FZ200 Diffraction Limit - Panasonic Tech Service

Started Aug 27, 2013 | Discussions thread
Stephen Barrett Contributing Member • Posts: 683
Re: FZ200 Diffraction Limit - Panasonic Tech Service

Bridge Cameras

As Detail Man has indicated, there are various factors that affect resolution. The two most important factors, however, are the diffraction limit of the lens and the resolution of the sensor. At low F-numbers, it is the pixel density of the sensor that limits resolution. Around f/3.5 to f/4.0 the lens resolution and the sensor resolution are becoming comparable. When you get to higher F-numbers, it is the lens diffraction that limits the resolution. So, perhaps the Panasonic tech people were trying to indicate that diffraction effects begin to dominate once the F-number gets above approximately 4. This is the same for all of the small-sensor cameras.


It is interesting that the resolution of large-sensor cameras (including DSLRs with full-frame sensors or APSC size) is dominated by the sensor until you get to very long focal lengths. (Focal length enters the problem because of the interplay of the lens and sensor resolutions.) Because of the low pixel density on a DSLR, it requires a very expensive long-focal length lens to match the overall resolution of a bridge camera. There is an article that I wrote on this topic with some simple equations in the appendix for calculating the approximate 9% MTF resolution, including the lens and sensor components and their combination:


The equations are for white light and are not as detailed as using Magnitude Transfer Functions (MTF), but they are much simpler and I have found them to match what I see in tests for telephoto, macro and "telemacro" situations.

Other Related Articles and Postings:

My article on Telemacro using the same equations:
My article on Macro Test Targets:
http://www.dpreview.com/articles/5039116594/my-search-for-an-inexpensive-macro-test-target More on Macro Test Targets (Challenge: How Small Can You See) :http://forums.dpreview.com/forums/post/50011528

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