I stand corrected :) Bulent --------------------------------------------------------------------- http://patoloji.gen.tr http://celasun.wordpress.com/ http://www.flickr.com/photos/bc_the_path/ http://photo.net/photodb/user?user_id=2226822 http://www.pentaxphotogallery.com/artists/bulentcelasun
2016-07-07 17:59 GMT+03:00 Mark Roberts <[email protected]>: > Bulent Celasun wrote: > >>>and this increases the size of the image circle >> >>... decreases... > > Nope. Moving the lens farther from the focus plane increases the size > of the image circle. Also, by increasing the area of coverage, it > decreases the intensity of the light falling on the imaging area and > necessitates longer exposures. This is why non-TTL metering requires > exposure compensation at high magnification. > > > >>Bulent >>--------------------------------------------------------------------- >>http://patoloji.gen.tr >>http://celasun.wordpress.com/ >>http://www.flickr.com/photos/bc_the_path/ >>http://photo.net/photodb/user?user_id=2226822 >>http://www.pentaxphotogallery.com/artists/bulentcelasun >> >> >>2016-07-07 15:10 GMT+03:00 Bill <[email protected]>: >>> On 7/7/2016 5:28 AM, Zos Xavius wrote: >>>> >>>> I bet its like the 60-250 and there is just a baffle inside to block >>>> light for aps-c. >>> >>> >>> That is typical behavior for lenses in general. Close focusing moves the >>> glass farther away from the sensor, and this increases the size of the image >>> circle. >>> Anyone who has used a large format camera will be familiar with this. >>> >>> bill >>> >>>> >>>> On Wed, Jul 6, 2016 at 6:24 PM, Larry Colen <[email protected]> wrote: >>>>> >>>>> I just did a quick test with the DA35 on the K-1 to see at which aperture >>>>> vignetting becomes a problem. The short answer is that aperture doesn't >>>>> make much difference, focus distance does. If you are focused to less >>>>> than >>>>> about 20cm/8" the lens will not vignette. Further away than that, and >>>>> something occludes the corners of the sensor. >>>>> >>>>> That explains why when I tested it, which it turns out to have been with >>>>> macro shots, I didn't see any vignetting, but when I used it to >>>>> photograph >>>>> the sushi, I did. >>>>> >>>>> -- >>>>> Larry Colen [email protected] (postbox on min4est) http://red4est.com/lrc >>>>> >>>>> >>>>> -- >>>>> PDML Pentax-Discuss Mail List >>>>> [email protected] >>>>> http://pdml.net/mailman/listinfo/pdml_pdml.net >>>>> to UNSUBSCRIBE from the PDML, please visit the link directly above and >>>>> follow the directions. >>>> >>>> >>> >>> >>> -- >>> PDML Pentax-Discuss Mail List >>> [email protected] >>> http://pdml.net/mailman/listinfo/pdml_pdml.net >>> to UNSUBSCRIBE from the PDML, please visit the link directly above and >>> follow the directions. > > -- > Mark Roberts - Photography & Multimedia > www.robertstech.com > > > > > > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
