This week’s Gary’s Parries topics are:
1. CMOS Image Sensors Explained
2. How To Include Yourself In Your Own Photos
3. Fashion Model Seeks Fun-Loving Digital Camera With Long Zoom
Introducing Gary’s Parries. Everything you’ve always wanted to know about digital cameras but were afraid to ask. No question is too difficult, or too easy. As a Principal Software Engineer, and a former Assistant Professor of Computer Information Systems, as well as a recording studio owner/operator, and now, a digital camera enthusiast, GARY has more digital camera knowledge in his entire brain than most people would have in their little finger. And, in the unlikely event GARY does not know the answer to your question, he will answer it anyway, true to the spirit of the word “Parries”, a fencing term which, in this context, means “cleverly evasive answers”. So let your imaginations go wild. Email all of your nagging questions to: firstname.lastname@example.org, and then, En Garde!
The best question of the week will receive a small prize from the PhotographyBLOG goody bag, so send your questions now. If you would like your name, location, email address, and/or website included in the column with your question, please expressly give your permission in the email, along with the information you would like included. No private information will be included without your consent.
What is the difference between a CMOS Image Sensor and a CCD?
[Warning: the following is a highly technical discussion. If you are uninterested in such discussions, please skip to Question 2 - Ed.]
I can answer that question in one sentence.
A CMOS Image Sensor works differently than a CCD (Charge Coupled Device) which, as the name implies, processes the analog electrical charges that have accumulated at each photosite as a result of, and in proportion to, the light intensity at the photosite, such that all charges are shifted vertically, an entire row at a time, into a holding buffer where they are then shifted horizontally, one pixel at a time, into an output buffer where the pixel’s electrical charge is amplified, converted to a digital voltage, and then stored in digital memory in order to make room for the next pixel to receive such processing, processing which you would expect to be highly susceptible to errors, considering all the errors that would be introduced in an analogous situation of measuring a bucket’s water level by first transferring its water into and out of literally thousands of buckets in sequence, that situation being in complete contrast to CMOS Image Sensors, which employ the same circuit technology utilized in many tens of thousands of other CMOS circuit types already on the market, and not just in cameras, as is the case with CCDs, thereby making it economically feasible to integrate the additionally required circuitry at each photosite of the CMOS Image Sensor, for not only buffering and amplifying its electrical charge, thus enabling individual access to each photosite using a simple x-y addressing scheme, that is far less susceptible to errors than CCD charge transfers, but also for implementing hardware noise reduction circuitry which, unlike its software noise reduction counterpart, will not degrade image detail in the least, leaving one to conclude that, while there are many advantages to CMOS Image Sensors over CCDs, these advantages could all be lumped into one of the following two major categories: (1) advanced circuit technology, and (2) economies of scale.
I prefer to vacation alone. It’s not that I am anti-social, it’s just that I do not like having to interact with other people in social situations. Even so, I do enjoy taking pictures of the many different sights I encounter in my travels, but the problem is, none of the pictures I take ever have me in them. I have tried shooting self-portraits at arm’s length with the desired sights in the background, but I often misjudge their framing, and end up with some part of me cut out of the picture. How can I avoid this problem? My camera does not have a fold-out LCD, or a wide-angle lens.
Try practicing at home in front of and facing a mirror. Hold your camera at arm’s length and point it at yourself while observing the camera’s LCD in the mirror until you get the desired framing. Then lower your arm, and once again try positioning the camera for the desired framing. Check the LCD in the mirror to see if you were close. Repeat this process until you are able to return the camera to the desired position each and every time. Either that, or get a friend.
Gary, are you really married? My name is Jennifer and I’m a 29 year old fashion model with an interest in digital photography. I would like to purchase a digital camera, one I can keep with me at all times, and use without a computer, just like you described for your “wife”. You seem to know quite a bit about digital cameras, and I was hoping you could turn me on to a good one.
[For more information on the above referenced camera, read the article “Take My Wife’s Digital Camera ... Please” - Ed.]
Jennifer, yes, I’m married to my lovely wife (whose name escapes me at the moment). Still, I would be very happy to help you with your problem, but I will need to know a little more about you, and your intended use of the camera. Are you looking for a compact with a long zoom? If so, get in line behind my wife. That seems to be the one aspect of compact cameras most troubling to manufacturers. I am hoping something suitable will be introduced at the PMA show coming up at the end of this month, and I will keep you posted. But don’t hold your breath. As I like to say, “I’ll see it when I believe it.”
Column photo “The Photographer” by Brenda LaFleur of Brenda LaFleur Photography.