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Author Topic: Black blob problem  (Read 4175 times)

JonB8305

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Black blob problem
« on: May 01, 2013, 11:18:48 PM »
Ok here is the issue, whenever I do a studio shoot and the subject is wearing black (regardless of the back ground color) the photo shows just a black blob unless i turn up the exposure in post which just makes the black more grey.

How do I get the photo to show the detail in dark black clothing?

Is this a dynamic range limitation?


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Black blob problem
« on: May 01, 2013, 11:18:48 PM »

J.R.

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Re: Black blob problem
« Reply #1 on: May 01, 2013, 11:22:48 PM »
Hi,

Maybe you need to post some samples for the sake of illustration.

Regards ... J.R.
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JonB8305

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Re: Black blob problem
« Reply #2 on: May 01, 2013, 11:26:28 PM »
Sorry.

privatebydesign

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Re: Black blob problem
« Reply #3 on: May 01, 2013, 11:33:47 PM »


Quote
How do I get the photo to show the detail in dark black clothing?


You need to light and expose for it. So you need the light at the right angle to show the texture and you need to expose so that the texture is not all in Zone 0, to show detail and texture some of your black must be exposed at Zone I or even II. http://en.wikipedia.org/wiki/Zone_System

Quote
Is this a dynamic range limitation?


Absolutely not, you are controlling the light and the dynamic range in a studio environment.
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JonB8305

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Re: Black blob problem
« Reply #4 on: May 01, 2013, 11:37:40 PM »


Quote
How do I get the photo to show the detail in dark black clothing?


You need to light and expose for it. So you need the light at the right angle to show the texture and you need to expose so that the texture is not all in Zone 0, to show detail and texture some of your black must be exposed at Zone I or even II. http://en.wikipedia.org/wiki/Zone_System

Quote
Is this a dynamic range limitation?


Absolutely not, you are controlling the light and the dynamic range in a studio environment.


Thanks for the info. I need to up my technical skill sets.

JonB8305

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Re: Black blob problem
« Reply #5 on: May 01, 2013, 11:52:57 PM »


Quote
How do I get the photo to show the detail in dark black clothing?


You need to light and expose for it. So you need the light at the right angle to show the texture and you need to expose so that the texture is not all in Zone 0, to show detail and texture some of your black must be exposed at Zone I or even II. http://en.wikipedia.org/wiki/Zone_System

Quote
Is this a dynamic range limitation?


Absolutely not, you are controlling the light and the dynamic range in a studio environment.


The wiki article says that i would need to take multiple pictures at different exposures and combine to get the detail right. Is that the only way?

When I set the aperture and shutter speed it's for a given for the exposure of the light at a specific point in the scene so taking multiple pics makes sense, but is that the only way? Should I just make my camera adjustments based on the darkest area of the photo?

Mt Spokane Photography

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Re: Black blob problem
« Reply #6 on: May 01, 2013, 11:56:31 PM »
I use Canon Utilities to tether my camera in the studio to a computer and view the image live on my large screen,  You can then remotely control the camera settings, see the effects as you adjust lighting, view a live histogram, and generally make adjustments until you see the image as you want it.
 
Then capture it and save it as well as opening the file in a editor if you choose   This really speeds up difficult shots, and you have control over focus and exposure parameters including depth of field preview.
 
Canon has some very powerful tools that are free!

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Re: Black blob problem
« Reply #6 on: May 01, 2013, 11:56:31 PM »

J.R.

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Re: Black blob problem
« Reply #7 on: May 02, 2013, 12:00:07 AM »
Agree with what has been suggested by pbd & mt. spokane. 

The shot seems to have been taken with white fluorescent light coming from the left casting deep shadows in the already dark clothing. It appears more of an issue with the lighting than the camera.

A few more points - 

What camera were you shooting with. I have this weird problem with my 5D3 and the 6D which "seem" to underexpose by 1/2 or 2/3 of a stop. Maybe you are experiencing a similar phenomenon.  I usually compensate this by ETTR and bringing down the highlights in post.
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JonB8305

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Re: Black blob problem
« Reply #8 on: May 02, 2013, 12:13:58 AM »
Agree with what has been suggested by pbd & mt. spokane. 

The shot seems to have been taken with white fluorescent light coming from the left casting deep shadows in the already dark clothing. It appears more of an issue with the lighting than the camera.

A few more points - 

What camera were you shooting with. I have this weird problem with my 5D3 and the 6D which "seem" to underexpose by 1/2 or 2/3 of a stop. Maybe you are experiencing a similar phenomenon.  I usually compensate this by ETTR and bringing down the highlights in post.

I shoot with a Canon 6D with Profoto D1 studio kit. No light meter though so my exposure is random. Not that I'm any good anyway, Im just learning.

privatebydesign

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Re: Black blob problem
« Reply #9 on: May 02, 2013, 12:18:46 AM »
Quote
The wiki article says that i would need to take multiple pictures at different exposures and combine to get the detail right. Is that the only way?

No, it only says you need to do that when the DR within the scene exceeds your sensors abilities, that is not the case here, you are controlling the amount of light so you are controlling the DR.

I didn't really imply you should follow the zone system, I meant if you don't expose some of the black as grey it will all be a blob!  :)

Here is the most important bit from the wiki "The key element in the scene is identified, and that element is placed on the desired zone; the other elements in the scene then fall where they may."

Now you are controlling the light, so you need to make sure the scene is contained within your cameras DR, if you decide that detail in the dark shadows is important (your key element) you need to expose so the very darkest areas of the scene are black, but that most of the black suit is grey Zone I and II, without blowing the highlights in the white shirt. Then adjust your blacks and shadows sliders in post to get the suit where you imagined it. If there is not enough contrast in the suit to separate the detail you need to use a levels curve control to spread out the tones in the suit.
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JonB8305

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Re: Black blob problem
« Reply #10 on: May 02, 2013, 12:26:40 AM »
Quote
The wiki article says that i would need to take multiple pictures at different exposures and combine to get the detail right. Is that the only way?

No, it only says you need to do that when the DR within the scene exceeds your sensors abilities, that is not the case here, you are controlling the amount of light so you are controlling the DR.

I didn't really imply you should follow the zone system, I meant if you don't expose some of the black as grey it will all be a blob!  :)

Here is the most important bit from the wiki "The key element in the scene is identified, and that element is placed on the desired zone; the other elements in the scene then fall where they may."

Now you are controlling the light, so you need to make sure the scene is contained within your cameras DR, if you decide that detail in the dark shadows is important (your key element) you need to expose so the very darkest areas of the scene are black, but that most of the black suit is grey Zone I and II, without blowing the highlights in the white shirt. Then adjust your blacks and shadows sliders in post to get the suit where you imagined it. If there is not enough contrast in the suit to separate the detail you need to use a levels curve control to spread out the tones in the suit.

I've used Nik software to increase the exposure in the target area but for some reason the area became noisy and grey. I'll eventually get it right. I'll do as you say and properly expose the target area and see how it goes, I think thats the best solution.

privatebydesign

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Re: Black blob problem
« Reply #11 on: May 02, 2013, 12:33:31 AM »
Get the book Light: Science And Magic. It has comprehensive explanations on how to light and shoot black; and white and clear! It is THE book for understanding lighting.

http://www.amazon.com/Light-Science-Magic-Introduction-Photographic/dp/0240812255/ref=sr_1_2?ie=UTF8&qid=1367469104&sr=8-2&keywords=light+the+science+and+magic
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alexanderferdinand

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Re: Black blob problem
« Reply #12 on: May 02, 2013, 02:51:11 AM »
+1.

Although not a native  english speaking person I would highly recommend this book.

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Re: Black blob problem
« Reply #12 on: May 02, 2013, 02:51:11 AM »

brad goda

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Re: Black blob problem
« Reply #13 on: May 02, 2013, 05:25:25 AM »
1. better lighting
2. shoot raw and learn raw processing
3. learn what contrast means.

meli

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Re: Black blob problem
« Reply #14 on: May 02, 2013, 06:27:19 AM »
Shooting a black object is not so much about pumping kwatts of light to it or raising shadows. Its all in the reflections /highlights. Play around with some reflectors and/or big softboxes and you'll see you can actually shoot anything black with great definition even in a dark room.

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Re: Black blob problem
« Reply #14 on: May 02, 2013, 06:27:19 AM »