I just walked out the door and shot, using the Auto setting, the first
thing I saw. The photo is ordinary, and that's not the point.
What does exif data tell me that I should want to know?
Forget make, model, and date. What does, for example, YCbcR mean, and
what is "cosited" or "co-sited"? What's to be learned from this and
how is it used?
What I would like to know is what my setting was: Auto, A, S, P, or
M. Since I'm still experimenting the D40, I'd take several pix of the
same thing using different settings for comparison.
When I look at Exif with the Adobe Photoshop browser, I see a list of
tags and numbers. Like EXIF TAG 49189=82. What's that?
Other than the camera used, the date, and a few basics, what's this
tell me and who uses it how?
On Sun, 06 Jan 2008 18:03:54 -0500, tony cooper wrote:
> This link:
> http://i48.photobucket.com/albums/f2...3/rockexif.jpg
> is to an image with the exif data (from Irfanview) superimposed on it.
>
> I just walked out the door and shot, using the Auto setting, the first
> thing I saw. The photo is ordinary, and that's not the point.
>
> What does exif data tell me that I should want to know?
>
> Forget make, model, and date. What does, for example, YCbcR mean, and
> what is "cosited" or "co-sited"? What's to be learned from this and
> how is it used?
>
> What I would like to know is what my setting was: Auto, A, S, P, or
> M. Since I'm still experimenting the D40, I'd take several pix of the
> same thing using different settings for comparison.
>
> When I look at Exif with the Adobe Photoshop browser, I see a list of
> tags and numbers. Like EXIF TAG 49189=82. What's that?
>
> Other than the camera used, the date, and a few basics, what's this
> tell me and who uses it how?
There are programs to show the exif data on your photos. Among other date
usually included is lens focal length, exposure speed, ISO setting,
whether flash was used, white balance setting and a lot more technical
data. Exact data recorded will vary from camera to camera. How you might
use it is more up to you - for example, you might want to know what
settings were made for exposure under certain conditions - so you could
duplicate or alter for more appropriate values next time.
ray wrote:
> On Sun, 06 Jan 2008 18:03:54 -0500, tony cooper wrote:
>
>> This link:
>> http://i48.photobucket.com/albums/f2...3/rockexif.jpg
>> is to an image with the exif data (from Irfanview) superimposed on it.
>>
>> I just walked out the door and shot, using the Auto setting, the first
>> thing I saw. The photo is ordinary, and that's not the point.
>>
>> What does exif data tell me that I should want to know?
>>
>> Forget make, model, and date. What does, for example, YCbcR mean, and
>> what is "cosited" or "co-sited"? What's to be learned from this and
>> how is it used?
>>
>> What I would like to know is what my setting was: Auto, A, S, P, or
>> M. Since I'm still experimenting the D40, I'd take several pix of the
>> same thing using different settings for comparison.
>>
>> When I look at Exif with the Adobe Photoshop browser, I see a list of
>> tags and numbers. Like EXIF TAG 49189=82. What's that?
>>
>> Other than the camera used, the date, and a few basics, what's this
>> tell me and who uses it how?
>
> There are programs to show the exif data on your photos. Among other date
> usually included is lens focal length, exposure speed, ISO setting,
> whether flash was used, white balance setting and a lot more technical
> data. Exact data recorded will vary from camera to camera. How you might
> use it is more up to you - for example, you might want to know what
> settings were made for exposure under certain conditions - so you could
> duplicate or alter for more appropriate values next time.
>
I set Irfanview to display a few important things (focal length,
shutter, aperture, ISO) in full screen mode. It's handy for sorting to
have it right there.
tony cooper <tony_cooper213@earthlink.net> wrote:
>This link:
>http://i48.photobucket.com/albums/f2...3/rockexif.jpg
>is to an image with the exif data (from Irfanview) superimposed on it.
>What does exif data tell me that I should want to know?
Most intersting are probably lens, apperture setting, shutter speed, and ISO
setting. Also focal length and flash and VR info (don't know if the last one
is captured).
Other useful information could be e.g. GPS location.
>What I would like to know is what my setting was: Auto, A, S, P, or
>M.
If you are using the scene modes then that information can be found under
"Scene Capture Type".
For A versus S versus P versus M it really doesn't matter if you locked in
1/250s and the camera selected F8 or if you locked in F8 and the camera
selected 1/250s. The exposure will be the same.
More interesting would be exposure adjustments.
In article <l1n2o3psuqb08sfe5nushts9451dgf44n0@4ax.com>,
tony cooper <tony_cooper213@earthlink.net> wrote:
> This link:
> http://i48.photobucket.com/albums/f2...3/rockexif.jpg
> is to an image with the exif data (from Irfanview) superimposed on it.
>
> I just walked out the door and shot, using the Auto setting, the first
> thing I saw. The photo is ordinary, and that's not the point.
>
> What does exif data tell me that I should want to know?
>
> Forget make, model, and date. What does, for example, YCbcR mean, and
> what is "cosited" or "co-sited"? What's to be learned from this and
> how is it used?
I think that's JPEG data, not EXIF data. It is specifying the
fractional pixel alignment between the full resolution luminance channel
and the lower resolution color channels. It's way more than anyone
needs to know about.
> What I would like to know is what my setting was: Auto, A, S, P, or
> M. Since I'm still experimenting the D40, I'd take several pix of the
> same thing using different settings for comparison.
That might be "Exposure Program" but the camera didn't provide it.
> When I look at Exif with the Adobe Photoshop browser, I see a list of
> tags and numbers. Like EXIF TAG 49189=82. What's that?
The EXIF tags are numerically encoded to make the header smaller.
Photoshop doesn't know what code C025 means so it's giving it
numerically. That code might be non-standard.
> Other than the camera used, the date, and a few basics, what's this
> tell me and who uses it how?
>
EXIF can hold timestamps, comments, copyright info, GPS coordinates,
white balance correction, the name of the lens used, and much more. It
can simplify automatic indexing and processing for professionals that
work with many thousands of photos.
--
I don't read Google's spam. Reply with another service.
In message <mcmurtri-F6F8E7.19535906012008@news.dslextreme.com>, Kevin
McMurtrie <mcmurtri@dslextreme.com> writes
>In article <l1n2o3psuqb08sfe5nushts9451dgf44n0@4ax.com>,
> tony cooper <tony_cooper213@earthlink.net> wrote:
>
>> This link:
>> http://i48.photobucket.com/albums/f2...3/rockexif.jpg
>> is to an image with the exif data (from Irfanview) superimposed on it.
>>
>> I just walked out the door and shot, using the Auto setting, the first
>> thing I saw. The photo is ordinary, and that's not the point.
>>
>> What does exif data tell me that I should want to know?
>>
>> Forget make, model, and date. What does, for example, YCbcR mean, and
>> what is "cosited" or "co-sited"? What's to be learned from this and
>> how is it used?
>
>
>I think that's JPEG data, not EXIF data.
It is exif data. You can get the same thing with TIF or RAW files
--
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
\/\/\/\/\ Chris Hills Staffs England /\/\/\/\/
/\/\/ chris@phaedsys.orgwww.phaedsys.org \/\/\
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
tony cooper wrote:
> This link:
> http://i48.photobucket.com/albums/f2...3/rockexif.jpg
> is to an image with the exif data (from Irfanview) superimposed on it.
>
> I just walked out the door and shot, using the Auto setting, the first
> thing I saw. The photo is ordinary, and that's not the point.
>
> What does exif data tell me that I should want to know?
>
> Forget make, model, and date. What does, for example, YCbcR mean, and
> what is "cosited" or "co-sited"? What's to be learned from this and
> how is it used?
>
> What I would like to know is what my setting was: Auto, A, S, P, or
> M. Since I'm still experimenting the D40, I'd take several pix of the
> same thing using different settings for comparison.
>
> When I look at Exif with the Adobe Photoshop browser, I see a list of
> tags and numbers. Like EXIF TAG 49189=82. What's that?
>
> Other than the camera used, the date, and a few basics, what's this
> tell me and who uses it how?
Many internet photo competition sites will not accept entries unless the
exif data is 1) present, and 2) shows when the picture was taken.
I accept that the date and time can be changed in the exif file, but not
everyone knows how to do this.
"tony cooper" <tony_cooper213@earthlink.net> wrote in message
news:l1n2o3psuqb08sfe5nushts9451dgf44n0@4ax.com...
> This link:
> http://i48.photobucket.com/albums/f2...3/rockexif.jpg
> is to an image with the exif data (from Irfanview) superimposed on it.
>
> I just walked out the door and shot, using the Auto setting, the first
> thing I saw. The photo is ordinary, and that's not the point.
>
> What does exif data tell me that I should want to know?
>
> Forget make, model, and date. What does, for example, YCbcR mean, and
> what is "cosited" or "co-sited"? What's to be learned from this and
> how is it used?
>
> What I would like to know is what my setting was: Auto, A, S, P, or
> M. Since I'm still experimenting the D40, I'd take several pix of the
> same thing using different settings for comparison.
>
> When I look at Exif with the Adobe Photoshop browser, I see a list of
> tags and numbers. Like EXIF TAG 49189=82. What's that?
>
> Other than the camera used, the date, and a few basics, what's this
> tell me and who uses it how?
> --
> Tony Cooper - Orlando, Florida
Your simple question has a not so simple answer. First not all image display
programs show ALL the exif data and some data is stored in many different
places so to be compatable with many different display programs. Also each
camera manufacturer and model stores different amounts of data. So some
cameras barely store the basics of shutter, f-stop, etc while others store a
HUGE amount of data. Much of which will likely have no meaning for you.
As to what you can learn from this data, this is also variable. For example,
if you take lots of variations of a single photo and then when you decide
which one captures what you wanted you can go to the exif to see what
settings you used for this one and the ones you didn't like, and compare to
see what settings made the difference. You will probably just want to read a
very few fields and ignore the ones that don't have anything to do with you.
Fields that detail where and how large the thumbnail image is stored in the
image file probably won't be something you care about. The fields detailing
the make model and physical makeup of the sensor/processor/etc probably
won't be of concern. But by concentrating on the fields that tell you the
specifics of the things you CAN control (Shutter, aperture, focal length,
etc) it can help you to get a feel for how to set your camera in future
similar situations. Of course if you are mostly taking "snap shots" using
most of the auto functions of your camera, the exif data may be much less
useful to you. You can still want the date and time of "creation" (when the
image was shot), and knowing if the flash was on or off, etc.
Also by compairing data across several similar photos you may find that
there are effects that show up in one photo and not in another that you may
want to duplicate in the future. For example when shooting moving water
(rocky brook, waterfall, etc) you will find that a very short shutter speed
will stop the motion and give one effect, while one with a slower shutter
will give a blur to the falling water that gives another effect. They are
both desirable and enhance a particular emotion or desired result. By having
experience of taking these images and by consulting the exif, you can
duplicate the effect you want because you already know what range of
settings will give you the image you want.
You could do the same with a notebook and a pen and write down all the
settings for each shot you take, but now the exif does it automatically. The
camera you have may store WAY more data than you want and may not store the
data you wish it did, but the data is there.
BTW you specifically ask about what setting you were at (Auto, Shutter
priority, etc). Not all cameras store this, and some display programs may
not display it even if the camera stored it. I know that that setting IS
stored with my Pentax and when I use an exif reader that I got a long time
ago (exiftool) it does show this setting. My camera stores about 5 pages of
information and most of it is of no use to me, and the same information may
appear in many places and in many different formats. You might try looking
at the exif data with many different programs (standard MS "properties",
Photoshop, etc) and see if the data you want IS there but just not shown
with the program you originally used.
On Sun, 06 Jan 2008 18:03:54 -0500, tony cooper
<tony_cooper213@earthlink.net> wrote:
>
>What does exif data tell me that I should want to know?
>
See http://en.wikipedia.org/wiki/Exif
On Mon, 7 Jan 2008 03:56:00 -0600, "Randy Berbaum"
<rberbaum@prairienet.org> wrote:
>> When I look at Exif with the Adobe Photoshop browser, I see a list of
>> tags and numbers. Like EXIF TAG 49189=82. What's that?
>>
>> Other than the camera used, the date, and a few basics, what's this
>> tell me and who uses it how?
>> --
>> Tony Cooper - Orlando, Florida
>
>Your simple question has a not so simple answer.
>BTW you specifically ask about what setting you were at (Auto, Shutter
>priority, etc).
Thanks for the comments. Some of the information I knew because I did
Google up Exif and do some reading before posting. Some of the uses -
like knowing what f/stop was used - is easy enough to understand
without looking anything up. I already re-name files and store by
folder and date. All of my 2007 family pix are in one folder stored
by month and day.
What I was looking for was what I'm missing: some use that I haven't
figured out on my own that everyone else is using beneficially. The
"Duh!" factor. Doesn't sound like there is one.
I'm interested in the Auto, A, Macro settings used because I do a lot
of bench and tripod shots of the same type of objects and I'm
experimenting on which setting produces the best results. The
equipment and distance is always the same, but the setting differs.
I wish that my Nikon would allow me add this to exif.
Currently I'm using a file name code: A11blackC-015. This tells me
that this image was taken using Aperture, f/11, with background C.
This requires re-naming files. No biggie, though.
EXIF data - What do you learn? 
Linear Mode
