# 500mm fixed lens wont work with my adapter?



## leejt1986 (Jul 31, 2010)

I have a 500mm prooptic fixed mirror lens i got off ebay. I thought of using my 2x extender and i get a message saying about cleaning the lens contact. 

Is there a reason it wont work? is it because of the type of lens?


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## Josh66 (Jul 31, 2010)

leejt1986 said:


> ... and i get a message saying about cleaning the lens contact.



Did you try cleaning the lens contacts?


It may not autofocus with the adapter, but other than that - I see no reason why it wouldn't work...


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## Sw1tchFX (Jul 31, 2010)

a 2x teleconverter on an (i'm assuming) f/8 mirror lens...1000mm f/16.. good luck seeing through the viewfinder, let alone getting a picture that's remotely sharp!


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## Josh66 (Jul 31, 2010)

Sw1tchFX said:


> a 2x teleconverter on an (i'm assuming) f/8 mirror lens...1000mm f/16.. good luck seeing through the viewfinder, let alone getting a picture that's remotely sharp!



It's probably not too bad...  I have a 1200mm f/13.3 telescope that I have shot through a few times.  The hardest part is focusing, and having a rock steady platform to shoot from.  I've mainly just used it for things like the moon (fills the frame perfectly with no cropping).

The viewfinder image is brighter than you'd think.  I don't think f/16 (or close to that) would be much worse.



But yeah - mirror lens, so no AF anyway (oops, missed that in my first post).

Actually, the lens contacts shouldn't even matter at all - it's a manual lens, there is no electronic communication.

What mode are you trying to use it in?  I'm pretty sure it will only work in manual.  Any other mode will think that you don't have a lens on the camera.  Manual doesn't care if you have a lens or not.


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## leejt1986 (Aug 1, 2010)

How would I go about cleaning the contact lens? 

I dont know if this matters, but its a Vivitar extender and it say its for canon eos lenses, my 500 isnt a Canon lens. Could that be why?


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## leejt1986 (Aug 1, 2010)

O|||||||O said:


> But yeah - mirror lens, so no AF anyway (oops, missed that in my first post).
> 
> Actually, the lens contacts shouldn't even matter at all - it's a manual lens, there is no electronic communication.



That was my first thought as to why the extender wouldnt work in the first place


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## Josh66 (Aug 1, 2010)

leejt1986 said:


> How would I go about cleaning the contact lens?


A lot of people suggest using a pencil eraser, or even the other end (graphite).  I don't think that's really the problem now though - since it's a manual lens.  There isn't anything on the lens for the contacts to make contact with...




leejt1986 said:


> I dont know if this matters, but its a Vivitar extender and it say its for canon eos lenses, my 500 isnt a Canon lens. Could that be why?



The lens does have an EF mount though, right?


What mode are you shooting in?  I think it will only work in manual mode.

Does it work without the extender?


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## leejt1986 (Aug 1, 2010)

O|||||||O said:


> The lens does have an EF mount though, right?



Yes I think so 



O|||||||O said:


> What mode are you shooting in?  I think it will only work in manual mode.
> 
> Does it work without the extender?



I've tried every mode...same error message in each


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## Josh66 (Aug 1, 2010)

With _and_ without the extender?


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## leejt1986 (Aug 1, 2010)

O|||||||O said:


> With _and_ without the extender?



the lens works fine without the extender and the extender works on my 70-300mm lens


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## Derrel (Aug 1, 2010)

Well...does the 500mm mirror lens have contacts on the back of it??? Since virtually all mirror lenses (except the new Sony 500mm AF) are manual focus, and since mirror lenses only have one aperture, there is no real, pressing absolute need for them to be fitted with electrical contacts...and many mirror lenses are designed so that the manufacturer or reseller can easily adapt the mount to fit multiple camera brands. A good many 500mm mirror lenses are relatively cheap designs, so, maybe this one's not engineered with total compatibility for *your* particular camera brand's mount and all permutations of teleconverter.

What brand of camera and what brand of TC are you using?


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## Josh66 (Aug 1, 2010)

Derrel said:


> A good many 500mm mirror lenses are relatively cheap designs, so, maybe this one's not engineered with total compatibility for *your* particular camera brand's mount and all permutations of teleconverter.



Even so - as long as the mount was machined correctly (shouldn't be too hard...), how could it be 'incompatible'?  Granted - there will be no electronic communication, but that shouldn't matter.  I have a body cap modified as a pinhole 'lens'.  It's just a body cap with a hole in it.  I also have the t-ring for my telescope - just a chunk of steel machined to the right shape.

Neither of those have electronic contacts, but they both work fine...

Hell, if I really had to - I could make a fist with a small hole in it and hold that up to the camera - it would work just as well as the t-ring or pinhole body cap...

It would be far from ideal, but you can't deny that I would be able to produce a photo using just my hand...


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## Derrel (Aug 1, 2010)

Canon EOS bodies suffer from many Err problems when the contacts are not "perfect"...and with up to 10 contacts on many EOS-mount lenses and EIGHT contacts inside EOS bodies....plus contacts on the telephoto converter--the possibilities of an incompatible lens/converter/camera combination are quite high. After all, the camera is reporting a Contact error...I've had both my main Canon bodies Err out when contacts were not quite right, giving me Err99 messages and locking up the cameras, multiple times. The idea that all that is needed is the proper mechanical connection does not apply to the EOS system like it does to some other systems...EOS is very dependent upon the proper electronic interface between lens and body, and there are Err codes that go along with that.

If one component is out of whack, like the converter has lost a solder connection, it will "futz up" the whole works...your example is one of components that have NO electronic interface...that is quite different from components that DO have an interface (ie, which DO have contacts)....the presence of contacts enables the electronic interface....the total absence of contacts, like on a plastic lens or body cap, does NOT enable the contact system, but bypasses the system...

Ergo...my original response...


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## j-dogg (Aug 1, 2010)

I have a Digital Rebel XTi and a Fotodiox Nikon/EOS adapter, I have mounted and shot all of my Nikkor film lenses some 40+ years old with no issues, and it works in some of the auto modes, even full auto. 

I get no autofocus and have to manually set my f-stop, and somehow the camera knows this and will not let me adjust the f-stop on the body which reads F00. But it meters and know what shutter speeds it needs, and most of the time it's pretty accurate and gives good exposure, but I use it in full manual mode anyways.


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## Derrel (Aug 1, 2010)

j-dogg said:


> I have a Digital Rebel XTi and a Fotodiox Nikon/EOS adapter, I have mounted and shot all of my Nikkor film lenses some 40+ years old with no issues, and it works in some of the auto modes, even full auto.
> 
> I get no autofocus and have to manually set my f-stop, and somehow the camera knows this and will not let me adjust the f-stop on the body which reads F00. But it meters and know what shutter speeds it needs, and most of the time it's pretty accurate and gives good exposure, but I use it in full manual mode anyways.



EXACTLY, j-dogg...I use Nikon-mount lenses on my Canon's quite often..and since the adapters have no contacts whatsoever, there is no activation of the electronic interface in the Canon body,and the cameras shoot just fine. I suspect there's a contact problem somewhere in the OP's setup,and the camera is telling him via a warning message that there is a contact issue...


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## Josh66 (Aug 1, 2010)

You know - other than a brief stint with Minolta film gear, all I've ever used was Canon, EOS mount.

I have never had a single error - not ONE.  Grated, I've only been doing this for about 10 years, but still - 10 years, no errors.

Not even anything that would _resemble_ any sort of malfunction...

And I have never cleaned the lens contacts a single time.


I don't know ... maybe I'm just lucky.  They said that when I had an AR-10 that actually worked (Armalite).  It's been nothing but the best for me - and I have abused the **** out of it - believe me...lol.  Same with all my Canon gear.  It's seen a lot of abuse, but it all still works, and I've never had a single error.  Like I said, maybe I'm just lucky.

From where I stand though, it just looks like it's good stuff...


In this specific case though - since there are no contacts to speak of...  As long as the mount is the proper dimensions, I don't see why it wouldn't work.  I know for a fact that it would work on any of my cameras, I can't figure out why it would be different on another camera with the same mount...


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## Derrel (Aug 1, 2010)

I think there ARE contacts involved...on the teleconverter...

You're lucky...a Google search on Canon +Error99 brings up 1.4 million hits...

Sigma lenses on Canon have locked me up multiple times...


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## Josh66 (Aug 1, 2010)

Derrel said:


> I think there ARE contacts involved...on the teleconverter...



Yes, but assuming that there are no contacts on the lens - there is no circuit.

If there are no contacts on the lens, whatever contacts may or may not be on the teleconverter shouldn't matter.

It wouldn't be any different than putting the body cap on...


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## j-dogg (Aug 1, 2010)

Derrel said:


> j-dogg said:
> 
> 
> > I have a Digital Rebel XTi and a Fotodiox Nikon/EOS adapter, I have mounted and shot all of my Nikkor film lenses some 40+ years old with no issues, and it works in some of the auto modes, even full auto.
> ...



Can't believe I didn't think of this sooner, but find someone or a camera shop with the same camera and try it on theirs. I helped a lady solve an issue she had with a 75-300 USM III lens on her Rebel, she would get the same message with the lens fully extended in full auto mode. I have the exact same camera and her lens would do it on mine too, and we put on a 400mm f2.8 L on both of them and it was fine.


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## Derrel (Aug 2, 2010)

O|||||||O said:


> Derrel said:
> 
> 
> > I think there ARE contacts involved...on the teleconverter...
> ...



1- The converter HAS contacts--on the front and the rear.

2- A body cap has NO contacts.

Ergo, it is quite different from putting on a body cap. Regardless, using a 2x teleconverter on a 500mm f/8 mirror lens does not make much sense. Just crop at the PC--it will yield a better result.


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## leejt1986 (Aug 2, 2010)

Hmm...I'm still not clear on if it'll work even if i clean the censors


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