50mm film lens equals ?? in DSLR

[larry_bolger]

Is a 50 mm lens equal in DSLR I seem to not feel zoomed in with 70mm Digital?

 

Is there a table for equivalants since I already feel they are not the same.

 

On cross country trip in April thought i zoomed on buffalo with 70 mm but it

took post processing to get close up.

[richsimmons]

You have to take into consideration the lens factor. The A100 has a crop factor of 1.5. So a 50 mm lens will act like a 75mm 1.5 x 50 = 75.

[larry_bolger]

Ok so any lens will be 1.5 x focal length?

 

How about if it is specific to DSLR not adapted is it the same?

 

Where did you get the 1.5 factor?

 

This would explain why it didn't feel close up, was less than what I would normally see with 35mm.

 

Thabk you

[richsimmons]

Any DSLR with a smaller than 35mm frame will have a crop factor. Most are 1.5 or 1.6. Olympus is 2.0. I got the sony's crop factor from this web site and confirmed it through Google. You can also look at this in-depth review http://www.dpreview.com/reviews/sonydslra100/page2.asp.

 

Every lens I've seen so far gives you the mm spec and you have to do the math.

 

If you want the camera to act like a 50mm, then you have to get a 33.3mm lense. The closet they have is a 35mm that I know of, which is 52mm equiv.

[ellis_vener_photography]

"Ok so any lens will be 1.5 x focal length?"

 

It depends o nthe height and width ofthesensor compared to the 24x36mm format size. A Nikon DSLR or the Sony/Minolta uses a CCD thatis roughly 16mm x 24mm so the math works out that, for angle of viewthere's a 1.5x magnification or crop factor -- in other words if you usedthesame lens on a 24x36mm film body and body with a 1.5x crop factor the angle of view recorded by the DSLR will be 1.5 x 50 mm = 75mm. The viewfinderforthe DSLR takes this into account so what you see throug hthe viewfinderwill be very close to what is recorded.

[craig_gillette]

The lenses don't change, 50mm is 50mm but the depending on the camera the sensors are smaller than film (some "full frame" sensors are essentially the same size). The crop factor works by trimming off the edges, essentially cropping the image. It looks like magnification because when you print or view, you get the already cropped portion and the subject fills a larger part of the viewed area.

 

On a full frame sensor or film, approx. 50mm is "normal" and seems to have no magnification. So a 100mm lens would seem to be 2x magnification, and so on, a 300mm lens would "magnify" like a 6x pair of binoculars.

 

On a 1.5 crop factor dslr, that 50mm lens gets you 1.5x magnification, not much. But a 70mm lens would only get you 105mm or essentially 2x magnification. That's not a lot of zoom/magnification. Outside of opera glasses, 6x is where most binoculars start. So with a 28-70mm lens, or something similar, that's just beginning to get into telephoto ranges.