Pixtus - Photography Forum, Photographers, Photo Tips

skally · **true black -** 06-19-2007, 05:24 PM

i've been taking pictures for less than a year...i use a kodak z650...i'm so new to this that the obvious things miss me...the other day someone said that digital cameras cannot capture true black, just shades of gray...what in the word does this mean?...i'm not about to start using a film camera but i'm curious to know what this issue is all about...

suzyjazz · 06-19-2007, 05:35 PM

I don't know about this, but I am sure someone else will chime in to validate this or debunk it, whichever the case may be. This idea doesn't make sense to me.

erisian pope · 06-19-2007, 05:42 PM

I am also bewildered by this claim. I have taken pictures where the histogram shows too much of my image is all the way at the black point. In photoshop this color value is #000000, which is black. It seems like calling anything "true" would be subjective at best.

Does anyone know what this refers to?

What is "true black" anyway (assuming #000000 isn't necessarily "true")?

johnastovall · 05:52 PM

Quote:

Originally Posted by skally

i've been taking pictures for less than a year...i use a kodak z650...i'm so new to this that the obvious things miss me...the other day someone said that digital cameras cannot capture true black, just shades of gray...what in the word does this mean?...i'm not about to start using a film camera but i'm curious to know what this issue is all about...

I don't know or care what the camera captures but I can print a true black or level to one so what's the problem?

By the way, a true black is just 0,0,0 but that's only in RGB. In CYMK it's 50/50/50/100.

Film may not capture a true black, you got to that in the print and the contrast range of your paper.

What kind of post processing have you ever done and with what? Ever set a black point?

It's non-issue.

kenw · 06-19-2007, 06:43 PM

actually it sounds like a 47th generation mis-retelling greyscaling with digital produces different results than "true black and white" from b&w papers.

They do it differently, but they can do it.

skally · 06-19-2007, 07:18 PM

these are interesting responses...i don't have a clue what the tech stuff is all about...black point or greyscaling...sorry...i wasn't joking when i said i've only taken pictures for 10 months or so...i'm glad i joined this group...i think i'm going to learn something about photography from you guys...

Daniel W. · 06-20-2007, 12:39 AM

Then again, you can capture a false black.

When I shoot kids in school-tuxedos, they often come out with a purple tint, often under tungsten stage light.

If you wash a tuxedo jacket in the wash, it comes out purple, blue, or pink.

But, "true" black is determined by the monitor, camera, source, lighting. I'm not sure about "grey." I just adjust to a calibrated monitor for what looks like black in print, or on the web.

Philosophically, nothing we see is really black - just darker shades of gray. Only the lack of light and being able to see is really black.

... or I could be needing more sleep.

Arnor · 06-20-2007, 12:54 AM

Hi Daniel,

Quote:

Originally Posted by Daniel W.

If you wash a tuxedo jacket in the wash, it comes out purple, blue, or pink.

WOW - that is very interesting information! Is that only in tungsten light or any light? Interested in the tux: can you get it black again if you have it dry cleaned or???

Best regards,

johnastovall · 06-20-2007, 06:53 AM

Quote:

Originally Posted by Daniel W.

Then again, you can capture a false black.

When I shoot kids in school-tuxedos, they often come out with a purple tint, often under tungsten stage light.

If you wash a tuxedo jacket in the wash, it comes out purple, blue, or pink.

But, "true" black is determined by the monitor, camera, source, lighting. I'm not sure about "grey." I just adjust to a calibrated monitor for what looks like black in print, or on the web.

Philosophically, nothing we see is really black - just darker shades of gray. Only the lack of light and being able to see is really black.

... or I could be needing more sleep.

What kind of camera? Purple black is often a sign of IR containation coming from symthectic fabric. Just ask any M8 owner, some Nikon models have it to a lessor degree.

kenw · 06-20-2007, 08:02 AM

many black dyes will fade to purple. sharpie ink is an example, as are numerous old "formerly black" socks in my rag drawer. Subtle but very much a purple tint. No camera required.

RaymondShay · 10:22 AM

Digital cameras will indeed capture TRUE black. Positively. Perhaps your buddy misspoke, but BLACK is simply the COMPETE absence of RED, GREEN AND BLUE. The RGB value is, of course, 0,0,0.

However 99% of all people doing professional post processing will change TRUE BLACK to ALMOST TRUE BLACK (12,12,12). This is so that we can start to see some detail in areas of the image that are nearly black (sometimes refered to as "details in the shadows")..

PS if you have the time to read a quick tutorial on how this is done YOU COULD LOOK HERE.

Arnor · 06-20-2007, 11:41 AM

Raymond,

Thanks for the link and the tutorial:) Learn something new every day:)

Best regards,

johnastovall · 06-20-2007, 02:03 PM

Quote:

Originally Posted by RaymondShay

Digital cameras will indeed capture TRUE black. Positively. Perhaps your buddy misspoke, but BLACK is simply the COMPETE absence of RED, GREEN AND BLUE. The RGB value is, of course, 0,0,0.

However 99% of all people doing professional post processing will change TRUE BLACK to ALMOST TRUE BLACK (12,12,12). This is so that we can start to see some detail in areas of the image that are nearly black (sometimes refered to as "details in the shadows")..

PS if you have the time to read a quick tutorial on how this is done YOU COULD LOOK HERE.

Well 99% are wrong at least if you learned zones. You keep shadow details but there should be a true black as well as a true white if you have exposed correctly and looked at the full tonal range you want from an image.

Daniel W. · 06-20-2007, 02:21 PM

Stovall,

Pentax *istDL, K10D, Canon 300D, all have showed the purple effect. I get stopped by parents with varying degrees of point and shoot asking me why sometimes there's turn out purple too. I said under tungsten because it's what I notice it the most under. I dont recall seeing it under studio strobes (5500k) or any strobe I think, for that matter.

AFAIK - Purple tux syndrome cannot be fixed, unless you re-dyed the jacket... of course if you had washed a tux jacket, you probably woudl've done considerable damage to the silk liner parts, if applies. But I just usually see the jackets thrown out / donated / shipped off to Ball High school (whose colors are purple and yellow.)

I kid on that last one.

RaymondShay · 06-20-2007, 02:42 PM

Quote:

Originally Posted by johnastovall

Well 99% are wrong at least if you learned zones. You keep shadow details but there should be a true black as well as a true white if you have exposed correctly and looked at the full tonal range you want from an image.

I sort of wish you had looked at the tutorial before responding, it indeed descibes the correct method. It is a post-processing standard to set min and max to approx 12,12,12 and 247,247,247.