EF26-60 f/2L ?

[Gazer]

Any optical physicists out there that can comment on the possibility of this lens? 'Cause this is what I need in my line-up.

[OsmosisStudios]

Originally Posted by Gazer

Any optical physicists out there that can comment on the possibility of this lens? 'Cause this is what I need in my line-up.

Dont hold your breath. It's likely possible (60mm f/2 is only 30mm). The trick is making f/2 ZOOMS.

Why not get the 24-70 f/2.8? You lose a stop, but other than that you're good to go.

[Gazer]

Originally Posted by OsmosisStudios

Dont hold your breath. It's likely possible (60mm f/2 is only 30mm). The trick is making f/2 ZOOMS.

Why not get the 24-70 f/2.8? You lose a stop, but other than that you're good to go.

In short, because the 24-70 (IMO) is due for an upgrade (and I'm hoping Canon's R&D feel the same), and I'd really like to have that extra stop (much preferrably to the addition of IS).

I've been hesitant to select my glass in this focal range, restricting myself to either the wide end (24mm prime) and the 70-200 range instead. I suppose that unless I hear an anouncement from Canon within the next 6 months, I likely will pick-up the 24-70.

[Elmo]

I cannot see many folks paying at least $6000.00 for such a lens expecially as it would way about 5 lbs. Lets not even talk about filters etc.

[Gazer]

Originally Posted by Elmo

I cannot see many folks paying at least $6000.00 for such a lens expecially as it would way about 5 lbs. Lets not even talk about filters etc.

$6000? 5lbs? Are you just randomly choosing numbers out of thin air? Expressing an educated guess? or, qualified in any way to make such a claim? (I'm not asking in a derogatory sense, but rather asking sincerely.)

I'm by no means technically-minded when it comes to optic design, but I was thinking of a lens filter size around 82mm. Based on what you're saying, this would not be possible ... The thought of carrying a 5lb behemoth around my neck makes me shudder as well.

[OsmosisStudios]

Originally Posted by Elmo

I cannot see many folks paying at least $6000.00 for such a lens expecially as it would way about 5 lbs. Lets not even talk about filters etc.

How do you figure? It'd likely be about the same size as the current 24-70.

[Elmo]

OK first it is a full stop larger this wil require twice the surface area for the glass. This would double the weight of the 24-70. Except for a slightly shorter max FL. Biu with increased diameter comes an equivelant increase in thickness. Therefore as the 24-70 weighs in at 2.1 lbs. The bigger glass would weigh in at about 4 lbs with reduced fl Add in some for added thickness of glass, stronger mounting etc 5 lbs would not seem unreasonable.

As for price 24 -70 is about 1400.00 if you double that (twice as much material we are at 2800.00. Everything considered a lens of this class will have IS whether you want it or not. The Old IS on L glass runs about 700.00 now the price is about 3500.00 . Add to that for the improved iS say another 500.00 and we are at 4000.00 . Now add for bad lens blanks for larger glass (why do you think big long glass cost so much) add say 500.00 now we are at 4500.00 add in for future inflation tho keep price relatively constant over the next year or so and 5000.00 is now resonable and that is based on street prices. So MSRP could easily be $6000.00. At that we have added no R&D or other little things.

[OsmosisStudios]

Originally Posted by Elmo

OK first it is a full stop larger this wil require twice the surface area for the glass.

What?

70mm @ f/2.8 = 25mm
60mm @ f/2 = 30mm

How does adding 5mm to the diameter of the aperture DOUBLE the size of a lens?

Wanna try again?

*note: I've disregarded the rest of your post as this alone destroys your argument*

[vandergus]

Originally Posted by OsmosisStudios

What?

70mm @ f/2.8 = 25mm
60mm @ f/2 = 30mm

How does adding 5mm to the diameter of the aperture DOUBLE the size of a lens?

Wanna try again?

*note: I've disregarded the rest of your post as this alone destroys your argument*

And yet the front element of the 24-70mm f2.8 is over twice that diameter. These ideal equation have very little correlation with real lenses. Especially standard zooms.

*note: I've disregarded the rest of this thread as completely useless, seat of the pants speculation.

[OsmosisStudios]

Originally Posted by vandergus

And yet the front element of the 24-70mm f2.8 is over twice that diameter. These ideal equation have very little correlation with real lenses. Especially standard zooms.

*note: I've disregarded the rest of this thread as completely useless, seat of the pants speculation.

The 24-70 uses a 77mm filter. If we assume a correlation of that nature (25mm * 3.1=77) then a hypothetical 26-60 f/2 would have a 93mm filter. While that is LARGE, it isnt TWICE the size as Elmo had mentioned. Of course, even that is assuming some rather vague math.