firemanchip wrote in post #17365434
I was looking at the 24-105L 4.0 IS that will be coming with my 6D as soon as I pull the trigger and order it. It says that the IS is the equivalent of 3 stops. Am I correct that 1 stop = .4 as far as aperture goes? If so then 3 stops would make it the same as a 2.8 without IS?
- Aperture controls Depth of Field (DOF).
- IS has zero affect on Aperture - F2.8 is F2.8, F4 will never be F2.8 in terms of DoF just because the lens is stabilized
- IS is really about one thing in my opinion, and that is letting you handhold long focal length lens at lower shutter speeds
- this of course raises the question, with your 24-105 lens, when the lens is at 70 - 105, are you going to be taking pictures of things that aren't moving or are moving slowly that you can utilize slower shutter speeds
- since you are getting a 6D with a 24-105 all purpose lens, my guess is the answer to that is going to be yes - i.e. some walk about travel stuff (buildings don't move), portraits at 70 - 105mm at F4 and 1/30 SS, and walk about video (this is a great Full Frame all purpose video lens)
- since the general quoted formula of setting your minimum SS = 1/Focal Length and 1/105 (the longest of your 24-105) is either 1/100 SS or maybe 1/120 (lets assume this), then 3 Full Stops (which equals 3 doubling or halfings of light) equals (1/120 -> 1/60 -> 1/30 -> 1/15) - therefore, if the claim by Canon of the IS's ability on this lens is accurate, you can expect to be able to take a reasonable picture of a still subject at 1/15th SS when shooting at 105mm.
- if this claim is correct, then this is a very good thing because if the light was not great and 1/120th SS required 12,800 ISO to have good exposure (a very noisy ISO), then by moving the SS to 1/15th, you would be able drop the ISO from 12,800 to 6,400 to 3,200 to 1,600 - and at ISO 1600 and 1/15th or ISO 3,200 and 1/30th you are going to get a way better picture (less noise) than at ISO 12,800 and 1/120th SS which you would likely have needed to use with a non-IS lens
Hockey and wedding photographer. Favourite camera / lens combos: a 1DX II with a Tamron 45 1.8 VC, an A7Rii with a Canon 24-70F2.8L II, and a 5DSR with a Tamron 85 1.8 VC. Every lens I own I strongly recommend [Canon (35Lii, 100L Macro, 24-70F2.8ii, 70-200F2.8ii, 100-400Lii), Tamron (45 1.8, 85 1.8), Sigma 24-105]. If there are better lenses out there let me know because I haven't found them.