Be Thankful For Olympus Gear

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

boggis the cat wrote:

John King wrote:

Even if the results have been spectacular failures; and there have been many of them! Digital is far cheaper to make many spectacular failures - thereby creating a far more immediate and thus better learning environment, IMNSHO. Unfortunately, digital also creates an environment where far too many people have the attitude "I'll just fix it in post processing.". This goes equally for composition (using the wrong lens or framing); exposure; subject matter ("I'll just add in/subtract whatever I want/don't want later.").

I find it interesting that many people seem convinced that it is easier to take bad shots, or use equipment that has unpredictable behaviour, then 'fix' the photo in post.

Hmm.  I've never seen someone say that.

Yet these same people will then happily claim that using an auto-exposure mode is abdicating responsibility and thus not 'legitimate' photography (Program or Program-shift is what I tend to use by far the most, due to what I tend to shoot most).

Auto ISO is an excellent tool.

This is just sloppy, regardless of the level of the camera being used. We have the wonderful choice of fantastic tools at our disposal so that some people can be just plain sloppy in their use of them.

He stresses the exposure triangle of ISO, aperture and shutter speed and how to use these exposure parameters to achieve the desired aesthetic results. Although I have little to learn from anything he has written (the book belongs to a friend, and he lent it to me to audit), it is terrific looking at his wonderful photos. He is also a very clear communicator. I like to have read a book before recommending it to others ... and I could not recommend his book too highly.

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

Has anyone said such a thing?

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.

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).

ISO is not "sensitivity".  What the ISO setting does, aside from indirectly affect exposure by changing the f-ratio, shutter speed, and/or flash power in accordance with the camera's meter, is apply a gain to the captured signal.

For cameras that do not have ISOless sensors, this gain results in less read noise at higher ISOs, which is why, for example, f/2.8 1/100 ISO 1600 will be less noisy than f/2.8 1/100 ISO 400 pushed two stops.  See here for an example.

On the other hand, when the signal is pushed, depending on the DR of the scene, portions of the scene can be pushed outside the bit depth of the image file, resulting in more of the scene being blown than if a lower ISO were used.  In other words, the competent photographer balances noise vs blown highlights when using higher ISOs for a given exposure (keeping in mind, of course, that the exposure is a function solely of the scene luminance, f-ratio, and shutter speed -- the role of ISO is simply internal processing).

However, for a camera with an ISOless sensor, the read noise is constant throughout the ISO range, and thus there is no noise reduction when using higher ISOs.  The use of a higher ISO on such a system merely results in more blown highlights.  See here for an example.

A natural question, then, is why would anyone with a camera sporting an ISOless sensor would shoot anything other than base ISO?  The answer is simple:  manufacturers have not yet incorporated an ISOless UI where the LCD playback and OOC jpg are set for a zeroed meter (plus or minus any EC).  Thus, the operational disadvantages of shooting in an ISOless style often outweigh the IQ advantages without an ISOless UI.  This is such a pity, 'cause it's an easy thing to add in firmware.

It is also interesting to note how relaxed he is about a whole lot of subjects and how both the particular aperture and shutter speed chosen don't matter a lot of the time, as long as they are "correct" for the lighting situation, but sometimes they are at the crux of the photo taken. Again, I agree.

Absolutely right.  The downside of using 'auto' modes is that you may sometimes miss an opportunity that you may have seen if you had been using aperture priority, then you note it after the fact and realise that it could have been a great shot.

Auto modes are simply for when you feel the decisions the camera makes are better than the decisions you would have made, or at least "good enough", and speed is important.

Everything is a trade-off, of course, and for people who believe that capturing a shot 'in camera' is not that high a priority perhaps they get more satisfaction from fiddling in Photoshop or what have you.

As I alluded to above, sometimes speed is critical, and being able to make corrections in post is operationally more important than "getting it right" in camera.  A simple example is shooting RAW and setting the white balance in the conversion -- taking time to set the correct white balance in camera may cause the photographer to miss shots.

I just get confused, lose track of what I am trying to get to, 'fix' one thing only to obliterate other more important elements, and end up going in circles until the shot looks 'OK' (but not what I had hoped for when I started wasting time chasing the concept), then compare to the OOC JPEGs and find that they're better... 

Makes sense.

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