rbfanman wrote:
The DX camera will have a 1.5 crop factor, and so give the field of view of a longer lens. The 35mm lens will produce images like a 52.5mm lens, the 50mm lens will produce 75mm like images, and the 85mm lens will produce images like a 127.5mm lens. The 35mm, and 50mm, would be OK for street photos, though not ideal, but be less than ideal for portraits, though the 50mm will do better on portraits than the 35mm. The 85mm will do good portrait work, but not be so great for street photos.
This is a not accurate. A 35mm crop sensor lens has the same depth of field as a 35mm full sensor lens. The crop factor simply enlarges the photo, it doesn't change the depth of field in the photo. Both lenses spread the subject out and push it away, exactly the same way. If I take an image with a 35mm crop sensor lens on a crop sensor camera and do the same with a 35 mm full frame lens on a full frame camera,
from the exact same spot, and crop the full frame images to match the crop sensor images, they resulting images should be identical.
But a 52.5 mm lens, both crop and full sensor will produce images that have a different depth of field than the 35 mm lens. The images will not be equal. If I take a 35mm crop sensor lens on a crop sensor camera, take the same image with a 52.5 lens on a full sensor camera, crop them to the same size, the images will not be equal, the depth of field will be different!
This is important in portrait photography since with portraits of people, you want to go to the telephoto side of 50mm for the more flattering depth of field rather than wide angle side of 50mm with the spread out depth of field. A 35mm or 50mm crop sensor lens on a crop sensor camera will not get you the effect you want for portraits.