On Dec 9, 2012, at 10:48 AM, Tom C wrote: >> From: Larry Colen <[email protected]> >> >> Tom, >> >> You've mentioned 24 MP a few times. How large are you printing that you need >> 24MP? > > Larry, Larry, Larry, LARRY! Don't take the phun out of photography. :)
Don't be silly, the image quality of the gear has nothing to do with with the fun of photography. However, taking a technical subject and beating on it until the dead horse is nothing but a smoking crater where a greasy spot used to be is half the fun of the PDML. > > I'm typically printing (having printed to be precise) at 20x30 inches. In that case, I can certainly see why you would need a system with high resolution. Especially if people are looking at your prints from three inches away. > >> Also, what APS-C camera has that resolution? > > Sony SLT-A99, Sony NEX-7, Nikon D3200, Nikon D5200... not to mention > the fabled Pentax K-3 is a 24MP APS-C sensor body, and Canon is > looking at doing one if they haven't already. And going by DxOmarks, or pretty much any other reliable test, how many of them actually outperform the K5 ( or II or IIs) in terms of image quality? > > Historically on this list and many others, when 'OUR' camera > manufacturer's offerings have been surpassed by a competitor, a > commonly expressed attitude is 'Why would anyone need that? I'm > perfectly happy with what I have and need nothing more'. The persons > 'whining' for more are labeled as complainers. Then when 'OUR' camera > manufacturer releases a new product that has essentially those same > characteristics, many jump on the bandwagon and proclaim it as the > best ever and how it beats the pants off the prior model. It's > dichotomous to say the least. My question wasn't entirely rhetorical. I suppose I could have saved the lives of a few thousand wasted electrons by simply asking "what benefit does a sensor that outresolves most lenses, and almost every display method I use gain me, especially at the expense of performance in areas where I am frequently running up against the limits of the camera? And, for what it's worth, last night in order to get the shutter speed I wanted at f/1.8, I had to push the ISO to the 8,000-16,000 range. > >> >> In other words, with an AA filter, a 24MP APS-C lens will definitely be >> diffraction limited by f/8.0. Without an AA filter, assuming > >> that the lens is sharp enough, diffraction is probably having an effect by >> f/4 or f/5.6. >> >> 4um is 250/mm, which I understand works out to 125 lp/mm. > > I understand what you've written, yet nevertheless, an increase in > resolution is just that, and it's visible at larger sizes more readily > than smaller. Also one can crop more easily and still maintain > sufficient resolution. That's interesting. I suppose it is something that needs to be experienced in person. Wasn't there a test recently where they took two cameras, one much higher resolution than the other, made a couple of 16x20 prints and even the most casual observer was able to tell the difference between them? Anybody have a link to that? I guess that sensors that outresolve the lenses improve the quality of photographs in the same way that oxygen free 4guage cables improve the sound quality of home stereos. </jocular sarcasm> > > Noise? Smaller pixels seem to mean more noise, but it then again it > seems that manufacturers continue to beat that noise down, and > therefore today we have cameras (not all) with the highest MP > resolution ever and very low if not lowest noise. In addition, extreme > high ISO shooting is not the one and only holy grail. Many photographs > are taken at ISO's where noise is not a factor, and therefore the > increased resolution benefits each of those images (unless maybe your > shooting a beauty pageant). :) But what about frames per second? How can you live without a camera that photographs at 24 frames per second? I certainly don't say that low ISO noise is the only thing that matters. I am saying that it, and dynamic range, are what I run up against the most often in terms of sensor performance limits. > > <snipped for size> > >> It seems as if you want a sensor that has approximately twice the resolution >> of a very good prime lens, which correlates roughly with the Nyquist rate, >> which would mean that you would never need an anti-aliasing filter, because >> even without getting into diffraction limiting, you're already past the >> Nyquist rate. >> >> Is this why you feel that 24 MP is so necessary in an APS sensor camera? > > The reason I feel it's necessary for Pentax (not every person who owns > a camera) is because they'll get slaughtered in the marketplace if > they don't. What if Pentax decided they didn't need to go beyond 6MP > when other mfrs. were pursuing 8, 10, 12? Who goes out and buys a > brand new 6MP DLSR these days? This is where we are getting to the core of the matter. Marketing. It's easier to sell simple, easy to understand numbers. Particularly to people that wouldn't take significantly cleaner photos with a D800E than they would with a cell phone. > > <snipped again> > >> Although you implied market forces require that sort of resolution, which >> means that the average photographer who uses their SLR as an expensive point >> and shoot is printing that large. Or, are you just saying that it is one of >> those marketing things, where people aren't satisfied with less than 300 >> cubic inches of displacement in their car's engine, whether or not the >> customer would ever use the power, or whether or not a car with a much >> smaller engine would outperform it? >> >> As I see it, I'm either not technically inclined enough, and I am totally >> missing the analysis of why16MP, or even 12, is not enough, and why a camera >> needs 24 MP in order to be marketable. Or, it could be that I'm far too much >> of a geek, and am missing something critical by only looking at the physics >> of the situation. The latter is quite possible, because I also can't >> understand why suburban housewives in Coastal California where it never >> snows, need a 5,000 pound four wheel drive SUV, that seats eight, has a 6 >> liter motor that puts out 300 hp. > > _________ > > It's because of the market factors Larry, not the technicalities or > the most prevalent uses. If your competition has it you must also to > remain competitive. And I believe, all things roughly equal, > resolution trumps all just as it did in the film days and just as > aperture trumps all when it comes to telescopes. > > Mark my words, if Pentax comes out with a 24MP APS-C DSLR, many many > will purchase it and not look back. Possibly even you. And if > perchance a Pentax FF DSLR were to come out, same thing. We are not debating the relative merits of 24x36 versus 16x24. If I could afford it I would love to have a FF sensor camera, as that would effectively nearly double the number of lenses I owned, since most of my lenses are FF compatible, and they would each behave differently on a FF camera than they do on an APS camera. > > Who really, really needs a V-8 or a turbo? Yet Audi is making a V10. In the automotive analogy, cylinders are more equivalent to pixels and displacement is more equivalent to sensor size. Although, with cars smaller cylinders tend to work better and in cameras larger pixels do. But, yes, lets look at cylinders? How many 16 cylinder cars are being made these days? I think Bugatti made a w-16 a while back. Didn't it sell for something like a million dollars? How about 12 cylinder cars? But, what we were talking about was high resolution on a small sensor, so lets talk about small displacement V-8s. How many Daimler SP-250s do you see on the road these days? That was a 2.5 liter V-8. But most people are driving cars in the 1.5 to 2 liter range. How many V8s do you see in that range? How many V12s? Didn't formula 1 used to have a bunch of 2 liter V-12s back in the day? Here is one V8 which I believe is a 2 liter: http://thekneeslider.com/archives/2005/02/09/hayabusa-v8-engine/ I wonder why Honda doesn't put one of those in their Accord. The car would perform so much better with the extra two cylinders. As to turbochargers, I've got a lot of friends that put turbochargers on their miatas. Those cars go like scalded apes. For about 25 minutes on the track, which is about as long as the cooling system can keep up. -- Larry Colen [email protected] sent from i4est -- 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.
