Will ef-s lenses go telephoto or super-tele?

[pete_biro]

Short expiry on this one - will canon (or others) go the way of ef-s

lenses (i.e. smaller image circle lenses) in the telephoto range like

Olympus has started to do? I'd love to see a fixed 500mm lens that is

smaller and lighter than the one i lug around now on my 10d. For

wildlife, 8mp or 12 mp on a 1.6x sensor is plenty resolution and

enlargability and this mated to smaller lenses would be great!

[mark_chappell]

<I> I'd love to see a fixed 500mm lens that is smaller and lighter than the one i lug

around now on my 10d.</i><P>

 

The size of the sensor and image circle doesn't really have much (if any) impact on the

physical size of a telephoto lens of a given aperture. If you want (say) a 500/4 lens, it has

to have a front element of a certain diameter (in this case about 125 mm) and a length

based on focal length and optical design. You can tweak the optical design a bit with

exotic materials or techniques (like, DO lenses, however successful -- or not -- you think

they've proven to be), but it boils down to the fact that a 500/4 mm lens is a 500/4 mm

lens, no matter what camera it's mounted on and what sized sensor the image circle is

designed for.<P>

 

It's true that if you want a <B>field of view</b> on a APS-sensor camera that's the same

as with a 500 mm on full-frame 35 mm film, you need a shorter (and hence physically

smaller) lens. For Canon's 1.6X 'crop factor', the APS-equivalent focal length to 500 mm

on full-frame is about 312 mm. A 300/4 is indeed a heck of a lot smaller than a 500/

4.<P>

 

It's been said a number of times on PN, by people who seem to know what they're talking

about, that for a lens designer, there's no real need (or gain) from going the 'EF-S' or

equivalent route for telephotos -- that is, if you set out to design a 500/4, it's not much

easier to design an EF-S lens than a 'regular' lens for 35 mm film. That isn't the

case for

wideangles, hence the recent flood of EF-S wideangle zooms like the Canon 10-22, or the

Nikon (12-24) or 3rd party equivalents.

[steve santikarn]

I have asked this question before and most people that responded seem to think that the answer is no. The EF-S lens were made for wide angles apparently. But I like it for the weight saving, this is why I used the Pentax MX for so long. I would like to see a decent 75-300 EF-S IS telephoto lens (my USM is not very good, the DO is too expensive, and the 75-200 L IS with 1.4x is too heavy).

[bobatkins]

There's no point in EF-S telephoto lenses. They won't be significantly smaller, lighter, cheaper or better than EF lenses.

 

EF-S is essentially only useful at shorter focal lengths. Note that the 55-200/4.5-5.6 which was reintroduced with the Digital Rebel is an EF lens, not and EF-S lens.

 

The EF75-300/4-5.6 is $150. There's no way they're going to make it cheaper by making it EF-S, so they might as well use an EF mount and serve all markets.

 

As pointed out above, the EF300/4 on a 20D has about the same view as a EF500/4 on a full frame camera. There's your "cheaper, lighter" lens. 1/3 the weight and 1/5 the price!

[Greg M]

In your case (and mine) it wouldn't matter if they did make one since the 10D doesn't allow you to mount ef-s lenses.

[jon_austin]

It didn't make sense (IMO) for Canon to produce its new 60mm USM macro lens as an EF-S mount, either, so go figure. If they'd have made this lens with an EF mount, I'd have probably bought one (and I own a 20D).

 

I think Canon has unwisely chosen to lose a significant amount of target opportunity with the EF-S 60 macro, in what is apparently (to me) a misguided effort to bolster the EF-S line.

[bobatkins]

The 60mm EF-S macro is evidently a way to give EF-S lens users something that acts (from the FOV viewpoint) like the "traditional" 100mm macro on full frame cameras.

 

I don't really know whey they made it EF-S. Might have made more sense to make it EF, since the EF 50 macro isn't USM and only goes to 2:1, not 1:1, so there could be a market for an EF 50/2.8 macro USM or EF60/2.8 macro USM that goes to 1:1.

 

It's certainly not EF-S to make it cheaper, since it's the same price as the EF 100/2.8 macro USM (around $450), though it is about 1/2 the weight. On the other hand the 50/2.5 macro is even lighter and only 1/2 the cost (if you don't mind not having 1:1).

[jon_austin]

Good evening, Dr. Atkins!

 

I concur that the marketing behind the 60mm EF-S macro is intended "to give EF-S lens users something that acts (from the FOV viewpoint) like the "traditional" 100mm macro on full frame cameras."

 

And I already own the excellent 50mm AFD compact macro you mention.

 

My guess is that if they had made the new 60mm USM Macro an EF mount, they could have priced it lower in anticipation of leveraging the sales potential of the entire base of EOS owners, instead of the limited market of EF-S mount owners.

 

Sooner or later, all those dRebel and 20D owners are going to have to figure out that they're not restricted to buying EF-S lenses only!

[robin_sibson1]

Whilst I am sure that the comments about the pointlessness of EF-S long lenses are correct, there are probably good reasons why the new 60/2.8 macro is an EF-S: possibly it exploits the availability of a shorter distance between the rear element and the focal plane, but I would have thought the most likely reason was that it exploits the smaller image circle that is all that the APS-sized sensor requires. Making a full-frame 60mm lens that focuses to x1, and meets the very demanding sharpness, flatness-of-field and freedom-from-distortion standards required for a true macro lens is perfectly feasible, but perhaps not with an IF approach to the design, so you would probably have a much bulkier and heavier lens with a linear focusing movement. Which is, after all, how the 50/2.5 is designed, but by limiting its native focusing range to x0.5 Canon have kept down the weight and bulk.

[matt_sallis]

Pete,

 

Great News! You can already get a fixed (nearly) 500mm f2.8 for your 10D (or 20D) (assuming your talking about equivalent field of view to 35mm film) and it doesn't need a new mount.

 

It currently has 'Canon 300mm f2.8L IS' printed on it and it's a stunning performer. It's a lot smaller, lighter and a stop faster than a 500mm f4, but when mounted on a 10D or 20D has the equivalent FOV to 480mm. That 1.6 crop is a beauty for wildlife isn't it!

 

Cheers,

Matt

[mark u]

...only if Canon make an EF-S only mount DSLR.

[isaac sibson]

Which is physically impossible as EF lenses will always fit onto an EF-S mount.

 

Additionally, the biggest market for super-teles is professional. These guys are using EOS 1D series bodies to a large extent, particularly for sports (where you see forests of Great White Lenses). These cameras aren't EF-S, so it is unlikely canon would produce an EF-S lens for this market when there is no technical advantage over EF.

[jim_larson1]

<i>Whilst I am sure that the comments about the pointlessness of EF-S long lenses are correct, there are probably good reasons why the new 60/2.8 macro is an EF-S: possibly it exploits the availability of a shorter distance between the rear element and the focal plane, but I would have thought the most likely reason was that it exploits the smaller image circle that is all that the APS-sized sensor requires.</i>

<p>

It may be more of a matter of exploiting a percieved market niche. . .if the 100/2.8 is their most popular EF prime. . .then presumably 60/2.8 EF-S sales will be huge. . .and if the 100/2.8 can sell for $450. . then that is a logical price for the 60/2.8 EF-S. <p>

It is, after all, made for digital. It's better.

<p>

My prediction for next lens release: 55-200/EF-S IS for $450. (EF-S equivilent of the $425 75-300/IS)

[vincent_j_m]

Going by the pricing of the 17-85 IS, the above mentioned EF-S lens is going to be more expensive. After all, if it's digital and EF-S it has to be more expensive than the now obsolete non digital stuff right?

[peter_phan]

<i>will canon (or others) go the way of ef-s lenses (i.e. smaller image circle lenses) in the telephoto range like Olympus has started to do? I'd love to see a fixed 500mm lens that is smaller and lighter than the one i lug around now on my 10d.</i>

<p>

The Olympus 300/2.8 lens for their 4/3 system weighs 7.2 lbs, and measures 11.1" long by 5.1" wide. And it costs $6,999.95 (although there is currently a $700 rebate being offered). The Canon 300/2.8L IS lens weighs 6 lbs, and measures 9.9" long by 5" wide. And it only costs $3,899.95. So for the same focal length of lens, 4/3 really has not resulted in a smaller, lighter, or cheaper lens. It's only the high 2X magnification factor of the 4/3 system that gives you the impression that you're getting more for less. Just chop down the Canon's sensor and you get more-or-less them same 4/3 "advantage" in the telephoto range.

[dogbert]

"It's certainly not EF-S to make it cheaper, since it's the same price as the EF 100/2.8 macro USM (around $450)."

 

Many of the above threads seem to suggest that because EF-S lenses are expensive to buy, they must be expensive to make. I think this is a fallacy. Canon's profits have been quite healthy because of the digital revolution, which makes me think there must be a widening of margins between their manufacturing costs and the prices they are charging. That's how companies increase profits!

 

IMO what canon is doing is reducing costs through manufactuirng EF-S lenses while charging as much as they think they can get. After all they are trying to make a profit first and foremost, not necessarily trying to be generous to their customers.

 

Could somebody please explain to me? Doesn't a reduced image circle mean less glass is required in a lens design, and since machining high quality optical glass to make lenses has to be a prime cost consideration (no pun intended) doesn't this mean there would be a big cost advantage in making EF-S lenses. After all the reason 500 mm f4 cost a lot has to be the glass, not the metal casing and electronics that come with it, which must be easy to mass produce.

[bobatkins]

Design costs are the same. You still have to pay the design staff and buy them the same computers and software! Fabrication costs are similar. You still have to grind the lenses, make the body and parts and assemble them.

 

As someone pointed out earlier, a 500/4 lens requires a front element that is at least 125mm in diameter, whether it has a 10mm image circle or a 60mm image circle. The expense in telephoto lenses is the large apochromatic (ED and/or Fluorite) front element(s), not the smaller back elements (which could be slightly smaller in lenses with reduced coverage).

 

So unless you need short back focus (wideangle lenses), EF-S has pretty minimal advantage. Even there the practical advantage is somewhat questionable.

[dogbert]

"My prediction for next lens release: 55-200/EF-S IS for $450. (EF-S equivilent of the $425 75-300/IS)"

 

Actually that is one lens I would like to see. A 70-210 f3.5-4.5 IS USM with good optics (say simmilar to the 28-135). If it retailed for the same price as the 75-300 Canon would be on to a winner, but if the optics were no better then there would be no point. Might as well go for the 75-300 IS.

[terry_gatenby1]

I seem to remember Chuck Westfall (a canon rep) commenting on another forum that EF `s` was ineffective on focal lengths greater than about 40mm (around the time of the release of the first EFs - the 18-55mm rebel kit lens), regards T.

[bobatkins]

That is true. The EOS system has a 44mm spacing between the lens mount and the sensor/film. Lenses having longer focal lengths don't need to be retrofocus designs and therefore can't benefit from having the rear elelemnt closer to the film.

 

In fact I'd bet that lenses longer than maybe 24mm don't benefit either since mild retrofocus designs are easy and good.

 

Where it SHOULD benefit most is in the construction of really short fl lenses like the 10-22. However Tokina seem to have managed to make a decent 12-24 without EF-S and Tamron (any day now....) will be releasing their 11-18 in standard EF mount. If the only thing that EF-S delivers is the ability to make a 10mm lens rather than an 11mm or 12mm, I can't say I'd consider it worth the trouble. Since I haven't tested any of the superwides, I can't comment on relative optical performance.

[digitmstr]

There is no reason (or benefit) to make teles or super-teles in EF mount. The *only* reason that mount was created is to make wide and super-wide angle lenses for the 1.6 sensor.

[jim_larson1]

Wait. . I am confused. . .so why is the 60/2.8 Macro not a standard EF lens?

 

If you don't NEED the short backfocus to make it work. . if the design/development costs are really the same. . .and the material costs virtually irrelevant. . .why EF-S?

 

The 60/EF-S makes me go out and buy a 85/1.8 before they are discontinued!

[jon_austin]

Jim: Thanks for reiterating my question. (I never did read a satisfactory answer.)

[pete_biro]

Aaahhh, no i see! It only benefits the wides ... thanks v much to all! Well, it could benefit teles but only slightly as pointed out by bob.

[mark u]

I guess Isaac had more success than I did mounting a lens by aligning the red dot on an EF lens with the white dot on an EF/EF-S mount DSLR body. He also ignores the possibility that an EF-S only DSLR might contain circuitry that refuses to recognise anything other than an EF-S lens - hardly new technology for Canon to do that -just ask Sigma and Tokina.