From ad607@FreeNet.Carleton.CA Wed Oct 26 09:02:11 1994 Newsgroups: rec.photo.advanced Path: news.ifm.liu.se!liuida!sunic!uunet!europa.eng.gtefsd.com!howland.reston.ans.net!cs.utexas.edu!utnut!nott!cunews!freenet.carleton.ca!FreeNet.Carleton.CA!ad607 From: ad607@FreeNet.Carleton.CA (Darrell A. Larose) Subject: Digital vs. Photography Message-ID: Keywords: resolution, pixels Sender: news@freenet.carleton.ca (Usenet News Admin) Reply-To: ad607@FreeNet.Carleton.CA (Darrell A. Larose) Organization: The National Capital FreeNet Date: Tue, 25 Oct 1994 19:16:54 GMT Lines: 101 Film Resolution vs. Digital Resolution Resolving Power lp/mm TOC TOC film type ISO lp/mm@1.6:1 lp/mm@1000:1 TRP # Tri-X pan 400 50 100 8,640,000 T-Max 400 400 50 125 13,500,000 Plus-X pan 125 50 125 13,500,000 K-64 64 50 100 8,640,000 K-25 25 63 100 8,640,000 T-Max 100 100 63 200 34,560,000 Fuji Velvia 50 * 150 ** 19,440,000 Panatomic-X 32 80 200 34,560,000 Ektar 25 25 80 200 34,560,000 Tech-Pan 25*** 100 320 88,473,600 Tech-Pan 120 25 100 320 368,640,000 Based upon manufacturers data sheets. ** Fuji only published this figure. *** Pictorial recommendation from Kodak. Special purpose films such as microfilm material not listed, but would most likely exceed Tech-Pan figures. TRP# is a calculation based on maximum resolving power multiplied by film format. Digital Imaging device image resolution pixels file size Photo CD 128x192 (Base/16) 24,576 70K Photo CD 256x384 (Base/4) 98,304 280K Photoman 496x365 (grey scale) 181,040 not given Photo CD 512x768 (Base) 393,215 1.12 Meg Photo CD 1024x1536(Basex4) 1,527,864 4.5 Meg Kodak DCS 1524x1012(18x24mm)* 1,542,288 4.5 Meg? Leaf D.B.# 2048x2048 4,194,304 not given Photo CD 2048x3072(Basex16) 6,291,456 18 Meg CoolScan 2592x3888(35mm) 10,077,696 not given Photo CD 4096x6144(Basex64) 25,165,824 72 Meg Logitech Photoman is low resolution B&W digital camera. * CCD sensor element size or about the same as a 1/2 frame 35mm camera # Leaf Digital Back for Hasselbald system. As you can see digital imaging still lags behind conventional photography in image resolution, BUT! it is not that far behind. A Kodak Pro Photo CD image scanned at the Basex64 resolution is pretty impressive, albeit a very large file size of 72 Meg. The highest quality will currently be derived from high quality conventional slides or negatives that are then scanned via the Pro Photo Cd or via a slide scanner. The current Kodak/Nikon DCS 200 lags behind in several ways. The first is because the CCD array is smaller than the 35mm (24x36mm) film format as a result the camera is not as convenient to use. Your 50mm standard lens effectively becomes a short telephoto. In fact all your lenses will function with this 2x magnification over your still camera. Kodak is working on new CCD arrays that will offer even higher resolutions. It is also very expensive, most of us can't afford to own it. The Leaf Digital back offers other problems, currently it is a still life camera, not suited for any moving subjects. this camera works by making three separate scans for each image. So if anything in the picture moves you will not have full colour image on that portion of the image. For a studio session it will be alright. But still a Pro Photo CD Basex64 scan of a neg or slide of the same set-up will still exhibit higher quality. Before we all get too smug about our wonderful still cameras, we must consider something very important. That is even though film like Tech-Pan can have resolving power of up to 320 line pair/mm, our lenses can't resolve that much. Back in the early eighties when Tech-Pan was first marketed by Kodak (in its current form) Leica in their publication magazine said the film can resolve more than our lenses can. So with the resolution that will be loss through the optical path of your system, the conventional photography/digital imaging will draw even closer. Finally even more resolution will be lost in either projection of your slides. Projector lenses are pretty poor in comparison with the lenses we all use in the rest of our photography. If we print our work there will be further losses of resolution caused by the enlarger lens and other factors such as paper resolution (I can't remember having ever seen resolution figures printed for paper) and the Callier effect. I firmly believe that digital imaging will soon displace conventional photography from the pedestal (IMHO) -- Darrell A. Larose.... ad607@freenet.carleton.ca "..Just hitchhiking along the info highway..."