Magnesium vs. Plastic Body Construction

With the 60d being released there has been a lot of harping for and against the new 'plastic' body vs. magnesium. My questions are as follows:

• Have any of you ever had a situation where you can say that having a metal body truly saved your camera?
  
  
• Have any of you ever had a situation where plastic was enough?
  

I expect magnesium is tougher than plastic though whether the difference is substantial I'm not qualified to comment. It is a lightweight metal. Unless you use your camera as a lump hammer I would have been just as happy with a plastic body on my 7D.

MichaelBernard wrote in post #11095558
I can't for the life of me think of any situation where a camera would be adversely affected by being constructed of modern composite plastics vs. magnesium.

i place a lot of value on how a camera handles, and the magnesium body has always been a welcome feature. i can't judge the 60D as i've never held one, but i remember the solid feel of my old 40D being a determining factor when i purchased it over an XTi some odd years ago. now more than ever, a solid, weighted body is something that i cherish. it's the same reason why 1-series bodies feel so.. "right" when paired with a heavier lens like the 70-200mm f/2.8L IS rather than smaller, lighter bodies.

i'd give it a shot, but i'd be willing to guess that i wouldn't be as comfortable mounting my 85L to a body any smaller or lighter than a 5D. it just wouldn't feel right.

MichaelBernard wrote in post #11095558
Isn't magnesium one of the softest metals? Please discuss productively.

Yes, but its not likely they're using pure magnesium. Think alloy, such as used on auto wheels. Very high strength to weight ratio stuff.

However, todays plastics are tough as well, especially glass or carbon composites. The one series, at $5k, really should be a carbon fiber composite IMHO.

artyman wrote in post #11095577
I expect magnesium is tougher than plastic though whether the difference is substantial I'm not qualified to comment. It is a lightweight metal. Unless you use your camera as a lump hammer I would have been just as happy with a plastic body on my 7D.

Done:

http://www.youtube.com​/watch?v=D1tTBncIsm8


Spoiler alert: Plastic for the win!

JC4 wrote in post #11095624
Yes, but its not likely they're using pure magnesium. Think alloy, such as used on auto wheels. Very high strength to weight ratio stuff.

However, todays plastics are tough as well, especially glass or carbon composites. The one series, at $5k, really should be a carbon fiber composite IMHO.

This. While I do think there's a psychological effect in knowing that a camera has a metal body, plastic technology has come a very long way in the past decade.

I have never dropped a camera body before, but after seeing DigitalRev's video on stress testing camera bodies (some people don't take them seriously, but they did abuse the hell out of those two cameras), I wouldn't think twice about getting a modern one with a plastic body

Having used a Rebel XT for many years ~ the alloy body of my 50D was a extremely nice upgrade. That being said, my Dad just picked up a 60D and brought it over last night. The build quality and overall feel of both cameras is very similar... I wouldn't be bothered in the slightest by the quality & feel of the newer "plastic" body. The only real difference I noticed was that the alloy body was initially cooler to the touch.

Shock absorption should be a more important criteria than material hardness, IMO. With that said, I wouldn't disregard a camera because it was made of say, polycarbonate vs magnesium.

hieu1004 wrote in post #11095679
Shock absorption should be a more important criteria than material hardness, IMO. With that said, I wouldn't disregard a camera because it was made of say, polycarbonate vs magnesium.

+1...I don't think the strength of the body material itself is the primary concern (plastic or metal...it's plenty strong to take abuse). The problem is all the juicy, soft electronics and glass inside will be destroyed before the body itself is damaged enough to matter.

joebob23 wrote in post #11095660
This. While I do think there's a psychological effect in knowing that a camera has a metal body, plastic technology has come a very long way in the past decade.

I have never dropped a camera body before, but after seeing DigitalRev's video on stress testing camera bodies (some people don't take them seriously, but they did abuse the hell out of those two cameras), I wouldn't think twice about getting a modern one with a plastic body

Anyone that has used the Otterbox brand cases for their smartphones can attest to that.

As the consumer, I get to choose what I want to spend my money on. My preference is magnesium (yes, I've owned Rebels in the past) because it has a quality feel to it that I appreciate in a high end camera. Canon has ticked many of their customers off with the 60D and the dumbing down of the xxD line. The plastic body was the straw that broke the camel's back for many of us.

Well, when it comes to material properties, the key difference between the use of magnesium vs polycarbonates is ductility
magnesium alloys ( i have no idea of compositions, so im assuming it'll obey the general consenses of metal properties) is ductility

magnesium being more ductile will have a larger tendency to deform elastically (repairable dents) rather than crack when subject to large external stresses (from falls, baseball bats, angry wives) whereas plastics would just crack

however, plastics have come a very very long way, and some plastics have a high resistance towards deformation, probably high enough to withstand a dragon punch from ryu/ken. (ok maybe not)

personal opinions here
i do think magnesium imparts psychological confidence on durability, but plastics isn't really all that bad. I'd take magnesium over plastic anyday, but hey whatever works and whatever floats your boat right?

hieu1004 wrote in post #11095679
Shock absorption should be a more important criteria than material hardness, IMO. With that said, I wouldn't disregard a camera because it was made of say, polycarbonate vs magnesium.

THIS. What good is a non dented body with a broken shutter due to shock?

The magnesium body is a product spec and photographers like product specs. People assume magnesium is better because it is metal. Composites have come a long way and I think would hold up just fine.

Having dropped a rebel XTi, from about 4 feet to blacktop I know that it held up fine and continued to shoot for a year until I sold it. There were some scratches on the casing but no defromation of the plastic body.

Well, it seems to me that the 7D is redefining what we might consider the Canon "prosumer crop" camera big-time, following the Nikon lead with the D200, whereas the 60D is defining another "niche" a step "down" from the hefty prosumer. I haven't heard that the 60D is "worse" than the 50D except for this "plastic" thing and the lack of MA, but it seems like people need to recognize that things have shifted, and if you want something more hefty/pro, the 7D line is/will be the thing of choice, period, and can't expect the xxD series to cut new "prosumer ground".