Welcome to my blog, I'm Charles Johnson - a scientist and an amateur photographer. This site is devoted to all aspects of science related to photography. For more information read my About page.

This blog is © 2007-2011
Charles S. Johnson, Jr.
All rights reserved.
Comments[0] 03:39PM Jan 17, 2012 by Charles in General
Many of us try to obtain high-resolution images with high signal-to-noise ratios through the use of good equipment and good techniques. Unfortunately, some of our efforts are wasted when we display our images online and in small prints. It is only with 13”x19” and larger prints that high image quality can be appreciated. At some point in the future, large electronic displays will replace paper prints and will require the same high quality images now required for prints, but we are not there yet and printing is still the way to produce exhibition quality displays. In this entry I discuss what I have learned on the way to producing exhibition quality prints. It is aimed at serious amateur photographers who want to display their prints and even to sell some of them.[Read More]
Comments[2] 09:35PM Dec 26, 2011 by Charles in General
Some of us photographic seniors have negatives and slides that we need to digitize, and that can be a problem. In general dedicated film scanners are better than flatbed scanners for copying film, but many film scanners have vanished from the market; and the good ones that remain tend to be expensive. One alternative is to search for a good flatbed scanner that has an integrated transparency unit and make do with that. For example recent reviews demonstrate that the Epson 700 and 750 are satisfactory film scanners. I went a cheaper route a few years ago and purchased an HP G4050 scanner for prints and an occasional negative or slide. [Read More]
Comments[0] 09:18PM Nov 13, 2011 by Charles in General
One pair of corrections has been added to the list of correction for SCP. The complete list (pdf document) can be found here.
Comments[0] 09:24AM Aug 23, 2011 by Charles in General
My knowledge of art history is limited, but I am a great fan of René Magritte (1898-1967). Magritte is described as a Belgian surrealist artist, though he claimed his work was not surrealism. In any event he was extremely original and far outside the accepted traditions of art. If you are not familiar with Magritte, I suggest that you enter “Rene Magritte images” into your favorite search engine and take a look before you read any farther.[Read More]
Comments[1] 06:45PM Aug 02, 2011 by Charles in General
I was motivated to get the iPad by an article in dpreview.com. Now after using the iPad for several months, I have some comments. It is slick, and it does some things well, but overall I am disappointed.[Read More]
Comments[0] 01:26PM Aug 01, 2011 by Charles in General
This question is often directed to me. Long time readers of this blog will recall that a couple of years ago I produced and sold an eBook edition here. When SCP was sold to A.K. Peters, Ltd., I had to stop selling my eBook version.[Read More]
Comments[0] 03:35PM Jul 29, 2011 by Charles in General
My review of 500px last week was generally positive, but still it did not do justice to the site. What I missed, and what should be emphasized is the importance of the concept of “community.” When some of my first uploads were only viewed a few times and received relatively few positive votes, I was disappointed. Then some of my more successful shots started receiving comments, and I was prompted to examine the galleries of the commenters. That was a revelation. I found that other nature photographers were reaching more viewers and generating higher ratings than I was with images not obviously better than mine.[Read More]
Comments[0] 04:09PM Jul 23, 2011 by Charles in General
I welcome reviews of SCP. Reviews from experts are the most helpful to me, but I also learn from readers with different backgrounds and expectations. However, this week an Amazon.com reader listed the book as “Good but lacking” and proceeded to say that “…there is nothing in the book covering aperture or depth of field.” This is so amazing to me that I must comment. [Read More]
Comments[0] 03:05PM Jul 23, 2011 by Charles in General
500px is not like SmugMug, Flickr, etc. It is a place to get immediate feedback on your uploaded images, and to show your work with great colors and resolution. What the founders want is the best of your best and your portfolio of winners. [Read More]
Comments[0] 11:38AM Jul 11, 2011 by Charles in General
The trip: After hearing nature photographers rave about the beauty of southern Utah for years, we finally got around to visiting in April. Fortunately, I got a copy of Laurent Martrès’s book, “Photographing the Southwest, Vol. 1,” and we were able to do some planning before setting out. [Read More]
Comments[0] 11:47AM Jul 08, 2011 by Charles in General
This is a repeat listing. A list of corrections can be found here. A complete set of high-resolution photographs can be seen in this slide show.
Comments[0] 11:08AM Jul 08, 2011 by Charles in General
Forget equivalent, forget crop factor, none of that matters. Just measure the size of the image of an object on your camera’s sensor or film. Use height, width, or any other dimension you like. Then measure the size of the object you photographed. Divide the size of the image by the size of the object and voilà, you have the magnification.[Read More]
Comments[0] 03:24PM Jun 27, 2011 by Charles in General
The recent announcement from Lytro about their plenoptic consumer camera has stirred up a lot of interest. However, from the comments in various forums I see that there is confusion about what it is, and what it is not. This has prompted me to prepare a short (2 page) article describing how such plenoptic cameras work. It can be accessed here:
Comments[0] 03:12PM Mar 24, 2011 by Charles in General
In the February 28 blog I revealed my interest in panoramas and mirrors. Since that time, I have had a few failures and have learned about how to make more robust panoramas. Now I would like to comment on my experiences and to display couple of new results.[Read More]
Comments[0] 02:34PM Mar 04, 2011 by Charles in General
A mind boggling solar-lunar image is displayed here. The artist is Chris Kotsiopoulos, and his site www.Greeksky.gr is a wonderland of exciting photography. It pushes all the right buttons for those who love art, photography, science, and history. Chris has the knowledge and the photographic equipment, some of it specially modified for his projects, to capture stunning images. Furthermore, he is willing to work 30 hours in a stretch to get all the images necessary for a unique panorama in time and space. Enjoy!