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Author Topic: How much DR do we need?  (Read 10340 times)

TMARK

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Re: How much DR do we need?
« Reply #20 on: April 08, 2013, 02:10:07 pm »

Almost all classic painters, from Leonardo onward (and probably even before him), were very particular about the quality and longevity of their paints. They were known to experiment, mix and match, trying to find a perfect formula. Looks like most of them succeeded, although some artwork faded faster than others.

True, but this was before manufactured paints.  They had to make their own paint.  I know some painters who still make their own paint, but its more of a fetish than anything else.  Liquitex, Utrecht, etc.  You have to mix your color but you know it will last.
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NikoJorj

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Re: How much DR do we need?
« Reply #21 on: April 11, 2013, 04:28:13 am »

Finally, if we include the sun we can have infinite dynamic range, except setting sun, it will always be clipped.
As said elsewhere, it's just in that case that I need more DR than my canon can give me : sunset or sunrise.
You have to be careful not to blow anything in the sun or that lovely hue will be gone (F! jpeg histogram!) and the foreground is solely illuminated by the dawn/dusk part of the sky, yet our eyes can see some detail and hues there, often complimentary to those in the skies.
I got examples in the 12EV territory from what rawdigger says ; alas, banding starts at 9-10EV and makes not so pretty shadows (see example, as it's a pano it barely shows at this size but it's only 1500px wide, it couldn't print well).


As for lens flare, I would also think it plays a part in the equation, but I couldn't even qualify it.
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Nicolas from Grenoble
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PhotoEcosse

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Re: How much DR do we need?
« Reply #22 on: April 11, 2013, 05:26:03 am »

To answer the original question

Quote
How much DR do we need?

In my experience of landscape photography, the most that I have had to add to the 14.3 EV provided by the Nikon D800 sensor is 8 EV in shots which do not include the direct sun in the image. This has been achieved by taking 9 exposures at 1-stop intervals and merging in HDR Efex Pro2.

So I guess my answer to the question is 22 EV DR.
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Bart_van_der_Wolf

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Re: How much DR do we need?
« Reply #23 on: April 11, 2013, 07:27:17 am »

As for lens flare, I would also think it plays a part in the equation, but I couldn't even qualify it.

Hi,

Correct. Lens glare will seriously limit the effective DR that can be recorded on the Sensor (which has a much larger engineering DR). Each air/lens surface transition will add some stray light that will add to the shadows more as a percentage that to the highlights. A glare of 1% will potentially reduce the dynamic range to 6.64 stops (locally if you are lucky, globally if not so lucky).

The use of a properly dimensioned (= uncomfortable in use, because deep) lens hood can help a bit, but some internal reflections will occur in any lens, due to the air/lens surface transitions and internal reflections. Quality coatings, and mechanical lens design will help, but we cannot influence that. We can try to use better shielding of non-image forming light to somewhat improve the situation.

Cheers,
Bart
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jrsforums

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Re: How much DR do we need?
« Reply #24 on: April 11, 2013, 09:47:54 am »

To answer the original question

In my experience of landscape photography, the most that I have had to add to the 14.3 EV provided by the Nikon D800 sensor is 8 EV in shots which do not include the direct sun in the image. This has been achieved by taking 9 exposures at 1-stop intervals and merging in HDR Efex Pro2.

So I guess my answer to the question is 22 EV DR.

I think this would only be the case if your base shot had captured the highest significant highlight at just below clipping in RAW....and then each add'l shot was +1EV, until the shadows were all captured on the left.

John
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John

MarkL

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Re: How much DR do we need?
« Reply #25 on: April 12, 2013, 06:36:59 am »

Other than the resolution, this is the biggest difference I noticed moving from D700 to D800. This really has made a difference shooting in hard contrasty light I like and issues like having blown skies on overcast days. For landscape work it means no moe (or less) eposure blending or grad filters and with the sun in the frame you can never really have enough.  I’d rather have more than less even if I don’t ‘need’ it all that often because it means there is more margin for error.
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PhotoEcosse

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Re: How much DR do we need?
« Reply #26 on: April 13, 2013, 03:08:54 pm »

I think this would only be the case if your base shot had captured the highest significant highlight at just below clipping in RAW....and then each add'l shot was +1EV, until the shadows were all captured on the left.

John

Not quite like that, John.

If we take the "base" shot as the one that the camera's meter suggests was correctly exposed, then the highlights were hopelessly blown and there was no detail at all in the shadows. +4 EV was necessary to kill all the highlight clipping while -4 EV was required to reveal the shadow detail.
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jrsforums

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Re: How much DR do we need?
« Reply #27 on: April 13, 2013, 03:41:22 pm »

Not quite like that, John.

If we take the "base" shot as the one that the camera's meter suggests was correctly exposed, then the highlights were hopelessly blown and there was no detail at all in the shadows. +4 EV was necessary to kill all the highlight clipping while -4 EV was required to reveal the shadow detail.

When you have the camera meter, you have no idea what "zone" of the scene it is setting as middle grey.  You are therefore shooting blind.  You have no idea if -4EV will capture the significant highlights...or be much too much.  Same with +4EV on the low end.  So your response on the number of stops need, overall, hold no basis of fact. 

Your method could work if you analysed each RAW image in something like RAWdigger to see what EV it clipped at and where the lows where capyured.  Unfortunately, if you have specular highlights or the sun, which you had no expectation in capturing and were going to let blow out, RAWdigger cannot distinguish between significant and insignificant.

You need to calibrate your camera to know the clipping point in RAW.  I have found, on my 5D3, it is ~+3.5 stops, if I spot meter the brightest significant highlight.  Once you have that, you can increase the EV until you see on the histogram that you have captured the darkest shadow.  (I will actually overdo the shadows to ensure that I have add'l detail). 

I find this method provide two possible benefits.  First, it will maximize the DR captured, which often will allow one image to sufice....whereas the camera matrix/evaluative or centerweighted metering will often not.  Second, it can allow you to minimize the number of shots required for blending/HDR.

John
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John

Greg D

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Re: How much DR do we need? ( A general comment by the OP)
« Reply #28 on: April 14, 2013, 05:11:30 pm »

Hi,

The reason I posted my observations was mostly that I feel DR is overemphasized. I have very seldom encountered subjects with very wide DR.


I encounter this problem all the time, and I don't think my photography is that unusual.  I often shoot scenes with whitewater in deep forest, and such scenes will often exceed the DR of pretty much any camera, and in such cases, you simply can't sacrifice the highlights.  Exposure stacking may not be an option because of wind, etc.  Sometimes you just have to work around it and accept silhouetted shadows, but it's nice to not be backed into that corner.  I shot with Canon crop cameras for most of my shooting years, then switched to Nikon (D7000), which had 3 or so stops more of DR according to most analyses.  This reduced the incidence of exceeded DR a little, but the most important difference was what could be done with the underexposed shadows - pretty much nothing on Canon files, without creating ugly noise, but 2 or 3 stops worth of recovery from the Nikon.  I know this is common knowledge, and as I said, I don't think my photography is unusual, so why wouldn't any outdoor photog want all the DR available?
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Ellis Vener

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Re: How much DR do we need?
« Reply #29 on: April 14, 2013, 08:41:33 pm »

The only correct answer is: As much as possible.
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