Sometimes when I'm comparing this and that and poking here and looking there at photography, equipment, and processing I stand back and marvel at the magnitude of science and engineering that go into making any of this possible. I've written this before but I feel the need to underscore this point. It's "magical" on some level. Consider what knowledge, which materials, what kind of manufacturing it takes to make each step in this process.
- Light hits a light sensitive diode
- Diode emits a tiny electrical signal
- Hardware applies gain to amplify the signal (ISO sets the amplification level)
- Amplified signal enters an analog to digital converter (ADC)
- Digitized information exits the ADC (may receive additional signal processing as in the cases of extended ISO settings)
- Digital information can now be written into a RAW file
- This RAW file can then be loaded into software on a computer/tablette/mobile-phone
- De-Mosaic function performed on a RAW file
- Individual "pixels" of RGGB (red, 2x green, blue) information is processed using surrounding "pixel" data to calculate color and luminosity
- Such that there is now a different kind of information (de-mosaic calculated) for each "pixel"
- Changing each and every original red, 2x green and blue locations into full color with brightness information
- De-Moscaic'd images still look ghastly as the colors are still "off", so...
- Software "massages" a de-mosaic'd image using ICC, DCP, or other "camera profile" filters
- The image is now displayed to the user
- User can now begin performing additional modifications using the tools the software provides
After all this we can now consider various elements of the image making system. In my case I've looked at lenses. To me it's absolutely amazing that after passing through the process described above that I can now wonder if one lens is "sharper" than another. I'm completely and utterly reliant on all that knowledge, understanding, engineering, manufacturing, materials, and software just to reach this potentially interesting point.
Whew! It sometimes takes my breath away.
With this in mind I wanted to see how the modern Sony FE 55mm f/1.8 ZA compared with an old c.1973 Nikon Nikkor-P (Xenotar) 105mm f/2.5 pre-Ai lens. Here's what I found.
It's easy for me to see the newer Sony FE is sharper than the Nikkor-P. Though I have to admit the old Nikkor-P still looks pretty good. The differences between the two lenses come down to the Sony FE being the contrastier optic when I use the exact same image processing pipeline applied to both lenses.
This leaves room for choosing a different process pipeline. Software is flexible in ways I never experienced in the old film/chemistry days when the Nikkor-P was first introduced. I will consider the role of software sharpening in image processing in the next entry on this topic.
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