Steve's Digicams Forums

Steve's Digicams Forums (https://forums.steves-digicams.com/)
-   General Discussion (https://forums.steves-digicams.com/general-discussion-11/)
-   -   [Recovered Thread: 98106] (https://forums.steves-digicams.com/general-discussion-11/%5Brecovered-thread-98106%5D-95772/)

Morag2 Jul 20, 2006 12:43 AM

Hey all, I have been looking at a few DSLR cameras and I had a question about there telephoto capabilities. Most people seem to be mentioning lenses with 35mm equivalents of 50-200 and 70-300 as telephoto lenses, but that seems a little bit short to me.

My fixed lens camera (Kodak P850) has a maximum focal length of 432mm... so does this mean I can zoom in more than those DSLR telephoto lenses? I use my zoom almost excessively and I find even my 432mm lacking, so what kind of lens in a DSLR would allow me to zoom in more than with my P850. Because basically, I would never upgrade to a camera that didn't have the ability to zoom in more than my P850, because I would find myself missing that 432mm very quickly.

Justin Hancock Jul 20, 2006 1:11 AM

I may be incorrect (someone correct me if I'm wrong) but you need to remember that only top-of-the-line DSLRs feature full-frame (35mm) sensors. Most others feature a crop factor because they don't have full-frame sensors.

For example, the Canon Rebel XT features a crop factor of 1.6, therefore a 70-300mm lense would reach 480mm.

1.6 x 300 = 480mm

Norm in Fujino Jul 20, 2006 1:19 AM

Morag2 wrote:
Quote:

Hey all, I have been looking at a few DSLR cameras and I had a question about there telephoto capabilities. Most people seem to be mentioning lenses with 35mm equivalents of 50-200 and 70-300 as telephoto lenses, but that seems a little bit short to me.

My fixed lens camera (Kodak P850) has a maximum focal length of 432mm... so does this mean I can zoom in more than those DSLR telephoto lenses?
If you're correctly quoting the numbers, yes. However, my guess is that the numbers (you gave no brands) are referring to the actual lens ranges, and not specifically the "35mm full frame" equivalents. For example, Olympus has a ZD 50-200mm zoom, but that is its actual focal length; its "equivalent" range is 100-400mm (2x factor with the four-thirds cameras).

The Sigma and Nikon 70-300mm zooms are also native focal lengths, not 35mm equivalents. Couple that with an APS-C sensor camera (1.6x factor), and the "equivalent" focal length range would be 112-480mm.


rey Jul 20, 2006 2:18 AM

According to Steve's review the P850 does have a 36-432 equiv in 35mm. P&S cameras have much smaller sensors, and that's why they sacrifice wide angle for telephoto. I learn this last year when I was renting out my apartment and I couldn't take a picture of my apartment in one shot no matter how pressed I was against the corner of the room.

Nikon DSLRs has a 1.5 multiplier, so a 70-300 is like 105-450mm. Canon has a 1.6 multiplier, except for the 5D, which is full frame.

The great thing with DSLR is you can swap lenses.


jacks Jul 20, 2006 10:47 AM

Most people are mentioning lenses in the 200-300mm lengths because any longer and the lenses start to get very big and even more expensive. 300mm is as long as mid-priced zooms get. Slr lenses go much longer however if you have the budget for them. Sigma, for example, do a 300-800mm which doubles as a pretty decent telescope. On a 4/3 camera this would effectively be a 1600mm lens! A 300mmf5.6 zoom is about the size of a camera at minimum zoom. A 300mmf4 or a longer lens and you start attaching the camera to the lens rather than the other way around.
A dslr at an effective focal length of 480mm (which can be done fairly cheaply) will blow away your P850. The lens will probably be gathering around 5-10 times as much light spread over maybe 1 - 2 times as many pixels meaning much more detail and far less noise.

DBB Jul 20, 2006 10:47 AM

Morag2 wrote:
Quote:

My fixed lens camera (Kodak P850) has a maximum focal length of 432mm... so does this mean I can zoom in more than those DSLR telephoto lenses?
Actually your Kodak has a lens with a field of view that equals a 432mm lens, but is not actually a 432mm lens. A 300mm lens on a DLSR will wind up giveng you more actual detail then the 432 you are using with the Kodak. The cropping factor makes these comparisons with true focal length, but it is actually an apples and orages comparison. You will get more pixels on the target with a narrow field of view then a normal view, but that's still not true magnification.

Dave

Morag2 Jul 20, 2006 11:16 AM

Alright all, I still can't say this is crystal clear in my mind, but I'm understanding the general idea. Thank you.

bernabeu Jul 20, 2006 11:21 AM

you can't get a decent hand held shot at 400mm without an extremely fast shutter speed (1/1000 at least)

therefor you need a 'fast' lens (f2.8 or better) and hi ISO (200-800)

no choice but a dSLR

bobbyz Jul 20, 2006 11:39 AM

bernabeu wrote:
Quote:

you can't get a decent hand held shot at 400mm without an extremely fast shutter speed (1/1000 at least)

therefor you need a 'fast' lens (f2.8 or better) and hi ISO (200-800)

no choice but a dSLR
You can:

1. use tripod or

2. get a p&s with built in IS, like panasonic FZ series

Sure they won't be like from dSLR with expensive glass but good enough for most folks printing 8x10.

You need f2.8 glass mostly forsports, night sports in particular. That's where dSLRs shien with their low noise high ISOs.




Morag2 Jul 20, 2006 12:26 PM

bernabeu wrote:
Quote:

you can't get a decent hand held shot at 400mm without an extremely fast shutter speed (1/1000 at least)

therefor you need a 'fast' lens (f2.8 or better) and hi ISO (200-800)

no choice but a dSLR
My camera doesn't really have that problem, I shoot at 432mm on my camera with very low shutter speeds and often don't have a problem. (I do have IS). I usually work with ISO 100 and aperature of f3.2 or even smaller sometimes.... is it IS that makes that difference? Because my image quality is just fine. (And I've used shutterspeeds as low as 1/50 on full telephoto)


All times are GMT -5. The time now is 3:53 PM.