Digital ISO

[hawkinsws]

I am looking to finally leave 35mm and go Digital. I see that you can select the ISO for exposures. In film higher ISO means larger grain. Does this translate to digital as well?

[Iguanasan]

Yes, it does, sort of. In digital, it translates to noise but a pixel is a pixel and the size of the pixels don't change. That being said, the newer, higher-end camera bodies are remarkably good at keeping the noise level down in amazingly high ISO settings. Here's some samples I found after a quick Google search: Samples - Canon EOS 7D High ISO Images | David's Simple Photography

[hawkinsws]

Thanks for the feed back. I guess the follow up is basic 35mm zoom lenses were 28-80mm lenses. What I see now are 18-55 mm lenses is this equivalent? Thanks

[Iguanasan]

Thanks for the feed back. I guess the follow up is basic 35mm zoom lenses were 28-80mm lenses. What I see now are 18-55 mm lenses is this equivalent? Thanks

Well, there are lots of different lenses about but yes, in this case the kit lens has migrated to a 18-55mm. The general reason for this is that most of the digital sensors in the cameras were not the same size as a 35mm film. They are, in fact, called crop sensors and generally have a crop factor of about 1.6 or 1.7. What this means is that due to the size of the sensor the image is, for all intents and purposes, zoomed by a factor of 1.6 or 1.7. So, 18 * 1.6 = 28mm and 55 * 1.6 = 88mm which gives you about the same range.

The exception to the rule, of course, is the full frame sensors that are now in many of the more expensive cameras.

[Gremlich]

To echo Iguanasan, with the cropped sensor (DX) like that found in the Nikon D90, a 35mm for example would be equivalent to about a 51mm on a 35mm film/full sensor (FX) digital. That's part of the reason I went with the Nikkor 35mm f/1.8, because I liked shooting with the Nikkor 50mm f/1.4 on my Nikon FM (I went with the f/1.8 for cost). I used a 135mm portrait with the FM, so, I'm thinking the 85mm will be the next lens I get for my D90 (which comes standard with the 18-105mm kit lens, which I really like).

[hawkinsws]

Thank you for explaining.