Long Exposure vs. High ISO

Jun 242010
 
 June 24, 2010  Posted by Habenero at 8:31 pm How To, Photography , , , , , , ,  No Responses »

Shooting in low light can be a challenge.  One has to strike a balance between using a high ISO, or a slow shutter speed to capture an image.  The choice you make can make all the difference in getting a memorable image.  Using film, a high ISO meant 400 most of the time, and in the late 1980′s, the limit crept up to 3200 (if you liked large amounts of grain in your image).  I tended to keep my film selection to the finer grained ISO’s.  I rarely shot at 400 ISO, preferring to shoot with 25 to 100 for most of my early images.  A heavy tripod was an essential part of my equipment.  Now that I am shooting digitally, I tend to keep my ISO around 400 and I like to hand hold most of my shots.  My gear is lighter, and my knees appreciate the lack of excess weight.

The biggest advantage of long exposures is better color saturation.  Slot canyon photographs are prime examples of what long exposures do best.  Notice the colors and richness that a long exposure provides.  This image was shot using 100 ISO film, f-16, and about 37 seconds for the exposure.  I would probably use similar techniques had I shot this using digital equipment.  The most important thing to keep in mind when making long exposures with a digital camera is that longer exposures introduce more noise in the image.  This is because the longer the sensor is energized for capturing an image, the more it heats up.  The extra heat is seen as Gaussian distributed noise in your final image.

Images made using higher ISO’s in digital cameras also have a larger amount of noise.  It is caused by a sensor that is being driven at a higher potential (voltage) than the lower ISO images.  Thus you will see more noise in the lighter areas with a high ISO than in the darker areas.  This non random noise is similar to that of film grain and can be exploited in the creation of old style images and Sepia tones.  This image of some swing dancers is indicative of a low light level, short exposure, high ISO digital shot.  

Your selection of ISO and exposure should always be made so as to achieve your desired image.  Get creative and play around with them.  Nikon, Canon, and every other camera maker out there do not have your vision in mind when they set their camera’s Auto settings.

Lens Repair

Jun 132010
 
 June 13, 2010  Posted by Habenero at 8:58 pm General Notice , , , ,  No Responses »

There are no user serviceable parts for most good lenses. Does this mean one should avoid taking their lenses apart if they break down? Short answer is YES. The longer answer is it depends upon your background, the tools you have on hand, your comfort zone when it comes to working with parts with very small springs, switches and screws, and the area in which you can work. That said, I do not recommend you take your lenses apart unless they are completely out of warranty, and you have already committed to buying a replacement.

That said, I just opened up a Sigma 28-105 with a Canon mount (it is not my lens, but the owner had nothing to lose by anything I did to it) that had stopped working. It would focus and zoom, but the iris was stuck somewhere around f/11.  The problem manifested itself after prolonged exposure to the Arizona torture chamber known as a car trunk.   There are only a few reasons an iris that is electronically controlled will stop working.

  • The contacts to the camera are too dirty, not this time.
  • The gears that couple the motor to the iris have lost teeth, not in this case.
  • The iris is jammed, it works just fine manually.
  • The ribbon cable that provides power to the stepper motor, BINGO!

Now I can only hope to remember where all the parts go by the time I find a replacement for the ribbon cable.

Camera Selection 101

Apr 282010
 
 April 28, 2010  Posted by Habenero at 6:24 pm How To, Photography , , , , , , ,  No Responses »

I use Nikon camera equipment, so what I am about to say may not make Nikon extremely happy.  Only you know what camera will be best for you to use.  I always tell people to go to a camera store or the camera department of a store you like to shop at.  Pick up the various cameras and look through them.  Test the ease at which you can change the settings.  Look carefully at the menu and see if it makes sense to you.  The camera that best meets all the criteria of comfort, features, and quality that you demand of it is the camera you should buy.  The camera manufacturers would like you to think that their cameras and lenses are superior to their competition, and sometimes they are, but if you do not find the camera comfortable to use, you are not going to recommend it to anyone else.  That said, I bought my Nikon’s because they have always met my needs.

The big 3 camera makers, Nikon, Canon and Pentax, each make high quality camera’s.  Nikon is rugged and has top notch glass.  Canon is a bit more varied than Nikon and also has great glass.  Pentax is a bit more innovative and rugged, and their glass is quite good, with cost becoming more important in my selection, if I were starting out today, I would seriously consider Pentax.

My choice of Nikon was made long ago when I started shooting film.  The controls of my camera are intuitive to me.  I know where to find the commands I use most often on my cameras.  The transition from film to digital was not difficult because Nikon kept most of them in the same location I had gotten used to using.  Their menu for the features that I wanted to learn made them easy to find. I suspect Canon and Pentax did things in a similar manner.

So when selecting a camera, choose the one you find most comfortable when it is set up with a lens that you prefer.  That is the only way you will be happy shooting.

Print at Home, Maybe Not

Apr 202010
 
 April 20, 2010  Posted by Habenero at 10:38 pm How To, Photography , , , , , , , , , ,  No Responses »

When you take photos, how you post process them is dependent upon the output format you plan to display them. If you are using them only for email or web pages, you are pretty much done as soon as you cut the resolution and size down and create the jpeg. If you plan to make hard copies of the images, a bit more work is required. How do I ensure what my screen shows me will match the print? How large is the final print? Where is it going to be displayed? What is the best method to produce the print? The answer to these questions determine the survivability of your print.

To ensure that what you monitor shows you matches the print can be done in several ways. The best method (and the only one worth doing) is calibrating your monitor to the industry standard. There are several manufacturers that make tools for doing this. I own a Spyder 2. Calibrate your monitor at least once a month, more often as it ages, and every time you move the monitor to a new location. When calibrating your monitor keep the lighting around it at the same level it normally is when you edit photos, as ambient light affects the calibration results. There are some calibration target photos you can adjust your monitor with, but they do not ensure your monitor is meeting the industry standards, and if you adjust your monitor using them there is no guarantee that your printed image will match very well. The absolutely worst way to adjust your monitor is to print an image and then adjust your monitor to match. Doing that only makes your printed images and monitor match, but if you have to send the file to someone else, it may look extremely bad! Whichever method you use, remain consistent with it. The biggest advantage of a calibrated monitor is the uniformity your images will have between different displays and printing devices.

Email and web use generally does not need a resolution greater than 72 DPI, and a maximum dimension of around 10″ These settings produce very good images for most computer applications, but printing them gives poor results. Further security for the images can be made by encasing them in flash files, disabling right clicking, water marking, or any combination of these techniques, Be assured, if somebody really wants to steal an image from your site, they can, so only allow them to get an image that is of low resolution. Keep your high resolution files on your computer and an external media (CD, DVD, External HD, Etc.)

Post processing for a printed image takes more care. Images on the screen have about 7 stops of lightness (about the same as slide film) whereas, paper handles about 5 stops. The excess information has to be removed and either you will be doing it on your computer, or you are at the mercy of someone else. Even if you print the files straight from the camera, you are ceding the post processing to the camera’s and the printer’s manufacturers. The results may be good, but they will be weighted towards making an average shot that includes people. Since I am a control freak when it comes to my images, I post process them using Adobe Photoshop. I shoot in camera raw, which gives me the maximum amount of data my Nikon D300 can gather. I adjust color temperature, brightness, contrast and the histogram Adobe Camera Raw and then export a PSD file to Photoshop. There I fine tune using curves and saturation in adjustment layers and masks. I try to find out what the lighting will be in the area that my photos will be seen and adjust the color to create the best image for that kind of lighting. Just prior to sending the file to the printer, I make a final adjustment so that my output file will match the printers profile for the paper that has been chosen.

Printers, whether attached to your computer or located in a lab often have a profile or digital print parameter file that can be applied to your image so that the calibrated monitor will show you a truer representation of the finished product. Epson, Canon and HP have generalized profiles that are to be used for specific papers run through the printer. If you choose to go a more commercial route, many of the labs have down loadable profiles for the same purpose. When you have a file that has been optimized for a specific printer, you will get the best results. If you have a lab make prints for you and you have already optimized the file, be sure to inform the lab technician that ALL CORRECTIONS MUST BE OFF. This is because most labs deal with people that have not bothered to do any adjustments on their own and your efforts will be trashed if the computer in the equipment tries to further enhance your work.

I base my current print output on the cost. Printing at home costs about $4.50 to print an 8″ x 12″ print on my Epson when archival ink and paper are added up. Since I have a local lab (Costco) that can produce an image on Fuji Archival Paper for $1.99, it wouldn’t require being a genius to figure out which place is getting my business (sorry Epson).

Consider hiring a photographer!

Apr 202010
 
 April 20, 2010  Posted by Habenero at 4:43 pm General Notice , , , , , , , , , , ,  No Responses »

Cheap access to powerful camera equipment makes it so anybody that wants to call themselves a photographer does so. The big camera manufacturers, Nikon, Canon, Pentax, etc., have put a lot of effort into figuring out what and how most people shoot and their latest cameras are designed to enhance those aspects of photos. When a photo straight out of the camera looks good, the logical question follows, Why should I pay someone to take a picture I can do myself? Is there a reason to hire a photographer? Can’t everyone with a good camera take great pictures?

You should never hire a photographer to take a picture you yourself could do! You do not hire a photographer because his camera is better than yours, it may not be. You do not hire a photographer just because you need someone to push the button on a camera. You hire a photographer that has a particular style of work you like. The artistic vision of a photographer is his knowledge of what his camera can do, what types of poses fit the occasion, and the kind of post processing he or his lab performs. Photographers look not only at the subject, but also at the details in the background, foreground, and middle ground and use their choices of white balance, ISO, shutter speed, f-stop, and sense of timing to create their shot. You hire a photographer because you like what they create out of a scene.

Equipment is not capable of compensating for mistakes like; the lamp post growing out of Uncle Bob’s head, the garbage can just behind the banquet table, or the toilet seen in the mirror the bride is using to apply her makeup. Your photographer should see those things and adjust the shot to compensate (they will not be in his direct from camera shots). The most expensive camera when placed in the hands of a novice will produce pictures that look like they were shot by a novice. A good photographer, can take just about any camera and compose a shot that looks great.

The best photographers get great shots consistently right out of the camera, but will still have a bit of post processing done. Photoshop, Gimp or some other software will be used to ensure that skin tones will be correct in all shots, that minor blemishes not already concealed by makeup are hidden, and that the look of the images remains consistent. Be wary of any photographer that does not do any post production work.

Some photographers create works of art! Even if you know where a particular shot was done, and the time of day, you may not be able to capture a shot similar to the one done by a photographic master. Cameras set in “program” mode with auto white balance are by nature, going to give a good exposure for skin tones. Most great landscapes come out rather poorly when shot that way. Overly red or orange scenes throw off the camera’s sensor, similarly, so will overly dark or overly light scenes. There is far more to taking a picture than pushing a button. If you see a photographic work that you like, buy it! If it is one of mine, I will gladly tell you how I created it! I assure you, since all photos tell lies (if only of omission), telling how I created the image you see is the only way you will find out the truth the image conveys!

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