Pentax K-7 EXIF Data Reliable? Mac OS X The Culprit - FIXED

[rei_vilo]

Bonsoir,

I bought a neutral filter ND8 and played with slow speed, obvioulsy on a tripod and with a remote and 3 s timer

Here's the result:



Problem is, when I take the same picture without the filter, the EXIF data are the same: speed temps d'exposition is 8  



Side by side




What's wrong with my pictures? Who's the culprit:

• The Pentax K-7 1.02 firmware?
• The standard Mac OS X 10.5.8 viewer app?

This is really annoying  

Have you experienced the same problem

Best regards,

[Kristian]

It's french, what is your shutter speed?

Edit: sorry, you have allready told me, 8;) Whitch program are you useing?

[spyglass]

I would examine the data in the camera first (accessed by depressing the "info" button when reviewing a photo ("play"). Check to see whether the exposure data is correct in the camera for each photo, or if it too appears to be identical.
If the data is being recorded correctly in the camera for each photo, then the data is either not being transmitted properly (the association of the EXIF is not being maintained, or it is not being understood by the software that opening and viewing it. To check whether the EXIF association is being maintained during transmit ion simply download the picture to your computer and use a 3rd party EXIF program to view the photo and its information. If it is correct, then the software or version you are currently using is defective. If you find that it is not correct you can assume that the EXIF is not being associated and or transmitted with the photo. 

We know that an exposure is made up of three relationships (aperture opening, exposure time, and sensitivity). Using an ND8 filter would affect the shot by 3 stops. This is a significant amount.  If the wheel was spinning in both shots we can safely assume that one of the affected settings was the shutter speed due to the motion blurred of the wheel. So if nothing else we should at least see a change to the exposure time / shutter speed.

Please let us know what you find out as this is very interesting and very important. Many people rely on the EXIF data being correct and documented / embedded with the image file for future reference. 

Spyglass

[calsan]

I think the Apple Preview application may be unreliable.  I have noticed quite a few bugs in the new "Snow Leopard" system.

I would compare the EXIF with that reported by Pentax Digital Camera Utility Software.

[rei_vilo]

Bonjour,

Thank you for your answers and the protocol I'm going to test.

I'll report the results...

Best regards,

[rei_vilo]

Bonjour,

I did some tests according to the protocol suggested by spyglass. Calum's assumption was right.

• The excellent EXIF Tool utility reported correct values.  
   
  

  IMGP0593.JPG 2010:01:10 17:29:28 f/3.2 1/10s iso100 50.0 mm (PENTAX K-7 + smc PENTAX-DA* 16-50mm F2.8 ED AL [IF] SDM)
  IMGP0594.JPG 2010:01:10 17:30:35 f/11.0 8s iso100 50.0 mm (PENTAX K-7 + smc PENTAX-DA* 16-50mm F2.8 ED AL [IF] SDM)

• iPhoto on my iMac running on Mac OS 10.5.8 reported then wrong, as posted earlier.
• iPhoto on my iMac running on Mac OS 10.6.2 and the latest camera patch reported them right.
  
  
  

So the culprit was the non-updated Mac OS.

I feel better now   . Thanks for your help   !

[calsan]

This could be an update to this problem.  Apple has released a patch for Pentax K-x and K-7 raw processing in iPhoto and Aperture.  Available through software update.

Read more here
http://support.apple.com/kb/DL1035

[rei_vilo]

Thank you for the tip, Calsan