Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
09-04-2015, 09:12 AM   #16
Pentaxian




Join Date: Oct 2011
Location: Savannah, GA
Posts: 5,005
QuoteOriginally posted by grahame Quote
FL information is for SR system. K3's SR system has to move a much bigger unit quickly and precisely than on Q's to compensate the camera shake. I guess the mathematic models to calculate the movement is so complicated and might be easier to preset some FLs.
Just guess.
I think the opposite (sort of) is the difference -- the Q's sensor is so small that there is such a big difference between 1mm of focal length which makes the Q's extra precision needed (and you can even enter decimals on the Q, e.g. 10.5mm) and the fact that with adapted lenses you are dealing with extreme telephoto and so again precision is important. Whereas on the bigger sensor the difference between say 100 & 105 is negligible for SR purposes. That's not saying it wouldn't be nice anyway to use exact values just to get the EXIF right. Although it should be noted that on manual lenses, if you turn off SR, it doesn't even record any focal length in EXIF, so I don't think they care about that much. (At least on older models, maybe it does on the K-3?)

09-04-2015, 11:40 AM   #17
Pentaxian
ScooterMaxi Jim's Avatar

Join Date: Jul 2009
Location: Minnesota
Posts: 1,509
Original Poster
QuoteOriginally posted by vonBaloney Quote
I think the opposite (sort of) is the difference -- the Q's sensor is so small that there is such a big difference between 1mm of focal length which makes the Q's extra precision needed (and you can even enter decimals on the Q, e.g. 10.5mm) and the fact that with adapted lenses you are dealing with extreme telephoto and so again precision is important. Whereas on the bigger sensor the difference between say 100 & 105 is negligible for SR purposes. That's not saying it wouldn't be nice anyway to use exact values just to get the EXIF right. Although it should be noted that on manual lenses, if you turn off SR, it doesn't even record any focal length in EXIF, so I don't think they care about that much. (At least on older models, maybe it does on the K-3?)
Have no idea how the sensor difference relates, but surely the computer storage space available would be less on the Q; I'd say the "they don't care about that much" is the most likely explanation, unfortunately.

The K-3 retains the FL entered at boot with the SR off. I do recall earlier models where that info was oddly not retained, so at they "fixed" that bit of code.
09-04-2015, 11:49 AM   #18
Pentaxian




Join Date: Oct 2011
Location: Savannah, GA
Posts: 5,005
QuoteOriginally posted by ScooterMaxi Jim Quote
The K-3 retains the FL entered at boot with the SR off. I do recall earlier models where that info was oddly not retained, so at they "fixed" that bit of code.
Good, as far as that goes. I was actually thinking of making an EXIF "fixer" program that could enter lens data for manual lenses into the EXIF that are unidentified or others that are wrongly identified), plus fix the focal length values. Something that would know what YOUR lenses are and quickly fix a batch of photos after a shoot so it wasn't a cumbersome process...
09-04-2015, 01:01 PM   #19
Pentaxian
ScooterMaxi Jim's Avatar

Join Date: Jul 2009
Location: Minnesota
Posts: 1,509
Original Poster
QuoteOriginally posted by vonBaloney Quote
Good, as far as that goes. I was actually thinking of making an EXIF "fixer" program that could enter lens data for manual lenses into the EXIF that are unidentified or others that are wrongly identified), plus fix the focal length values. Something that would know what YOUR lenses are and quickly fix a batch of photos after a shoot so it wasn't a cumbersome process...
Yeah, that would be great. I pretty much care most about the image - so going to any extra effort regarding fixing EXIF or geo-tagging isn't worth it to me on a file-by-file basis. On occasion, I'll use EXIF Pilot, especially if I happen to not to set the lens FL properly when changing them quickly. Not often, though.

Following up on an earlier (somewhat unrelated) discussion we were having regarding UWA - I do now understand better about your desire to use these lenses at closest focus, and tried it on my dog. You can get interesting results - like this: Devo arrives - James Robins - Powered by Phanfare By the way, true to my desire not to fix the EXIF, the lens was the Rokinon 14mm (not a 12mm as indicated).

09-04-2015, 01:21 PM   #20
Pentaxian




Join Date: Oct 2011
Location: Savannah, GA
Posts: 5,005
QuoteOriginally posted by ScooterMaxi Jim Quote
Yeah, that would be great. I pretty much care most about the image - so going to any extra effort regarding fixing EXIF or geo-tagging isn't worth it to me on a file-by-file basis. On occasion, I'll use EXIF Pilot, especially if I happen to not to set the lens FL properly when changing them quickly. Not often, though.

Following up on an earlier (somewhat unrelated) discussion we were having regarding UWA - I do now understand better about your desire to use these lenses at closest focus, and tried it on my dog. You can get interesting results - like this: Devo arrives - James Robins - Powered by Phanfare By the way, true to my desire not to fix the EXIF, the lens was the Rokinon 14mm (not a 12mm as indicated).
Hard to go wrong with your dog...
09-04-2015, 01:30 PM   #21
Pentaxian
ScooterMaxi Jim's Avatar

Join Date: Jul 2009
Location: Minnesota
Posts: 1,509
Original Poster
Not all dogs will allow you to stick a 77mm front element six inches from their cheek (keeping in mind that 12" minimum focus is the film plane distance). Take note, the f/stop was set to 5.0 - I do like using that aperture setting.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
aperture, dslr, f/4.5, f/5.6, fl, input, k-3, k3, length, lens, lenses, pentax, pentax k-3, range, settings, sigma, sr, stop, system
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
How do variable aperture zooms report the aperture? IchabodCrane Pentax SLR Lens Discussion 11 06-26-2015 06:41 AM
Focal Length & Aperture: fast/slow pentexas Pentax SLR Lens Discussion 12 12-31-2014 10:19 AM
Variable aperture zooms DOF and Light. D1N0 Pentax SLR Lens Discussion 4 09-16-2014 08:40 PM
focal length prime vs zooms sany Pentax SLR Lens Discussion 7 05-15-2011 01:14 PM
Variable vs. fixed aperture zooms: am I missing something here? Finn Pentax SLR Lens Discussion 11 05-15-2007 05:05 AM



All times are GMT -7. The time now is 12:30 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top