Correct me if I am totally wrong, but isn't the k-7 sensor size the same as sony sensors with a 1.5x crop? Canon is the only oddball I know of with their slightly smaller 1.6x crop sensor. Ok....I just googled it. The difference is .1mm horizontally between the k-7 and k-5. Not enough to even noticable.
On Sun, Sep 8, 2013 at 1:54 PM, P.J. Alling <webstertwenty...@gmail.com> wrote: > That's true, it's "around" 7.5mm. However almost all of this is pretty > fuzzy. A full frame fisheye is supposed to cover 180° across the diagonal > of the format. > > Depending on the curvature that the lens imparts that can be done with a > number of different focal lengths in the same ball park can be designed to > do that. > > Then when you get to APS-C, well, there's Canon's standard sensor size, the > Sony sensors which are slightly larger, the K20D/K-7 with a sensor that's > intermediate between them, and whatever Samsung is using these days. > > Hell, even "full frame" digital sensors aren't exactly the same size as the > standard film gate for 35mm film cameras. > > So it's unlikely that a full frame fisheye will actually fit the classical > definition on any format. Though it would be easiest to do for m4/3 and 4/3 > system cameras since the sensor dimensions are fully specified. > > > On 9/8/2013 1:31 PM, Dario Bonazza wrote: >> >> Fisheye for m4/3 is around 7.5mm. This is what I have: >> >> http://www.ephotozine.com/article/samyang-7-5mm-f-3-5-umc-fisheye-lens-review-19847 >> Dario >> >> >> -----Messaggio originale----- From: P.J. Alling >> Sent: Sunday, September 08, 2013 7:12 PM >> To: Pentax-Discuss Mail List >> Subject: Re: Which second party camera system do you like? Mini-survey >> >> With rectilinear lenses doing format translations is easy. AOV is AOV, >> but Fisheye lenses make hash those kinds of comparisons. I have a Pentax >> 17mm fisheye, and an old 12mm semi circular, (on film), fisheye made by >> Sigma in the early 60's. I don't have any examples currently, (and >> don't even have my film scanner attached to my current machine), but the >> 12mm on APS-C digital actually seemed to cover more than the 17mm did on >> film even though the 12mm was 18mm/e. I'm pretty sure that comparing >> fisheye lenses, AOV, by focal length is a fools errand. >> >> On 9/8/2013 12:53 PM, Aahz Maruch wrote: >>> >>> On Sun, Sep 08, 2013, Godfrey DiGiorgi wrote: >>>> >>>> On Sep 7, 2013, at 9:43 PM, Aahz Maruch <a...@pobox.com> wrote: >>>>> >>>>> Sure, but there's nothing like the 8mm fisheye you can get for APS-C >>>>> for >>>>> 12mm/e. For most purposes, you're correct that's sufficient, but >>>>> people >>>>> who really care about extreme wide-angle are likely to be less >>>>> satisfied >>>>> with m4/3. >>>> >>>> "For most purposes ..." Don't be ridiculous. >>>> >>>> A fish-eye lens is a specialty lens, and the ONLY wide-angle lens >>>> focal length not listed in native Micro-FourThirds mount. Perhaps >>>> that's because there's a superb fish-eye lens in FourThirds SLR mount, >>>> which work on mFT bodies with any of the four available, dedicated >>>> Panasonic and Olympus FourThirds to Micro-FourThirds mount adapters >>>> for 100% full function operation. >>> >>> The point is that m4/3 8mm is 16mm/e. >>> >>>> Your comment sounds like it fits one of the categories in Ctein's most >>>> recent column on "The Online Photographer": >>>> >>>> http://theonlinephotographer.typepad.com/the_online_photographer/2013/09/bad-science-vs-good-science-a-guide-for-the-layperson-part-1.html >>>> >>>> Check out the "God of the Gaps" category. ;-) >>> >>> <shrug> Some people regularly claim that they want FF over APS-C due to >>> wide-angle versus crop-factor -- given that Marnie didn't even know that >>> m4/3 has 2x crop factor compared with APS-C's 1.5x, I think it was >>> entirely reasonable to mention the wide-angle issue. I certainly don't >>> think it'll play a significant role in her decision given her telephoto >>> preference (or if it does, it'll have a reverse significance). >>> >>> Side note: most of my shooting is also telephoto (except for macro), so >>> I'm definitely not grinding any axe favoring wide-angle and I consider >>> the m4/3 crop factor a plus myself because it makes for lighter and >>> smaller telephoto lenses. >> >> >> > > > -- > A newspaper is a device for making the ignorant more ignorant, and the > crazy, crazier. > > - H.L.Mencken > > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > 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 PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
