[tuco]

with film a lower ASA/ISO = smaller grain (sort of lower noise)** and lower DR (higher contrast)

You can get pretty good tonal scale with Delta 3200 film. And the characteristic response to the highlights is film brand dependent. The base + fog density on 3200 film is pretty high compared to lower ISO films making it a factor for DR.

Delta 3200






T-Max 400

[

[stevebrot]

with film a lower ASA/ISO = smaller grain (sort of lower noise)** and lower DR (higher contrast)

I'm pretty sure you have the dynamic range (contrast) part backward when using normal development and definitely wrong with compensating technique, but perhaps we have a confusion of terms.


Steve

[automorphism]

How much detail you can get out of your scene depends on the amount of light in your scene, other variables being optimal. So while it is true that higher ISO usually means less detail because higher ISOs are required for less light or a higher shutter speed, that is only a side effect of the amount of light in the scene.

Therefore, don't worry about ISO. Of course, use the lowest you need, but let the camera do that in Av or TAv mode. If you blindly just use the lowest ISO possible, you'll underexpose and raising the exposure in post will be the same or worse than doing it in the camera.

Instead, maximize the amount of light reaching the sensor. That means using the lowest shutter speed possible and the widest aperture possible, keeping in mind that of course the apparent sharpness may decrease a little if your aperture is too wide, or you start to blur your image because your shutter speed is too low.

[swanlefitte]

. On BW film, mainly Tri-x, the grain, even when pushed, was not objectionable and many like the aesthetics.

I hear that often and digital grain is bad.

How about a film grain filter over digital grain?

[Just1MoreDave]

With digital, it's really easy to set up a still scene with lots of contrast and take test shots on a tripod with different ISOs. You need a light level so that you can use a fixed aperture. Then for each doubling of ISO (one stop increase in sensitivity) you can make the shutter speed shorter. Make sure SR is off because you're on a tripod, and disable noise reduction so you can see the noise before the camera fixes it. I think exposure lock, Av mode and setting the ISO directly should work for all Pentax bodies.

One result of this test is to see how an image that looks very noisy at 100% doesn't look that bad at smaller viewing sizes, reflecting the common advice in the first post. We all know that whether your camera allows the highest ISO of 1600 or 1638400, that looks like crap. So you want to know where "pretty good" is. It's also interesting to compare cameras.

[yucafrita]

I hear that often and digital grain is bad.

How about a film grain filter over digital grain?

For my eye at least, it is looking very different. This may be due to being used to viewing film in the past vs digital being the new kid on the block. On digital, "grain" is noise and this (high ISO noise) usually looks like colors blocks jumbled around. Kinda Tetris throw-up (sorry).

I think film grain is more pleasing. But why? On BW, you have sorta "grey scale tonality". On color film, you don't have these aberrant color blocks lying around. The different colors grains are more uniformly distributed, they don't cluster together.

I have to say, however, that I think Pentax is doing a great job regarding high ISO. Sometimes I have shots around 8000 ISO and they look clean (unprocessed, w/o pixel peeping). On film, the picture may already degrade.

How should a film grain filter over digital grain work? Some software offer this IIRC, but apart from some hipster aesthetics, I would always go for as few grain / noise as possible, regardless if film or digital.

The ASA (as for American Standards Association) photographic exposure system, originally defined in ASA Z38.2.1 (since 1943) and ASA PH2.5 (since 1954), together with the DIN system (DIN 4512 since 1934), became the basis for the ISO system (since 1974), currently used worldwide (ISO 6, ISO 2240, ISO 5800, ISO 12232).

American National Standards Institute - Wikipedia

The ASA, consolidated with other organizations, became the American National Standards Institute ("ANSI"); the International Standards Organization ("ISO") took over the film-sensitivity standard.

[Paul the Sunman]

However what most people consider noise form high ISO is actually what would be better termed shot noise since photons are arriving randomly.

Don't you just hate quantum mechanics? What business does light have in coming in discrete packets?

Shot noise tends to dominate in brighter regions, but thermal noise is more prominent in the shadows, especially in the blue channel where the amplification is higher.

[MossyRocks]

Kinda Tetris throw-up (sorry).

I like this description. Color noise in digital images is bad when it becomes noticeable.

[MossyRocks]

Don't you just hate quantum mechanics? What business does light have in coming in discrete packets?

Shot noise tends to dominate in brighter regions, but thermal noise is more prominent in the shadows, especially in the blue channel where the amplification is higher.

Why do you think I used tossing marbles in my example. Thermal noise is also a quantum effect but as you point out correctly is something that happens more in the shadows or at those extremely high ISO settings where everything was in the shadows. Almost all of my high ISO long exposure shooting is with astrophotography so I get lots of shot noise (how many photons am I actually getting from things 25 million light years away) plus lots of those local quantum effects like the thermal ones or various quantum effects at the gate level from having those sensitive electronics running for extended periods of time.

[aslyfox]

thanks to all who have responded

I can even understand some of the responses

so the higher ISO might cause some problems with large enlargements but not to the extent of a higher ASA rating for film

is that basically correct

[Rondec]

thanks to all who have responded

I can even understand some of the responses

so the higher ISO might cause some problems with large enlargements but not to the extent of a higher ASA rating for film

is that basically correct

You shoot jpegs, right, Allen? So, when shooting jpegs on a K-3 you'll find sharpest photos will be at lower iso.

When shooting RAW, the big thing that you see is that you have better dynamic range at low iso. That means that you can adjust your shadow areas up a lot more at low iso than at high iso without noise coming in.

At really high iso you will have more noise and less dynamic range -- sometimes to the point that you might as well convert the image to black and white (and even then it may not look great due to the lack of dynamic range).

[aslyfox]

You shoot jpegs, right, Allen? So, when shooting jpegs on a K-3 you'll find sharpest photos will be at lower iso.

When shooting RAW, the big thing that you see is that you have better dynamic range at low iso. That means that you can adjust your shadow areas up a lot more at low iso than at high iso without noise coming in.

At really high iso you will have more noise and less dynamic range -- sometimes to the point that you might as well convert the image to black and white (and even then it may not look great due to the lack of dynamic range).

yeah I shoot Jpeg

thanks for that clarification

[Rondec]

yeah I shoot Jpeg

thanks for that clarification

With shooting jpegs I think you’ll find a max iso where noise bothers you. With my K3 it was over 800.