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  1. #11
    Join Date
    Feb 2006
    Location
    Des Plaines, IL
    Posts
    9,554
    Their advertised price of the A700 + kit lens is a travesty, bigw00dy ... and you can tell them I said so, too!

    I mean, look at this ... geez louise!

    If you emailed this to me ... I'd block ya!
    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

  2. #12
    Join Date
    Jan 2008
    Location
    Ohio, USA.
    Posts
    1,161
    Good diagram and information Don, thats the kin dof stuff I find really handy, have printed it off and put it in my big 3 ring binder of stuff I should know. i go back and flip through it pretty often. each time I try to learn soemthing new i forget something, or I just wonder if I will ever get this figured out!
    A-mount from Tokina again you say.....HMMMMMMNNNNNNN now thats intersting.
    Sony A700_____________Minolta AF 50mm. F/1.7
    Minolta AF 70-210mm F/3.5-4.5 Tamron AF 17-50mm F/2.8 XR DiII LD Asp. [IF]
    Tamron SP AF 70-200mm. F/2.8 DI LD [IF] Macro
    Tamron AF 70-300mm F/4-5.6 Di LD Macro 1:2
    Tokina AF 28-70mm F/3.5-4.5
    Tokina AF AT-X 80-400mm F/4.5-5.6
    http://flickr.com/

  3. #13
    Join Date
    Jan 2008
    Location
    Ohio, USA.
    Posts
    1,161
    umm whats a 12MP 'anti shade' self cleaning sensor? maybe thats why it's so expensive?
    accepts ALL Maxxum lenses, may not AF but will accept. LOL just having fun guys.
    Sony A700_____________Minolta AF 50mm. F/1.7
    Minolta AF 70-210mm F/3.5-4.5 Tamron AF 17-50mm F/2.8 XR DiII LD Asp. [IF]
    Tamron SP AF 70-200mm. F/2.8 DI LD [IF] Macro
    Tamron AF 70-300mm F/4-5.6 Di LD Macro 1:2
    Tokina AF 28-70mm F/3.5-4.5
    Tokina AF AT-X 80-400mm F/4.5-5.6
    http://flickr.com/

  4. #14
    Join Date
    Feb 2006
    Location
    Des Plaines, IL
    Posts
    9,554

    Cool What can the A900 do w/ a 20mm f/1.8 lens?

    There are some striking differences in effect with the 20mm f/1.8 mounted on the A900 body. Basically, the DOF increases under the same situation.

    Here a diagram of the change: (Remember same distances, same aperture - f/1.8)

    Name:  DOF for the 20mm f18 on A900.JPG
Views: 99
Size:  124.3 KB

    As you can easily see ... not only do you get you get 30-degrees more Field of View (FoV) and nearly 2x the DOF at 10-feet away ... but, you also get a whole bunch more DOF at 20-feet ... almost 10 times more!

    If you needed a reason to buy the A900 ... this is a decent one. Plus, if you put the α900 in "CROP" mode, you can whack that DOF right back down to the first diagram ... and get some bokeh in that "bright" shot. It's like having a 20mm and a 30mm lens on your camera.
    Last edited by DonSchap; 05-29-2009 at 08:36 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

  5. #15
    Join Date
    Feb 2006
    Location
    Des Plaines, IL
    Posts
    9,554

    Smile Concerning the Tokina A-mount issue ...

    It is very exciting for SONY DSLRs to have the "Tokina option" in the cards, because then lens prices have a real chance to come down a bit, with competition for everyone's hard earned buck.

    Tokina, first and foremost, makes a darn good lens ... definitely worthy of consideration when sized up against a lens of equal capability. That being said, here is the current Tokina lens line up, filter-size, weight and B&H prices (based on the Nikon/Canon mounts):

    • AT-X 116 Pro DX 11-16mm f/2.8 77mm (19.8 oz) - $600
    • AT-X 165 Pro DX 16-50mm f/2.8 77mm (21.5 oz) - $600
    • AT-X 535 Pro DX 50-135mm f/2.8 67mm (29.8 oz) - $530
    • AT-X 124 AF Pro DX II 12-24mm f/4 77mm (19.0 oz) - $550
    • AT-X M35 Pro DX 35mm f/2.8 Macro 52mm (12.0 oz) - $400
    • AT-X M100 AF Pro D 100mm f/2.8 Macro 55mm (19.0 oz) - $400
    • AT-X 107 DX Fish-Eye 10-17mm f/3.5-4.5 NA (12.3 oz) - $580
    • AT-X 840 AF D 80-400mm f/4.5-5.6 72 (35.9 oz) - $620


    The total of it all is $4280 ... which, honestly, is not bad at all when compared to SONY, SIGMA or TAMRON lens of similar capability. Obviously, Image Quality or IQ will be the real deciding vote (maybe weight) ... but cost, not so much.

    Enjoy ... they may see you in December, I guess.
    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

  6. #16
    Join Date
    Dec 2006
    Location
    God's Country - Australia
    Posts
    10,415
    the only options worth considering are the wideangles, the 11-16 being a definate on any list. sigma pretty much provide the best 3rd party option for most other things.
    D800e l V3 l AW1 l 16-35 l 35 l 50 l 85 l 105 l EM1 l 7.5 l 12-40 l 14 l 17 l 25 l 45 l 60 l 75
    flickr

  7. #17
    Join Date
    Nov 2008
    Location
    Monmouthshire, UK
    Posts
    2,152
    Don, I'm not sure I'm 100% with you on this one.

    I'm not taking issue with your feelings on DOF. A big reason for my wanting the A900 is to recover the DOF lost by the crop sensor and not for the 24MP resolution of the sensor. I've written elsewhere that my wish is for a cheaper Full Frame A8** with 12/15MP Sensor. That's enough res for me and it would bring with it the benefit of increased Sensor sensitivity. A 12MP FF Sensor would enable each receptor to capture twice as many pixels which is a huge advantage.

    Anyway back to your wide angle. The problem I have with your solution is in the FOV (field of view) rather than DOF (depth of field.
    Using your example at school plays and recitals using an
    A700 with 20mm lens focused at 20ft the Horizontal FOV is 24ft x 16ft.
    A700 with 50mm lens focused at 20ft the Horizontal FOV is 9'7" x 6'5".
    A bit of elementary arithmetic shows that the image sizes are different by a factor of 6.
    Put a different way, the subjects captured by the 20mm lens will be one sixth the size of those recorded by the 50mm lens.
    To get the same FOV with the 20mm you'd need to move in to 8ft.
    So yes, the DOF of the 20mm is 10x that of the 50mm but in the swings and roundabouts game the 50mm gains it back in it's FOV.

    That's just an opinion, of course. In a different circumstance, photographing a large object for instance the WA wins every time. This boat pic would not have been possible without one (17/35 Minolta at 17mm f2.8).

    Name:  44 Lightship.jpg
Views: 83
Size:  405.4 KB

  8. #18
    Join Date
    Feb 2006
    Location
    Des Plaines, IL
    Posts
    9,554
    I will redraw the the first diagram and edit it back into the thread. You are completely correct about proportionality ... and I initially made an error. It will be corrected. Good eye, though.

    EDIT: The first diagram has been corrected ... and Sean, you may want to reprint it. It is visually a little more accurate describing the change that takes place with the different sensors.

    If you kind of overlay the two ... you immediately see the difference in Field of View or "Angle of View" (FoV) and Depth of Field (DOF)

    Overlay of the APS-C sensor vs the A900 FF sensor
    Name:  DOF for the 20mm f18 on A700-A900 dashed.JPG
Views: 64
Size:  153.0 KB

    Again, Peter, thank for pointing that out and I hope this clears the air. I find it relatively interesting analyzing the shot for its effect ... and finding a good way to mitigate it. I suppose I should say I'm not going to burden the idea of Depth of Field with too many numeric restrictions, but just give a rough idea of the overall effect with aperture and the sensor size.
    Last edited by DonSchap; 05-30-2009 at 10:40 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

  9. #19
    Join Date
    Feb 2006
    Location
    Des Plaines, IL
    Posts
    9,554

    Cool When there's "noise" in the darkness ...

    I guess what got me to consider the 20mm f/1.8 was one night, I was sitting around with the SIGMA 10-20mm f/4-5.6 DC EX mounted and snapping interior shots under "typical" indoor lighting @ 20mm f/5.6 ... which is the brightest aperture that you can get at 20mm with that particular lens.

    Word problem:

    Shot at ISO-1600 and a shutter speed of 1/15th sec. ... even with noise NR and some High ISO adjustments ... the paneling looked like ... well, unacceptable. I call it "dark noise" ... where the camera is struggling to resolve deep color or shadow.

    Moving up to ISO-800 and shutter speed of 1/8th ... again ... the dark noise is just not very good

    Taking it to ISO-400 and a shutter speed of 1/4 ... this is really testing Don's steady grip ... the dark noise is still there, but is looking better.

    Finally, ISO-200 and a complimentary shutter speed of 1/2 sec We are at Don's handheld, Super SteadyShot limit (YMMV)... the noise is "acceptable", but this is hard work. I'm literally having to "bake the shot" ... and God forbid anything even thinks of moving ... or even breathing.

    Now, taking the same Ev shot at f/1.8 ... that is 3 & 1/3rds f-stops wider than f/5.6.

    f/5.6 = beginning f/stop (which is 1/64th of source lighting)
    f/5
    f/4.5
    f/4 = 1 f/stop wider (1/32nd of source lighting)
    f/3.5
    f/3.2
    f/2.8 = 2 f/stops wider (1/16th of source lighting)
    f/2.5
    f/2.2
    f/2 = 3 f/stops wider (1/8th of source lighting)

    f/1.8 -> 3 & 1/3 f/stops wider (which winds up being 1/6th of source lighting )

    In effect, I can use ISO-200 at 1/20 sec. (a solid steady shot) and effectively eliminate the dark noise. Almost taking images with impunity. Even an intro-DSLR with this lens could do a bang-up job, because ... you are out of the noise! (IMO: Best solution for images using an intro-camera -> better glass. You can always move to a better body, later. Glass always is what it is, not matter what the body. )

    I figure if flash is verboten ... this is the next best thing.

    Now, there are those who would argue to use 10mm @ f/4, which buys back an f-stop of light ... and then crop. Yeah ... there is that, but at 10mm, you can introduce some pretty nasty distortion, too. If you don't believe it, go take some 10mm & 20mm shots, alternating back and forth ... have fun. Then -> post process and see how much work there is straightening out 10mm-shots and make them look like 20mm-ones. It will be educational.

    One thing to bear in mind ... advantage-wise with a 10-20mm zoom ... the Field of View is from 102.4 to 63.8 ... 102.4 covers a lot of ground.
    Last edited by DonSchap; 05-30-2009 at 05:13 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. #20
    Join Date
    Mar 2009
    Location
    San Diego, CA
    Posts
    602
    Quote Originally Posted by DonSchap View Post
    There are some striking differences in effect with the 20mm f/1.8 mounted on the A900 body. Basically, the DOF increases under the same situation. ...


    As you can easily see ... not only do you get you get 30-degrees more Field of View (FoV) and nearly 2x the DOF at 10-feet away ... but, you also get a whole bunch more DOF at 20-feet ... almost 10 times more!

    If you needed a reason to buy the A900 ... this is a decent one. Plus, if you put the α900 in "CROP" mode, you can whack that DOF right back down to the first diagram ... and get some bokeh in that "bright" shot. It's like having a 20mm and a 30mm lens on your camera.
    Thanks Don for the great info. I have yet to use the APS-C function on my α900. I might just try it, if only to figure out the resulting MP resolution - the manual doesn't say what MP resolution you get when the APS-C function is on.
    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???

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