EXCERPT page containing first few paragraphs. 2019-09-18 11:56:11
UA_SEARCH_BOT_null @ 184.108.40.206
I built a crude camera obscura:
- Cardboard box with crude hole to stick the front of the lens out.
- Tracing paper for the projected image (paper taped over a hole cut in stiff gatorfoam.
- Photographed the image visible on the tracing paper.
I checked the image circle at 14mm, 18mm, 25mm and 35mm. I had only crude materials to work with, but I can be certain of the results.
The image circle projected by the lens has a soft outline, so precisely where it ends is somewhat ambiguous (stopping down a lens extends the image circle slightly and better defines its edge, but there is no way to stop down the Olympus 14-35mm because it uses an electronic aperture control).
Below is what I measured at infinity focus. Figure ±1mm depending on how one counts the blurry and vignetted edge of the image circle (which can be seen below).
Article continues for subscribers...
Diglloyd Guide to Mirrorless is by yearly subscription. Subscribe now for about 25 cents a day ($90/year).
BEST DEAL: get full access to ALL 8 PUBLICATIONS for only 68 cents a day ($249.95)!
Diglloyd Guide to Mirrorless offers comprehensive integrated coverage of most APS-C and full frame mirrorless cameras and lenses.
Special emphasis is placed on Sony full-frame, including Sony lenses and the high performance Zeiss Batis and Zeiss Loxia lenses plus Rokinon/Samyang and others. Fujifilm X, Olympus and Panasonic M4/3, Sigma dp Merrill and dp/sd Quattro are also covered in depth. Years in the making, it offers a wealth of material for choosing and using a mirrorless camera.
- Make better images by learning how to get the best results right away. For example, the best way to set up your Sony camera.
- Save money by choosing the right lens for your needs the first time, particularly with the numerous lenses available for Sony.
- Make better images, a sort of “cheat sheet” saving yourself months or years of ad-hoc learning—best practices and how-to and processing parameters are discussed and shown.
- Jaw-dropping image quality found nowhere else utilizing Retina-grade images up to full camera resolution, plus large crops.
- 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 Sony.