Color Slides

tomfrh · Aug 5, 2016

Les Sarile said:
Are there any of these testing results available for independent review?

This one I linked to earlier is good.

https://www.onlandscape.co.uk/2014/12/36-megapixels-vs-6x7-velvia/

http://petapixel.com/2014/12/18/comparing-image-quality-film-digital/

There are others online you can search for.

Les Sarile · Aug 5, 2016

tomfrh said:
This one I linked to earlier is good.

There are others online you can search for.

Are these your own or third party?

You said you did testing.

tomfrh · Aug 6, 2016

Les Sarile said:
Are these your own or third party?

You said you did testing.

Those are by others. I did my own before i saw those ones. Mine weren't as comprehensive as that.

I was using one format only, and was shooting a finely detailed world map on the wall, which has colour detail and text at all different scales.

I shot a few slides at F8, then put lens on digi and shot at different distances. The d image matched the detail in the projected slide at about 12-15mp, ie when the camera was a bit further away.

It wasn't a lab test, but it told me enough to know claims of 50,100,400mp are nonsense for 35mm trannys

tom43 · Aug 6, 2016

tomfrh said:
That's your answer, which you arrived at via very questionable assumptions and calculations.

My answer, which I arrived at through direct testing, and which ther people have arrived at with testing, is that 35mm slide are good for about 12-20mp, depending on the breaks.

If someone does some microscope analysis of real photographic slides and and proves they're good for much more than that I'd be thrilled, as I love slides. But so far I haven't seen it.

This exactely has been done by multiple sources in Germany (including Zeiss company), where we still have a quite large slide film community. Please find the results by this link: http://www.aphog.de/?p=364

For high quality slide films you need very good lenses and in best case a very good microscope for evaluation. All data indicates that slide films reach ca. 120-140 lines per millimeter as mentioned in my earlier posting. Nevertheless the resolution is highly depending on the contrast of the scene, which is completely different from digital images. Depending on the contrast the resolution of Velvia is somewhere between 12 MP and 50 MP (e.g. black text on white background).

B/W slide film based on CMS20 II from Adox is only limited by the lens and you can achieve resolutions higher than 100 MP with a 35mm camera. As an owner of a Nikon D810 I can assure that the resolution of such images is far beyond the 36 MP digital images.

To give the audience some impressions, please look at these high-end scans:

http://www.high-end-scans.de/high-end-scan-trommelscan-kleinbild.html

Also for larger formats...
Dead Link Removed

Diapositivo · Aug 6, 2016

tomfrh said:
That's your answer, which you arrived at via very questionable assumptions and calculations.

My answer, which I arrived at through direct testing, and which ther people have arrived at with testing, is that 35mm slide are good for about 12-20mp, depending on the breaks.

Beyond that the d sensors start pulling ahead.

If someone does some microscope analysis of real photographic slides and and proves they're good for much more than that I'd be thrilled, as I love slides. But so far I haven't seen it.

I think you did not get my point.
I said that with a quality desktop scanner anybody can reach the 3.650 ppi resolution, equalling theoretical 18 mp and very near the 15 mp of your own test.

The reason why I arrive to the answer that digital cannot match film is on the qualitative, not pixel count, side. Digital capture of whatever pixel density hits the white ceiling abruptly and clips. Slide film (or film in general) does not. It's another aspect of image quality and, on that front, digital capture is very much behind.

Given ideal lighting conditions and ideal (non-diffracting) aperture, a 30mp sensors gives you a 30 mp image, and if that's your point, I agree with that.

tomfrh · Aug 6, 2016

tom43 said:
As an owner of a Nikon D810 I can assure that the resolution of such images is far beyond the 36 MP digital images.

Adox cms II, sure!

tomfrh · Aug 6, 2016

Diapositivo said:
Digital capture of whatever pixel density hits the white ceiling abruptly and clips. Slide film (or film in general) does not.

Slide film isn't so good once it hits the ceiling either!

Even less room and less forgiving that a modem dig sensor!

Diapositivo · Aug 6, 2016

tomfrh said:
Slide film isn't so good once it hits the ceiling either!

Even less room and less forgiving that a modem dig sensor!

I disagree in the strongest terms on that specific point. I think this is an off-topic though, so I'll leave it there. Maybe we'll meet again in a thread about clipping and slide film shoulder and we'll discuss that more in depth

AgX · Aug 6, 2016

Most published comparisons between film and sensor lack some insight, as it is a tricky matter.
Better should be practical comparisons. But here often apples and oranges were compared.

Anyway, to add something here a comparison by one of our own fellow members:
http://www.boeringa.demon.nl/menu_technic_ektar100.htm

trondsi · Aug 6, 2016

Provia 100f is the only slide film currently available that will produce pleasing skin tones in most light conditions, so that would definitely be my suggestion in this case.

tomfrh · Aug 6, 2016

Diapositivo said:
I disagree in the strongest terms on that specific point

I'm thinking of situations where I've managed to save things shot as RAW that would be irretrievably blown out with slide film.

trondsi said:
Provia 100f is the only slide film currently available that will produce pleasing skin tones in most light conditions,

yes provia is good for people where Velvia can run into trouble. however I find velvia can look ok in cool daylight.

trondsi · Aug 6, 2016

That's true. Provia really shines in warm light.

MattKing · Aug 7, 2016

Whenever I see one of these discussions I am reminded of a long detailed APUG post I once wrote. It was a thing of beauty - it melded logic, rhetoric and, if I do say so, linguistic artistry, all in the aid of an important premise.

I was so proud of it, and then Sean and the moderators went and deleted the thread, because it really was just another film vs. digital argument.

Anyways, my premise was this: any time you try to use one system's technology to evaluate the other, it won't result in a fair and particularly useful result.

If you have to digitize film to make an objective analysis, film will suffer from the digitization part of the process.

Just as if you have to project or otherwise make more continuous digital output, in order to compare it with analogue output from film.

Poisson Du Jour · Aug 7, 2016

tomfrh said:
Slide film isn't so good once it hits the ceiling either!

Even less room and less forgiving that a modem dig sensor!

I think that is gilding the lily just a bit. A great deal can be done with RVP, RDP to outrun and outclass a dig sensor. The trick is matching film to the lighting conditions and not being cavalier about exposure. Scant few scenes cannot be made on the prime E6 emulsions we have; but then the same scenes don't particularly nod their lid when made with digi-fanboi toys. I have not once needed to resort to digital in order to produce a scene. Just a modicum of multispot metering and math.

tomfrh · Aug 7, 2016

Poisson Du Jour said:
I have not once needed to resort to digital in order to produce a scene. Just a modicum of multispot metering

What do you do when the scene is very contrasty?

Poisson Du Jour · Aug 7, 2016

tomfrh said:
What do you do when the scene is very contrasty?

If there are no highlights (typically water) that will be compromised:

a) For RVP, to EI40* or as-is (50)
b) Set and lock-in a mid-tone (greycard for this usually, but not always)
c) Multiweight shadows and higher tones (often 2 of each, not one)
d) Average all; then
e) Shift midtone if values are unweighted either side of + or —. Shifting the midtone shifts all values until balance is obtained.
f) The shifted readings are then transferred to the camera and the scene shot.

*Most of the time I do not bother with re-rating RVP at EI40; it is more
generally useful in 35mm to leverage out all the contrast packed into the
small size; the larger the format, the easier it is to meter and control contrast.

As a polariser is used in all of my work, spectrals are first examined through the camera at full polarisation.
Everything is then metered and the POL FF set (+2.0 in soft to hazy conditions; +1.5 in brighter areas with detail in shadows).

If one goes out hell-bent on exposing RVP in bright sunlight, with deep, dark shadows, more spectrals than Donald Trump's cheeks and features that cry to be held (water, for instance), expect serious trouble. It's not what RVP was designed for. You can try Provia for a somewhat better result but you must still meter with care. That's the nature of E6 film: it doesn't suffer fools gladly.

tomfrh · Aug 9, 2016

Thanks poisson

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