Equivilent digital focal length to 35mm focal length?

Question

I have Sony DSC-H2. It's 6 megapixels. Optical zoom is 12X.
It seems whatever the digital focal length is I times it by 6 and SEEMS to be pretty accurate. Any idea how much I times my digital focal length on my new toy to get close to 35MM focal length? Fuji E900. 3X optical, 9 megapixels.

Answer 1

Here ya go: your E900 has a 1/1.6" sensor measuring about 8mm x 6mm. The sensor to compare with measures 36mm x 24mm. Divide the larger length by the smaller length, then do the same for width: 36/8=4.5 and 24/6=4. The discrepancy is due to differing aspect ratios, the smaller sensor being 4:3 while the larger one is 3:2. For differing aspect ratios, the length multiplier is normally used to calculate the 35mm equivalent, and in the case of a 1/1.6" sensor, that's 4.5 (it's actually 4.4444444444 but what's a few decimals).

**EDIT** I just noticed Dr. Sam already gave you the correct ballpark multiplier, so just consider my answer as confirmation and award him the points. Unless you prefer 4.5 versus 4.4 haha!

Answer 2

http://www.dpreview.com/reviews/compare_post.asp?method=sidebyside&cameras=sony_dsch2%2Cfuji_finepixe900z&show=all says that your 35 mm equivalence is 32-128 mm. I don't see the actual focal length of the lens, so I can't give you the multiplier. It depends on the size of your sensor, though.

The H2's 35 mm equiv. is 36-432 mm. I know that the crop factor for its 1/2.5" sensor is 6.03, so I can work it backwards and I find that the true focal length of your Sony lens is 5.97-71.64 mm. It might be labeled 6-72 mm.

Look around the lens barrel of your new toy and see what the real focal length is. It's usually engraved right there. Your crop factor is going to be about 4.4, but that's my guesstimate. If that's correct, your lens should say 7.2-28.8 mm on it. Whatever is DOES say, divide the smaller number into 32. Divide the larger number into 128. The result of each division should be virtually the same number. This number is your crop factor. (lens factor, magnification factor, etc...)

Answer 3

From your ancient past, do you remember anything called APS sized film? You know, the smallest widely available film type. Well, that's pretty much what your "modern" camera is. Just multiply whatever lens you currently have by 1.6 and this will be the new focal length.

Answer 4

its a simple formula

its times 35


so 3 x 35mm is eqiv to 105mm

2x35=70

1x35=35

10x35=350

they are a little approximate though

a

Answer 5

the focal length is dependent on the lens diameter and your ccd size...