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10-15-2015, 03:17 PM   #1
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Negatives vs. Positives

Learning as much as I can...a teeny bit at a time. I ran across a post elsewhere that made references to printing and enlarging using either positives or negatives (re: film). Is there an easy to understand description of what this might mean...maybe in 25 words or less? Thanks!!


Dave

10-15-2015, 03:42 PM   #2
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Film 101: What is the difference between negative and slide film?

Positive film is also known as slide film. When you process it you get a positive image that can be viewed with a projector etc. Negative film needs to be printed as a positive (usually on paper) to be viewed. When you print a 35mm negative you usually use an enlarger, because otherwise the print is 36x24mm...

Printing slide film is much easier today than it was in the past because we can digitize it with a scanner, 25 years ago it was a different story.

Last edited by boriscleto; 10-15-2015 at 03:48 PM.
10-15-2015, 04:39 PM   #3
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Printing color is not all that hard, but it is very different that printing B&W. The question can not really be answered in 25 words or less.

With color, you have to have a great deal of control on all aspects. Color film has printed recommendations for CYM settings on your light source, film and paper. Burning and dodging can create pretty bizarre color shifts. The temperature of the chemicals must be held within narrow tolerances. Add into this, everything except the exposure on the paper, must be carried out in complete darkness, no safelights for color processing. You get to see the image when the process is completed not during the process as in B&W. (The one thing I really miss in photography is watching a B&W image "come up" in the tray).

With slide film, it is much the same, except you don't get as much detailed information about what color filters to add into the mix to get the image to print correctly and good color balance is a black art.

As for when it was possible to print color slides directly to print, think the early 1970's. That is when my father and I built a darkroom (initially B&W) and we branched out to color when my father bought a Besler 23C with Dichro Head. We used Cibachrome to print Kodachrome, Ektachrome and Fujichrome slides.

I still have the enlarger, but my home is on a septic tank. Heavy metal poisoning (Silver et all) is not something that will occur.

The Elitist - formerly known as PDL

Last edited by PDL; 10-15-2015 at 04:43 PM. Reason: Answer 25 word question.
10-15-2015, 05:00 PM   #4
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So...when I used to select either print or slide film for my 35mm camera in the 80's, I was using these definitions:

Positive film, also know as slide film, yields positives typically viewed as slides on a light table or projector.
Negative film yields images that are typically enlarged and printed on paper for viewing.

Correct? I think I got it. Thanks.

Dave

10-15-2015, 08:27 PM   #5
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QuoteQuote:
=

Printing slide film is much easier today than it was in the past because we can digitize it with a scanner, 25 years ago it was a different story.
Boris, thanks for the info. May I follow-up by making an assumption and asking another question?

I assume then that if I wanted to print positive film today using the scanner you mention, that the 36x24mm positive is scanned/digitized and the software embedded there or on my computer would enlarge the image to my specs for printing. So...unlike my 1980 experience, to end up with a print wouldn't I purchase and shoot slide film rather than print film?

Thanks again.
10-15-2015, 08:51 PM   #6
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QuoteOriginally posted by daveward Quote
I assume then that if I wanted to print positive film today using the scanner you mention, that the 36x24mm positive is scanned/digitized and the software embedded there or on my computer would enlarge the image to my specs for printing. So...unlike my 1980 experience, to end up with a print wouldn't I purchase and shoot slide film rather than print film?
The scanner will scan at resolution up to the maximum for the device. The scan resolution determines the pixel dimensions of the digitized image. This is true for both positive and negative film, though the quality of the film image itself determines the detail available for capture. What does that mean for printing?

Non-Real World Example:

- 35mm film (0.94" x 1.42")
- Scanned at 1000 dpi resolution
- Resulting digital image will be 940x1420 pixels (1.3 Mpixels)
- Print at 100 dpi --> 9.4" x 14.2"

You can ask the printer driver to print larger using data interpolation but it will not have any more detail than the original scan. A more realistic approach for better results would be to scan at 4000 dpi* resulting in a 3700x5680 image (21 Mpixels) and correspondingly greater ability to print large. As for film...the better color negative films have capture resolution equivalent to the best slide films from the '80s.


Steve

* There is more to a quality scan than pixel dimensions. The scanner optical path is critical. Factoring in optical deficiencies, the better non-commercial flatbed scanners max out at about 2400 dpi. Most dedicated film scanners max out below 4000 dpi while drum scanners (and equivalent devices) can push upwards of 8000 dpi.

Last edited by stevebrot; 10-15-2015 at 09:03 PM.
10-15-2015, 09:12 PM   #7
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QuoteOriginally posted by stevebrot Quote
The scanner will scan at resolution up to the maximum for the device. The scan resolution determines the pixel dimensions of the digitized image. This is true for both positive and negative film,
Steve, thanks!!! To be honest, the parts I fully understood are in quotes above. I suppose the underlying question for me is this: if I wish the final result to be an 8x10 print, should I buy positive or negative film?

Thanks again.

Dave
10-15-2015, 10:09 PM   #8
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QuoteOriginally posted by daveward Quote
if I wish the final result to be an 8x10 print, should I buy positive or negative film?
The answer has nothing to do with what size of print you want, the question you have to answer is which film gives you the best photograph. That's a subjective decision based on what you are looking for in colour rendition, granularity, dynamic range and a couple of other factors that I can't think of right now. It's not even down to positive vs. negative, although your options for slide film (positives) are getting shorter all the time. Scanners work just as well with positives as negatives, and assuming you use the same format of camera with both types of film, the piece of polyester or acetate with layers of silver halide crystals on it is the same size, hence the same number of pixels.

In days of old, or if you want an anachronistic experience today, you would get prints by exposing photographic paper to light instead of spraying microscopic dots of inks on it. To get the best results from positives in larger sizes required an intermediary step of creating a larger format negative from the 35mm slide, which was then used to make the final print. I've got a 16" x 24" print of the twin towers taken with consumer grade Ektachrome hanging on my wall, produced this way. Prints developed in a darkroom have a special quality to them that can't quite be duplicated with a scanner and digital printers, but unless you specifically want that "look" I would go straight to digital. There are some very good software film emulators that can make your digital camera image look like it came out of a film camera. That's not what you asked, but there is always a question behind the question, right?

10-16-2015, 08:36 AM   #9
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QuoteOriginally posted by RGlasel Quote
That's not what you asked, but there is always a question behind the question, right?
RGlasel...ha, ha...there is always a question behind the question, especially during this exploratory phase. That's why I am parked here in Troubleshooting and Beginner Help. I shot 35mm slides in the 80's and stopped the hobby cold til now. Then, the process was of no interest, today it is. My questions are waaay more basic I believe than the answers being offered...which is not necessarily bad...just means I have to scour the answers for what I think I'm looking for.

All I think I'm getting at, fundamentally, is a mental picture of the process of buying the film to yield a print and perhaps acquiring a scanner to do some of the work myself. Not obvious to you is that I do not know what equipment in total is needed, beyond a scanner. So perhaps my real question is this: in the 80's I assumed to to my own thing would have required a darkroom and chemicals and stuff...what is it I need today to be self sufficient?

Thanks.

Dave
10-16-2015, 01:36 PM   #10
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QuoteOriginally posted by daveward Quote
what equipment in total is needed, beyond a scanner
The only other thing is software, because the raw output from the scanner needs to be converted to something that looks remotely like your prints. Regardless of how good the software is, to get good results you still need a really good scanner. I just assumed that if I could scan prints and be happy with the results, I could scan film with the same equipment and I was wrong. I send out my slides to be scanned now.

The other thing I'll add is that there is nothing wrong with digital prints from slides, but if you aren't going to project those slides on a screen, there is no benefit that I know of from digitizing positives instead of negatives. Your only option in most places for positive film is Fujichrome, which may or may not suit your tastes, so it's pretty hard to recommend positive film over negative if you are only going to be digitizing them. I only dropped out of shooting film (nearly 100% slides) for a few years before I got my K-30 and I was only taking pictures to get souvenirs of my life instead of creating art, so my experience is probably not the same as yours.

QuoteOriginally posted by daveward Quote
what is it I need today to be self sufficient?
You have to ask yourself why you want to shoot film. If it is to practice a craft, then you can go so far as to make your own photographic paper and quality used darkroom equipment is available for a fraction of its original value. If you want to refresh your memories of shooting film 25 years ago without setting up a slide projector to look at your images, shoot negative film and get it digitized when you get it developed. If you want very good to excellent results, scanning for yourself is time consuming, requires a scanner that is worth as much as your camera and in the end you don't end up with a better product than if you pay to have your film digitized. The scenario I haven't mentioned is when you want to digitize old slides and negatives; if you have enough of them or if you enjoy restoring old photos, then I can see making the investment in a good scanner. On the other hand, a camera shop where I live offers to digitize a "shoebox" full of prints and negatives for a fixed fee, so a scanner is optional for this scenario as well.
10-16-2015, 04:06 PM   #11
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All you really need to produce a nice 8x10 is a flatbed scanner with a transparency adapter, like the CanoScan 9000F or Epson V600, and some negatives or slides.

Most scanners now have some sort of dust/spot removal built in, but a rocket blower and Photographic Emulsion Cleaner are good to have too.
10-20-2015, 09:17 PM   #12
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QuoteOriginally posted by RGlasel Quote
If you want very good to excellent results, scanning for yourself is time consuming, requires a scanner that is worth as much as your camera and in the end you don't end up with a better product than if you pay to have your film digitized.
OTOH, minilab scanning is done with full auto - machines evaluating the negative for you, and the very low price they charge usually means you may not get much help with issues. Usually - there may be exceptions, you will find no remedies from the staff either.

The first example below is a scan of a negative - Kodak Gold 100.



The second example is a scan from my Coolscan of the same frame of Kodak Gold 100.



Obviously the difference just in color would make you think that they are not the same frame of film.

Dave,
Keep in mind that negatives will require "interpretation" to convert to a positive. A positive (slide, transparency, diapositive) will not require interpretation.
10-21-2015, 11:30 AM   #13
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QuoteOriginally posted by LesDMess Quote
minilab scanning is done with full auto - machines evaluating the negative for you, and the very low price they charge usually means you may not get much help with issues. Usually - there may be exceptions, you will find no remedies from the staff either.
I have to agree, your example is really off, although I can see where the combination of bright fuchsia and glossy black could throw the auto-tone algorithm for a loop. This cost me $5 per roll, and the colour isn't perfect, but I would have the same issues with prints directly from the negative.
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10-21-2015, 07:25 PM   #14
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QuoteOriginally posted by LesDMess Quote
OTOH, minilab scanning is done with full auto - machines evaluating the negative for you, and the very low price they charge usually means you may not get much help with issues. Usually - there may be exceptions, you will find no remedies from the staff either.
Yep...I bought my Coolscan 5000ED out of frustration with minilab scans. The very first roll through the Coolscan made me a believer. You can't really blame the lab. Their scanner is usually optimized for the printer they use for enlargements. People bring the CD back in when they want bigger prints, not the original negs.


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10-21-2015, 07:28 PM   #15
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QuoteOriginally posted by RGlasel Quote
I have to agree, your example is really off, although I can see where the combination of bright fuchsia and glossy black could throw the auto-tone algorithm for a loop. This cost me $5 per roll, and the colour isn't perfect, but I would have the same issues with prints directly from the negative.
There is artifact on the second image that would not be there on a well-made custom scan. I would wager that what looks like grain is not on the negative.


Steve
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