DO lenses ?

pazzy · Feb 12, 2008

With these lenses

70 300MM F4.5 5.6 DO IS and

70 300MM F4.5 5.6 IS

both by Canon , the price difference is a lot more with DO,
is this just for the more compact size or is DO better image quality ?

Big Mike · Feb 12, 2008

Diffractive Optics.

The basic idea is that they use 'special' lens elements which make the lens smaller and lighter. The quality is also top notch.

I've heard that Canon has said that DO lenses are considered to be in the L family...so that's top of the line.

yeti · Feb 12, 2008

DO means that the lens uses diffraction as well as refraction to bend light within the lens. It's a really cool idea that allows Canon to create a very powerful lens without making you carry lots of glass.

In addition to that diffraction optics apparently has color-aberration opposite to that of refraction optics, so having diffractive element along with the refractive element results in image that is just right.

The downside is the effect DO lenses have on your wallet.

keith204 · Feb 12, 2008

if I remember right, you're looking at $1300-1400 for a 70-300 DO lens. If this is in your budget, then look into a 70-200 f/2.8L lens... or if you can afford a bit more, go with a 70-200 f/2.8L IS

Of course, it's a larger lens, but personally I'd rather a large lens that goes to f/2.8 than a small lens that's f/4.5-5.6.

That One Guy · Feb 12, 2008

keith204 said:
if I remember right, you're looking at $1300-1400 for a 70-300 DO lens. If this is in your budget, then look into a 70-200 f/2.8L lens... or if you can afford a bit more, go with a 70-200 f/2.8L IS

Of course, it's a larger lens, but personally I'd rather a large lens that goes to f/2.8 than a small lens that's f/4.5-5.6.

was going to say the same thing.

if you mostly shoot outdoors or in well lit areas, then try the 70-200mmf4L for around $550

usayit · Feb 12, 2008

The DO lens in the OP is not considered part of the L lenses of Canon

IMO,

The DO lenses are pretty much pointless in the Canon line. THere is no clear market for them and they don't sell well. THeir price point puts them in direct competition with other similar focal length zooms in the Canon line and they don't compete well in the IQ department. The DO lenses don't handle CA very well at all.

yeti · Feb 12, 2008

Just a speculation on my part:

Right now the DO line is testing the waters. There isn't really many lens to choose from and those that are available are boring, unless of course you want a compact lens that fits in your pocket.

In the future we might see more and more of these, including the L-series. Maybe that 70-200L f/2.8 is the next candidate for DOsification and it will finally end up being something I can carry around

Wouldn't it be nice? Unlike everyone here I am actually fond of the concept, but Canon can't expect me to pay an L-series pricetag for a non-L-series lens.

usayit · Feb 12, 2008

That has been the speculation since the first DO lens was released in 2001.... I would have thought more lenses would have been DO'zed by now.

My speculation...
The market has voiced its opinion... sacrificing sharpness and the optics ability to control CA is not worth adding "compactness" within the price point they have set. Canon probably has heard the message and hasn't devouted more R&D to DO lenses.

I highly doubt you will see a 70-200 f2.8 L DO. Diffractive optics just can't go head to head with the optics of the current version AND those looking for something more compact will more than likely head towards the 70-200 f4 L which also has wonderful IQ. It takes a lot of good glass design to make a f2.8 zoom across the focal range.

THe 70-300 DO is still a big lens..... not pocketable by any means.

keith204 · Feb 12, 2008

"Bigger is better." I'd rather get a bigger bag than a smaller lens to fit my current bag.

My wife and I got backstage passes to a concert with nationally known bands once, since we showed up with a 70-200 2.8. We look back on that and it doesn't seem real. We were able to say "ok, we want to meet the Supertones at 4:30, and Jars of Clay at 7:00" and our wishes were granted.

yeti · Feb 13, 2008

usayit said:
My speculation...
The market has voiced its opinion... sacrificing sharpness and the optics ability to control CA is not worth adding "compactness" within the price point they have set. Canon probably has heard the message and hasn't devouted more R&D to DO lenses.

The concept is sound, the implementation is poor. What you are looking at is an emerging technology, which is naturally not that great when it first arrives. After all, the first computer wouldn't even work! I am fully aware that DO lenses seem to have some softness to them that you just can't get rid of. Image Quality is crap, but the real feat here is that they managed to make a lens out of it at all! Canon needs a finer diffraction grating within the DO element to make the softness go away as my guess is this is caused by diffraction minima. I am not sure what they use for it (Canon certainly won't tell me if I ask), but maybe they need some new material or something.

Don't write off DO just yet, good ideas can only really be killed by better ideas and this one might very well come back. My speculation is that you are looking at a technology that has shown potential to do what integrated circuits did to computer technology: miniaturize miniaturize miniaturize.

nicfargo · Feb 13, 2008

If I get a DO lens, how am I supposed to look professional and superior to everyone else :-(

Big Mike · Feb 13, 2008

If I get a DO lens, how am I supposed to look professional and superior to everyone else

They may not have the fancy red ring...but they have a shinny green one

Carthage · May 4, 2010

Canon's EF 70-300 DO lens is a much maligned and underrated lens :grumpy:

. I bought mine mainly for travelling as I required something relatively light and discrete; nothing draws unwanted attention like one of Canon's white telephotos. I only own L lenses (except 50mm f1.4) and I was sceptical before buying; I'm glad I did as some of my best shots have been taken with this lens. It may only have a green ring but it feels and performs as good as any of its red ringed relatives.

Garbz · May 7, 2010

yeti said:
The concept is sound, the implementation is poor. What you are looking at is an emerging technology, which is naturally not that great when it first arrives.

Actually not really. What you're looking at is technology used in lighthouses and first made by Fresnel in the early 1800s.
Let me make something very clear. There not technological voodoo with optics. Optics and electromagnetics are two fields where the simulation matches the practical production exactly, and production has gotten simply incredible. We simply know all there is to know about bending light with glass, and the only technological advancements can really come from new materials or new methods.

All there is in lens design is compromises. DO isn't a dip in new technology, it's a test to see if the market will accept a smaller more compact lens which exhibits funny glows in out of focus areas and has very little CA control due to the fresnel lenses used.

The CA can probably be corrected, but then the lens may be larger or what not, that's all part of the design decision, though not sure how they would correct for out of focus glows.