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Canon 24/3.5L II: Infrared
For extensive coverage of infrared, see the diglloyd Guide to Digital Infrared Photography.
There are very few wide angle lenses of any brand that can avoid a troublesome “hot spot” effect when stopped down to f/8 or more. In fact, all of the Canon mid-range and wide-angle zooms range from marginal to poor when stopped down beyond f/5.6; a central bright hot spot begins to ruin the image.
The Zeiss ZF 25/2.8 IR-Distagon with special coatings is terrific, but it’s a specialty lens and hard to persuade Zeiss to sell one, having limited availability, and being targeted for industrial users. Aside from the 25/2.8 IR-Distagon, wide angle lenses that perform well in infrared without hot spots are all but non-existent.
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Diglloyd DAP is DSLR-oriented, but also contains workflow and other topics. Much of the focus is on Canon and Nikon but also Pentax and Pentax medium format.
Special emphasis is placed on lens evaluation, focusing on Canon and Nikon and Sigma lenses, but with a few others like Rokinon/Samyang.
- Make better images by learning how to get the best results right away.
- Save money by choosing the right lens for your needs the first time, particularly some of the new Sigma Art lenses vs Nikon and Canon.
- Workflow discusses image organization, raw conversion and post processing. Many examples show processing parameters for direct insight into how the image was converted.
- Jaw-dropping image quality found nowhere else utilizing Retina-grade images up to full camera resolution, plus large crops [past 2 years or so].
- Real world examples with insights found nowhere else. Make sharper images just by understanding lens behavior you won’t read about elsewhere.
- Aperture series from wide open through stopped down, showing the full range of lens performance and bokeh.
- Optical quality analysis of field curvature, focus shift, sharpness, flare, distortion, and performance in the field.
Want a preview? Click on any page below to see an excerpt as well as extensive blog coverage, for example on Nikon or on Canon or on Pentax.
