Is the D40 outdated yet?

[ChrisA]

Pardon my ignorance... but what constitutes "medium format" in the digital age? I know that one of Canon's 35mm 1d series gives a resolution of 16 megapixels. Hasselblad has medium format digital backs that do 22 megapixels (probably even more now).

Format refers to the physical size of the image sensor. Is it 7mm across, 24mm acros or 60mm across? "medium format means what it always did an image that is between 60x45mm and 70x60cm in size.

Resolution means how many samples you take of the image. If you take 6MP or 22MP For the most part resolution is independent of image size. Some you could have a "crop body" Nikon DX camera with 22MP or a medium format (45mm x 60mm) camera with the same 22mp.

What yu gain with medium format is greater sensitivity and lower noise. In practice however the larger sensors do have more pixels not not in proportion to the increase in area of the sensor.

 

[OreoCookie]

I believe the OTHER fellow has it right - for a given magnification on the "film" plane size, the larger format will have less DOF.

It was a mishap, I meant to write larger depth of field. The explanation is still correct, the DOF is a function of the focal length of a lens. If the sensor/film format is larger, then you need longer focal lengths to achieve the same viewing angle, hence for equivalent viewing angles, the DOF is smaller for larger sensors.

 

[scamateur]

It was a mishap, I meant to write larger depth of field. The explanation is still correct, the DOF is a function of the focal length of a lens. If the sensor/film format is larger, then you need longer focal lengths to achieve the same viewing angle, hence for equivalent viewing angles, the DOF is smaller for larger sensors.

Then I suppose we're saying the same thing. I would refer the questioner to the neat diagrams and clear explanations (and free calculators!) at DOFmaster.com. I'm sure there are other good references, too, but I liked that one.

 

[miloblithe]

Oops. My fault on the DOF question. I meant something along the lines of greater control of DOF, meaning less DOF. My bad.

As for APS-C lenses being cheaper, I'm not sure that applies to ultrawides. The 10/11/12-20/22/24 type APS-C lenses are pretty expensive, compared to "equivilent" full-frame lenses, although I'm not sure what an equivalent lens would be.

Nikon's 18-35 f/3.5-4.5 is like a $400 lens, vrs Nikon's 12-24 f/4 at about $1000.

Canon's 10-22 f/3.5-4.5 is about $100 more than the 17-40 f/4.

Tamron's 11-18 f/4.5-5.6 is about $200 more than their 17-35 f/2.8-4.0.

Not exactly equivalent lenses, arguably, but it's hard to come up with direct comparisons.