Digital SLR Resolution Chart                         Back to Notes on Photography
by Makoto Honda                September 3, 2005
 

General

The table below shows how many "resolution" dots are captured on the film - in the case of a digital camera, on the digital file. This is distinct from the number of pixels on the sensor. The number of "resolution" dots is a true measure of how sharp the captured image can be. It goes without saying that the image sharpness is dependent on the lens used as well. The table is prepared for lens resolutions in the range of 100 - 800 lp/mm (Click here to see the discussion of lens resolution.) The table is prepared for the digital sensor's pixel counts in the range of 2 MP to 32000 MP (mega pixels). If you think a 32 GP (gig pixels) camera is a bit far-fetched, keep reading. The picture sharpness, or the total number of "resolution" dots, is also affected by the sensor size - the larger the better. The table compares three sensor sizes: Full-frame 35mm format (24 x 36mm), the APS-C size format (16 x 24mm), and Four-Thirds format (12 x 18mm).

How to read the table:
Column 1 - This shows the mega pixel (MP) number of the camera, given in the range of 2 MP to 32000 MP.
Column 2 - This shows the number of pixels along the height and width of the sensor.
Column 3 - This shows the sensor resolution, in lp/mm (line pairs per millimeter), for the full-35mm format (24 x 36mm).
Column 4 - This shows the total "resolution" dots for the full-35mm format (24 x 36mm).
Column 5  & Column 6 - These are the same as Columns 4 & 5 for APS-C size (16 x 24mm).
Column 7  & Column 8 - These are the same as Columns 4 & 5 for Four-Thirds format (12 x 18mm, about).

Some point-and-shoot cameras today offer 7 MP (mega pixels), a la Canon PowerShot 500, and the mega pixel war has no sign of letup. Some of these compact cameras have a tiny sensor size of about 5 x 7mm. This is one fifth (linearly) of the full-35mm format. That is, the full 35mm format has 25 times larger area. That means if we pack these digital sensors over the entire 35mm format size, the total mega pixel count would be 175 MP. We still have many issues to overcome for small er sensors, not least of which is a noise problem, especially at higher ISO settings. But these problems will be solved eventually. So, a 35mm format camera with 200 MP is not unrealistic, even today. And, maybe 1000 MP tomorrow. This is my justification for providing the table covering 64 giga pixels.