Luminous Landscape Forum
Equipment & Techniques => Cameras, Lenses and Shooting gear => Topic started by: marcmccalmont on December 11, 2008, 07:21:39 am
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Since DxOmark added the 5DII to their rankings I updated the list I made earlier.
Something has been bothering me about DxO Mark rankings and Michaels review of the A900 made me think that a fourth factor, resolution is missing from these ratings. Resolution counts, for a given size print the more resolution the more realistic the fine detail, i.e. foliage, hair etc. Perceived detail is a function of the pixels in each dimension or the square root of the pixel count. So I took DxO mark rankings and used it for 3/4 of the weighting and added 1/4 of the square root of the resolution and re-ranked the top 9 cameras. The formula I used was ((DxO Mark x 3) + (20 x sqrt(mpixel count)) / 4
10 mpx = 63.2, 12 mpx = 69.2, 13mpx = 72, 15 mpx = 77.4, 17mpx = 82.4, 21 mpx = 91.6, 24mpx = 98
Rankings with resolution as a factor:
- A900 = 83.675
- 1DsIII = 83.125
- 5DII = 82.15
- D3 = 77.75
- D700 = 77.675
- 1DsII = 76.1
- D90 = 71.75
- 5D = 71.175
- Gx20 = 70.875
- 1DIII = 69.05
A ranking closer to what photographers are seeing! check my math too!
I also took the ranking weighted by resolution and divided by retail price to get a value rating:
- GX20 669
- D90 581
- 5D 356
- 5DII 304
- D700 288
- A900 278
- D3 181
- 1DIII 170
- 1DsIII 109
- 1DsII 170
Marc
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Hi,
DxO marks are taking resolution into account by normalizing to an A4 print. If you check their graphs they have two options "screen" and "print", I'm pretty sure their DxO mark is based on "print". I would also add that trying to put a single figure of merit is simply stupid. DxO mark is based on three figures of merit Landscape, Studio and sports/reporting and on a print size of A4. DxO says that it takes about five DxO points for a visible difference. The DxO data is a gold mine if you look at the curves, by the way, really good stuff! I don't understand why they have taken A4 as a base for comparison, but I trust DxO quite a bit, they have a very sophisticated RAW-converter and also sophisticated image analysis software.
Resolution is of little merit if you don't print big. On the other hand if you want to sell your pictures or want to have the option to enlarge BIG than high resolution is most helpful, but you still need to keep those pixels sharp (pronounce as mirror lockup and tripod).
Best regards
Erik
Since DxOmark added the 5DII to their rankings I updated the list I made earlier.
Something has been bothering me about DxO Mark rankings and Michaels review of the A900 made me think that a fourth factor, resolution is missing from these ratings. Resolution counts, for a given size print the more resolution the more realistic the fine detail, i.e. foliage, hair etc. Perceived detail is a function of the pixels in each dimension or the square root of the pixel count. So I took DxO mark rankings and used it for 3/4 of the weighting and added 1/4 of the square root of the resolution and re-ranked the top 9 cameras. The formula I used was ((DxO Mark x 3) + (20 x sqrt(mpixel count)) / 4
10 mpx = 63.2, 12 mpx = 69.2, 13mpx = 72, 15 mpx = 77.4, 17mpx = 82.4, 21 mpx = 91.6, 24mpx = 98
Rankings with resolution as a factor:
- A900 = 83.675
- 1DsIII = 83.125
- 5DII = 82.15
- D3 = 77.75
- D700 = 77.675
- 1DsII = 76.1
- D90 = 71.75
- 5D = 71.175
- Gx20 = 70.875
- 1DIII = 69.05
A ranking closer to what photographers are seeing! check my math too!
I also took the ranking weighted by resolution and divided by retail price to get a value rating:
- GX20 669
- D90 581
- 5D 356
- 5DII 304
- D700 288
- A900 278
- D3 181
- 1DIII 170
- 1DsIII 109
- 1DsII 170
Marc
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I guess my point was I had a gut feeling after reading Michael's review of the A900 (where he referenced DxO Mark data) that DxO Mark doesn't weigh resolution enough because most print larger than A4 say A3+ or bigger. I would also like to see a value ranking. I agree DxO is very good (my favorite converter BTW) and DxO Mark is a treasure chest of information. I was hoping the thread would stimulate a discussion that would lead to a review including
sensor ranking, resolution and value as numeric values for comparison. I understand DxO Mark was designed as a ranking of sensor quality not an overall rating of the camera, but I would still like to see more of the "Big Picture". So what I was trying to do (probably not expressed well) was not reduce it to one figure of merit but add 2 more to the 3 that DxO already has, resolution and value.
Marc
I'm also delighted that DxO Mark seems to correlate well with what I am seeing as differences between my 5D and 5D2.