NEW ARTICLE: Crop Factor
- Thread starter Tim
- Start date
PolynesianMedic
Global Moderator
Great article Tim!
I would concur Tim, however:
Lens distortion with sweet spot only applies to when you use a lens designed for a larger sensor. ; It doesn't apply to lenses specifically designed for the format (i.e. EF-S, DX, 4/3 lenses, Tamron's Di II series, etc.)
I would explain depth of field to be that a crop camera's depth of field should be calculated at the pre-crop focal length value. (since DOF is calculated by focal length, aperture and distance to film plane)
So yes it does have a larger depth of field, because using a 50/1.4 lens, your DOF should be calculated by using a 50mm lens rather than a 75/80 lens. Because a 80/1.4 (85 is the closest, I know) lens would produce shallower DOF at the same other 2 variables than a 50/1.4. ;
I'd also mention diffraction issues with a cropped sensor - how it shows up earlier, and this is why P&S usually have limited aperture values.
Lens distortion with sweet spot only applies to when you use a lens designed for a larger sensor. ; It doesn't apply to lenses specifically designed for the format (i.e. EF-S, DX, 4/3 lenses, Tamron's Di II series, etc.)
I would explain depth of field to be that a crop camera's depth of field should be calculated at the pre-crop focal length value. (since DOF is calculated by focal length, aperture and distance to film plane)
So yes it does have a larger depth of field, because using a 50/1.4 lens, your DOF should be calculated by using a 50mm lens rather than a 75/80 lens. Because a 80/1.4 (85 is the closest, I know) lens would produce shallower DOF at the same other 2 variables than a 50/1.4. ;
I'd also mention diffraction issues with a cropped sensor - how it shows up earlier, and this is why P&S usually have limited aperture values.
Excellent article Tim. I understood the basics of Crop Factor, but this article helped me to understand the finer points & it helped to support a decision that I plan to take action on in the next couple years. A couple months back, as I began to understand a little about crop factor, I decided that my next camera would be Full Frame & right now, that 5D Mark II is looking really good. I think that would go real well with 70-200mm 2.8, 50mm 1.8 & maybe a 24-70mm 2.8. What do you think?
"Cooleo" said:
i think you NEED to click my link if you are going to score that kind of booty! ; it's a nice kit you are proposing that would cover quite a few situations in the parks, for sure. ; i would go one up and get the 50 f/1.4 if you can swing it.... ; MUCH better lens.
Cooleo, I am right there with you. ; Next time full frame all the way, but I will hold onto my 40D since I like it a lot. ; Everyone needs two bodies! ; One of my favorite sites is to see the photogs on the back of the motorcycles during the Tour de France and they usually have two cameras hung around their necks with two different lenses. ; Granted they are probably both full frame cameras, but I will be happy with one of each.