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View Full Version : EXIF: Incorrect "Exposure Time" value


flyingdutchie
Mar-19-2005, 06:17 PM
Sometimes the the EXIF values for "Exposure Time" on a picture in my smugmug gallery are incorrect.

E.g. the EXIF data contains this:
"Tv(Shutter Speed) : 1/13"

But this is presented in smugmug:
"Exposure Time 769230s (7692307/10)"

(This is the picture: http://flyingdutchie.smugmug.com/gallery/116685/3/17811594/Large)

This does not seem really correct :D

Is there a possiblity that smugmug just shows the EXIF data 'as-is', instead of trying to convert it into some other smugmug-format?

-- Anton Spaans.

fish
Mar-19-2005, 08:15 PM
I like your exposure bias too...I had no idea Nikon's were so precise. :rofl


-0.66666666666667

flyingdutchie
Mar-19-2005, 08:23 PM
I like your exposure bias too...I had no idea Nikon's were so precise. :rofl


-0.66666666666667
:): Yep, but that's because the actual EXIF value is
"Exposure Compensation : -2/3"

So, i guess smugmug is calculating it into a decimal number...

The more reason that it would be nice if Smugmug would show the EXIF data 'as-is'. E.g. the EXIF for this particular picture (from my first post in this thread) is:

ExifTool Version Number : 3.60
File Name : C:\WINDOWS\tmp.jpg
File Size : 2094KB
File Type : JPG
Software : Adobe Photoshop CS Windows
Components Configuration : YCbCr
Flash : No Flash
Sub Sec Time : 20
Sub Sec Time Original : 20
Sub Sec Time Digitized : 20
Flash Pix Version : 0100
Exif Image Width : 3208
Exif Image Length : 2200
CFA Pattern :
Compression : JPEG
Thumbnail Offset : 762
Thumbnail Length : 4932
Photoshop Thumbnail : (Binary data 4932 bytes, use -b option to extract)
Tv(Shutter Speed) : 1/13
Av(Aperture Value) : 2.8
Exposure Program : Aperture-priority AE
Exif Version : 0220
Shooting Date/Time : 2005:03:19 19:11:00
Date Time Digitized : 2005:03:19 19:11:00
Exposure Compensation : -2/3
Max Aperture Value : 2.8
Metering Mode : Multi-segment
Light Source : Unknown (0)
Fired : False
Return : 0
Mode : 0
Function : False
Red Eye Mode : False
Focal Length : 82.0mm
User Comment : t Anton Spaans, 2004
Flashpix Version : 0100
Color Space : sRGB
Pixel X Dimension : 3208
Pixel Y Dimension : 2200
Sensing Method : One-chip color area
File Source : Digital Camera
Scene Type : Directly photographed
Make : NIKON CORPORATION
Camera Model Name : NIKON D70
Orientation : Horizontal (normal)
X Resolution : 300
Y Resolution : 300
Resolution Unit : inches
Y Cb Cr Positioning : Centered
Date/Time Of Digitization : 2005:03:19 19:11:00
Date/Time Of Last Modification : 2005:03:19 21:40:26
Metadata Date : 2005:03:19 21:40:26
Creator Tool : Adobe Photoshop CS Windows
Document ID : adobe:docid:photoshop:61e86586-98e9-11d9-8448-fbaebd73867a
Format : image/jpeg
Image Width : 3208
Image Height : 2200
Av(Aperture Value) : 2.8
Image Size : 3208x2200
Tv(Shutter Speed) : 1/13
Thumbnail Image : (Binary data 4932 bytes, use -b option to extract)
Focal Length : 82.0mm

fish
Mar-19-2005, 08:30 PM
whoa! how'd you get your camera to embed a smilie in the EXIF data? :scratch

Document ID : adobe:docid:photoshop:61e86586-98e9-11d9-8448-fbaebd73867a



I agree...exif should not be massaged, if at all possible.

onethumb
Mar-19-2005, 11:17 PM
:): Yep, but that's because the actual EXIF value is
"Exposure Compensation : -2/3"

So, i guess smugmug is calculating it into a decimal number...

The more reason that it would be nice if Smugmug would show the EXIF data 'as-is'.

Actually, if we want to get precise, there is no "Exposure Compensation" value in the EXIF spec. Instead, it's "Exposure Bias". Additionally, "Exposure Bias" is specified as being a decimal value in the range of -99.99 to 99.99, *not* in fractions denoted by, say, 2/3. See for yourself: EXIF 2.2 spec (http://www.exif.org/Exif2-2.PDF)

The point is, I *am* showing the data as-is for that value. Wherever you got your data from is showing you a modified calculation - I'm not. I happen to think that maybe we should display it as a fraction, since it's easier to read - but you can't have it both ways. :) What'll it be, display "as-is" or display as something more human readable?

I'm still looking into the Exposure Time to see what's up, but I've now seen that (clearly wrong) value in two seperate programs (and 1/13 in two programs, too), so it might be that there's some confusion over the spec. I'm storing exactly what our EXIF library is reading it, and it's current and up-to-date. It might be out of my hands, since I didn't write the library, but I'll keep looking.

Don

onethumb
Mar-19-2005, 11:22 PM
I agree...exif should not be massaged, if at all possible.

Ok, you guys have really gotta make up your mind. I used to display *all* EXIF data without any massaging.

But you guys threw a fit when "Flash" just had the numeric value (say, "19" instead of "flash fired, auto mode"). So I had to massage it to say the nice human version.

Now you say you don't want the data massaged. Which will it be?

Don

onethumb
Mar-19-2005, 11:27 PM
While we're on the subject, let me give you a little insight to my private little hell.

It's called EXIF data. :)

I've spent more time fiddling with EXIF data stuff than I have building major features, like the entire keywords feature and interface.

Why? Because all the different camera manufacturers produce *different* EXIF data from each other, despite the fact that there's a nice published spec. What's more, a surprising number of image editing software packages actually corrupt and destroy the EXIF data. Some cameras even generate corrupt, malformed EXIF data as the photo is taken!

Somehow, we have to deal with all the different non-official versions of EXIF and also detect and discard corrupt data. We adhere to the spec as closely as we possibly can, and probably 25% of uploaded photos still have some non-spec problems. And on top of that, a vocal few people seem to constantly have problems with the way we store and display the data we are able to get cleanly.

Finally, almost no-one ever clicks on the link. It's a tiny fraction, probably less than 0.1% of our photos have had their EXIF data viewed.

Short version: I spend days and weeks working on EXIF data, which no-one ever views, instead of building much more useful features. I do it because you guys really seem to love it, and I want you guys to love smugmug.

But moving targets are much harder to hit. :)

Don

flyingdutchie
Mar-20-2005, 06:46 AM
While we're on the subject, let me give you a little insight to my private little hell.

It's called EXIF data. :)

I've spent more time fiddling with EXIF data stuff than I have building major features, like the entire keywords feature and interface.

Why? Because all the different camera manufacturers produce *different* EXIF data from each other, despite the fact that there's a nice published spec. What's more, a surprising number of image editing software packages actually corrupt and destroy the EXIF data. Some cameras even generate corrupt, malformed EXIF data as the photo is taken!

Somehow, we have to deal with all the different non-official versions of EXIF and also detect and discard corrupt data. We adhere to the spec as closely as we possibly can, and probably 25% of uploaded photos still have some non-spec problems. And on top of that, a vocal few people seem to constantly have problems with the way we store and display the data we are able to get cleanly.

Finally, almost no-one ever clicks on the link. It's a tiny fraction, probably less than 0.1% of our photos have had their EXIF data viewed.

Short version: I spend days and weeks working on EXIF data, which no-one ever views, instead of building much more useful features. I do it because you guys really seem to love it, and I want you guys to love smugmug.

But moving targets are much harder to hit. :)

DonWow.. that's a fast response! :):
I can imagine it is a bit "damned if you do, damned if you don't" situation with processing and showing EXIF. EXIF being a standard and almost no manufacturer adhering to it..... I'm a software engineer as well, i can see your problem here, Don.

The EXIF dump i showed in my second post in this thread is generated from this PERL based tool: http://www.sno.phy.queensu.ca/~phil/exiftool/

Thanks for looking into it Don.
-- Anton.

fish
Mar-20-2005, 08:01 AM
Ok, you guys have really gotta make up your mind. I used to display *all* EXIF data without any massaging.

But you guys threw a fit when "Flash" just had the numeric value (say, "19" instead of "flash fired, auto mode"). So I had to massage it to say the nice human version.

Now you say you don't want the data massaged. Which will it be?

Don


Gotcha. Okay, as one who deals with "standards" all day long, I understand the issue. I still stand by my statement that the data shouldn't be massaged...it just has to be "right".

I still find it kinda funny that exposure bias is precise to 14 digits, especially considering it's adjusted by turning a dial one click. :lol

Nikolai
Mar-20-2005, 08:28 AM
Don,
I totally understand the situation with EXIF.
However, I don't see why you simply can't deliver 3 columns instead of 2.
One would be the tag, second - the data you "massaged", and the third one - the original, raw data (your example "19" instead of "auto mode, flash fired").
Or, for the worst case scenario when even tags do not match the standard, simply two bicolumnar tables instead of one: one yours, one "raw"...
This way those who don't like your interpretation can always go to the raw part and have fun themselves..
Just a thought..

rainforest1155
Mar-20-2005, 09:12 AM
Finally, almost no-one ever clicks on the link. It's a tiny fraction, probably less than 0.1% of our photos have had their EXIF data viewed.Don, I appreciate your hard work on the EXIF stuff and you're right for most of the time people don't click on the exif-link. Therefore I would like in addition to what Nikolai said -
However, I don't see why you simply can't deliver 3 columns instead of 2.
One would be the tag, second - the data you "massaged", and the third one - the original, raw data (your example "19" instead of "auto mode, flash fired").
Or, for the worst case scenario when even tags do not match the standard, simply two bicolumnar tables instead of one: one yours, one "raw"...
This way those who don't like your interpretation can always go to the raw part and have fun themselves..- I would like to have the option to display basic exif-infos like exposure time, F number, ISO and flash directly under the pictures. This should be customizalbe so everybody can pick his camera specific fields.
This should apply to all views, as far as it is possible, but especially in the journal view, as there is no EXIF-button under the pictures.

Who's with me? :D

Nikolai
Mar-20-2005, 09:25 AM
I would like to have the option to display basic exif-infos like exposure time, F number, ISO and flash directly under the pictures. This should be customizalbe so everybody can pick his camera specific fields.
This should apply to all views, as far as it is possible, but especially in the journal view, as there is no EXIF-button under the pictures.

Who's with me? :D
But that one may be helluva s.o.b. to do right...

However, with SE eventually (not tomorrow, as always:-) you may be lucky - I can read exif/iptc (in case you never opened upoad caption editor - it's there, provided there is some exif/iptc info to show), so I was thinking of automating the process of bringing some of it into image title/description.

Yet, as in Don's case, amount of time/effort I'd have to spend to do it right (no two camera brands with the same EXIF, no two major software brands with the same IPTC.. I'd say 30-40 hours, and that with 10-12 hours of a weekly cap I have for SE) versus amount of possible users who'd benefit from it (10? 3? me and you only?) makes it a *very* low priority..

Cheers!:1drink

rainforest1155
Mar-21-2005, 04:42 AM
However, with SE eventually (not tomorrow, as always:-) you may be lucky - I can read exif/iptc (in case you never opened upoad caption editor - it's there, provided there is some exif/iptc info to show), so I was thinking of automating the process of bringing some of it into image title/description.Yeah Nikolai, I've seen this function, wasn't I one of the persons to request this feature? :rofl
Putting everything into the caption makes the important part that most of the users tend to read (if any at all) hard to read, because it's flooded with technical information. In journal style this is very doable, because of html-formation.
Problem with proposing styles to people is that they tend to ignore this. I've seen it in my panorama gallery. Almost nobody visiting my 360° pictures views them at my proposed original size although these pictures even in large aren't more than a little stripe with not much recognizable.

If I could at least force a gallery style with my basic account, although I really would like to have more infos under the picture in the other styles. SM already provides the camera name, so some standard exif-fields shouldn't be to hard. A start would be Fnumber, ISO and exposure time which doesn't involve any calculations and guesses on SM-side, does it? :wink

Thanks for reading,
Sebastian

P.S. I'm not the only one. Actually DoctorIt now puts his exif into the caption, because there's no way to display exif in journal-view without clicking on the picture and then on the exif-link.

afx
Feb-06-2008, 07:38 AM
I consider it rather shameful, that Smugmug is not even able to show simple exposure times in values photographers are used to see.
If you have problems deciding or decoding things, grab exiftools and use that as a reference.
Seeing a shutter speed of 1/20 displayed as 0.0500s (13421773/268435456) is definitely disgusting.

cheers
afx

Andy
Feb-06-2008, 07:41 AM
I consider it rather shameful, that Smugmug is not even able to show simple exposure times in values photographers are used to see.
If you have problems deciding or decoding things, grab exiftools and use that as a reference.
Seeing a shutter speed of 1/20 displayed as 0.0500s (13421773/268435456) is definitely disgusting.

cheers
afx
Hi, can you give a link to such badness, so I can see? Thanks!

afx
Feb-06-2008, 08:09 AM
Hi, can you give a link to such badness, so I can see? Thanks!

Basically any image under afx.smugmug.com
http://afx.smugmug.com/popular/1/91572602#91572602
http://afx.smugmug.com/gallery/4260716#250325959

Or here
http://lostgravity.smugmug.com/gallery/3591951#204152425

Any tool I use on those files (XnView, exiftools, iMatch, digikam, Exif Viewer, FxIF) shows correct values.

cheers
afx

janniklindquist
Mar-23-2008, 12:05 PM
I consider it rather shameful, that Smugmug is not even able to show simple exposure times in values photographers are used to see.
If you have problems deciding or decoding things, grab exiftools and use that as a reference.
Seeing a shutter speed of 1/20 displayed as 0.0500s (13421773/268435456) is definitely disgusting.

cheers
afx

Amen, afx! I have tons of problems with SmugMug's handling of EXIF. Most of my images have screwed information and, in particular, the dates are wrong. I am very disappointed to read that we shouldn't worry about stuff like that as hardly no-one checks our EXIF-data. Please wake up, SmugMug! The problem is that I can't sort a single gallery correctly because of screwed up EXIF-info! And *please* don't tell me that it is some of my software that is responsible for this. The very same images that appear with garbled EXIF in SmugMug, shows up perfectly in *every* single piece of software I have ever tried and at *every* other online photo-service.

To me, SmugMug is clearly the most perfect photo-service available - *if it wasn't for this absurd problem*! As almost perfect as SmugMug is, I am *not* going to adjust EXIF on tens of thousand of images in order to have them show up correctly in SmugMug.

Example gallery (http://janniklindquist.smugmug.com/gallery/4567435_GvL8K#269209423)

afx
Mar-23-2008, 01:47 PM
There are plenty of free libraries that handle that data properly. There is no excusefor Smugmug. ;-(

afx