# Canon EF 800mm f/5.6 DO IS in Development? [CR2]



## Canon Rumors Guy (Aug 11, 2015)

```
When Canon updated the EF 400mm f/4 DO IS with a verison II, most felt that was a good sign they were still developing DO technology and lenses and we could see more added to the EF lineup.</p>
<p>An update to the EF 800mm f/5.6L IS has been mentioned ever since the new EF 600mm f/4L IS II was announced back in 2011, though nothing has come to market as of yet. Such a lens is a low volume proposition, and there are a lot of other areas Canon can make money on lenses.</p>
<p>I’ve seen talk on forums recently about an 800 DO and whether or not folks would buy one, and at what cost.</p>
<p>We’re told after a lengthy conversation that Canon is indeed continuing to develop DO super telephoto lenses and that 800mm is one of the optical designs. We’ve seen <a href="http://www.canonrumors.com/2012/07/patents-ef-600-f5-6-do-800-f5-6-do/" target="_blank">patents in the past showing an optical design for an 800mm f/5.6 DO IS</a>.</p>
<p>I got the feeling that any replacement of the 800mm f/5.6L IS would be DO. What would it cost? I’d say somewhere between $15,000-$20,000USD.</p>
<p>Nothing is imminent, but it was a good conversation.</p>
```


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## Chaitanya (Aug 11, 2015)

I would prefer non DO 500 f5.6 or 400 f4 foron budget birding.


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## RGF (Aug 11, 2015)

The great 100-400 II makes the 200-400 less desirable. That means I need a longer lens. 600 is ideal but the current non-DO 600 II is rather large and heavy. A 600 DO would be more useful to me than an 800 DO.


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## dufflover (Aug 11, 2015)

Chaitanya said:


> I would prefer non DO 500 f5.6 or 400 f4 foron budget birding.



Relative budget 
For Canon anything that is bigger than 77mm/82mm is basically in that $5k+++++ super-telephoto price range.

I'd love Sigma to revamp their supertele prime lines with some of their new-found gusto and design processes. Just so there's an alternative to these. I find my Sigma 120-300 OS with a 1.4x to be quite decent (at f/4.5) but there's definitely room to still improve on it.


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## LonelyBoy (Aug 11, 2015)

dufflover said:


> Relative budget
> For Canon anything that is bigger than 77mm/82mm is basically in that $5k+++++ super-telephoto price range.
> 
> I'd love Sigma to revamp their supertele prime lines with some of their new-found gusto and design processes. Just so there's an alternative to these. I find my Sigma 120-300 OS with a 1.4x to be quite decent (at f/4.5) but there's definitely room to still improve on it.



I think Sigma would only do that if they can severely undercut Canon on price - the tepid response to their 24-105A (relative to the 50A, for example) indicates that in a head-to-head people will almost always choose the Canon. Their better success is by being where Canon isn't (the 50A and 18-35A especially) and offering great options there.


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## GMCPhotographics (Aug 11, 2015)

This is a really smart idea from Canon. The 400mm f2.8 LIS II with a mkIII 2xTC is pretty much as sharp, but the AF is a little sluggish in comparison. It's darn light (comparitively too). The 600mm f4 LIS II with a mkIII 1.4xTC is again, just as sharp and the AF is pretty close in terms of speed and accuracy. It's lighter and cheaper too. So one has to wonder what a native 800mm f5.6 could offer over the other two options? DO is the answer. Make it a lot lighter and a lot shorter and it could in theory be a little bit longer than the native 400 f2.8. If it's as light, I recon that it'll find itself into a number of pro line ups. Imagine this with a 1.4x TC on a 7DII! That's an effective 1800mm focal length.


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## Pixel (Aug 11, 2015)

RGF said:


> The great 100-400 II makes the 200-400 less desirable.


Speak for yourself on that.


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## Pitbullo (Aug 11, 2015)

It may be a stupid question, but what is DO design compared to non-DO?


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## NancyP (Aug 11, 2015)

Darn that G.A.S! It is fun to ogle the goods, though, rather like "lifestyles of the rich and famous". 

DO = diffractive optics = basically, a Fresnel lens component in the design, reducing weight greatly.


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## Pitbullo (Aug 11, 2015)

Thank you very much!


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## 9VIII (Aug 11, 2015)

Some people might still prefer a 600f4DO, and I'm sure it's coming, but the current 800 is older.

I was taking pictures of my niece on horseback with a Samyang 800mm Mirror lens this weekend, on crop. That 1280mm framing was just about perfect from about 60 meters back, a distance you'd still be lucky to catch a moose at.
Not that it never happens, but it's rare enough, and you don't really want to get closer to some animals.
Now if only they can give it at least .2x Maximum Magnification too, 800mm would probably be perfect for getting macro shots without bending over.


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## seattlebirdman (Aug 11, 2015)

It doesn't seem like DO technology would make it much lighter than their regular materials. 

I did a comparison of the 400DO II to the 300 2.8 II with a 1.4 extender. Because the 300 with extender gives you 5% more focal length that is equal to another 12% more glass added to the 400 DO II. This would mean DO technology only saves at most 9% weight. Assumption being if Canon made a 420mm f4 it would weight at or less than what a 300 2.8 II plus and 1.4 Extender weighs.

Now if we extend this logic and use the weight of the 600 f4 as a base then a new 800 f5.6 (regular technology) would likely weight in right at 8 pounds. A DO version of this might be 7lb 4 ounces.


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## Hesbehindyou (Aug 11, 2015)

800 DO makes sense - it's yet another lens that gives Canon something no other companies can. This is the sort of thing that keeps (a small section of) professional photogs in the Canon camp.

A few thoughts on other points made:

A poster mentioned only modest savings in weight; the shorter length is also a big asset, especially if it makes the difference between carry on or hold.

Yet another poster mentioned they'd prefer a much more modestly priced lens in a shorter focal length. I read this as low-volume, low-margin. Canon would much prefer high-margin on their low volume products 

Finally, a third poster wanted Sigma to re-do their super-teles using the same class leading/equalling processes they've used on their recent releases. Unfortunately the exceptionally shallow depth of field with sharp drop off into out of focus areas that long focal length lenses produce means Sigma may wish to hold off until they've nailed the autofocus. Bigger reasons for Sigma not producing a new range of super teles are:
- Super teles don't lend themselves to mass production methods in the same way lenses with smaller elements do. This, coupled with being relatively low volume items means competing on price becomes harder (harder to get economies of scale coupled with less 'scale').
- Given relatively limited resources, Sigma would probably target higher growth areas. Given smaller-sensor cameras with adequate image quality, full frame super telephotos cease to become a sensible option in many shooting scenarios (both on cost and size/weight grounds). Alternative to full frame telephotos will get better over time, and in a market that could well start shrinking.
- A range of professional telephoto lenses has the hidden costs of servicing support above and beyond smaller lenses... this would be a substantial and on-going cost.


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## RGF (Aug 11, 2015)

Pixel said:


> RGF said:
> 
> 
> > The great 100-400 II makes the 200-400 less desirable.
> ...



I did. You could say the 200-400 makes the 100-400 II less desirable.

Point is both are great lenses and there is a lot of overlap. 

1Dx + 100-400 and 7D II + 200-400 makes a great combination.

1Dx + 100-400 and 1Dx + 600 DO (future lens) is another great combo and perhaps even better ?


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## wopbv4 (Aug 11, 2015)

Hesbehindyou said:


> 800 DO makes sense - it's yet another lens that gives Canon something no other companies can. This is the sort of thing that keeps (a small section of) professional photogs in the Canon camp.
> 
> A few thoughts on other points made:
> 
> ...


I agree with most of the above.
I have the 400 DO f4 II. Serial number 0000044, so there are two options; either I was very keen to buy this lens or they just do not sell many of these lenses.
Main reason why I bought the DO over the F2.8 was that I wanted a lens that I can hold handheld. Yes, weight is important, but also where that weight "sits". The DO is is about the same size and weight as a 70-200 F2.8 II and it feels the same, just slightly heavier. The DO on a 1DX is perfectly balanced weight wise. I can easily handheld this lens for an afternoon.
I just wonder what the main advantage would be for an 800 mm DO? It will need support, tripod, bean bag.., so all the palaver about weight, length is secondary to IQ.
I noticed on my 400 DO that chromatic aberration is negligible, it might be intrinsic to the design?


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## [email protected] (Aug 11, 2015)

._.. a third poster wanted Sigma to re-do their super-teles using the same class leading/equalling processes they've used on their recent releases. Unfortunately the exceptionally shallow depth of field with sharp drop off into out of focus areas that long focal length lenses produce means Sigma may wish to hold off until they've nailed the autofocus. 
_

I'm less worried about that with Sigma. I have three of their lenses, and I used the dock on all three and feel they focus better than my L glass afterward, although not as quickly. Using the dock on a zoom is a lengthy, painful process, with the possibility of error coming in due to tedium. But the process with primes is quick and easy, IMO.



_- Super teles don't lend themselves to mass production methods in the same way lenses with smaller elements do. This, coupled with being relatively low volume items means competing on price becomes harder (harder to get economies of scale coupled with less 'scale').
_

A related point: the greater the percentage of the manufacturing cost of a lens that is the glass elements leaves less and less margin possibilities as the lens gets bigger. When they're growing crystals to become lens elements - or buying them in - they have fixed costs and cannot magically buy or create such commodities at half price. 


_- Given relatively limited resources, Sigma would probably target higher growth areas. Given smaller-sensor cameras with adequate image quality, full frame super telephotos cease to become a sensible option in many shooting scenarios (both on cost and size/weight grounds). Alternative to full frame telephotos will get better over time, and in a market that could well start shrinking.
_

I think that might be a misreading of what the new Sigma is all about. The new CEO (son of old) is just as monomaniacal about keeping their manufacturing in their hometown. But he is building the business not on volume, but rather higher margin products. They do not want to offshore production again and go back to the old Sigma. That means that they need to focus on higher end lenses to get the most value for their manufacturing capacity, which will grow only relatively slowly. Yes, these lenses might be 1/2 the price of a Canon equivalent, but they're not competing on price. 

They have a system where they retool lines every few months to make batches of various higher-end lenses. I think this is well suited to the supertelephoto lenses. 

It is also true that they are interested in the smaller ILC camera systems, but largely (so far) to leverage their existing designs. If the little cameras wind up being a large portion of their production, then I could see the supertelephotos taking a back seat, as they'll be less desirable to that market. But that hasn't even started to happen. 

Sigma makes a big deal about doing lens designs in categories that others have not already done. As a result, I could see them jumping on a 600 f/5.6. (Nikkor and Pentax used to have versions of that back in the stone ages.) All they'd need to show is that it's better IQ than the 150-600 zooms at 600 (not hard) and has IQ within 95 percent of the 600mm F/4 IS II (rather harder). They would likely price that at $2k.


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## Steve (Aug 11, 2015)

wopbv4 said:


> I just wonder what the main advantage would be for an 800 mm DO? It will need support, tripod, bean bag.., so all the palaver about weight, length is secondary to IQ.



A modern update of the 800mm, assuming the same amount weight savings that the 500mm and 600mm updates got, would be around 7-7.5lbs which is easily handholdable. A DO version would be even lighter, shorter and more portable. I could see how a lot of people would be interested in a sub-7lb 800mm lens that (might) fit in airplane overhead storage. It might actually make the 800mm f5.6 useful because, as it stands now, I can't see any reason why anyone would shell out that kind of money when the 600mm with a 1.4 TC is just as good (if not better)with more flexibility and a bit more reach. Making the 800mm significantly more portable would give it a reason to exist.


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## Mt Spokane Photography (Aug 12, 2015)

Pitbullo said:


> It may be a stupid question, but what is DO design compared to non-DO?



Its pretty easy to google this, the subject is pretty difficult to explain in detail. Canon's recent DO patent used in the new 400mm DO uses two DO surfaces which are bonded to regular lens elements and placed very close together. It works better than the traditional DO method of designing a lens.

Basically, Diffractive Optical lenses can successfully bend light more sharply than glass lenses. This means a lens can be made shorter. A shorter lens weighs less. Diameter is not going to become smaller, it might even get larger. This is a over simplification, but you get the general idea.


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## Kestrel (Aug 12, 2015)

An 800mm f5.6 will still require a 6" diameter objective lens, so this will still be a large lens overall. The main advantage will be in shorter overall length, with some nominal weight savings (perhaps 2 lbs over the current 800, so this lens might be in the neighborhood of 8 lbs). 

For sure this 2 pounds weight savings will come at a high cost!


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## chromophore (Aug 12, 2015)

Mt Spokane Photography said:


> Pitbullo said:
> 
> 
> > It may be a stupid question, but what is DO design compared to non-DO?
> ...



Something worth noting is that the thing about diffractive optics that makes it especially appealing to use at long focal lengths has as much to do with its inverted dispersion characteristics, and not merely its refractive power.

What I mean by this is that yes, a diffractive lens element can achieve greater weight reduction for a given refractive power, much in the way that a Fresnel lens element is less massive than an equivalent smooth convex lens of the same material. This facilitates the placement of a diffractive element with higher net refractive power in the optical path without requiring a lens of higher curvature.

But if this were the only part of the story, then why not simply use a material with higher refractive index? The answer is because of the adverse effect on dispersion, which typically increases with refractive index, and becomes increasingly hard to control as a function of focal length.

Dispersion, as one may recall, is the variation of refractive index as a function of wavelength. A lens with high dispersion will exhibit a greater difference in the angle of refraction of red light compared to violet light; whereas a lens with low dispersion will show a smaller difference. The creation of a rainbow by refracting white light through a prism is the dispersion phenomenon in effect.

Dispersion obviously creates problems for panchromatic lens design because the difference in refractive indices will result in chromatic aberration, which can be broadly classified into two coexisting types:

Axial: the plane of sharpest focus varies with wavelength.
Lateral: the focal length (image magnification) varies with wavelength.

In practice, every properly designed lens exhibits some combination of the two simultaneously. In lenses with particularly fast apertures, axial color predominates because the depth of field is so small, allowing the observer to see the effect (which is why it disappears when stopped down). But in lenses with long focal lengths, the latter predominates, and it is independent of f-number.

The correction of dispersion is accomplished by using glass of different refractive indices in different power combinations, thus allowing the partial compensation at the extremes of the spectrum. Further correction (apochromatic design) is accomplished by introducing materials with anomalous dispersion--in particular, fluorite, which not only has low dispersion, but its distribution of dispersion is different than other glasses (a detailed explanation is available for those who are interested).

However, the problem with fluorite is that the refractive power is low. So you'd have to use a lot of it--which is expensive--to achieve good correction for long focal lengths, which is why the EF 800/5.6L IS was designed with two large-diameter fluorite elements.

So back to DO. Why use DO? The reason is that while most glass (and fluorite) have dispersion characteristics such that index of refraction decreases with increasing wavelength (red light is bent less than violet), a DO lens is the reverse: red light is bent MORE than violet. This is a gift: because of this inversion, a DO lens can be simultaneously used to increase refractive power (shortening the barrel and reducing element mass), but it also facilitates this to the benefit of correcting CA. You end up using less fluorite (see the EF 400/4L DO IS design), and yet you get apochromatic performance. It's a win-win.

Well, not really. Nothing in lens design comes for free. The problem with DO is that manufacturing tolerances have to be extraordinarily tight, and even then, there is increased potential for reduced contrast and increased flare. Canon, to their credit, has done a remarkable job of mitigating these downsides through refinements in their manufacturing processes. But DO is always going to be a more expensive technology compared to traditional glass.

Anyway, that is the super-long, most-of-the-gory-details explanation. It's a combination of dispersion and refractive power that comprises the appeal of diffractive optics. It's almost uniquely suited to long focal length designs.


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## 9VIII (Aug 12, 2015)

Hesbehindyou said:


> ...the shorter length is also a big asset, especially if it makes the difference between carry on or hold...



I want to say that if they could make an 800mm lens 15" long, they would have a lot of people lining up for that lens.
But that's probably asking a lot. A lot a lot, the 400DO only cuts half an inch off vs. the 300f2.8, which is virtually the same comparison.
So maybe the 800DO would be 17" (currently 18").

The next big question in my mind is how small can they make a 600DO? Basically as far as I'm concerned anything longer than 500mm that fits into the same size category as the 500f4 is the next big lens to have...
Unless they start throwing around built in TC's too, make people choose between an ultralight 600DO and heavier 500+TC (or a 400f2.8+2XTC, now that would drive people up the wall).


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## candc (Aug 12, 2015)

You can't really compare a longer fl lens with a shorter one +tc for length. They don't design lenses that way. If you look at this diagram of the 400do compared to a standard 400 then you see its a substantial length reduction. That same 26% reduction combined with series ii materials would make for a fantastic update to the 800.


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## 9VIII (Aug 12, 2015)

Oh crap, now I'm imagining what a 600f5.6DO would look like.
The 400f5.6 is already 20% shorter than a regular 400f4, I wonder how much DO would compound with the smaller aperture?

Edit: Hmm, actually it might not be much different from the 300f2.8+2XTC, probably just a little lighter and a little shorter, so it's mostly still about returning top AF performance.


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## dolina (Aug 12, 2015)

Where's the 1200mm 5.6 DO?


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## C_Raven (Aug 12, 2015)

As someone said, Sigma should offer lens designs in categories that others have not already done. What about supertelephoto lenses for APS-C cameras? Could they be cheaper relative to full-frame lenses?


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## FEBS (Aug 12, 2015)

RGF said:


> Pixel said:
> 
> 
> > RGF said:
> ...



+1 about the 100-400II and the 200-400

For my safari in September (Uganda, also rain forest) I'm still doubting between

1Dx + 100-400II or 1Dx + 300 2.8ii and if needed with 1.4x
the other camera is fixed (1Dx + 600 ii + 1.4x)

The 200-400 will stay at home at that moment


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## Deleted member 91053 (Aug 12, 2015)

Steve said:


> I can't see any reason why anyone would shell out that kind of money when the 600mm with a 1.4 TC is just as good (if not better)with more flexibility and a bit more reach. Making the 800mm significantly more portable would give it a reason to exist.



If you live anywhere near South Wales I will be happy to demonstrate the existing Canon 800mm's "reason to exist". I use it FAR more than I ever used my 600.
Naturally you are welcome to use your own camera and it is quite practical to handhold for short (ish) periods. As to the 600 Mk2 + a 1.4, the pundits on the web tell me that it is as good or better than the 800. Well I don't know what testing they were using but I can assure you from personal experience that it is simply not! Without the extender the 600 Mk2 is a better (but shorter) lens, with the 1.4 Mk2 or 3 (various samples tried) it is very, very good but not as good as the bare 800.

Now if Canon could bring out an 800 DO at 3.5 Kilos or less then I will be in the queue! They can't make huge weight savings over the current model as it is already halfway to a Mk2 lens, but with DO optics it could get VERY interesting.


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## Hesbehindyou (Aug 12, 2015)

C_Raven said:


> As someone said, Sigma should offer lens designs in categories that others have not already done. What about supertelephoto lenses for APS-C cameras? Could they be cheaper relative to full-frame lenses?



I read somewhere that the size advantage of EF-S vs EF lenses diminishes with lengthening focal lengths, with 300mm being around the point at which sizes get equal. I'm just parroting info here - I'm sure someone will step in with actual knowledge on this.

Anyone?


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## chromophore (Aug 12, 2015)

Hesbehindyou said:


> C_Raven said:
> 
> 
> > As someone said, Sigma should offer lens designs in categories that others have not already done. What about supertelephoto lenses for APS-C cameras? Could they be cheaper relative to full-frame lenses?
> ...



If an EF-S lens and EF lens have the same numerical focal length (i.e., at infinity focus, both lenses project the same image, irrespective of the sensor size), then the only design issue that affects size is that the smaller mirror box for APS-C format cameras permits an EF-S lens to be designed with a shorter back focus distance. However, this only affects wide-angle lenses. Anything longer than around, say, 40 mm, would not have the back focus distance be a significant design constraint.

If, however, we consider the effect of a smaller sensor--that is to say, we compare EF-S lenses against EF lenses with an equivalent field of view as captured by their respective sensors, then there is a substantial difference at virtually all focal lengths, since in effect, an EF-S lens at 100 mm would be "focal-length equivalent" to an EF lens at 160 mm; and at 400 mm, equivalent to 640 mm. So if you care only about light-gathering ability and sensor field of view (and no other issues like noise or depth of field), then a 400/5.6 mounted to an APS-C DSLR would be comparable to a 640/5.6 on an "full-frame" DSLR.

But then factoring in noise and depth of field, the picture gets complicated again, and the size/weight advantage of EF-S is not so clear. The takeaway is that there is no hard and fast rule. There are tradeoffs and advantages, depending on how you look at it.


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## Hector1970 (Aug 13, 2015)

I was curious is any one know who comes up with the new improved designs in optics in Canon.
Is it old guys who have been working on these lens for 40 years or is it new young designers with new ideas and up to date on new technology.
It must be getting to the point in technology that it would take ages to learn all the previous advances and current designs with such knowledge as how to improve upon it.
When I got my first PC in 1982 A Sinclair Spectrum you had a fair idea of what was inside one and how it worked.
The same with Camera's previously they were mechanical and you could see how it worked.
Nowadays 99.999% of young people have no idea what's in a laptop or ipad or iphone actually works or what's inside it. There must be so few people in the world who could improve on the current designs on camera lens.


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## chromophore (Aug 13, 2015)

Hector1970 said:


> I was curious is any one know who comes up with the new improved designs in optics in Canon.
> Is it old guys who have been working on these lens for 40 years or is it new young designers with new ideas and up to date on new technology.
> It must be getting to the point in technology that it would take ages to learn all the previous advances and current designs with such knowledge as how to improve upon it.
> When I got my first PC in 1982 A Sinclair Spectrum you had a fair idea of what was inside one and how it worked.
> ...



Photographic optics design is certainly more sophisticated than it was decades ago, primarily as a result of massive advances in computing power that have facilitated the modeling and simulation of lenses.

However, the model is only as good as our understanding of the physics underlying the optical system. This then involves concepts from mathematics, physics, and materials science.

The issue is not about the age of people designing lenses; it is more about the amount of research into our understanding of optical physics and the long-term financial benefits. Computers are ubiquitous. Camera systems for large formats are not, and are unlikely to ever be so. And the consequence of this is that far more research and attention is being placed on things like sensor design and optical system design on small scales--that is to say, things that will fit in mobile phones. But even here, the emphasis is on consumer-level performance.

For "large" format lenses (and by "large" I mean anything that is not a point-and-shoot), a big challenge also lies in production: these designs are still primarily manufactured by hand. Certainly there is more automation than in the past, but for the most part, these are handcrafted, especially lenses with large-diameter elements such as those found in supertelephotos. Fluorite crystal, for example, is pretty much polished by hand, individually, by very experienced and discerning technicians. This is nothing like integrated circuit manufacturing, which is done almost entirely by robots, on wafers of silicon--if there is a defect, you might lose one chip out of a hundred; but lenses in comparison are huge. Tiny cameraphone lenses are easy to crank out with extremely small tolerances; DSLR lenses are several orders of magnitude larger, significantly more complex in design, and thus their manufacturing remains dependent on individual craftsmanship.


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## rbr (Aug 16, 2015)

johnf3f said:


> Steve said:
> 
> 
> > I can't see any reason why anyone would shell out that kind of money when the 600mm with a 1.4 TC is just as good (if not better)with more flexibility and a bit more reach. Making the 800mm significantly more portable would give it a reason to exist.
> ...



As another 800mmL owner and fan who used 600mm lenses for years and photographs a lot of small birds in the field, I'll also add that the 800+1.4x is noticeably better than a 600+2x. If you want a 600mm lens then buy one of those . If you buy one and find yourself using it mostly with a 1.4x and 2x, then you're better off with an 800. It's a lot more convenient taking a 1.4x on and off an 800 than having to switch between the two tc's on the 600 and fiddling around with a bunch of lens caps regardless of the optical qualities. By the time you add the weight of the tripod and head along with the camera, the weight difference between the 800 and new 600 is meaningless.


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## Deleted member 91053 (Aug 16, 2015)

Interested in your observations rbr.
Personally I haven't had much luck using extenders with my Canon 800mm. Don't get me wrong I am delighted with the lens it's just that I have been happier using it as a bare lens.
Looks like I need to do a little more testing to make sure that I am getting the full potential of this lens!


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## candc (Aug 17, 2015)

Canon has done a great job developing the "do" lens design. Problem is they don't seem able to produce them in significant numbers. If they can figure out an efficient manufacturing process then l think all the future superteles will be of the "do" design.


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## rbr (Aug 17, 2015)

johnf3f said:


> Interested in your observations rbr.
> Personally I haven't had much luck using extenders with my Canon 800mm. Don't get me wrong I am delighted with the lens it's just that I have been happier using it as a bare lens.
> Looks like I need to do a little more testing to make sure that I am getting the full potential of this lens!



I wouldn't hesitate to use the 1.4x with the 800 assuming you have a camera that offers AF with an effective f8 lens. You may need to do a micro adjust for the focusing differently that with the bare lens. Also heat shimmer can be a bigger problem, so early mornings and late afternoons are best. The light is better then anyway. I've sold literally hundreds of bird photos taken with that combination. The 800 has the same 4 stop IS as all the series II big whites and you can routinely get sharp photos (on a good tripod, of course) down to 1/125 sec. at 1120mm with a still subject if you're careful. Most of the songbird photos I've taken in recent years have been with that combination :

http://roysephotos.com/


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## Deleted member 91053 (Aug 17, 2015)

rbr said:


> johnf3f said:
> 
> 
> > Interested in your observations rbr.
> ...



Thanks for your reply! My camera is the 1DX so AF should not be an issue. I have both the Canon 1.4 and 2 x Mk3 extenders that work very well in my 300 F2.8, so I will have to give them a go again and perhaps do a little focus adjustment. I haven't bothered much with the extenders as I rarely need them - but still handy to have in reserve.
I note your comments regarding the IS, however I have found that the third mode gives me the best and most consistent results. I tried this mode in the first days of 2014 and have used nothing else since. Since then I have switched all three of my IS lenses to this mode and am being rewarded with better images and a noticeably higher hit rate. Now you are probably thinking that I have lost my marbles as there are only 2 modes well there is another mode that works much better and that is OFF.
Thanks for your advice regarding the extenders, I will give them another go, and try disabling your IS for a while. My hit/keeper rate has improved noticeably.


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## Steve (Aug 18, 2015)

johnf3f said:


> If you live anywhere near South Wales I will be happy to demonstrate the existing Canon 800mm's "reason to exist". I use it FAR more than I ever used my 600.
> Naturally you are welcome to use your own camera and it is quite practical to handhold for short (ish) periods. As to the 600 Mk2 + a 1.4, the pundits on the web tell me that it is as good or better than the 800. Well I don't know what testing they were using but I can assure you from personal experience that it is simply not! Without the extender the 600 Mk2 is a better (but shorter) lens, with the 1.4 Mk2 or 3 (various samples tried) it is very, very good but not as good as the bare 800.
> 
> Now if Canon could bring out an 800 DO at 3.5 Kilos or less then I will be in the queue! They can't make huge weight savings over the current model as it is already halfway to a Mk2 lens, but with DO optics it could get VERY interesting.



Ha, thanks! If I was anywhere nearby I'd definitely take you up on that offer. I guess what I was trying to say was that if one had to pick one or the other, I imagine most would go for the 600mm f4 IS II. I know that I would, my friends that shoot birds/wildlife agree and Bryan over at TDP has said as much as well. I've seen many 600 f4 IS II's out in the wild but never the 800. It seems to me that most people are really only going to have the ability to purchase one or the other (if at all!) and the flexibility of the 600 makes more sense. I know that with my Sigma 300-800 I find myself zooming out to frame properly way more often than I thought I would when I bought it and I rarely find myself wishing for more reach (realistically, anyway - atmospheric haze and all that).


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## hendrik-sg (Aug 18, 2015)

May i ask you, why do you use the 1dx with 800 and 1.4x? a 7d (or better 7dii) would have more focal lenght and maybe better AF with the native 80 mm lens? only reason i can see is for more bokeh or faster Frame rate, but i would expext the Frame rate to be handicaped by the autofocus as f8?

For me (with other lenses) the row of focal lenght was 5d2+300 2.8, 50d+300 2.8, 50d+2xiii+300 2.8





rbr said:


> johnf3f said:
> 
> 
> > Interested in your observations rbr.
> ...


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## Deleted member 91053 (Aug 18, 2015)

To hendrik-sg

Firstly the 7D/7D2 will not give more focal length than a 1DX, it will merely give a narrower field of view through the viewfinder and reproduce a smaller part of the area that the lens covers. Additionally the image will need to be enlarged more for printing etc.
The advantage of cameras like the Canon 7D (APSC) series is that they have higher pixel density (or more pixels on target as some say). If, for example, we take the 1DX and 7D they have effectively the same number of pixels but the sensor of the 1DX is about 2.6 times the area so the "Pixel Density" is far lower. In theory this should mean less detail is resolved, in practice it sometimes does - but only by a small margin. The larger (less populated) sensor of the 1DX (and similar cameras) allows the use of far larger pixels which resolve proportionately more detail and have a far wider effective ISO range. The net result is that I may loose some reach compared to a 7D2 (not 7D Mk1) but I gain IQ and versatility.
Having used or owned a number of the Canon APSC cameras (though I have not tested the 7D2 very extensively) I much prefer their full frame cameras for wildlife work. Attaced is an example of a Bittern I photographed last year and a crop of the same image. Please note these are unaltered RAW files just converted to JPEG and scaled for the web - there is no processing/sharpening in PP. As a side note I am not absolutely certain that I would have got this image with another camera as the speed and responsiveness of the 1DX was barely enough - I don't even use IS anymore as it slows things down too much!


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