On 3 Sep 2005 at 17:17, Keith Green wrote: > Cotty wrote: > > > > On 2/9/05, James B.Davis, discombobulated, unleashed: > > > >>I haven't checked into using other makers' lenses on EOS cameras but > >>generally I thought infinity focus was lost. Perhaps there is a place > >>then for the odd other maker lens. I could use a Pentax 15mm like that > >>too. Is that a Pentax screw mount lens? Oh, the model indicates a K > >>mount which is likely not the old screw mount I'm thinking of... > > > > The 15mm is also found in a screwmount, yes - but very rare and will > > fetch upwards of 5 or 600 bucks US. > > > > I mentioned cost, but actually the 85 mil isn't cheap - I paid nearly > > $700 for mine and it's not mint! Just like the old style sometimes - it > > helps me on my inevitable path to becoming an old fart. > > > > The Canon L lenses are brilliant, and for AF, I couldn't imagine using > > anything else other than USM - the focussing on my zooms is so quick, any > > non-Canon user is blown away by the performance :-) Along with IS, this > > was why I switched to Canon a few years ago when I decided to go all- > > digital. The choice was a good one. > > > > Cheers, > > Cotty > > Cotty, > > The one area where I see criticism of Canon's lenses is when wide-angles are > used on a full-frame sensor. > > The argument seems to be that because the light rays are spread so much, > because of the retro-focus design, the lens is not optimised for digital > although it is fine for film. This tends to make the image soft in the > corners. > > Hope that I got that bit right :-) > > Didn't someone once post a URL for a site that did lens tests on digital > equipment. > > As I am still shooting film, I have no personal experience of this. > > It may, of course, be that all manufacturers will have this problem, when > they produce full-frame DSLRs.
Nope, some chips apparently can function without the micro-lenses (which causes this angle-of-impact-vulnerability in the first place, TTBOMK). The Dalsa chip (the one that will be used in the Mamiya ZD medium format DSLR & digi-back) is one of those.... (although you could deliberate whether 36x48mm is full-format in any legacy/analog context....;)) (but together with their promised 26mm wide-angle, that would be a blast.... http://www.mamiya.nl/productenkm.phtml?prdid=2&kmid=1&pr=214 ) http://www.dalsa.com/pi/products/DSC.asp xxxxxxxxxx Digital Professional Photography Sensors The world's leading professional imaging sensors Our 22-megapixel professional still photography image sensor with industry-leading dynamic range and unmatched overall image quality Capturing the picture "seen" by a photographer requires a sensor with needle-sharp resolution and superb dynamic range to show every detail and shade, fast frame rate to capture action, and great field coverage for wide angles. Over the whole photographic process, digital capture can exceed analog film quality, but only if the sensor is up to the task. The sensor one of the most critical factors in the imaging chainwithout an exceptional sensor, you will limit the image quality of your visions. Quick list FTF2416: 4Mpixel FTF3020: 6Mpixel FTF4027: 11Mpixel FTF4052: 22Mpixel DALSA's Professional Imaging group in Eindhoven, The Netherlands, has designed and supplied the world's leading professional photography sensors for many years. With our new 11 and 22 megapixel sensors, we are more committed than ever to delivering the industry's highest image quality and performance in multi-megapixel area sensors. And as an independent supplier, we're here to help professional camera manufacturers design our sensors into their cameras. Beyond analog film quality TrueFrame sensors Our 6, 11, and 22 megapixel sensors take digital photographs beyond the limits of analog film. DALSA's dedicated, unique TrueFrame Image Sensor technology delivers the market's best overall image capture. Inherently higher charge capacity with lower noise gives the dynamic range needed for higher contrast images, with grain-free blacks and increased exposure headroom. This superb image quality comes with low power dissipation, which means less heating of the camera and sensor, and hence lower picture noise. The low power requirement also significantly lengthens battery life for mobile applications. All our TrueFrame CCDs are basically compatible, enablling a camera design platform for a range of products that address the specific needs of different applications and users. To simplify camera design even more, we offer peripheral chipsets to optimize camera performance with the lowest costs and highest flexibility. Differentiators With characteristics such as these, the design of our pixels gives our sensors a clear advantage in image fidelity: * Fill factor: the fill factor of our sensors is typically 80- 90%. Interline CCDs and CMOS sensors have much lower fill factors due to the extra structures or circuits they place on every pixel. And to provide antiblooming, many competitors' full-frame or frame-transfer CCDs use a lateral overflow drain on each pixel, reducing fill factor. DALSA's designs offer vertical antiblooming, which drains excess charge vertically into the substrate, preserving very high fill factor while still protecting against overexposure. * Low dark current and Low noise: the quality or our pixel design and fabrication means our sensors offer very low noise, even without the cooling or additional noise-reduction circuits competitors frequently require. And with our sensors, noise stays low even at higher frame rates. * Better angular response: DALSA sensors provide excellent angular response, a characteristic that is very important when using fast lenses and wide angles. We offer thinner polysilicon layers and fewer structures above the charge-collection region of the pixel to reflect and distort incident light, and with our high fill factor, DALSA sensors generally do not require microlenses. Microlenses help increase effective fill factor in some sensors, but they make the performance of the pixels highly dependent on the angle of incoming light rays. Microlensed pixels do not respond uniformly at larger iris openings (low f-numbers), particularly at at the edges of the sensor. * Superior color filters: Our proprietary pigment process delivers very precise color performance that remains stable over time. Products Product Description Resolution Pixel Size Active Area FTF2416C 4 Megapixel Color CCD 2460 x 1640 9 x 9µm 22.1mm x 14.8mm FTF2416M 4 Megapixel Monochrome CCD 2460 x 1640 9 x 9µm 22.1mm x 14.8mm FTF3020C 6 Megapixel Color CCD 3072 x 2048 12 x 12µm 36.9mm x 24.6mm FTF3020M 6 Megapixel Monochrome CCD 3072 x 2048 12 x 12µm 36.9mm x 24.6mm FTF4027C 11 Megapixel Color CCD 4008 x 2672 9 x 9µm 36.1mm x 24mm FTF4052C 22 Megapixel Color CCD 4008 x 5344 9 x 9µm 36.1mm x 48.1mm FTF4052M 22 Megapixel Monochrome CCD 4008 x 5344 9 x 9µm 36.1mm x 48.1mm xxxxxxxxxxxxx The most scary thing for Canon is that this ZD SLR weighs even *less*e & weight as the current 1Ds....;)) http://www.letsgodigital.org/html/events/PHOTOKINA- 2004/news/mamiya/ZD_en.html http://makeashorterlink.com/?I2FF12ABB If I had to start from scratch with a new system, I might be tempted.... -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand <[EMAIL PROTECTED]> [note: 'a-one' & 'en-el'!] * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
