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Old Jul 24, 2006, 9:25 AM   #11
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Morag2 wrote:
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bernabeu wrote:
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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)
I thought the purpose of this thread was DSLR not digicam? There's a huge weight/balance difference between an ultrazoom digicam and a DSLR with a telephoto on it. You really can't extrapolate like that - holding 1lb steady vs. 4-6 lbs is a big difference (you wouldn't think so but it is)
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Old Jul 24, 2006, 9:39 AM   #12
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Ah, thank you JohnG, I didn't really take that into consideration. Although I have to wonder, if they can fit 432mm into a 1 pound Prosumer, then how come it weighs 6 pounds when you attach a lens to an SLR? Is that just quality of the lens and what not?
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Old Jul 24, 2006, 11:05 AM   #13
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Morag2,

The actual weight will depend on the optics involved. In general, a lens is going to be larger because the sensor in a DSLR requires a larger image circle than the sensor in a digicam. That means you need a larger diameter lens. Larger diameter = more weight. Actual weight will also very by the number of lens elements and max aperture and lens body construction (plastic vs. metal).

For instance, the Canon 400mm 2.8 lens is 11.8 lbs (17 lens elements and a 2.8 aperture). The Canon 100-400 4.5-5.6 lens is "just" 3.1 lbs (still 17 elements but 5.6 aperture zoomed out which means you don't need glass with as big of a diameter to achieve 5.6 at 400mm vs. 2.8 at 400mm). The Canon 400mm 5.6 lens is just 2.8 lbs (less elements than the zoom).

You can do some searches on google to find write-ups on the physics involved and why glass must be larger for the wide aperture and image circle.

And, you have to factor in the weight of the camera body:

Canon 350 = 17 oz

Canon 30D = 24.7 oz

Canon 1dMkII-N = 43.2 oz

Again, camera body weigth varies because of materials used in it's construction (biggest contributor)and the components it must house.




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Old Jul 24, 2006, 11:32 AM   #14
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The 432mm is an equivalent - meaning that you get the same CROP, but NOT the same magnification. I would guess that that actual mm is around 85.

If you compared the picture from the Kodak 432 and a true 400mm lens, there would be NO comparison in the detail captured.

And therefore you cannot compare the lens on the Kodak with the lens on an SLR or for that matter a DSLR.

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Old Jul 24, 2006, 1:26 PM   #15
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I agree with DBB, there's a big difference between taking a picture at 400+mm, and taking a High Quality picture at 400+mm. There are a lot of no-name lenses out there for SLRs which are basically "telescope quality", ie you see it close, but it doesn't mean if you take a picture of it, that the picture is worth printing or even keeping.

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Old Jul 24, 2006, 2:29 PM   #16
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JohnG wrote:
Quote:
Morag2 wrote:
Quote:
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)
I thought the purpose of this thread was DSLR not digicam? There's a huge weight/balance difference between an ultrazoom digicam and a DSLR with a telephoto on it. You really can't extrapolate like that - holding 1lb steady vs. 4-6 lbs is a big difference (you wouldn't think so but it is.

If the subject is moving IS is useless.

If you are shooting in sunlight at ISO 100, f4, the shutter speed would be 1/2000 according to the 'sunny sixteen' rule (iso 100, sunny day, f16, 1/125sec)

Your 'image quality' may be fine for your purpose, but, believe me, it will leave a great deal to be desired when enlarged and printed professionally on high grade paper.

This (example) can be printed 20x30 @ 200ppi:



Last edited by bernabeu; Jun 27, 2015 at 4:24 PM.
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Old Jul 24, 2006, 2:37 PM   #17
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Bernebeu,

While I don't disagree with you that image quality of a DSLR at 20x30 will be better than a digicam at 20x30 I'm not quite following the relevence to my post (normally there wouldn't need to be except you quoted my post in your response).

So, help me understand how my post regarding the weight of the system involved and hand-holding is relevant to your response? Not saying you're not right about the print size thing (I tend to agree with you) - I just want to make sure I'm not missing something else.
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Old Jul 24, 2006, 3:29 PM   #18
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within certain limits the heavier dSLR lens/camera combination can be held MUCH steadier than the little plastic P&S jobs

weight - inertia - technique - etc.

Last edited by bernabeu; Jun 27, 2015 at 4:24 PM.
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Old Jul 24, 2006, 6:41 PM   #19
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Alright, this is all clear to me now, thank you all very much!
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