Bit of a con, really ... ?

[Andy Champ]

Tim S wrote:

Andy Champ coughed up some electrons that declared:

Most common sort? Well, colour blindness is an obvious case. But
apparently a few women have 4-colour vision.

Just out of interest, what's the 4th colour?

Some sort of red, or orange, or... how the heck could I describe it?

And for true colour accuracy (though without speed or much resolution)
look at the Mantis Shrimp. IIRC it has sensors for polarisation and a
complete spectrometer build into its eye.

I'm getting that "Geordie" moment

They're eyes Tim, but not as we know them!

Andy

 

[dennis@home]

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:guf49b$fr8$1@news.motzarella.org...

As I pointed out earlier, the LCD is a great way to fine-tune the color
balance in real time.

Just shoot in RAW.
The colour balance is just a filter applied post shot to the RAW data.
You can then adjust it to whatever you want in the viewing conditions you
want when you "develop" your pictures.

True, but what if you want or need to use the JPG immediately?

Virtually all cameras that shoot in RAW can also do jpegs simultaneously.
Some (most?) also allow you to "develop" in the camera

 

[Arfa Daily]

"Bob Larter" <bobbylarter@gmail.com> wrote in message
news:guekh3$aga$3@blackhelicopter.databasix.com...

Arfa Daily wrote:
We had some pretty fussy customers back then with serious pots of money,
and I can't recall any colour accuracy issues ever arising - aside from
one particular customer who used to complain on a weekly basis that
colours were "bleeding through" (convergence issues !) and in the summer
that there was something wrong because the grass in front of the wicket
on the cricket, was yellow ...

LOL. It didn't occur to him that well trampled grass, in summer, is often
yellow?


--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

It was actually Mrs Fussy that always called us. Mr Fussy was an inoffensive
little thing who sat quietly up the corner ... No amount of explanation
would ever convince her that sometimes, grass *is* yellow. There was only
ever one engineer that she would have work on her set as well. I was his
apprentice, so I got to call on her with him. I clearly remember on one
occasion when my mentor was on holiday, the boss decided to send me on a
call to her, figuring that it would be ok, as she already knew me, and knew
that I was Peter's apprentice. When I turned up at her house, she wouldn't
even let me in the door. She told me that she was sure that I was very good,
but that I was not Peter, and he was the only one capable of adjusting her
TV just the way she liked it. The really amusing thing was that Peter never
really actually did anything other than take the back off and make twiddling
motions with his arms, and then ask her if it now looked better. Putting up
a test card showing a perfectly adjusted picture was also a no-no. She would
just trill "I don't care if you think that that silly picture looks right or
not. We don't sit here watching a test card, do we ?"

On one occasion when there was a real fault, and a replacement component had
to be soldered in, she marched into the room and said "Peter ! I do hope
that you're not smoking behind my television !" There are endless stories of
encounters with this customer, whom I swear was a real person,and who
behaved exactly as described.

Ah, happier and gentler times ...

Arfa

 

[Arfa Daily]

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:guef5m$6td$1@news.motzarella.org...

"Dave Plowman (News)" <dave@davenoise.co.uk> wrote in message
news:505ab62302dave@davenoise.co.uk...
In article <dFpOl.123771$A85.94314@newsfe03.ams2>, Arfa Daily
arfa.daily@ntlworld.com> wrote:

Contrary to what you believe about the phosphors on CRTs, I don't
believe that there has been any significant change in their colour
rendition capabilities since the earliest delta gun tubes in the uk,
which I worked with from about 1970

Oh, but there was. The original delta gun shadow mask tubes used the
correct NTSC phosphors. Which gave a pretty pure red. The rot really came
in with PIL tubes which used a very 'orange' red phosphor simply because
it allowed a brighter picture. And that had real implications to flesh
tones. Took many years before that was corrected.

I would almost bet my life that this is absolutely backwards -- it was the
original phosphors that were orangish, improving only with the rare-earth
phosphors of the early '60s. (I remember Sylvania's radio ads.)

In fact, I'm pretty certain that most of what's being posted about color
TV
and color analysis/reproduction is utter bilge. But I don't have a
comprehensive understanding of this material (it's not easy), so I'm
pretty
much keeping my mouth shut.

What I said about non-spectral colours, and the inability of a tri colour
CRT to genuinely reproduce them, is not bilge though - see the link that I
posted earlier in the thread, refering to this.

Arfa

 

[The Natural Philosopher]

Man at B&Q wrote:

On May 13, 12:31 pm, "dennis@home" <den...@killspam.kicks-ass.net
wrote:
"Arfa Daily" <arfa.da...@ntlworld.com> wrote in message

news:dFpOl.123771$A85.94314@newsfe03.ams2...

No, I wasn't either. I have two friends who both own top end digital SLRs,
one because he is a professional photographer, and the other because he is
a very keen hobbyist. I have looked at the viewfinder images closely on
both of these cameras, and the rendition of flesh tones in all the
varieties is excellent, and the professional of the two has commented to
me how good he thinks the viewfinder is at colour rendition under all
light levels (input that is, not viewing conditions).
Top level digital SLRs don't use any electronics in the viewfinder, its all
done with mirrors.

And your posts use smoke and mirrors.
In this case strangely rarely and uniquely, Dennis is correct. My SLR

has no electronics in the viewfinder. Its all done with mirrors.

 

[The Natural Philosopher]

Dave Plowman (News) wrote:

In article <gueklt$aga$4@blackhelicopter.databasix.com>,
Bob Larter <bobbylarter@gmail.com> wrote:
Top level digital SLRs don't use any electronics in the viewfinder,
its all done with mirrors. There are only a few that use electronic
viewfinders and they are low end.

Correct. I have two DSLRs, (Canon EOS 10D, & EOS 1Dmk2), & they both use
optical viewfinders. I certainly wouldn't waste my money on DSLRs with
electronic viewfinders.

Don't they have an LCD screen for viewing purposes, though? Not that you
can judge the variety of tones that make up a face on something so small.

Not really, no.

The LCD on mine is for menu items and occasionally a quick postview of
shots already taken.,

 

[The Natural Philosopher]

Arfa Daily wrote:

"dennis@home" <dennis@killspam.kicks-ass.net> wrote in message
news:gueb38$77d$1@news.datemas.de...

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:dFpOl.123771$A85.94314@newsfe03.ams2...

No, I wasn't either. I have two friends who both own top end digital
SLRs, one because he is a professional photographer, and the other
because he is a very keen hobbyist. I have looked at the viewfinder
images closely on both of these cameras, and the rendition of flesh tones
in all the varieties is excellent, and the professional of the two has
commented to me how good he thinks the viewfinder is at colour rendition
under all light levels (input that is, not viewing conditions).
Top level digital SLRs don't use any electronics in the viewfinder, its
all done with mirrors.
There are only a few that use electronic viewfinders and they are low end.

I'm pretty sure that one of them told me that his camera was over a grand's
worth, so I wouldn't call that particularly low end, although I am sure
there are others more expensive. If they do not have an LCD panel on them to
at least review the pictures you have taken, without having to plug the
thing into a computer, that rather defeats the object of it being a portable
'digital' camera, doesn't it ? Even the 3 grand offering on this page has a
3" LCD

http://www.calumetphoto.co.uk/Digital%20Cameras/Digital%20SLR/Nikon/?cm_mmc=GoogleUK-_-DSLR-_-DSLR-_-Nikon%20SLR&utm_source=google&utm_medium=cpc

Perhaps I am not being quite accurate in calling it a "viewfinder". I accept
that the higher end cameras have a proper optical viewfinder operating on
the SLR mirror / prism system, but the LCD panel also serves as a
supplementary viewfinder, as well as a display medium for photos already
taken.

It does not and cannot, because there is a fucking great mirror between
the lens and the CCD as well as a closed shutter.

OK?

Arfa

 

[The Natural Philosopher]

William Sommerwerck wrote:

Well, on some newer models you have a feature called "Live View",
where you can use the LCD to focus, etc, but no serious photographer
would use that in preference to the traditional viewfinder.

As I pointed out earlier, the LCD is a great way to fine-tune the color
balance in real time.


Why bother?

That's all doable post the event in photoshop.

What you DO need is a histogram display to show you haven't saturated
any of the channels. That you cant 'shop out.

I shoot entirely without more than a quick color temp adjustment, and
often not that.

If I want a crisper image for a product shot, I can do all that in software.

 

[The Natural Philosopher]

William Sommerwerck wrote:

As I pointed out earlier, the LCD is a great way to fine-tune the color
balance in real time.

Just shoot in RAW.
The colour balance is just a filter applied post shot to the RAW data.
You can then adjust it to whatever you want in the viewing conditions you
want when you "develop" your pictures.

True, but what if you want or need to use the JPG immediately?

Then you need a video camera ;-)

>

 

[The Natural Philosopher]

Stephen Howard wrote:

On Thu, 14 May 2009 00:21:51 +1000, Bob Larter <bobbylarter@gmail.com
wrote:

snip
Well, on some newer models you have a feature called "Live View", where
you can use the LCD to focus, etc, but no serious photographer would use
that in preference to the traditional viewfinder. OTOH, the LCD is
really handy to ensure that the shot turned out the way that you wanted
it to.

The value of an additional LCD view depends entirely on the sort of
photographic work you're doing. For close-up shots of complicated,
highly reflective objects a live view facility with pinpoint focussing
is a real boon - as is the ability to see the image in real time on a
computer screen. It allows for some very specialised techniques, such
as manipulating the depth-of-field by the millimetre.

You dont have a depth of field preview on the camera?

In fact because of the limitations of DSLR live view at the current
time I'd say it was more of a function of use to the studio
professional than the amateur.

I wouldn't even say that.

Regards,

 

[Alan Braggins]

In article <guelv2$tss$1@news.motzarella.org>, William Sommerwerck wrote:

I have two DSLRs, (Canon EOS 10D, & EOS 1Dmk2), & they both use
optical viewfinders. I certainly wouldn't waste my money on DSLRs with
[only] electronic viewfinders.

Are there any?

By definition, no. There's the Panasonic Lumix G1, which is basically
a DSLR with no mirror, pentaprism, or viewfinder, but that makes it
not actually an SLR. http://www.dpreview.com/reviews/panasonicdmcg1/

But the original claim was that there are few SLRs using electronic
viewfinders and they were all low end. In fact live view is becoming
more common, and the Canon EOS 5D Mark II, while not at the very top
end, is hardly low end either.

 

[Dave Plowman (News)]

In article <gufj4l$6eq$2@news.albasani.net>,
The Natural Philosopher <tnp@invalid.invalid> wrote:

Don't they have an LCD screen for viewing purposes, though? Not that
you can judge the variety of tones that make up a face on something so
small.

Not really, no.

The LCD on mine is for menu items and occasionally a quick postview of
shots already taken.,

That's what I mean. No point in having a digital camera if you can't look
at a pic instantly. Might as well stick to film.

--
*Everyone has a photographic memory. Some just don't have film*

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[Alan Braggins]

In article <4a09e6aa$0$517$5a6aecb4@news.aaisp.net.uk>, Tim S wrote:

Andy Champ coughed up some electrons that declared:

ZZactly@aol.com wrote:

Red green and blue are defined scientifically as primary colors. I
don't know where those standards came from, nor do I care

You may not care, but I'm going to tell you anyway

It's from Biology, not physics; RGB are the peak sensitivities of the
three colour receptors in the most common human retina. We're so poor
at telling them apart that a red-green mix looks pretty much like some
kind of yellow. (Narrow spectrum lamps are fine for TV, but they can
make your wallpaper look a bit odd, which is one of the CFL problems)

Most common sort? Well, colour blindness is an obvious case. But
apparently a few women have 4-colour vision.

Just out of interest, what's the 4th colour?

Two different "green" receptors.
http://en.wikipedia.org/wiki/Opsin#Classical_type_2_opsin_groups
With two different X chromosomes it's possible to have both
OPN1MW and OPN1MW2.

 

[The Natural Philosopher]

Dave Plowman (News) wrote:

In article <gufj4l$6eq$2@news.albasani.net>,
The Natural Philosopher <tnp@invalid.invalid> wrote:
Don't they have an LCD screen for viewing purposes, though? Not that
you can judge the variety of tones that make up a face on something so
small.

Not really, no.

The LCD on mine is for menu items and occasionally a quick postview of
shots already taken.,

That's what I mean. No point in having a digital camera if you can't look
at a pic instantly. Might as well stick to film.

Well I shot 150 pics on Sunday and ddi'nt look at a single one till

Sunday night. What's the point? they were action shots. They either
worked or they didn't.

About 10% were usable.

 

[Arfa Daily]

"The Natural Philosopher" <tnp@invalid.invalid> wrote in message
news:gufj95$6eq$3@news.albasani.net...

Arfa Daily wrote:
"dennis@home" <dennis@killspam.kicks-ass.net> wrote in message
news:gueb38$77d$1@news.datemas.de...

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:dFpOl.123771$A85.94314@newsfe03.ams2...

No, I wasn't either. I have two friends who both own top end digital
SLRs, one because he is a professional photographer, and the other
because he is a very keen hobbyist. I have looked at the viewfinder
images closely on both of these cameras, and the rendition of flesh
tones in all the varieties is excellent, and the professional of the
two has commented to me how good he thinks the viewfinder is at colour
rendition under all light levels (input that is, not viewing
conditions).
Top level digital SLRs don't use any electronics in the viewfinder, its
all done with mirrors.
There are only a few that use electronic viewfinders and they are low
end.

I'm pretty sure that one of them told me that his camera was over a
grand's worth, so I wouldn't call that particularly low end, although I
am sure there are others more expensive. If they do not have an LCD panel
on them to at least review the pictures you have taken, without having to
plug the thing into a computer, that rather defeats the object of it
being a portable 'digital' camera, doesn't it ? Even the 3 grand offering
on this page has a 3" LCD

http://www.calumetphoto.co.uk/Digital%20Cameras/Digital%20SLR/Nikon/?cm_mmc=GoogleUK-_-DSLR-_-DSLR-_-Nikon%20SLR&utm_source=google&utm_medium=cpc

Perhaps I am not being quite accurate in calling it a "viewfinder". I
accept that the higher end cameras have a proper optical viewfinder
operating on the SLR mirror / prism system, but the LCD panel also serves
as a supplementary viewfinder, as well as a display medium for photos
already taken.


It does not and cannot, because there is a fucking great mirror between
the lens and the CCD as well as a closed shutter.

OK?
Arfa

Calm down my boy ! It's just a newsgroup discussion ... d

Arfa

 

[Leonard Caillouet]

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:guf49b$fr8$1@news.motzarella.org...

As I pointed out earlier, the LCD is a great way to fine-tune the color
balance in real time.

Just shoot in RAW.
The colour balance is just a filter applied post shot to the RAW data.
You can then adjust it to whatever you want in the viewing conditions you
want when you "develop" your pictures.

True, but what if you want or need to use the JPG immediately?

My Nikon D60 has a raw+jpeg mode, and I think many others do as well. With
the size and speed of memory these days, it is not a big deal to store both.
I do this for my son's baseball games and zip up the jpegs and send them to
the other parents and if someone wants more versatility to tweak a
particular image I send them the raw file.

Leonard

 

[Leonard Caillouet]

"Bob Larter" <bobbylarter@gmail.com> wrote in message
news:guek8q$aga$2@blackhelicopter.databasix.com...

Leonard Caillouet wrote:
"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:jsaOl.30044$Ku5.27475@newsfe10.ams2...

As to whether LEDs as backlights do a good job, I'm sure that they must
be at least as good as CCFLs at colour rendering, otherwise, the
manufacturers wouldn't be making such a thing about it. Flesh tones look
perfectly fine on digital cameras which use LED backlit displays.


Looking perfectly fine is a very subjective assessment. It is fine for
most people, but you simply cannot assume that either technology will be
better or worse. It depends on many factors. Assumptions usually bite
you in the ass. You should know that by now, Arfa.

Me, if I want to know that my screen is rendering colour correctly, I
stick my Colorvision Spyder to it & measure it. That way, I know for sure.

Your Spyder will not give accurate results on narrow spectrum devices like
LED backlit displays, or even some LCDs with CCFLs or DLP and LCOS displays.
It depends greatly on the relation of the filters in your colorimeter to the
filters in the display, and the spectrum of the source. To accurately
measure many of the newer displays like the LED lit and the new laser based
DLP sets, you really need a spectrophotometer with very fine resolution,
preferably in the 1 nM range. Tristimulus colorimeters like the spyder and
all of the Sencore probes are rapidly becoming less useful.

Leonard

 

[Michael A. Terrell]

Arfa Daily wrote:

The Natural Philosopher wrote:

It does not and cannot, because there is a fucking great mirror between
the lens and the CCD as well as a closed shutter.

OK?
Arfa

Calm down my boy ! It's just a newsgroup discussion ... d

If you really want to stir him up, tell him all tobacco should be
banned. Then he will throw a hissy fit Phil Allison would be proud of.



--
You can't have a sense of humor, if you have no sense!

 

[johannes]

On 14 May 04:29, Michael A. Terrell wrote:

Arfa Daily wrote:

The Natural Philosopher wrote:

It does not and cannot, because there is a fucking great
mirror between the lens and the CCD as well as a closed
shutter.

OK?
Arfa

Calm down my boy ! It's just a newsgroup discussion ...
d


If you really want to stir him up, tell him all tobacco
should be
banned. Then he will throw a hissy fit Phil Allison would be
proud of.

Oh no! Please. No.

 

[William Sommerwerck]

"Leonard Caillouet" <nospam@noway.com> wrote in message
news:ZsKOl.45077$Jc3.11316@newsfe16.iad...

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:guf49b$fr8$1@news.motzarella.org...

As I pointed out earlier, the LCD is a great way to fine-tune the color
balance in real time.

Just shoot in RAW.
The colour balance is just a filter applied post shot to the RAW data.
You can then adjust it to whatever you want in the viewing conditions
you want when you "develop" your pictures.

True, but what if you want or need to use the JPG immediately?

My Nikon D60 has a raw+jpeg mode, and I think many others do as well.
With the size and speed of memory these days, it is not a big deal to
store
both. I do this for my son's baseball games and zip up the jpegs and send
them to the other parents and if someone wants more versatility to tweak a
particular image I send them the raw file.

I find it interesting how people -- carelessly, if not deliberately --
misread posts.

I was making the point that Live View is a good way to get accurate color
balance at the time the photo is taken, especially under light sources
without continuous spectra. The issue is not whether a camera can take raw
and compressed images at the same time, but whether one /needs/ a properly
balanced JPG image /right away/. This is impossible with a raw file.