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03-12-2013, 01:25 PM   #706
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QuoteOriginally posted by Cynog Ap Brychan Quote
That's not a lens in that picture! That's a Saturn 5 second stage!
Close, but no cigar -- rather, this:



Saturn IB at KSC, taken with a K-01 and the 21mm ltd, stopped down to get the starburst effect (& I disagree with Cynog Ap Brychan simply because I don't have a good photo of a Saturn V)

03-12-2013, 03:28 PM   #707
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QuoteOriginally posted by tclausen Quote
Saturn IB at KSC, taken with a K-01 and the 21mm ltd, stopped down to get the starburst effect (& I disagree with Cynog Ap Brychan simply because I don't have a good photo of a Saturn V)
Now that's what I call a telephoto!
03-12-2013, 05:35 PM   #708
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QuoteOriginally posted by normhead Quote
And I've blown up a couple of carbon fibre tennis rackets... the plastic stuff is good while it's good, but if you ever stress it so much it lets go, there's not much left.
The resins used to bind carbon fibre composites are highly susceptible to damage from ultraviolet light - the best way to protect CF products is to have them painted over by a thick coat of paint that doesn't get scratched or damaged*. But considering how tennis players play these days I don't even think stolid tungsten alloy would survive for long.

QuoteOriginally posted by johnmflores Quote
One of the good things about metals is how they fail; they will bend before they breaks
But that usually means something will either be bent or deformed by the malfunctioning part as well - also metal gears can leave shredded parts of themselves all over the interior of a camera which is a PITA to clean out and prevent further failures.

*one of my biggest criticisms of CF tripods is the exposed composite material.
03-12-2013, 06:09 PM   #709
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QuoteOriginally posted by ElJamoquio Quote
'Plastics' are called 'plastic' because they deform plastically (bending) rather than brittle-ly (breaking).

Not all plastics are like that of course, which is why many engineers prefer the term 'polymer'.

The ductility of CFRP is dictated by the carbon fiber, not the polymer.

As others have mentioned you could easily mould plastic into a shape that is much stronger than the equivalent-cost cast/stamped/machined metal. It just depends on what you want to do.

I have no doubts that the D600 is less durable than the top model (D3 or something). I also have no doubts that the D600 will not fail at the mount for me. I don't hand-hold 800mm lenses.
I don't mean to be picky (but I am) however the term "plastic" was originally used to distinguish the non-linear stress-strain curve of non-metallic materials from the linear ("elastic") characteristic of metallic materials. Metals also deform in a "plastic" manner beyond the elastic limit, ie where the deformation becomes permanent.

Incidentally, I had a tripod-mounted SP-F attached to a 300/4 SMC Takumar (all metal and glass both sides of the mount) knocked over by an errant small daughter, many years ago. All survived (even the daughter) with practically no damage. I wouldn't be over-confident about the same outcome with a non-metallic mount, but our longevity expectations are lower these days, anyway (except for daughters, naturally).

03-12-2013, 06:30 PM   #710
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QuoteOriginally posted by Sol Invictus Quote
Weakling. I regularly hand hold the Canon EF 1200mm f/5.6 L USM Lens...
http://static.bhphoto.com/images/images200x200/870227.jpg

Lens only weight; mostly air with a few very finely polished mirrors = Just shy of #200 depending upon finderscope.

Complete assembly = About six hundred pounds.

But at least it's an f8.o aperature with a focal length of over 4000mm
03-12-2013, 08:00 PM   #711
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QuoteOriginally posted by RobA_Oz Quote
I don't mean to be picky (but I am) however the term "plastic" was originally used to distinguish the non-linear stress-strain curve of non-metallic materials from the linear ("elastic") characteristic of metallic materials. Metals also deform in a "plastic" manner beyond the elastic limit, ie where the deformation becomes permanent.
I'm aware.
03-12-2013, 10:36 PM   #712
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QuoteOriginally posted by ElJamoquio Quote
I'm aware.
I suspected as much, but others may not have been.
03-13-2013, 05:31 PM   #713
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QuoteOriginally posted by Sol Invictus Quote
Fair enough, I see what you mean. Although I have yet to see a rash of broken lens mounts on the D7000 and D600.
No rash of mount breaks, but I have heard of it. I'm sure its less comon than the SDM faliures. That being said, I'm scare to get the 70-200 f2.8 for my D600 and let it hang with my Black Rapid strap... more so than I am of SDM faliure which I haven't experienced.

03-13-2013, 09:02 PM   #714
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QuoteOriginally posted by ElJamoquio Quote
'Plastics' are called 'plastic' because they deform plastically (bending) rather than brittle-ly (breaking).

Not all plastics are like that of course, which is why many engineers prefer the term 'polymer'.

The ductility of CFRP is dictated by the carbon fiber, not the polymer.

As others have mentioned you could easily mould plastic into a shape that is much stronger than the equivalent-cost cast/stamped/machined metal. It just depends on what you want to do.

I have no doubts that the D600 is less durable than the top model (D3 or something). I also have no doubts that the D600 will not fail at the mount for me. I don't hand-hold 800mm lenses.
Thanks for the refresher.

See dad, I would have made an awful engineer.

The D600 is likely less durable than the top model simply because it's designed to a lower price point, not due to some inherent disadvantage of the materials.
03-13-2013, 09:35 PM   #715
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re: 70-200mm

Wired:

You'd probably hang the camera off of the 70-200mm with the black rapid, at least that's how I do it anyhow. The 70-200mm weighs like 3x more than the camera, and it hangs pretty nice off the tripod mount. Doesn't work like that for the 24-70mm, but it doesn't feel like it's going to break any time soon.
03-22-2013, 06:08 PM   #716
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Getting back to topic, my chief drive for this long-awaited FF is a very selfish desire to get every fine detail I can out of the FA Limited lenses. I don't mind them on APS-C either though, so it's no big loss at all to me if it doesn't come in the next 10-20 years.
03-23-2013, 02:08 PM   #717
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Pentax's incremental upgrades are slight but deliberate and calculated. The FF model might well come out to be 24 Mp and thus have minimal benefit over the K-5 on paper, but practically, there may be more to it than meets the eye - high ISO capability, good size/weight for a FF camera, and a slick AF system.
03-23-2013, 02:27 PM - 1 Like   #718
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QuoteOriginally posted by Ash Quote
Pentax's incremental upgrades are slight but deliberate and calculated. The FF model might well come out to be 24 Mp and thus have minimal benefit over the K-5 on paper, but practically, there may be more to it than meets the eye - high ISO capability, good size/weight for a FF camera, and a slick AF system.
As I wrote on another thread, products are tactics, market segments are strategy.
03-23-2013, 06:16 PM   #719
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QuoteOriginally posted by monochrome Quote
As I wrote on another thread, products are tactics, market segments are strategy.
Nicely put.
03-24-2013, 09:17 AM   #720
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QuoteOriginally posted by Ash Quote
Pentax's incremental upgrades are slight but deliberate and calculated. The FF model might well come out to be 24 Mp and thus have minimal benefit over the K-5 on paper, but practically, there may be more to it than meets the eye - high ISO capability, good size/weight for a FF camera, and a slick AF system.
A 24MP FF will have ~40-50% better resolving power on the same lens as the K-5.
The FF will have more control over DOF (unless you're shooting at F/22 on APS-C).
The noise will be better if you tolerate or want smaller DOF.
The viewfinder will almost certainly be bigger and brighter.
Tracking moving subjects will be easier while maintaining equal resolution.
The AF point will be smaller for the same AF-point-performance, meaning that AF will be more precise inherently.

Last edited by ElJamoquio; 03-24-2013 at 09:23 AM.
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