Do you need full metal barrel?


ManWearPants

Senior Member
Jul 14, 2008
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In the wake of Canon releasing more L lenses. I am wondering in the age of advanced plastics. Do we still need full metal barrel lenses and optical glass.

Can plastics be used as a replacement for both the barrel as well as the optics?
 

You have a point there.... the Glass is more important anyway. But metal lens body does look and feel better :bsmilie:
 

You have a point there.... the Glass is more important anyway. But metal lens body does look and feel better :bsmilie:

I am thinking we use plastic as our spectacle optics now. Surely, plastics can bend light just as well as glass. However, I do not know if it works for a group of elements. Maybe plastics may turn yellowish after a while. I wouldn't mind if it is priced like $500 for a 24-70 f2.8 and it becomes unusable after 3 years.

If this is possible, then weight and cost reduction is on the cards.
 

I am thinking we use plastic as our spectacle optics now. Surely, plastics can bend light just as well as glass. However, I do not know if it works for a group of elements. Maybe plastics may turn yellowish after a while. I wouldn't mind if it is priced like $500 for a 24-70 f2.8 and it becomes unusable after 3 years.

If this is possible, then weight and cost reduction is on the cards.


I remember, for some times back.... my plastic lens scratch much more easily.... like really really easy :sweat:

But in the future.... who knows :bsmilie:
 

In the wake of Canon releasing more L lenses. I am wondering in the age of advanced plastics. Do we still need full metal barrel lenses and optical glass.

Can plastics be used as a replacement for both the barrel as well as the optics?

but u read the reaction of fellow csers for 60d, most commented its toy because plastic bodies (think they r non believer of "its the use not the gear" thingy).

so if "L" lens had plastic barrel though the glass elements are "L" std, they likely will say "its a toy" again.

many dont understand how tough engineering plastics r nowadays, in their mind, metal is the only tough matl they know as they r not mech engineer trained.
 

true polycarbonate easily wins most metal in terms hardness and and density ratio

but then agn some ppl like their gears to feel more substantial hence the mag alloy

in terms of lens and cam body construction plastic is rly usable but in terms of optics i have my reserve abt tht:sweat:hairline scratches appears too easily
 

so if "L" lens had plastic barrel though the glass elements are "L" std, they likely will say "its a toy" again.

many dont understand how tough engineering plastics r nowadays, in their mind, metal is the only tough matl they know as they r not mech engineer trained.

Not really... Canon's newer lens seem to be having more and more plastic in it... just look at the 100mm macro L IS
 

hmmm a noob question maybe

since so many of you support plastics
what i wanna ask is , will a block of very good plastics be able to smash a block of magnesium alloy ??
 

hmmm a noob question maybe

since so many of you support plastics
what i wanna ask is , will a block of very good plastics be able to smash a block of magnesium alloy ??

The point of using plastic is not so much as which is harder. If you drop a lens, whether metal or plastic, there will be damage. The point is do we need metal barrels? You need it for rifle cos of the explosive and the speed of bullet travelling within the barrel. But for lenses?

Imagine a 70-200 f2.8 made of plastic. Will be lighter to carry around, right?
 

Plastic - Cheap, Light.
Wonder why manufactures are not using them extensively
 

A guy I know dropped his D90 almost 10 ft onto concrete. It has a 70-200 f2.8 on it and it landed on the front element of the glass. Surprisingly the lens survived unscathed, whereas the body was fractured around the plastic molding.

Mag alloy is the way to go for pro spec bodies and lens IMO.
 

The point of using plastic is not so much as which is harder. If you drop a lens, whether metal or plastic, there will be damage. The point is do we need metal barrels? You need it for rifle cos of the explosive and the speed of bullet travelling within the barrel. But for lenses?

Imagine a 70-200 f2.8 made of plastic. Will be lighter to carry around, right?

my fren who was shooting for YOG as a youth volunteer
noticed that pro photographers treat their gear like crap. they can shovel people and other DSLRs away with their lenses and not feel any pinch, or fear of damaging the lens

pro photographers abuse their lens to get the shot, without having to worry/get distracted about the welfare of their gear

personally i would opt for a tougher and more durable finish, than a light one, and there must be occasions which demands such durability and toughness

get a powerful flash, you can change the settings such that it fires weaker
as compared to
get a weak flash, and not being able to set beyond the output limit of the flash

same logic

hence i asked if a block of very good plastic will be able to out perform a block of magnesium in terms of durability and toughness
if they are able to, then i would agree that it's dumb to have everything made with magnesium alloy

anyone who specializes in mech engineering care to shed some light?
 

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The point of using plastic is not so much as which is harder. If you drop a lens, whether metal or plastic, there will be damage. The point is do we need metal barrels? You need it for rifle cos of the explosive and the speed of bullet travelling within the barrel. But for lenses?

Another consideration is the tolerance.. metals can be machined to very tight tolerances to deliver the precision required.. plastics may not be able to..

Also, toughness matters in the sense that it has to withstand reasonable wear and tear.. i.e., it doesn't get loose after a couple of cycles of turning the focusing ring.. for e.g.
 

I am thinking we use plastic as our spectacle optics now. Surely, plastics can bend light just as well as glass. However, I do not know if it works for a group of elements. Maybe plastics may turn yellowish after a while. I wouldn't mind if it is priced like $500 for a 24-70 f2.8 and it becomes unusable after 3 years.

If this is possible, then weight and cost reduction is on the cards.

Er... plastic can never be as good as glass when it came to flatness in surface. Look at any plastic be it PMMA or others, it can never achieve what glass could, at least in the present... in the future, they might. Without the ability to achieve the clarity and transparency of glass, plastic optics will never give you the same quality of image.

Next is, glass is thinner, maybe because of its density and hardness. Plastic to achieve the same degree are thicker as compared to glass.
 

Interesting question. Now that I think about it, yeah, why not? I mean, we do not need to change EVERY component in a lens to plastic. Those that go through more wear (mount and gears and whatever screw stuff) can still remain metal. But the barrel, filter thread, I dunno what else, can be hard plastics right? I imagine the same materials as the Nalgene bottles (polycarbonate, if I'm not wrong). Those are tough! They're advertised as tough too! Really tough!

Besides, lenses are made to transmit light, not use as a baseball bat. I'm sure polycarbonate can take the shoving and all.
 

Interesting question. Now that I think about it, yeah, why not? I mean, we do not need to change EVERY component in a lens to plastic. Those that go through more wear (mount and gears and whatever screw stuff) can still remain metal. But the barrel, filter thread, I dunno what else, can be hard plastics right? I imagine the same materials as the Nalgene bottles (polycarbonate, if I'm not wrong). Those are tough! They're advertised as tough too! Really tough!

Besides, lenses are made to transmit light, not use as a baseball bat. I'm sure polycarbonate can take the shoving and all.

you might want to read this

http://www.healthylivingtalk.com/warning-do-you-have-nalgene-or-other-hard-plastic-drinking-bottles/

if you owned those bottles
some plastics release harmful toxins when exposed to certain conditions

anyway back to topic
getting used to the weight takes a matter of time
if you're arguing that the weight of lenses makes the day to day carriage of lenses inconvenient and a hassle, you can always choose other camera system like
MFT, LX5, NEX5, M9 etc etc... but if canon seriously decides to switch everything to plastic, i see it more as an opportunity for them to save cost

i prefer metal .
 

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pro photographers abuse their lens to get the shot, without having to worry/get distracted about the welfare of their gear

Because it's NOT THEIR gear. It belongs to the magazine/website/news agency/newspaper they work for.
 

Interesting question. Now that I think about it, yeah, why not? I mean, we do not need to change EVERY component in a lens to plastic. Those that go through more wear (mount and gears and whatever screw stuff) can still remain metal. But the barrel, filter thread, I dunno what else, can be hard plastics right? I imagine the same materials as the Nalgene bottles (polycarbonate, if I'm not wrong). Those are tough! They're advertised as tough too! Really tough!

Besides, lenses are made to transmit light, not use as a baseball bat. I'm sure polycarbonate can take the shoving and all.

It's like the Sony CZ lenses. The internal gearing, etc, is metal, but the outer shell has some tough plastic too.