BetterPhoto Q&A
Category: New Answers

ANOTHER Lens question/dilhema!!

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April 18, 2006

The 70-200 f2.8 is a lens designed for professional use (and priced accordingly), while the Sigma you have is more of a "consumer" type lens for regular folks ona budget. First, that Sigma lens dows not have Image Stabilization, and, as you know is slower. Also, the 70-200 is optically superior - gives sharper images - than the 28-300 - thanks to the use of better glass as well as the fact that, as a telephoto-only zoom with a 3x ratio it requires less compromise than does a wide-angle to tele zoom with a 10X zoom ratio.

Sigma makes some fine lenses, I have their 12-24, 120-300 f2.8 and their 180 Macro myself, but the 28-300 is just in a different class.

The Canon lens probably uses their USM focusing technology, which is both fast and silent (Nikon licenses it out as their VR technology, and Sigma calls their version HSM). I've used my 70-200 Nikkor at weddings - the fast speed allows for shallow DOF so the subject stands out from the background as well as for higher shutter speeds when flash is not possible.

Teleconverters can be quite good or pretty bad - depending on what you buy. No doubt the offerings from Canon are optimized and would be best (and most costly), but the high-level Tokina pro series has gotten a lot of good reviews. The lower priced stuff out there, though, is probably not worth it.

Hope that helps - sounds like you're catching "CAS"; what we in Nikon-land call "NAS" - Nikon Acquisition Syndrome

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April 18, 2006

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April 18, 2006

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April 18, 2006

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April 18, 2006

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April 18, 2006

Jon & Bob both gave excellent answers and info but they failed to clarify one thing for you. This whole focal length multiplier thing on DSLRs' using sensors smaller than a full frame. There really is no such thing as a magnification factor. A 200mm lens is going to produce the same image size, regardless what camera it's on.
The difference is that the smaller sensor makes a tighter crop of the image circle, than a 35mm would.
To put it this way, as I have with others. You should be able to picture this in your mind and then you'll have a better understanding.
Project a slide to completely fill a 50" screen. Now, replace the screen with one that is only 40", putting in exactly the same place. You can invision that the image size has not change, but, becaue the screen is now smaller, 20% of the image now spills out beyond the boundaries of the screen.
What manufactures are trying to show you with the multiplier is, that with a 200mm lens on a DSLR with a smaller than full frame sensor, you are only going to get the angle of coverage a 320mm lens would give on a full frame. The magnification of the lens itself is not multiplied. A 200mm lens is going to give you the same size image on an APS-C sensor as it would a 35mm. The only differnce is, it wouldn't include as much of the area surrounding your subject as on a 35mm.
As for the teleconverter on a lens, autofocus would still work so long as you are attaching it to a lens that is fast enough.
According to Canon, the autofocus won't work at aperatures smaller than 5.6, so the teleconverter attached to any lens with an aperature smaller than f/4.0 would not work. From f/4.0 and larger it should work fine.

Bob

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April 18, 2006

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April 18, 2006

So...about the focal length thing. The way that I look at it....

I have a 200mm f/2.8 lens. I say that it gives me the angle of view of a 320mm lens but it still gives me the depth of field of a 200mm lens. That being said, I believe it IS acting as a 320mm lens with slightly most depth of field (but still not very much at all at 200mm). You can argue with me all you want, but until you get in a tight spot or until you have a close subject with a 200mm lens on a camera like the 20D or similar dslr with a smaller aps (approx) sized sensor, it's fooey to say still imagine it as a 200mm lens and not 320mm. I also look at is as taking that smaller center chunck that the sensor captures, and stretching it out to fill a full frame.

The only real time when I don't think it's safe to pretend that a lens is 38mm instead of 24mm, or 28mm instead of 17mm is when you are using a focal length shorter than 100mm because the depth of field is going to be more than what you think it should be.

I know you know your stuff Bob, but I don't agree with the way you say that a multiplier doesn't exist. It's multiplying the focal length by 1.6 (or 1.5 or other) to get the field of view that the sensor with capture since that is how most of us associate this stuff. Not that you would use a lens that recorded a tighter crop, but that you want to use a lens that's around 300mm so you go for 200mm since the resulting image (which is really all that matters) is going to look nearly the same with a 320mm lens (if there were such a thing) except for very slightly more depth of field.

Not really complicated but people use weird ways of naming it...my opinion.

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April 19, 2006

It is was a compromise between cost and performance. Canon does make a couple of DSLRs with 35mm-sized sensors, but the cost of making those sensors is exponentially greater. The pro-bodied 1Ds is ~$7000. The more modest 5D is $3000, still ~2.5x the price of a 20D/30D.

So the manufacturers introduced DSLRs with smaller sensors about the size of APS-C film frame to get the selling price under $1500.

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April 19, 2006

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April 19, 2006

Personally, I don't feel like I need insanely wide angle lenses for my style of photography. Sometimes it's nice to have that wider angle, but I don't think it's necessarily unless you want to become a "jack-of-all-trades" like a lot of people try to become by buying wide angle lenses, zoom lenses, prime lenses, zoom telephoto lenses, macro lenses and all that stuff.

Could this be a possible reason?

PS, have you ever tried to print a photo from a cellphone? hahaha

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April 19, 2006

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April 19, 2006

I think the 70-200mm f/2.8 lens will be a good addition to your bag. Many people pair it up with a 24-70mm lens, but your 17-70mm lens should complement it nicely.

I have the Sigma versions of the 24-70mm f/2.8 and 70-200mm f/2.8 lenses. I keep the 24-70mm on my camera most of the time. The camera won't fit in my shoulder bag with the 70-200mm mounted, as it is also a large lens.

Chris

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April 19, 2006

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April 19, 2006

You certainly have the right to disagree. But whether you agree or not, a 100mm lens is going to project the same image circle and give the same magnification regardless of what camera it's mounted on.
The only thing that it going to change the focal length of a lens, and thus it's magnification, is a teleconverter.
I suppose the only way for you to find out for yourself would be if you knew someone with a fullfame DSLR of your make. Shoot a picture of something, anything that completlty fills the frame in the APS-C camera, then take that same lens and put it on a full frame DSLR. You would see that the subject itself is the same size in both pictures. The diffence being, the subject will look bigger in the frame overall because there is not as much area being covered. So, in a sense, you are right, a 200mm on an APS-C would give you the perspective of a 320mm lens on a full frame. However, the actual image magnification and the depth of field, would still be that of a 200mm.
So if Robyn is looking for a wider angle lens for confined areas, she would have to go with something wider than conventionally used on a 35 because it isn't going to take in the whole picture.
I agree with Jon on the compromise. That's why we have less than full frame sensor because of the cost.
Sometimes that could be a good thing. I'm sure cameras with the full sensor take a little longer to process all that information. I don't think the Canon EOS 1d MKII N or whatever it is would be shooting 8fps if it were full frame sensor of 16 megapixels. I wonder how sharp it really is though. It's an 8.2 megapixel like the 20D, but it's a slightly bigger sensor, though not full frame. I was wondering about Andrews hypothesis about a 6 megapixel full frame, then thought that the more you spread those pixles out, the less sharpness and detail. So, I really wonder now how the image quality of that MKII with a slightly larger sensor, stacks up against a 20D, when they both have the same number of pixels.

Bob

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April 19, 2006

You don't have to take my word for it. But for a good explanation copy the following link and paste it in your browser:

http://photoworkshop.com/canon/CMOS/fullframe-e/angle.html

A box will come up asking if you want to install a language, just click cancel and the Canon screen should launch explaining the differences. Hope this helps.

Bob

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April 19, 2006

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April 19, 2006

But in reality, the important part is the image that is recorded by that sensor. Take an image from a full-frame sensor camera and compare it side-by-side with an image taken with the same lens on a reduced frame sensor camera, and view both at 100%. The subject in the second image WILL be magnified. If you print each image as a 4x6, the subject in the second image again WILL be magnified.

So while saying that the focal length is not changed may be technically correct, I think it is also correct to say that a 100mm lens on my Digital Rebel will give me an image similar to the image I would get with a 160mm lens on a full-frame camera.

After all, the image is the goal. Why argue over the semantics of how the image is produced?

Chris

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April 19, 2006

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April 19, 2006

Don't worry, I'll get to the topic of the thread here sometime.

Geez, now I forgot what else I was going to say...OH yea! I have a Canon EOS 35mm rebel and while the coverage still isn't 100% in terms of what the sensor actually, captures, I see that the viewfinder is actually cropping what you're seeing and that they're technically the same size when you see the subject looking through the two viewfinders, just that unless you're really meticulous and you know what the viewfinder on a full frame camera (film or digital) looks like, most people won't notice that the viewfinder is that much smaller. My 20D looks closer to the size of a full frame camera than the viewfinder in some of Nikon's cameras like the D70 and D50 that I've looked at. That was the only time when I could really notice the the viewfinder was smaller and made it a little harder to manually focus.

Robyn, as for how many meters you'd have to stand back to get a full body shot with the 70-200...I threw on my Sigma 24-70 and zoomed in to 70mm and estimated my heigh (5'10") next to something in my apartment. To get nearly the my full height I believe that I had to stand around 4 meters away. That's kind of a rough estimate but it should give you an idea. I wont' even try to get a full body shot at 200mm because that would be insane haha. In addition, I would say that it's probably a good thing that you didn't get something like the EF-S 17-85mm IS USM just because it won't work on full frame cameras. I still use my 35mm Canon rebel so I won't be getting any EF-S lenses so I can be sure that my lenses are all compatible. Even though you'd have to stand back a little further for the 70-200, I'm sure the image quality would be great as well as the compression and depth of field given with the longer focal lengths. I recently had a test shoot applying at a local photo studio where they used cameras with a lens around 18-55 as their only lens. I hated using it because it really distorted at times. It was also a pretty small "studio" so it was kinda hard to back up far enough for my personal style.

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April 19, 2006

I would not like to say that I was arguing with anybody on anything. I just hate to see people being misled by the whole focal length factor that the camera industry has devised to explain the difference any given lens will have between full frame or a smaller than full frame sensor.
And while you are correct that a 100mm lens on a Rebel will give you roughly the same image, as far as perspective goes, as a 160mm lens on a full frame.
It's a matter of perspective, not actual magnification. It's simply very misleading to a lot of people, who have it in their mind that a 400mm lens on thier DSLR is the same as a 640mm on a 35mm camera.

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April 19, 2006

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April 19, 2006

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April 19, 2006

I love it sooo much. Amazon had it for $540.00 I believe and with the 40$ canon rebate. or was it $580.00 with 40 bucks rebate.. at any rate it was under 6 hundred and its awesome.. I wish I could afford the IS as I hate dragging the mono pod around but for the price of pristine glass and the quality of the shots.. I will stick the monopod in my ear if I have to.. its that good!
Craig-

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April 20, 2006

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April 20, 2006

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April 20, 2006

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April 20, 2006

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April 20, 2006

The 70-200 f2.8 IS with tripod collar is 3.5lbs

without IS is 2.8lbs, the picture had a tripod collar but it doesn't say that it comes with one so that's the weight without a tripod collar.

The 70-200 f/4.0 is 1.56 lbs and doesn't come with a tripod collar. I think you can buy one at B&H for around $115 which is insane but it's a very good thing to get.

There's the sigma version that a lot of people love. It's without IS but has a max ap of 2.8. It's optical quality probably isn't up to the Canon's level but I'll assume it's pretty good for around $800. If I was thinking about getting the IS lens, I would probably get the sigma one for $800 and then use the other money for Canon's 28-135mm IS USM because I'm already looking at that lens for portraits and the IS.

Hope this helps!

PS, honestly, do you notice a perspective different from 200 and 320 mm? especially 300 and 480 or so? I really only notice it when I'm at anything lower than 100mm like I said before.

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April 20, 2006

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April 21, 2006