Luminous Landscape Forum

Equipment & Techniques => Cameras, Lenses and Shooting gear => Topic started by: Giedo on January 04, 2006, 04:19:17 pm

Title: Primes and digital zoom...
Post by: Giedo on January 04, 2006, 04:19:17 pm
With the risk of being put on report by Michael for making too many silly statements on this forum within 24 hrs, I had another probably extremely silly thought ...
If current state-of-the-art lens technology that is used now mostly to improve zooms (this assumption is correct, right?) would be implemented on prime lenses, could these lenses be so superior in quality, that - in combination with future super sensors they could replace normal zooms and offer a faster, more light sensitive alternative?
I mean that in such a situation (super prime with super sensor) a digital zoom (or crop, which is a more appropriate word for it, I guess) that is used in consumer digital camera's could be of interest for advanced photographers as well.

Or am I completely wrong - again?
Title: Primes and digital zoom...
Post by: Dale_Cotton on January 04, 2006, 05:00:58 pm
First, let me congratulate you for surviving the ego avalanche to go another round. Certainly doesn't encourage one to sign up for a workshop does it?

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If current state-of-the-art lens technology that is used now mostly to improve zooms (this assumption is correct, right?) would be implemented on prime lenses, could these lenses be so superior in quality, that - in combination with future super sensors they could replace normal zooms and offer a faster, more light sensitive alternative?[a href=\"index.php?act=findpost&pid=55203\"][{POST_SNAPBACK}][/a]
My non-technical understanding is that the principle modern lens technology affecting optical quality is simply the digital computer that allows lens designers to solve the complex equations involved in optical design in seconds rather than months. Nevertheless, prime lens design is less complex than zoom, so the optimal prime designs were probably already identified before the computer. At least, I haven't heard of any breakthroughs in prime quality. The exception here might be SLR wide angle primes because the focal length is shorter than the minimum distance between lens and focal plane.

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I mean that in such a situation (super prime with super sensor) a digital zoom (or crop, which is a more appropriate word for it, I guess) that is used in consumer digital camera's could be of interest for advanced photographers as well.[a href=\"index.php?act=findpost&pid=55203\"][{POST_SNAPBACK}][/a]
The idea of a digital crop is far from silly. The Nikon D2X implements this to create a camera that is convertible from the high speed + low res a photojournalist or sports photog needs into the slower speed + high res everyone else needs (or at least covets).

IAC, there are lots going on in optics these days (a science formerly considered to be a closed book), including the mind-boggling new concept of negative refraction. Who can say whether your interesting speculation of today will be tomorrow's reality?
Title: Primes and digital zoom...
Post by: boku on January 04, 2006, 08:56:22 pm
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Certainly doesn't encourage one to sign up for a workshop does it?

Cold shot, no?
Title: Primes and digital zoom...
Post by: crspe on January 05, 2006, 04:46:39 am
Do not forget the absolute crappyness of digital zooming - If we take normal zoom lens which provides 4x zoom, eg 100 - 400; 70-300; 24-105; ... then if you were to try to do this using a single prime plus digital zoom (crop) then your wonderful $7000 1DsMkII just became a crappy 1Mpix camera at the zoomed end.

When using a digital soom, a zoom of 2x means a reduction in resolution of 4x. 4x zoom = 16x reduction in resolution. I do not think this would really be the cheapest / best way to make good pictures, even in the future.
Title: Primes and digital zoom...
Post by: BJL on January 05, 2006, 01:05:19 pm
Dale Cotton has answered very well I think, so I just have a general comment, inspired by a Mike Johnson essay about the fallacies of "connoisseurism".

Quality is perhaps best thought of in terms of how close we are to visible perfection, maybe scored as a percentage (like SQF scores for lenses).  As quality improves all around, the quality gap between a "lower quality, cheaper, more convenient" option and "higher quality, more expensive, less convenient" alternative shrinks. For example, maybe some decades ago, the best zooms scored only 70% for quality while good primes scored 90%, and many people could see and care about that 20% difference. But if today's best zooms score 95%, then even great efforts can only make primes better by less than 5%.

At the opposite extreme to this "percentage" idea, one of the greatest obfuscations and exaggerations of image quality differences is using sensor pixel counts as a measure of quality. I see no real sense to suggesting that the 1DSMkII gives 50% better prints than the original 1Ds simply due to having about 50% more pixels.