Comments on: Develping a Grading System for Digital Cameras http://www.dvorak.org/blog General interest observations and true web-log. Sun, 12 Feb 2012 18:49:51 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: CedarTree http://www.dvorak.org/blog/develping-a-grading-system-for-digital-cameras/comment-page-1/#comment-117314 CedarTree Sun, 02 Apr 2006 07:42:25 +0000 http://www.dvorak.org/blog/?page_id=4394#comment-117314 Commening on Jeff's DCUI system- its rationale is flawed, or atleast partially skewed. The photographic aspects that beg to be quatified are optical and physical: (Well, the optical side is also a branch of physics but let's leave this lable in place) Optics- Lens properties, most easily quantifiable is zoom range, but hey, the best lenses are prime (zoom=1) lenses, so this mostly represent usability and operability. Then there's lens speed and there's aperture range: fast lens with large aperture capture more light and offer possible better depth of field control. A fixed aperture (such as in mirror-lenses) is a limiting factor for shutter speed and DOP control. Many digital P&S cameras have an aperture range of about 3EV compared to 7EV in a consumer 35mm format lens. Physics- Here I mostly refer to image sensor capabilities. And the most significant quantity is not pixel count - it's apture area. sensor area may be more readily available but ideally the percentage of photo-site sensitive area to pixel area (reverse of pixel density) can leverage differences in sensor technologies. How much light can the sensor register is the second most important aspect after how much light can the lens focus. That amount of light devided into tinier pixels means less sensitivity and less dynamic range and lower s/n ratio and worse brightness gradients. Then what ? Here there is a split based on value for customer: how large and detailed the image is ready for print/enlargement or how good it is in per-pixel noise supression, dynamic range and contrast handling. Additionally there's processing power, writing speed, buffer size, photographic control parameters and so on valueable but less measurable aspects. What do i suggest, then ? for lens rating divide aperture range in EV by open-aperture number, having 1 as an average outcome (f/3 with 3EV range, smaller f numbers and bigger EV ranges preferable). for image sensors take 2 ratings, one for image quality enthusiasts: sensor size (or pixel size times pixel count), and the other for high-details and enlaging enthusiasts: simple pixel count. Rating I = zoom range X lens rating X sensor rating I Rating II = zoom range X lens rating X sensor rating II The is no single answer here afterall, I guess... Commening on Jeff’s DCUI system- its rationale is flawed, or atleast partially skewed.
The photographic aspects that beg to be quatified are optical and physical: (Well, the optical side is also a branch of physics but let’s leave this lable in place) Optics- Lens properties, most easily quantifiable is zoom range, but hey, the best lenses are prime (zoom=1) lenses, so this mostly represent usability and operability. Then there’s lens speed and there’s aperture range: fast lens with large aperture capture more light and offer possible better depth of field control. A fixed aperture (such as in mirror-lenses) is a limiting factor for shutter speed and DOP control. Many digital P&S cameras have an aperture range of about 3EV compared to 7EV in a consumer 35mm format lens.
Physics- Here I mostly refer to image sensor capabilities. And the most significant quantity is not pixel count – it’s apture area. sensor area may be more readily available but ideally the percentage of photo-site sensitive area to pixel area (reverse of pixel density) can leverage differences in sensor technologies. How much light can the sensor register is the second most important aspect after how much light can the lens focus. That amount of light devided into tinier pixels means less sensitivity and less dynamic range and lower s/n ratio and worse brightness gradients. Then what ? Here there is a split based on value for customer: how large and detailed the image is ready for print/enlargement or how good it is in per-pixel noise supression, dynamic range and contrast handling.
Additionally there’s processing power, writing speed, buffer size, photographic control parameters and so on valueable but less measurable aspects.
What do i suggest, then ?
for lens rating divide aperture range in EV by open-aperture number, having 1 as an average outcome (f/3 with 3EV range, smaller f numbers and bigger EV ranges preferable).
for image sensors take 2 ratings, one for image quality enthusiasts: sensor size (or pixel size times pixel count), and the other for high-details and enlaging enthusiasts: simple pixel count.
Rating I = zoom range X lens rating X sensor rating I
Rating II = zoom range X lens rating X sensor rating II
The is no single answer here afterall, I guess…

]]> By: Bob Hunt http://www.dvorak.org/blog/develping-a-grading-system-for-digital-cameras/comment-page-1/#comment-98612 Bob Hunt Wed, 01 Mar 2006 18:36:04 +0000 http://www.dvorak.org/blog/?page_id=4394#comment-98612 I like any kind of ratings. But my big problem is knowing the quality of the lens. How do I find this out? I like any kind of ratings. But my big problem is knowing the quality of the lens. How do I find this out?

]]> By: Isaiah Laderman http://www.dvorak.org/blog/develping-a-grading-system-for-digital-cameras/comment-page-1/#comment-98335 Isaiah Laderman Tue, 28 Feb 2006 18:38:38 +0000 http://www.dvorak.org/blog/?page_id=4394#comment-98335 Guys, Both your camera-rating systems are "last year". Your systems aim for the best general-purpose camera. The future of digital cameras is in specialization; cameras optimized for indoor sports photography, outdoor long shots, portraits, parties, pocket snapshots, closeups, etc. Guys,

Both your camera-rating systems are “last year”. Your systems aim for the best general-purpose camera. The future of digital cameras is in specialization; cameras optimized for indoor sports photography, outdoor long shots, portraits, parties, pocket snapshots, closeups, etc.

]]> By: Jeff Adams http://www.dvorak.org/blog/develping-a-grading-system-for-digital-cameras/comment-page-1/#comment-98260 Jeff Adams Tue, 28 Feb 2006 14:04:48 +0000 http://www.dvorak.org/blog/?page_id=4394#comment-98260 Hey John, More to the point, a grading system should be simple enough that you don't need to haul around a laptop reference guide to calculate it on the spot when faced with the decision of which PAS camera to buy. Your technique is also somewhat subjective, but even so, it still provides specific, useful data. I developed a method 6 months ago that is as valid today as it was then. It is called the DCUI or Digital Camera Utility Index and it is a by the numbers based objective comparison tool that produces verifiable and repeatable results every time. In fact, it is so simple I gave it to my 4th grade son as a story math problem and he figured it out. Most importantly, the DCUI is memorable so that it can be used on impulse to compare digital cameras on the spot say when you just gotta have one (but then again, when did impulse buying follow a logical formula?) DCUI works like this; multiply the optical zoom of any PAS camera by the raw megapixels it is capable of capturing. The resulting number gives a score of it's ability to take a broad range of photos; its usefulness, its UTILITY! But you are still comparing apples to oranges when you conduct a side by side with this number as compared to the price per DCUI or Relative DCUI. To calculate the relative DCUI, simply divide the cost into the DCUI and you get a $/DCUI much like Dollars per gallon works with gasoline. Judging the camera that you presented in the article, the Fuji FinePix E900 generates a DCUI of 9.0 x4.0 = 36. Pricegrabber.com shows the lowest price of $321.97 so the relative price per DCUI is almost exactly $10.00 (321/32). When I purchased my last PAS camera, the DCUI calculation pointed me to a Panasonic DMC-LZ2 which generated a DCUI of 32.16 (6.0x5.36) and a relative price DCUI of $6.43 at the time. Since then the price of this camera has dropped to around $175 which gives it a relative price per DCUI of $5.44. Your pick costs $10 for it's relative utility, mine is nearly half that at $5.44. Which is the better deal? You be the judge, but I suggest you save the point score for cameras that have a relatively close price per DCUI and use it as a tie-breaker. Hey John,

More to the point, a grading system should be simple enough that you don’t need to haul around a laptop reference guide to calculate it on the spot when faced with the decision of which PAS camera to buy. Your technique is also somewhat subjective, but even so, it still provides specific, useful data. I developed a method 6 months ago that is as valid today as it was then. It is called the DCUI or Digital Camera Utility Index and it is a by the numbers based objective comparison tool that produces verifiable and repeatable results every time. In fact, it is so simple I gave it to my 4th grade son as a story math problem and he figured it out. Most importantly, the DCUI is memorable so that it can be used on impulse to compare digital cameras on the spot say when you just gotta have one (but then again, when did impulse buying follow a logical formula?) DCUI works like this; multiply the optical zoom of any PAS camera by the raw megapixels it is capable of capturing. The resulting number gives a score of it’s ability to take a broad range of photos; its usefulness, its UTILITY! But you are still comparing apples to oranges when you conduct a side by side with this number as compared to the price per DCUI or Relative DCUI. To calculate the relative DCUI, simply divide the cost into the DCUI and you get a $/DCUI much like Dollars per gallon works with gasoline. Judging the camera that you presented in the article, the Fuji FinePix E900 generates a DCUI of 9.0 x4.0 = 36. Pricegrabber.com shows the lowest price of $321.97 so the relative price per DCUI is almost exactly $10.00 (321/32). When I purchased my last PAS camera, the DCUI calculation pointed me to a Panasonic DMC-LZ2 which generated a DCUI of 32.16 (6.0×5.36) and a relative price DCUI of $6.43 at the time. Since then the price of this camera has dropped to around $175 which gives it a relative price per DCUI of $5.44. Your pick costs $10 for it’s relative utility, mine is nearly half that at $5.44. Which is the better deal? You be the judge, but I suggest you save the point score for cameras that have a relatively close price per DCUI and use it as a tie-breaker.

]]> By: Jeff Adams http://www.dvorak.org/blog/develping-a-grading-system-for-digital-cameras/comment-page-1/#comment-98115 Jeff Adams Mon, 27 Feb 2006 22:01:18 +0000 http://www.dvorak.org/blog/?page_id=4394#comment-98115 John, As a decades long fan, I feel privileged to finally write to you. I agree with your Robert Parker approach to grading the "current" offerings of digital cameras, but your focus (no pun intended) is a subjective rating whereas, the linked article I wrote focuses entirely on objectively rating one digital camera vis-a-via another. Granted, the information in my article is 6 months dated in the context of the latest and greatest digital camera features and prices, but using BOTH your method and my Digital Camera Utility Index (DCUI) simultaneously creates an unbeatable and always CURRENT and CORRECT means of sorting through the chaff and the clutter of digital camera marketing fluff. Although my web site is www.ideallypc.com, the direct backdoor to my web site's article is http://www.thebuddybank.com/Fishing%20for%20your%20next%20Digital%20Camera.pdf I look forward to your reply and to your next column. Yours truely, Jeff Adams jeffa@ideallypc.com John,

As a decades long fan, I feel privileged to finally write to you.

I agree with your Robert Parker approach to grading the “current” offerings of digital cameras, but your focus (no pun intended) is a subjective rating whereas, the linked article I wrote focuses entirely on objectively rating one digital camera vis-a-via another. Granted, the information in my article is 6 months dated in the context of the latest and greatest digital camera features and prices, but using BOTH your method and my Digital Camera Utility Index (DCUI) simultaneously creates an unbeatable and always CURRENT and CORRECT means of sorting through the chaff and the clutter of digital camera marketing fluff.

Although my web site is http://www.ideallypc.com, the direct backdoor to my web site’s article is http://www.thebuddybank.com/Fishing%20for%20your%20next%20Digital%20Camera.pdf

I look forward to your reply and to your next column.

Yours truely,
Jeff Adams
jeffa@ideallypc.com

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