digital lens vs. 35 mm lens

I'm getting ready to invest in a 20D. I have a couple of Sigmas and a Tamron for my Rebel 2000 right now, but none quite as fast as I'd like (fastest is 28-80/f3.5-5.6). I really like what I've read about the Sigma 70-200/f2.8, but it's not "made" for digital. Sigma sells an 18-125/f3.5-5.6 DC that is "made" for digital but I'd like something a little faster.

Am I correct in that the image circle is designed to match the size of the image sensor of digital SLR cameras on Sigmas DC? What, if anything, do I lose by not going with a DC?

Thanks.

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Originally Posted by siberia1997

I'm getting ready to invest in a 20D. I have a couple of Sigmas and a Tamron for my Rebel 2000 right now, but none quite as fast as I'd like (fastest is 28-80/f3.5-5.6). I really like what I've read about the Sigma 70-200/f2.8, but it's not "made" for digital. Sigma sells an 18-125/f3.5-5.6 DC that is "made" for digital but I'd like something a little faster.

Am I correct in that the image circle is designed to match the size of the image sensor of digital SLR cameras on Sigmas DC? What, if anything, do I lose by not going with a DC?

Thanks.

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Yes, "made for digital" usually means that the lens has a smaller image circle. These are fine but can't be used for any camera bigger than APS size. I personally believe that reasonably-priced full frame sensors are the future so I stick with 35mm lenses and their larger image circles.

Tamron's DI series lenses work on both (from what I've read). Usually it's the widest lenses that have a smaller imaging circle so they can't be used full frame on 35mm. That's the only potential problem that you'd have by using a digital specific lens.

They're fine on film - however I don't have any digital specific lenses for the DSLR I've had for a year and a half, either. There are some real advantages based on what I've read, but they really won't be much of a concern unless you're in certain conditions and want to make big prints.

Down the road, full frame sensors will probably be more common (and less expensive) than they are today but I don't know that the smaller 1.5X sensors will go away. There are some real advantages to them. Here's my situation: I have a 1.5x camera and to keep the angle of view I get with a 20mm lens on a 35mm camera, I'll have to get a 14mm prime ($1000 or so). But to get a full-frame DSLR, I'd have to spend several thousand more - plus I'd lose the advantages of the 1.5x like my 80-200 f2.8 reaching out to the equivalent of 300 at f2.8.

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Originally Posted by another view

Tamron's DI series lenses work on both (from what I've read). Usually it's the widest lenses that have a smaller imaging circle so they can't be used full frame on 35mm. That's the only potential problem that you'd have by using a digital specific lens.

They're fine on film - however I don't have any digital specific lenses for the DSLR I've had for a year and a half, either. There are some real advantages based on what I've read, but they really won't be much of a concern unless you're in certain conditions and want to make big prints.

Down the road, full frame sensors will probably be more common (and less expensive) than they are today but I don't know that the smaller 1.5X sensors will go away. There are some real advantages to them. Here's my situation: I have a 1.5x camera and to keep the angle of view I get with a 20mm lens on a 35mm camera, I'll have to get a 14mm prime ($1000 or so). But to get a full-frame DSLR, I'd have to spend several thousand more - plus I'd lose the advantages of the 1.5x like my 80-200 f2.8 reaching out to the equivalent of 300 at f2.8.

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Indeed, that crop factor is a godsend to people like me that have a hobby of shooting surfing from the beach.

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Originally Posted by Ryguyinlj

Indeed, that crop factor is a godsend to people like me that have a hobby of shooting surfing from the beach.

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same here. SHooting sports without a press pass is tough, but with the crop factors, it makes it that much easier.