Canon LTM 100 3.5 needs help

Canon M39 M39 screw mount bodies/lenses

Erik L

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Apr 3, 2008
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i need to remove the front element to clean it. there is a problem, the aperture ring has no clicks just continous movement. is this a simple fix.

also what is the filter size for this one? so tiny.

5005461-946_display.jpg
 
It's been a while, but if I remember right, you can just unscrew the lens barrel from the focus helix.

Then take off the aperture ring (if needed) and get to the glass from behind, i.e. take off the rear element group, etc.

Roland.
 
This lens is clickless. That is not a fault, just the way it is made.

I couldn't remember if it had click-stops, or not. I sold mine a year ago when I got the all-black version. The black version has click-stops, and uses 40mm filters
 
Well, there were three versions made by Canon.

The first two are almost identical, except for subtle design changes, probably limited to the dropping of the "Serenar" trademark. I've owned the second version, and it was clickless. According to dexdog, the last version (III, the "all-black" version) has click-stops.

Hope that helps.


Cheers,
--joe.
 
I had two chromes over the last few years and both were without click stops. I recall in one of my Canon books reading that this was how they were made.
 
Well, there were three versions made by Canon.

The first two are almost identical, except for subtle design changes, probably limited to the dropping of the "Serenar" trademark. I've owned the second version, and it was clickless. According to dexdog, the last version (III, the "all-black" version) has click-stops.

Hope that helps.


Cheers,
--joe.

since mine doesnt say serenar then its the lightest version? its serial 50789
 
HI,

Depending on the serial # of your lens but all 100mm f/3.5 lenses before #80001 DID NOT have click stops. 100mm f/3.5 lenses serial # started at #49001. There are three TYPES (5, 6, & 7) which have click stops and all these are the predominantly black lenses.

TYPE 1 to 4 used 34mm filters while TYPES mentioned above used 40mm filters. Cheers Peter



PS All this info is in my Canon M39 book which will go to print in two weeks time.
 
Peter, thanks for clarifying. So, when are you taking orders for your book?

Hi, I have just started a new thread mentioning when I start taking pre-orders and the time frame I will receive the final product. I am really pleased what the final product will look like. Peter
 
i still cant get the ring to unscrew to remove the front element, thats the only dirty one

the only thing i could think of was stick a rubber glove under a bottle cap to grip
 
As I look at mine, I think the dress ring is an integral part of the front of the lens, note that the filter threads end before the dress ring starts.

So I suspect everything comes out through the back. Be sure to make discreet "match marks" before you unscrew anything there, you want to tighten it the same amount when you're done.

Considering that you will probably have to pull the diaphragm blades to do this, are you sure this isn't something you want to leave to a professional? It's a wonderful lens with great potential, you wouldn't want to trash it.
 
As I look at mine, I think the dress ring is an integral part of the front of the lens, note that the filter threads end before the dress ring starts.

So I suspect everything comes out through the back. Be sure to make discreet "match marks" before you unscrew anything there, you want to tighten it the same amount when you're done.

Considering that you will probably have to pull the diaphragm blades to do this, are you sure this isn't something you want to leave to a professional? It's a wonderful lens with great potential, you wouldn't want to trash it.

oh you are right i guess ill send it to dag or something
 
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The entire lens module unscrews. I used a piece of rubber grip mat used under rugs. Grasp the focus ring and use the rubber on the black ring. Mine was in very tight. I only needed to clean the middle elements, so I cannot tell you how to access the front one.
 
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i just got it back from DAG. nice and clean and smoother now that hes gone through it. tomorow ill take some pics with it, finally.
 
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