Be Thankful For Olympus Gear

Started Apr 23, 2013 | Discussions thread
John King
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Re: The "ISO-less camera" argument
In reply to Great Bustard, Apr 28, 2013

Great Bustard wrote:

John King wrote:

boggis the cat wrote:

Have you noticed that there is a bit of a push to argue that 'ISO' is no longer a valid concept?

That was one of Newman's favourite fight starters ...
I agree with Bryan Peterson's continued use of the "Exposure triangle" - ISO (sensitivity of the recording medium), Aperture (the hole in the diaphragm in the lens) and Shutter speed (how long the recording medium is exposed to the light source). Seems so self-evident, and has been used by photographers ever since photography began. No less valid today than it was 150 years ago ... . All other decisions are aesthetic decisions, and just as important in their own right. They are just not exposure parameters, per se. They are determined by the meber of the exposure set chosen. Peterson stresses this constantly.

There was a thread in the Open Talk forum where this was being discussed.  I jumped in here:

http://www.dpreview.com/forums/post/51328732

but did not get a reply to my argument for ISO in that thread.

Disagree with the idea that ISO is subjective. It may be a second level variable (and always has been, even with film ... ), but that is completely different from it being a "subjective" phenomenon ...

Am I missing something obvious?  I don't see how a sensor can have limitless 'sensitivity', so therefore we have to always consider that third element (even if we have an ever increasing latitude).

I agree. So does every photographer and author on the subject I have ever had anything to do with. Even auto ISO is still applying a value to the sensitivity of the recording medium. It's just blather to suggest otherwise, IMNSHO.

The sensitivity of a digital sensor is fixed, except inasmuch as read noise is less at higher ISOs for non-ISOless sensors.  In other words, f/2.8 1/100 ISO 400 and f/2.8 1/100 ISO 1600 have the same exposure for a given scene, but not the same brightness.

The advantage to the ISO 1600 photo is that it will be less noisy than the ISO 400 photo pushed to the same brightness if the sensor was not ISOless.  The disadvantage to the ISO 1600 photo is that more of it may be blown (due to the limited bit depth of the image file), regardless of whether the sensor is ISOless or not.

Recently, an excellent article on exposure was written by gollywop:

http://www.dpreview.com/articles/8148042898/exposure-vs-brightening

Love the bit about "in-camera processing". Just sort of relegates some of the most important technical aspects of how and what a digital camera does to the back burner. Bit like listening to the sound coming from a stylus and ignoring the amplifier between this and the speakers; or listening to a CD being played without any earphones or amplifier connected ...

As a side, he's also written an excellent article on colors management:

http://www.dpreview.com/articles/7270088913/color-management-a-walkthrough

"Excellent" in whose opinion?

Not as succinct as my own essay (NFP). Without spending more time in a detailed reading, I can't comment further than this. I would rather read the original authors, which I have already done, in the main. My essay on the subject is designed to remove the techno talk so that ordinary photographers can do these things without the necessity of wading through technical details.
IME, most photographers will not even read well written, straight forward, simple texts on any of these subjects, so the techno-babble has to be left out without over-simplifying the underlying workflow practices such that they become wrong. IMHO, he has not achieved this objective, even though a worthy effort.

BTW, From what I did read (quickly), some of the things said about printers has not been current since before 2004 or so. Ditto about colour spaces. See Schewe & Fraser "Real World Adobe Camera Raw with Adobe Photoshop CS5", Blatner & Fraser "Real World Adobe Photoshop CS" and Jurgen "The Digital Print" - among many other sources.

Not interested in discussing these things with you, as you are merely interested in things other than the photographic ramifications and use of these things.

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