ever opened a box of slides and had your breath taken away 
by the purity of color in the first slide? Imagine that same slide with a 
slight magenta or green cast. Or overexposed or underexposed by a stop. 
Many labs use the "latitude" to mask sloppy work, not imagining that the 
photographer had used the full exposure range of the film. 

 
> Correct me if I am wrong, but I thought that the reason that
> negative film has low contrast is that it will be printed in 
> a piece of paper and this will add contrast.  The reason that
> the slide has high contrast is that this is the final image and
> the contrast must be there.
> 
It's inherent in the design of the material. Slide films have different 
exposure ranges as a byproduct of other design considerations, like 
speed, grain size, color fidelity, etc.
	You're going to happier in the near future. The new generation of 
Kodak "Ektachrome" type films are going to leap ahead a generation in 
quality. And Fuji Reala of the next generation is hitting the market. It 
won't make photographers in my age group forget about Kodachrome or stop 
whining about Kodachrome120 being dropped, but you can bet while we're 
whining and complaining we'll have some of these new films in our 
cameras. 
> Isn't the limitted exposure range tied to the high contrast?
> 
You betcha.


> Isn't it technologically possible to produce slide film with
> low contrast?  Isn't that commercially undesirable?  (i.e people
> want to see contrast in their slides?)  Isn't the slide dupicating
> film a low-contrast slide film?
> 
Yes. But they know when they design the film several important factors- 
like the color temperature of the light source. Also the film is designed 
to produce good colors from light transmitted by the DYES in the source 
film, don't expect great results in the real world. Remember that these 
films are used under controlled, 'laboratory' conditions. Designing a 
film to give great results out there in the real world with varying color 
temperature, stored in wide temperature ranges, in different film 
speeds, and with a color response that 'looks' correct for foliage (you 
know our eyes see green twice as bright as it is? That's why 
institutional buildings were always painted light green) to fabrics that 
luminesce (like the black light effect). IMHO they do a great job, 
considering all the variables.



> John B. said once that his wishes that they made a low contrast
> slide film.  I do too.  I am getting sick and tired of high
> contrast in bright sunny days.  Why don't they make such a film
> so we don't all have to be in a constant look for "soft light"?
> (High contrast stereo slides can be tolerated in a viewer but are
> a total disaster in projection.)  What will happen if one uses 
> slide duplication film as a regular slide film?  (never found 
> the time to try this...)
> 
I wish too for a low contrast slide film. After twenty years of marriage 
my wife feels less like holding a reflector than she did when we were 
first together. Oh well. (Except, of course, when I have a model on the 
shoot... :) )
	Don't hold high hopes for a dupe film to give good results for the 
reasons above. Try some of the new films.

> Also, regarding slide duplication, even though one can match
> the original slide very well and even improve it, the duplicate
> slide lacks some of the snap of the original.  I claim that
> if someone shows me an original *stereo* slide in *my red button 
> viewer* and the best duplicate they can get, I can always tell 
> which one is the original and which one is the duplicate.
> 
> George Themelis
> 
> 
This is a generational problem. First generation is always better than 
second generation. Negative film is designed so the first genera tion is 
output from the negative. So you can repeat that quality over and over 
with the proper controls. 

I'd like to add two comments, if anyone is still reading at the bottom of 
the message.

First, BobH is, as usual, on the mark. Kodak Ektar is a wonderful film. 
Try some. Put the camera on a tripod. Use f8. Easy for people with 1950s 
cameras designed for slow films. Send it to a lab who knows what Ektar is 
(if your prints come back with a green cast, they don't know what they're 
doing). From a 35mm with decent lenses you can get GOOD 16x20 or 20x24 
results. I'm not just talking grain size, but that elusive quality that 
drives people to view cameras - a seamless, rich tonality in the 
transition from dark to light. They are changing this film, as so many 
labs had trouble printing it, and folding it in to their 'Gold" line of 
films. Check their web site, http://www.kodak.com/ , for all the info. 

Second, we have 900 people on P3D. We could assemble a list of questions 
and have someone from Kodak come on the list, answer the questions, and 
answer our questions online. We would have to be polite and not yell. 
Someone who really knows about films could answer questions so you 
wouldn't have to listen to a crackpot like me (feel the motivation?).
We could ask to speak to the person at Kodak who is responsible for their 
3D mounting. We could have someone from APS explain to us 
the new fine grained films that will be introduced there first (APS is a 
smaller format and to gain a foothold in the market the new films are 
being introduced there first).
Once we got Kodak to respond, getting Fuji and Ilford to respond would 
be easy. Want to tell Fuji that you like their new Reala, but they don't 
mount Realist stereo as Kodak does? 

These companies have been friendly to polite requests in the past. 
Ilford still sends samples of new products to interested photographers 
and allows their input to affect their designs. Wonder about the color 
characteristics of a batch of Kodak film or why a certain lot # won't 
feed through your Hasselblad magazines (only real life examples here)? 
Call and a human being will pull the records and address your concerns. 
Want to do stereo with Polaroid, want to beat it, scratch it, strip the 
emulsion and put it on a different medium? Call them. They'll tell you 
how to do it. If they don't know, they may send you film to play with and 
want to see the results. I just taught a course to inner city kids using 
a view camera and Polaroid industrial film to learn optical principles 
and photography. Better questions than when I taught visual design and 
photography in a school of architecture. Unsolicited, Polaroid sent 
several cases of film. Every kid had a chance to produce beautiful prints 
and learn how to exercise control, a not inconsequential lesson in a life 
of chaos.
	Anyway, we are a large group of consumers. Many of these companies 
want to help. Seems like this should lead to a logical next step.


------------------------------