tom_m2

The more choices you have in lenses, the more potential shots you get. However, personally, I never found very wide angle lenses particularly useful for landscapes.

 

In any case, the 17-85 will go significantly wider and is quite sharp. The 10-22 is even better and wider. I think for outdoors, those are excellent choices. The fixed focal length lenses are more useful for interior shots, where you need the extra f-stops.

I have both of them (well, the F10, but pretty much the same thing), and they are both great cameras. You can (roughly) think of the A620 as a rangefinder loaded with Velvia, and the Fuji F10/F11 as a P&S loaded with ISO 400 negative film.

 

If you're using an F70 with slide film, the A620 is probably close to what you're used to. However, the real replacement for an N70, and something that give you more versatility than either, is something like a digital Rebel XT.

I think for a walk-around lens, the 17-85 is probably a better choice than the 17-40L, because of weight, zoom range, price, and IS. The image quality of the 17-85 is very good and has never been an issue for me (I don't have the 17-40L, but I do have a bunch of prime lenses).

 

OTOH, if price and weight are no obstacles, you might as well get a 5D with prime lenses...

If you can spend the money for a 5D, then you are financially well off enough that you don't have to worry about what's going to happen in a few years.

 

Otherwise, the point is moot: just go with an APS sensor. A 20D (or even cheaper) a Rebel XT should be a nice backup body in any case.

The optical limit for 35mm sensors seems to be somewhere around 20-30Mpixels; roughly speaking, you just can't focus a spot smaller than that.

 

However, keep in mind that a 20 Mpixel camera doesn't actually have true 20 Mpixel resolution because it has three different color sensors; the actual RGB values at each pixel are interpolated.

 

Therefore, whatever the optical limit is, it makes sense to increase sensor resolution to about 3-4 times that because only then do you get full RGB information at each pixel.

I fail to understand this obsession with resolution: resolution is only one of many image properties and in many cases not the most important one. Once it's good enough to make sharp 8x10's, you're in the green for most applications. Anything beyond that is less related to image quality and more to conveniences like cropping.

 

The 5D is a full-frame camera; even if it had no resolution advantage over the 20D or Rebel, it would still be worth it just for the wide angle coverage. The 5D also has better AF performance and better low-light performance.

Yes: you should carefully consider for yourself why you want to switch. If you can't come up with good reasons, then save yourself the time and money and stay with Nikon.

 

What might be reasons to switch? You might need a specific TS-E or DO lens, or you might want a full-frame digital sensor.

 

What are reasons not to switch? You may be more satisfied with Nikon's exposure and autofocus systems, or there may be specific lenses in the Nikon system that you can't find an equivalent for in Canon's system.

The short answer is that Photoshop will probably do whatever you need, but so will dozens of other programs. Photoshop's disadvantages are its complexity, its user interface, and its price. My recommendation would be to start off with something simpler and get Photoshop only if you really need it. There are lots of free choices that are perfectly fine.

 

Personally, I'm of the opinion that most photographic images should not require editing at all to be publishable: just expose, focus, and frame right from the start and you'll save yourself a lot of work fiddling around on the computer.

About Henrik's Sigma 30mm/1.4 comparison, before you rush out and buy a Sigma, be sure to test it. I have tried 5 different instances of the Sigma lenses at different dealers, and I have been unable to find any that is even remotely close to that kind of performance. The Sigma also gives inconsistent focus on the Rebel XT.

 

Oh, and the Sigma doesn't provide full frame coverage, so you can't really use it with 35mm film.

"Take a sharp prime with as few elements a possible to maximize contrast and color, like a Tessar, and do your zooming at home in PhotoShop.

 

Good advice, except it's utterly useless. The only wide angle primes for the 20D are the 14mm and the 20mm. The former is outrageously expensive, and the latter is no better than the 10-22.

I think the 1.6x bodies are a feature; if they didn't exist, they'd have to be invented: they are smaller, lighter, permit smaller and lighter lenses, and give you a teleconversion factor. I'm going to be carrying one for a long time, in addition to a FF camera.

Let me second the recommendation for the Canon EF-S 10-22; it's a great lens, and it's a bit lighter and smaller than anything like it on a FF system.

The Sigma 24/1.8 is a brick, but the image quality is pretty good. The 24/2.8 is a compact and sharp lens, but it's a bit noisy. The 20/2.8 is quiet but big.

The 17-85 IS USM is a good, general purpose lens.

 

Beyond that, it depends on what you need.

 

A 35/2 or 50/1.4 will cover low light and shallow DOF.

 

The 10-22 USM is a great wide angle lens.

 

A 70-300 IS USM is a decent general purpose telephoto; I think in most situations, the IS is more important than the "L" quality. But if you mostly shoot from a tripod, the "L" may be better for you.

Here is a good comparison:

 

http://www.bobatkins.com/photography/digital/eos_digital_rebel_xt_vs_20d.html

 

Whether the differences matter to you, you have to decide for yourself based on your shooting style.

 

The only differences that mattered to me were the slightly better focus performance on the 20D vs. the lighter weight on the XT. The weight won out as far as I'm concerned. In particular, with a 24/2.8 or 50/1.4, the XT is small and unobtrusive, which is important to me.

As far as I remember, Olympus lenses communicate geometric distortion and vignetting information to the body, which can then correct the image. That means that they have a lot more design freedom in their lenses, since they don't need to worry (as much) about correcting those defects optically.

 

Canon can't do that for the L lenses, since those are also used with film. And they don't seem to bother doing it for the EF-S lenses (maybe there are patent problems, although that would seem silly, given that people have been doing the same sort of corrections on the desktop for a long time).

Nikon could have my business if they made a good set of prime lenses for APS sensors; in particular, I would like the equivalent of a 20/2.8, 28/2, and 50/1.4, at a reasonable size, reasonable cost, and stellar performance. Until they do, they don't seem fully committed to APS. Canon's FF sensors give me a sensible range of primes to work with.

I'd take the Canon 17-85 IS instead of the Tamron; you need the wide angle end, and the IS is really worth it, more than the 1-2 extra stops. If you need separation, carry a 50/1.8 (also good for backup).

 

I can't imagine 1G being enough; I go through 4G a day on a trip, and that's not even shooting raw. I'd recommend at least two 1G cards and disk storage or a laptop.

"Unless you want photo's the size of a house what stage do you stop increasing the camera's pixels?"

 

Lots of reasons. One important one is cropping--I like taking wide shots and then cropping on the computer. Another is post-processing. Perspective correction, for example, effectively loses pixels. It's easy to end up with a 2 Mpixel image from an 8 Mpixel camera.

 

Also, your 8 Mpixel camera is effectively only about 3 Mpixel, since color information is interpolated. A 22 Mpixel camera would finally give you around 8 Mpixel true resolution.

I think the simple answer is that, no, you won't be worse off using a higher pixel count at the equivalent focal length. Think of it this way: you can simply scale down you 16 Mpixel image to 8 Mpixel after the fact.

 

But the long answer is that it may matter to some degree. FF sensors have lower DOF at equivalent focal lenghts, which means that you may need a longer exposure. OTOH, FF sensors also give you less noise at high ISO, so that you may be able to capture at ISO 3200 instead of 800, reducing shake.

"And, what is the secret to the Zeiss wides that proves to yield better results in corner resolution and CA. I don't understand why Canon can't simply adapt the same technology from decades ago."

 

They have. That's why modern primes from Canon and Nikon are usually as good as Leica and Zeiss. To the degree that there are differences remaining, they are due to intrinsic factors, like SLR vs. rangefinder, film vs. digital, etc.

"That is how they design their lenses and make money from us"

 

It's called engineering tradeoffs. If they try to pack everything into one lens, price and weight get too high to be marketable.

 

There are some lenses that arguably make the wrong tradeoff. For example, the 28/1.8 ought to be optically better and it would be perfectly fine for it to be somewhat larger in return. I wouldn't go so far as to claim that that is some deliberate attempt at maximizing profit; the lack of a good 28/1.8 or 28/2 probably costs Canon a little in sales.

"The 20D has less noise at high ISO."

 

I haven't observed this. Do you have any evidence for that? And even if it were true, is it due to noise reduction algorithms or actual differences in the sensor?

 

I have to say, I greatly prefer the XT due to its smaller size. When I do need a firmer grip on the camera, then the XT with battery grip is still preferable to me to a 20D (with or without grip).

If you put the 28-105 lens on the 20D and on the XT, and you get soft images out of the 20D and crisp images out of the XT, then there is a technical problem either with the lens or with the body.

 

If all you are observing is that you are getting crisp images with the 28-105 on a full frame film camera and soft images on the 20D when you look at the pixels 1:1, then that's not all that surprising: the 20D demands higher resolution from a lens. That's why good digital lenses for 1.6x bodies tend to be not much smaller than equivalent good film lenses--it's hard to build good lenses for digital.

 

I wouldn't use the 28-105 on a 20D; it's not a convenient zoom range, and it's not a great lens even on film, so I would expect it to be worse on digital.

"Bigger pixels or not, you're utilizing the full coverage of the lens, and most lenses perform better in the center than in the corner"

 

Which is what I was saying.

 

However, with digital, these things are a whole different ballgame. In particular, neither vignetting nor distortion matter much because they can be corrected automatically. Furthermore, with the extra pixels of the 5D, you can place the subject near the center all the time, crop later for the composition, and still have roughly the same pixel count as the 20D. Given the awkward AF sensors on all Canon bodies and the extra flexibility, that sort of approach has its own appeal.

 

Realistically, none of the reaosnable Canon lenses have such drastic differences in corner and center performance that this is anything to worry about. I think you are pretty much always better off with a 5D in terms of quality. Its major disadvantages are price and weight.