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Re: [OM] IMGS: Baracoa, + Banding?

Subject: Re: [OM] IMGS: Baracoa, + Banding?
From: Tina Manley <tmanley@xxxxxxxxx>
Date: Wed, 20 May 2015 08:48:09 -0400
Yes, you are right, Moose.   I need to lose my fear of higher ISOs!

Thanks,

Tina

On Wed, May 20, 2015 at 1:00 AM, Moose <olymoose@xxxxxxxxx> wrote:

> I promised (threatened?) to post illustrative examples. <
> http://www.moosemystic.net/Gallery/Others/Manley/LNP.htm>
>
> The heart of my point is in the second image:
>
> 1. Lower left histogram is of the original image out of the camera.
>
> 2. I've arbitrarily raised the 'exposure' to something like I imagine
> would be good for the procedure I proposed. I'm not saying it's perfect,
> certainly not that it's what you would want after post. Upper left
> histogram shows what happens when you pull up the shadows. See all those
> spikes, separated by blank space? That's what happens when shadows down too
> far, where there are very few digital values to assign the analog input
> into. When pulled up, you have only a few, discrete, widely separated
> brightness values. So of course you get banding. Something with nuanced,
> continually varying brightness is broken into separate areas of only a few
> brightnesses.
>
> There's also some stacking in the upper mid tones, which will also mess
> with tonality. Light enough that one won't tend to see what's wrong,
> without looking at the histogram, but may sense something 'off'.
>
> 3. The lower right histogram is of a normal, daylight scenic, nicely
> balanced.
>
> 4. The upper right histogram is #3, pulled deeply down. You can see the
> similarity of the lowest part to #1. BUT, there are no gaps or stacks, so
> no banding or other artifacts from making it much darker.
>
> I believe if you had shot at ISO 1600, then pulled down (after NR), rather
> than 320 and pulling shadows up, the end result would be superior; and no
> banding.
>
> Version four is a simple application of the PS ShadowHighlight tool, which
> I think gives better results than the first version you posted. The couple
> in that version are good, but all the highlights are gray. Real lights
> don't have gray centers, drifting toward white at the edges, and the
> brightly lit front of the building and vendor's T-shirt have gone all gray.
>
> Even in this mild opening up of shadows, you can see the effect of
> shooting too dark showing up as stacks in the histogram, but not visible.
>
> HistoMoose
>
>
> On 5/11/2015 8:43 PM, Moose wrote:
>
>> On 5/11/2015 2:52 PM, Tina Manley wrote:
>>
>>> Thanks, Moose.  The original dng does not look terribly underexposed.  I
>>> can still see details in the shadows. Here it is:
>>>
>>> http://www.pbase.com/tinamanley/image/160035214
>>>
>>
>> You are confusing technical exposure to viewing exposure, to coin an
>> awkward phrase.
>>
>> What you have is an exposure good for viewing right out of the camera,
>> but that pushes the limits of the sensor system. What I proposed is an
>> overexposure corrected in post for viewing, one that lets the sensor system
>> work better.
>>
>>  Any more exposure and there would be even more totally blown out.
>>>
>>
>> I think only the bright lights, which are gone anyway. Remember, the
>> overly bright building facade, etc. come back down in post.
>>
>>  I've always resisted using higher ISOs but I guess I'll try and see if
>>> it makes a difference.
>>>
>>
>> Why? Even at ISO 3200, it's not as noisy as many of your great film shots
>> in the dark are grainy. :-)
>>
>> I'm still not sure why you care about the banding, as it can apparently
>> only be seen when the deep shadows are raised up to very unnatural levels.
>>
>> I need to get off this list madness and get ready to leave on a little
>> trip tomorrow, or I would do some illustrations. Maybe later.
>>
>> Travelin' Moose
>>
>>
>
> --
> What if the Hokey Pokey *IS* what it's all about?
> --
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