Photo Technical

Back to camera specification details; there’s still more to know – A43

The headline in the last issue for this column on photography was that it is “last installment on specs,” but like Freddie Krueger I’ve returned for one, two or more sequels.  It’s like anything else, for instance, to really know your vessel it helps to have a good handle on all the specifications.  A camera has a fair number and you can look at these articles as if you’re going through the owner’s manual.  I guess it is only as exciting as the interest and control you would like to have.

Therefore this is the fourth installment covering camera specifications you can find on such websites as dpreview.com. For continuity I continue to use the randomly chosen Lumix DMC-FX150 camera, manufactured by Panasonic.  We ended on white balance the last go around, and move on to:

Aperture range: F2.8 – F5.6 – This represents the settings for the size of the hole (diaphragm) of your lens relative to its focal length (distance from the image sensor/film to the outer glass of the lens).  It allows for the control of light and the depth of field.

Considering professional camera system lenses will give an aperture range of f2.8 to f22 on average, having only f2.8 to f5.6 is a limitation controlling light and on the depth of field a camera can attain.  Depth of field is the distance from a near object to a distant object the lens can keep in focus.  The lower f/stop (2.8 and greater as it goes down) allows less depth of field but more light to enter, which is helpful in low light.  A higher f/stop (5.6 and greater as it goes up) reduces the light reaching the sensor and extends depth of field.

Most often you would like to use a shallow depth of field in taking a portrait.  This allows you to focus on the face of your subject and have the background, generally being unimportant and distracting, to be out of focus (blurry).  For this the f/2.8-5.6 range is quiet adequate and useful.

On the other hand in scenic land and seascape photography (that may still include a subject) and close up/macro work having great depth of field is the desired ability.  This is when you look for higher aperture to come into play, which with this Lumix is f5.6.

There are other useful and creative reasons for having an array of apertures.  In 35 mm (equivalent) photography the range in full stops is 1.4, 2.0, 2.8, 4, 5.6, 8, 11, 16, 22, 32.  The first very light sensitive f/1.4 aperture is very expensive to buy in a lens, and the last, f/32, is not too common.

Anyway, with this and all pocket cameras the size and price account for these limitations.  Nearly all pocket cameras come with a 3 stop (or less) range and all manufacturers know the f2.8-5.6 is most user friendly, technically simplest and cost effective range to produce.  My pocket Leica has a range from f2.8 to f8 that is a one stop improvement.  Nevertheless the range for this Lumix camera is good among pocket cameras.  Many have less range – some have only one f/stop.

Min shutter: 60 sec – Now that’s good, sort of.  The shutter, like the aperture, controls light that reaches the image sensor/film.  It has no effect on depth of field.  Instead it controls the freezing-fast shutter speed or blurring (slow shutter speed) of motion, depending on what you creatively prefer.

Knowing my minimum shutter speed, my next question is does it have a “bulb” setting?  This is when as long as you press the shutter button the shutter window remains open.  It’s a creative thing, and I have used it a lot.

Shutters speeds in 35mm professional cameras generally range from slow – bulb, 60, 30, 15, 8, 4, 2, 1 second and onward to ½. ¼, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000, 1/4000, 1/8000 of a second, which is very fast.  I actually just read about a new camera, I think a Nikon (great product but watch their service) that has a 1/26000 (in that range) shutter speed.  Often these high end extremes due not translate too much usefulness, unless you go for stop action sports photography.

I checked nearly all the Canon pocket cameras quickly using dpreview.com and found everyone had a minimum shutter speed of 15 seconds.  The Lumix has two stop more creative fun and light controlling capability.  I like Canon, but this goes in the plus column for Panasonic.

Max shutter: 1/2000 sec – This setting allows in the least amount of light to reach the sensor/film, it is the best at stopping action, and I repeat generally finding myself less concerned with the top end speed of the shutter.  Do keep in mind it is a way of controlling light and that there limited capability of doing so with a 3 f/stop aperture control so on extremely bright days your camera can make use of this maximum shutter speed if you minimum (best and most sensitive) ISO speed is 100.   What they offer is good.  I would avoid going lower with 2 to 4 thousands of a second working just fine.

I’ll end this article here, but the specification list still has two dozen more categories to explore and clarify.  We covered only two items on the list this time – aperture and shutter.  They are so central to the function and creative capabilities of cameras, we could literally write extensive chapters on these two controls.  Next time we will begin with the built in flash specification, in the meantime I’ll take permission to go ashore.  Happy sailing!