Re: Canon Announces Two New EF Ultra Wide-Angle Zoom Lenses and White EOS Rebel SL1 Digital SLR Came
ok I'm tired of seeing arguments about how no one asked for a lens that several of us want and a few have already ordered.
I'm more interested in this topic:
You are spot on. I just ran first order approximation, using a 98 degree horizontal viewing angle and assuming that 77mm diameter threads occur right at the viewing angle boundary. In order to maintain a 98 degree viewing angle at 2 inches beyond this point, the filter surface would have to be 193mm wide. Add margin to that and you are right at 8" just to place something two inches beyond the lens -- and lenses that have 82mm fronts are even worse. I doubt that is going to happen though-- it is 4x the filter surface area and probably 10x the cost.
This isn't too hard to visualize though. if our filter is only 100mm and the front diameter is already 77mm (or 82mm), then you can see that the 100mm filter will have to be placed very close to maintain a 98 degree viewing angle.
using a 150mm instead of a 100mm filter would buy us some, but again the cost...
ok I'm tired of seeing arguments about how no one asked for a lens that several of us want and a few have already ordered.
I'm more interested in this topic:
ahsanford said:You are 100% dead on. You could just as easily have replaced my three bullet point idea with:
- Do something unnecessary.
- Do something unnecessary.
- Lee solves the problem with epically large hardware.
The first two ideas I offered were just make the nasty magic wand / deus ex machina solution of 'a company solving it' less big than it might have to be. For instance, I haven't done the trig, but the first two bullet points might keep filters down to 6" wide, but not doing those two things might require 8" filters.
- A
You are spot on. I just ran first order approximation, using a 98 degree horizontal viewing angle and assuming that 77mm diameter threads occur right at the viewing angle boundary. In order to maintain a 98 degree viewing angle at 2 inches beyond this point, the filter surface would have to be 193mm wide. Add margin to that and you are right at 8" just to place something two inches beyond the lens -- and lenses that have 82mm fronts are even worse. I doubt that is going to happen though-- it is 4x the filter surface area and probably 10x the cost.
This isn't too hard to visualize though. if our filter is only 100mm and the front diameter is already 77mm (or 82mm), then you can see that the 100mm filter will have to be placed very close to maintain a 98 degree viewing angle.
using a 150mm instead of a 100mm filter would buy us some, but again the cost...
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