----- Original Message ----- From: "J. C. O'Connell"
Subject: RE: M42 ultra-wide
wrong comparison, I said using APS lens of same focal length as FF lens makes sense when using a APS camera (istd). Someone claimed that they would never buy APS type lenses and I was pointing out the advantages to them.
You would only have to compare the size weight and cost of two 14mm lenses one FF, and one APS to see what I was talking about.
Your comparison is absolutely correct, but not of much use, unless all you are shooting is APS sized.
The DA 14mm
The DA 14mm f/2.8 offers APS sized coverage in a lens with 12 elements in 11 groups. It takes a 77mm filter is 3.3 inches in diameter, 2.7 inches long, and weighs 14.8 oz.
The A 15mm f/3.5 offers 35mm coverage with 13 elements in 12 groups, 3.1 inches long by 3.3 inches in diameter, and a comparatively porcine 20.9 ounces. It also gives up uncomfortably close to a stop of speed.
The Nikkor 14mm f/2.8 is also very big, a little bigger than the Pentax 15mm and 2.5 ounces heavier.
While the APS coverage lens is certainly smaller and lighter, it isn't hugely smaller, and surprisingly heavy.
There is certainly the matter of cost to factor in, the 15mm was a bloody expensive lens.
The advantage that the 15 has is that it works on full frame 35mm, something the DA lens doesn't.
William Robb
