Home News Buyers Guide About Advertising
 
 
 
   
Page 3 of 9 FirstFirst 12345 ... LastLast
Results 21 to 30 of 83
  1. #21
    Join Date
    Jun 2008
    Posts
    2,204
    It's 12MP cropped (exact same as the A700). Don't use it. It's just limiting yourself. Just take the big picture and crop as needed.
    flickr

    Canon 7D - 5D | 550EX - 430EX II - (2) PW FlexTT5 | 24-105 f4L | 70-200 f2.8L IS | 100 f2.8L IS | 50 f1.8 II

  2. #22
    Join Date
    Feb 2006
    Location
    Des Plaines, IL
    Posts
    9,554
    Basically ... going to "CROP" mode allows for a tighter and shallower DOF, in my calculations. A little flexibility, there, that may be worth consideration. I mean, at least YOU can play with it (at the same f/stop setting) ... I'm stuck at APS-C sensor widths with my PRIMES. LOL It's not going to change. If I use a 2x T/C ... I lengthen the lens, but I also change the base f/stop two f/stop tighter, e.g., f/1.8 -> f/5. What a waste of a prime, eh?
    Last edited by DonSchap; 05-30-2009 at 10:32 AM.
    Don Schap - BFA, Digital Photography
    A Photographer Is Forever
    Look, I did not create the optical laws of the Universe ... I simply learned to deal with them.
    Remember: It is usually the GLASS, not the camera (except for moving to Full Frame), that gives you the most improvement in your photography.

    flickr® & Sdi

  3. #23
    Join Date
    Jun 2008
    Posts
    2,204
    Cropping in PP with the crop sliders is no different than switching to crop mode so I'm not sure how the DOF would change. I don't own an A900, but from what I've read it's identical.
    flickr

    Canon 7D - 5D | 550EX - 430EX II - (2) PW FlexTT5 | 24-105 f4L | 70-200 f2.8L IS | 100 f2.8L IS | 50 f1.8 II

  4. #24
    Join Date
    Feb 2006
    Location
    Des Plaines, IL
    Posts
    9,554

    Cool It is ready for you to try ...

    NOT according to the DOF calculator, Ryan. If (big IF here) the "A900 Crop" reproduces the APS-C sensor results ... then it may be the case as I have stated. If "Crop" mode simply narrows the image ... then, it may not. I kind of wish I had one to try it out, before stepping in it.

    I would suggest you take a peek at it and do some exercises with various settings. Makes sure you specify the camera ... there are the APS-C sensors and and A900. They are different and "A900 Crop Mode" is not specified, per se.

    Maybe I should get an A900. Oh heck, there's always the SONY Style store ... they have one laying around, not doing much. Most people see that sticker price and recoil in horror!
    Last edited by DonSchap; 05-30-2009 at 10:35 AM.
    Don Schap - BFA, Digital Photography
    A Photographer Is Forever
    Look, I did not create the optical laws of the Universe ... I simply learned to deal with them.
    Remember: It is usually the GLASS, not the camera (except for moving to Full Frame), that gives you the most improvement in your photography.

    flickr® & Sdi

  5. #25
    Join Date
    Jun 2008
    Posts
    2,204
    I'm not 100% clear on the diagrams, but the FOV lessons obviously as you go from 1x to a 1.5x crop. The DOF can't possibly change because the crop is done in PP and I don't see how the A900's sensor size is changing. If it physically changed by using an aperture to block off light, then I could see that but I don't think that's how it works.
    flickr

    Canon 7D - 5D | 550EX - 430EX II - (2) PW FlexTT5 | 24-105 f4L | 70-200 f2.8L IS | 100 f2.8L IS | 50 f1.8 II

  6. #26
    Join Date
    Feb 2006
    Location
    Des Plaines, IL
    Posts
    9,554

    Red face Until we know for sure ...

    Well ... erring on the side of caution ... until I am absolutely sure, I will go with your supposition that the A900's DOF does NOT change when switching to "crop."

    I have made the edit to the overlay drawing ... taking the "A900 Crop" out of the diagram.

    Thanks for the catch, Ryan. ... there is just no sense putting ambiguous or improper info out there. It is bad enough that SONY doesn't offer that kind of relevant information in their associated USER manuals. Hey, they put the capability in the camera.
    Last edited by DonSchap; 05-30-2009 at 10:48 AM.
    Don Schap - BFA, Digital Photography
    A Photographer Is Forever
    Look, I did not create the optical laws of the Universe ... I simply learned to deal with them.
    Remember: It is usually the GLASS, not the camera (except for moving to Full Frame), that gives you the most improvement in your photography.

    flickr® & Sdi

  7. #27
    Join Date
    Mar 2009
    Location
    San Diego, CA
    Posts
    602
    Quote Originally Posted by DonSchap View Post
    NOT according to the DOF calculator, Ryan. If (big IF here) the "A900 Crop" reproduces the APS-C sensor results ... then it may be the case as I have stated. If "Crop" mode simply narrows the image ... then, it may not. I kind of wish I had one to try it out, before stepping in it.

    I would suggest you take a peek at it and do some exercises with various settings. Makes sure you specify the camera ... there are the APS-C sensors and and A900. They are different and "A900 Crop Mode" is not specified, per se.

    Maybe I should get an A900. Oh heck, there's always the SONY Style store ... they have one laying around, not doing much. Most people see that sticker price and recoil in horror!
    I'm trying to think about how to test it. I'm tempted to attach my Sony 50mm f/1.4 to the A900, set it on Aperature priority mode at f/1.4 and take two identical photos, one full frame and one APS-C to see if there's any change in DOF. Think it'll work
    Darin Wessel
    α 900
    Zooms: Tamron SP AF70-200mm f2.8 Di LD Macro; Sigma 28-90mm D macro, Konica-Minolta 18-70 f3.5-5.6
    Primes: Minolta 28mm f2.8; Sony 50mm f1.4
    Minolta RC-1000 remote commander

    Film:
    Calumet Cambo CC400 4x5 View Camera
    YashikaMat 6x6 TLR (other accessories)
    Minolta Maxxum 7000 w/ Minolta 35-80mm f/4-5.6 & Minolta 2800 flash
    Minolta Maxxum 5000i & Vivitar 728 AFM flash
    What's next???

  8. #28
    Join Date
    Jun 2008
    Posts
    2,204
    Quote Originally Posted by DWessel View Post
    I'm trying to think about how to test it. I'm tempted to attach my Sony 50mm f/1.4 to the A900, set it on Aperature priority mode at f/1.4 and take two identical photos, one full frame and one APS-C to see if there's any change in DOF. Think it'll work
    Focus on something close by, use a tripod and shoot in both modes, post up the full results!

    According to Don's guess, the bokeh (DOF) should be different between the two in the cropped area.

    I believe the two should be identical. The cropped picture will just be an identical fraction of the larger full-frame image.
    flickr

    Canon 7D - 5D | 550EX - 430EX II - (2) PW FlexTT5 | 24-105 f4L | 70-200 f2.8L IS | 100 f2.8L IS | 50 f1.8 II

  9. #29
    Join Date
    Feb 2006
    Location
    Des Plaines, IL
    Posts
    9,554

    Lightbulb Some quick figures

    Here's an idea with the 50mm set at f/2.8, not f/1.4 ... which may be too shallow to adequately determine a difference.

    These numbers allow seeing a real change in image. Use a tape measure and shoot along it, placing items (colored blocks)
    at the specified "N/C" extreme (Close/Far) distances. You should clearly see a change, if it does change.

    10-feet

    A900 . . . . Lens . . . . . Aperture . . . . DOF Width . , , Close . . . . . Far

    Crop . . . . 50mm . . . . . f/2.8 . . . . . . . 1.36 ft . . . . . 9.36 ft . . . 10.7 ft

    N/C . . . . .50mm . . . . . f/2.8 . . . . . . . 2.06 ft . . . . . 9 ft . . . . . 11 ft



    20 –feet

    A900 . . . . Lens . . . . . Aperture . . . . DOF Width . , , Close . . . . . Far

    Crop . . . . 50mm . . . . . f/2.8 . . . . . . . 5.6 ft . . . . . 17.6 ft . . . . 23.2 ft

    N/C . . . . .50mm . . . . . f/2.8 . . . . . . . 8.6 ft . . . . . 16.6 ft . . . . 25.2 ft

    .
    .
    N/C = Not crop (normal mode)

    Name:  DOF testing.JPG
Views: 82
Size:  43.8 KB
    Last edited by DonSchap; 05-30-2009 at 04:08 PM.
    Don Schap - BFA, Digital Photography
    A Photographer Is Forever
    Look, I did not create the optical laws of the Universe ... I simply learned to deal with them.
    Remember: It is usually the GLASS, not the camera (except for moving to Full Frame), that gives you the most improvement in your photography.

    flickr® & Sdi

  10. #30
    Join Date
    Nov 2008
    Location
    Monmouthshire, UK
    Posts
    2,152
    Oh Boy! Are you guys getting your knickers in a twist or what.
    If you take a pic with an A900 camera and crop it in Photoshop, the DOF won't change.
    That's all the crop mode does on camera. Ergo the DOF is the same.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •