digital EOS implications for macro?

[DoctorMoth]

Does the D-30 and D-60 affect macro lens performance other than to increase magnification by the 1.6 factor? I'm just getting interested in macro nature photography and looking to purchase either the Canon 100 2.8 Macro or the Canon 180 L 3.5 Macro both which have terrific reviews. But I'm thinking at about half the price wouldn't the 100 be a better lens (faster and about half the price at $475 or so instead of $1100 for the 3.5, although the 3.5 is designated as an "L"). The 100 would be in effect a 160 on the digital EOS. I'm assuming like with my other lenses there is no change in focusing distance. Is there any other differences between these two lenses other than the focal length?

[Roger_Cavanagh]

doctormoth,

It is not correct to refer to the D30/60 having an "increase in magnification". The smaller (compared to 35mm film) sensor reduces the field of view, otherwise lens performance will be the same.

I don't have either of the lenses you are considering, but I would say L glass is always expensive and does give superior results. Is it worth the money? I suppose it depends on how deep your pockets are. :)

Another point in favour of the 100 macro is the weight - less than half the 180. And there seem to be countless 100 owners who sing the praises of this lens.

It will be interesting to hear from someone who has tried both.

Regards,

[BobbyC]

I actually use a Tamron 90mm macro lens and it performs just as well on my D30 as my film camera (the 1.6 crop factor is the only difference, okay plus instant feedback, oh yeah better quality pictures, no film, less hassle. ;-)

[DoctorMoth]

I'm somewhat intrigued by your comments about "field of view" vs. image magnification, are you saying that a 100mm lens on the Canon 1v and the same lens on a D-60 would produce an identical image except that the D60 image would be in effect cropped by 60%. I'm not sure I follow that. Nearly every Canon Digital Eos review, website, etc. that I've seen refers to an inherent 1.6 corresponding increase of lens focal length as an advantage of increased magnification. Maybe I'm just not understanding the difference. On the other issue of the Canon macro lenses, on their website they basically imply no practical difference between the two other than that the 180mm allows you to be further away from your subject to get the same 1:1 image factor, and it comes with a rotating tripod mounting collar which is optional with the 100mm. From the user reviews I've read on the two lenses, it seems that the 100 is probably one of the sharpest lenses Canon produces even though it's not a "L," and a great bargain at under $500, less than half the 180 "L" version (which also I might add is a 3.5 vs the cheaper version's 2.8 which seems strange). I would have thought the "L" would have been the faster lens. It would seem to me that for half the price and with the 1.6 issue you would be getting quite a "bang for your buck."

[Roger_Cavanagh]

doctormoth wrote:
I'm somewhat intrigued by your comments about "field of view" vs. image magnification, are you saying that a 100mm lens on the Canon 1v and the same lens on a D-60 would produce an identical image except that the D60 image would be in effect cropped by 60%.

Yes, that is exactly what I am saying. It doesn't matter what camera a lens is used on, it will produce the same size image on the film/sensor plane. The D30/60 just uses a smaller part of that image.

I'm not sure I follow that. Nearly every Canon Digital Eos review, website, etc. that I've seen refers to an inherent 1.6 corresponding increase of lens focal length as an advantage of increased magnification.

If they really imply extra magnification, then they are writing tosh. The optical characteristics of a lens cannot change like that (digital zoom aside). The use of the term "magnification" is incorrect and confusing, but often what people mean is that the frame is filled because of the cropping. Thus if a subject taken with a D30+300m fills the frame, then 35mm SLR will need to use a 480mm lens to fill the frame. The film image is larger than the CMOS image, but, of course, both can be enlarged (by different amounts) to the same print size.

From the user reviews I've read on the two lenses, it seems that the 100 is probably one of the sharpest lenses Canon produces even though it's not a "L," and a great bargain at under $500, less than half the 180 "L" version (which also I might add is a 3.5 vs the cheaper version's 2.8 which seems strange). I would have thought the "L" would have been the faster lens. It would seem to me that for half the price and with the 1.6 issue you would be getting quite a "bang for your buck."

I entirely agree with that conclusion based on the evidence. Guess there are too many 180 macro users out there. :)

Regards,