brainiac wrote:
No. Strangely your telephotos will remain exactly the same focal length. If the pixel pitch is the same then you can just crop off half your full frame happy in the knowledge that your cropping has given you a 'telephoto advantage'. There is no telephoto gain for a particular pixel pitch. And here's the downside: the higher the pixel pitch, the more likely that your sensor exceeds the limits of your lenses' resolution. In other words, if your lens can illuminate a full frame then best results can be gained by using its full image circle. If it isn't long enough, don't crop, just get a longer lens.
Contrary to popular misconception, frame size doesn't deliver a telephoto advantage. Pixel pitch does. If the 5D2 had the same pixel pitch as the 400D, then puff goes your 'telephoto advantage'....Show more →
If I put my 100-400 on my 20D, the effective mm is 640mm. Right? In other words, if I had a 35 mm camera, it would be the same as a 640mm lens.
Now, with the 5D, it's effectively 400mm because of no crop factor. Must I crop every photo to get the 640? If so, that would be a pain.
Pixel pitch, frame size is science. I'm looking for "real world"!
JohnnyGCanon wrote:
If I put my 100-400 on my 20D, the effective mm is 640mm. Right? In other words, if I had a 35 mm camera, it would be the same as a 640mm lens.
Now, with the 5D, it's effectively 400mm because of no crop factor. Must I crop every photo to get the 640? If so, that would be a pain.
Pixel pitch, frame size is science. I'm looking for "real world"!
In the real world, if you had a 35mm camera, it would give you the very, very close to the same effective focal length as a 5D would. You would not get a 640mm effective length on a 35mm camera, especially since the 100-400 is designed for 35mm so the length indicated is the length the lens is currently at, more or less. If you want 640mm effective off a 35mm camera or FF body like the 5D, you would have to crop in the correct amount to narrow the field of view. That's how the real world works.
JohnnyGCanon wrote:
If I put my 100-400 on my 20D, the effective mm is 640mm. Right? In other words, if I had a 35 mm camera, it would be the same as a 640mm lens.
No it isn't the same as having a 640mm lens it's the same as taking a 35mm frame shot with a 400mm lens and cropping it to a bit smaller than a half-frame, but that crop happens to be located in the middle of the frame.
Now, with the 5D, it's effectively 400mm because of no crop factor. Must I crop every photo to get the 640? If so, that would be a pain.
You never "get the 640" you just get a cropped image (relative to the 35mm frame).
I guess one day they'll have 20MP 1/2.5" sensors noisefree at ISO6400, and then they can make zooms like 24-200 f/1.0.
What other big trade shows are there this year for Canon to announce other DSLRs, and to show them off? After PMA came and gone. Maybe they won't announce until next PMA.
There is Cebit in Germany in a few weeks, but that is consumer electronics in general, and Photokina in Sept. or Oct. in Cologne, Germany. There is a good chance of new models at Photokina.
Elie
RJJR wrote:
No it isn't the same as having a 640mm lens it's the same as taking a 35mm frame shot with a 400mm lens and cropping it to a bit smaller than a half-frame, but that crop happens to be located in the middle of the frame.
You never "get the 640" you just get a cropped image (relative to the 35mm frame).
If you are using film, which is resolution-independent of the camera body, and if you put your long lens on an APS body, you would just get a cropped image, because you would (or at least could) still be using the same film.
With your lens on a digital body, the "film" resolution is a fixed parameter of the camera, and that is the pixel pitch. If the pixel pitch of the APS body is the same as that of the FF body, then you still just get a cropped image. But if the PP of the APS body is higher than that of the FF body, then you get a higher res cropped image, from the centre of the lens's image circle, so you can enlarge it more than would be possible with a crop from the centre of the FF body. Your true multiplier will not be the full 1.6x difference between APS and FF. however, unless you have the same total number of pixels in each camera's sensor.
The whole "how long is that lens really?" thread gets a bit tedious.
A lens of a given focal length has that focal length. A 300mm lens is a 300mm lens.
That said, knowing the field of view of that 300mm lens on a particular camera body is significant, particularly if it is on my camera body. The "equivalent length" is a useful rule of thumb in that it gives us a quick and fairly intuitive way to understand how a given focal length will affect the image that I'll capture on my camera.
35mm film (or, today, full frame digital SLR) provides a useful frame of reference from which to understand the effect of familiar focal lengths when used on bodies with various sensor sizes: 1.6x 1.5x, 1.3x. This allows us to determine what focal length might produce an equivalent image at the sensor on cameras with various crop factor sensors.
In the film days, grain size was one factor that accounted for (and still does, between 35mm, MF, and so forth) an additional difference between "sensor" formats. Today the equivalent is photosite density, more or less. (Not just in terms of size but in terms of noise as well.)
All things being equal (not that they ever are) if the photosite density is equal on sensors of different dimensions one could crop to the equivalent of a smaller sensor and get the same pixel dimensions. Of course, that rarely is possible. A 5D has larger pixels than a Canon 1.6x body, so cropping out all but the 1.6x sensor sized center area leaves one with an image with fewer pixels.
And, yes, there are other differences. The DOF issues has been discussed quite a bit. There is also the issue of the magnification factor that will be required to create a print of given dimensions. (e.g.- larger percentage with smaller sensors.) and the effect this might have on such things are revealing lens "imperfections." There is even a circle of confusion (e.g. - defraction) issue that comes into play when you compare smaller and larger photosites.
Which brings me back to where I started. The "focal length equivalent" approach to determining what lens to use for a given "magnification effect" (term used with full awareness of what magnification does and does not mean - so please resist posting the explanation as follow up :-) is a useful proxy for "equivalent angle of view," and those who are very concerned about these things will also recognize how this relates to cropping (or enlarging) an image from different size sensors and so forth.
I'm starting to think that the 40D is just going to be a 30D with some 1DM3 features like auto iso and better AF, maybe Eye-focus, at about the same price point, probably just 10mp too. Then the 5D follow-on is going to be like 16mp and cheaper than the current camera, maybe like $2200 to start out. That way they bracket the D200. You want fast, we got the 40D and its cheaper, you want image quality and wides, we got the 6D, and its a bit more.
It keeps the high-low model that Canon seems to be employing. A pro-track 1Ds/1D and a prosumer xD/x0D, then Rebels for the rest. Full frame for the slow-quality camera and a crop for the speed-action use.
I'm interested in what 1DsII and 5D used prices do.
A friend of mine had a little peek at the price list of a Canon supplier here in the Netherlands. A few things stand out:
- 1D2N is gone from the list (no surprise, 1DIII is announced after all)
- 1DsII is gone (again no big surprise)
- 1DsIII not in the list yet (gee, no surprise here either)
- 580 EX II not listed yet
- Both old and new 16-35 are in the list
- There is a EF 85 f/1.8 Mk II listed. Typo ? New lens?
And several lens-kits (lens-lens and lens-extenter) other than the dSLR kits we've seen:
EF 135 2.0 L U + EXT 1.4
EF 16-35 2.8 L U + EF 70-200 2.8 IS
EF 17-40 4.0 L U + EF 70-200 4 L IS
EF 200 2.8 L II U + EXT 1.4
EF 300 4.0 L U IS + EXT 1.4
EF 35 1.4 L U + EF 24 1.4 L U
EF-S 10-22 + 17-85 IS USM
EF-S 10-22 + EF 70-300
drft wrote:
Everyone will be more concerned with Photokina 2008.
I don´t think so my friend, Photokina 2008 is going to be held in Köln (23th-28th September -2008); meanwhile the next PMA 2008 is going to be held on Feb´2008. Almost half a year later !!!
