Cameras again, a great compromise

[snafflehound]

Fairweather and Allison. I agree 100% about the Olympus XA. Light, simple, great pictures and very tough. A friend and I both have them. They're both over 10 years old. Almost all thier use has been in the mountains in all conditions. Mine even took a long swim in the Snoqualmie river and still works fine. Unfortunately no parts are available for them anymore accept what a repair shop may have kicking around. If either of your cameras dies, contact me. I'd like to keep mine going as long as possible.

S

[oo9]

I enjoy shooting with my heavy Canon A-1 w/multiple lenses. Great light meter, works well in snow. For motion picture I enjoy my Canon 514XL-S. C-8 fixed lens 9-45mm. 1:1.4 MacroThough slightly on the heavy side as well due to the metal construction both cameras are nearly BomB proof depending on the height.The 514 runs about $10.00 per minute not including editing time so try not chopping to much.Shoots amazingly well in snow for Super-8,creates sharp images if you focus well.

[beefcider]

Here is a better explanation of DOF on 35mm vs MF, I was probably wrong about the distance between the film plana and the rear element of the lens as being the culprit.

The real world application is that using a 35mm SLR will produce sharper results at faster shutter speeds thus allowing the use of finer grained films. Why bother taking a MF camera if you are going to shoot large grain film anyway? I've spent way too much time waiting for the wind to die down a bit so I shoot a 4 second exposure at f22 on a MF camera.

The following is taken from one of the many rec.photo groups where these discussions never end.

"If you haveever struggled to get enough DOF with a reasonable f-stop whileusing a "normal" length lens on 4x5 or 8x10 you will know thatlarger formats DO have less DOF.

Let's look at hyperfocal distance as an indicator of DOF.There is a simple formula for hyperfocal distance:

h = F^2 / (N*c)

h = hyperfocal distance F = focal length N = f-number c = diameter of circle of confusion

This formula comes from the Lens FAQ which David Jacobson poststo rec.photo.moderated and can also be found in any number of books.It is really simple to derive from similar triangles, but itis difficult to show this in a text medium, without pictures.

OK. Suppose we compare 35mm, and 6x7, which is about twice as bigin linear size. (No arguments over "4x as big in area", please!)Take a 50mm lens on 35mm, and a 100mm lens on 6x7. If you stand inthe same place with the two cameras, these give roughly the same"normal" perspective and angle of view. I want to compare howthe two formats do when taking the SAME picture.

Let's suppose my subject matter extends from 5 meters to infinity.To get it all in sharp focus, I need to set the lens so ithas a hyperfocal distance of 10 meters. I want to know whatf-stop I need. I can solve the above formula for N, the f-number:

N = F^2 / (h*c)

BUT I need to know the circle of confusion. Let's take c = 0.025 mm(1/100 inch) for 35mm. Since I only need to enlarge the 6x7 neghalf as much, I can use a twice-as-big circle-of-confusion for6x7; c = 0.05 mm.

OK, plug in the numbers (don't forget to convert h from meters to mm):

For 35mm, N = (50*50) / (10,000 * 0.025). N = 10, i.e. use f/10 (or f/11).

For 6x7, N = (100*100) / (10,000 * 0.05). N = 20, i.e. use f/20 (or f/22).

See? You need to stop down two extra stops, from f/11 to f/22, to getthe same depth of field.

Why is this? Basically, it's because of the F^2 in the formula.The hyperfocal distance gets larger - and the depth of field getssmaller - by a factor of 4 when you double the film size andlens size. The circle of confusion also gets larger, but onlyby a factor of 2. There's a factor of 2 left over. In orderto get back the depth of field you've lost, you have to makethe f-number go down by a factor of 2 (which is 2 f-stops).

Another way to look at it is this: out-of-focus areas are blurredbecause of the physical diameter of the aperture. That's whystopping down any lens (smaller diameter aperture) gives more depthof field.

If you stand in the same place and photograph the same scene withtwo lenses that give the same angle of view, you will get the sameDOF if the lenses have the same aperture diameter - physicaldiameter in mm, (NOT the same f/number).

The 50mm lens at f/10 has an aperture of 5mm.

The 100mm lens at f/10 has an aperture of 10mm, hence less DOF.To get the same DOF as the smaller lens, you need an apertureof 5mm, hence 100m lens at f/20.

If you don't believe me, try it. If you try taking a picture with a35mm camera and normal lens at f/8 or so, you will get respectableDOF. With a 6x7, normal lens, f/8, you will get less DOF. With a4x5 or 8x10 camera and its normal lens at f/8, you will get solittle DOF it will make your head spin. (Large format photographersrarely use apertures as fast as f/8 for this reason, but sometimesit can be put to creative use.)"

[gapertimmy]

There is a new chip for digitial cameras coming out in may that takes all three color readings on each pixel (R G B), i've seen some test shots and it is pretty damn amazing, much better than todays 2.X megapixel cameras. I'd say it rivals the saturation of film. <jon spray me down>

the first camera coming out with this new technology... a cool 3K

[beefcider]

That sort of demolishes Nikons D1 series...unless they are the ones coming out with the new camera. That's going to make my crappy 1.2 megapixel look awful.

wait, it looks awful anyway!