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Archive 2005 · Infinity focus with FD lenses

  
 
jrs915
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p.1 #1 · p.1 #1 · Infinity focus with FD lenses


I recently purchased a Canon 500 f4.5 FD lens to use for some wildlife photography. I also bought a cheap adapter and removed the glass part. I figured I wouldn't really miss the infinity focus much.

Unfortunately the amount of infinity focus is pretty great, to the point where I have about 50 ft when I am set to infinity.

My question is, based on the internal focusing, it appears that the lens could focus past infinity, but there is just some sort of stop at the focusing ring which doesn't allow it to go any futher.

Never seeing the inside of the lens, I'm not really sure if I could just take it apart or have a camera repair place take it apart and put the stop someplace further to allow it to focus past infinity, which should give me infinity focus

Any ideas?



Jun 29, 2005 at 04:26 AM
zwooba
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p.1 #2 · p.1 #2 · Infinity focus with FD lenses


Canon made(makes?) an adaptor that retains infinity adaptor and also acts as a mild teleconverter. Ther was a thread recently that mentioned this, but I can't seem to find it right now.


Jun 29, 2005 at 06:40 AM
Roy NN7DX
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p.1 #3 · p.1 #3 · Infinity focus with FD lenses


Hama Lens Mount Adapter - Canon FD & FL Lenses on Canon EOS Bodies
Mfr# HA30845 B&H# HALACFDCAF B&H Price: $ 119.95

This adapter allows for Canon FD and FL type lenses to be mounted onto a Canon EOS body.

Unlike other simple mount adapters, this is an optical adapter which is actually at the same time also a short teleconverter, which increases the focal lenght by a factor of 1.25x, and reduces the lens aperture by approx. one f/stop. This adapter allows for focusing at infinity.

Here



Jun 29, 2005 at 10:08 AM
Pham Minh Son
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p.1 #4 · p.1 #4 · Infinity focus with FD lenses


The Hama adapter with the optical element is not the choice. It will degrade your image quality to the point that you might as well just buy any other cheap lens and it will work better.

The only way to get infinity focus without loosing optical performance is to have the lens altered so that it will focus to infinity with a new built in EF rear bayonet. You will have to sacrifice the aperature ring in doing this alteration. Thus, you must shoot wide open in which is fine for the FD 500mm which is already at F4.5.

The way to alter the lens is to cut into the barrel and sacrifice the aperature ring. Use the neutral density filter as your stop down f stops when you need it.


-Son



Jun 29, 2005 at 10:15 PM
rico
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p.1 #5 · p.1 #5 · Infinity focus with FD lenses


Son, we miss you. Hope the honeymoon is going well. Return quickly, before Guy M has a complete meltdown!


Jun 29, 2005 at 10:23 PM
Pham Minh Son
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p.1 #6 · p.1 #6 · Infinity focus with FD lenses


Rico, I just came back from the honeymoon and just landed in Philadelphia a few hours ago. I am glad to be back and missing talking gear with everyone. I did not forget Guy in fact we have a wonderful discussion a day a go when I thought he was mad in selling the famous Zeiss Distagon 21mm F2.8. I will make sure to take care of Guy in this end. I noticed that he went nuts on the Leitz lens even manually praising the telephoto Leitz apo 180mm F2.0. Thus it is too late the melt down has begun and I have to save him from being in Zeiss exile.


Jun 29, 2005 at 11:48 PM
ent2b
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p.1 #7 · p.1 #7 · Infinity focus with FD lenses


Pham Minh Son wrote:
The only way to get infinity focus without loosing optical performance is to have the lens altered so that it will focus to infinity with a new built in EF rear bayonet.

-Son


just to clarify, is this true of any FD lens or just this one in particular?



Jun 29, 2005 at 11:56 PM
Pham Minh Son
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p.1 #8 · p.1 #8 · Infinity focus with FD lenses


Asim, it is true for all of the FD lens. What makes it so hard to convert these dorn FD lens to EF bayonet is that the FD rear mounting is so different and it has been known that we must sacrifice the aperature ring to make this possible in the alteration for inifnity focus. I am planing to make the modification for the canon FD 55mm F1.2 Aspherical lens to become EF and shoot wide open at f1.2. This lens is very sharp lens from canon. In fact even the Leitz Guru admitted that Canon put all effort out and they achieved amaizing results with the FD 55mm F1.2 Asherical lens. As we know there are folks here would love to see a 50mm f1.2L. However, we all been waiting but Canon is not going to give it to us. Thus, this is my next alternative. Besides, no one has seen the FD 55mm F1.2 Aspherical on digita sensor yet.

-Son



Jun 30, 2005 at 12:08 AM
Pham Minh Son
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p.1 #9 · p.1 #9 · Infinity focus with FD lenses


Asim,

If there was a simple way to convert these FD lens to EF bayonet mounting then ebay price on these nice lens would not be so redicuously so cheap.

-Son



Jun 30, 2005 at 12:09 AM
ent2b
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p.1 #10 · p.1 #10 · Infinity focus with FD lenses


btw, Son, congrats on your new status! perhaps i'll send you a FD 85L and have you convert it for me. I just missed one for $300 locally. but, i do imagine on a 20D, it will be harder to focus than on your FF body, which is a "III"?


Jun 30, 2005 at 12:34 AM
Pham Minh Son
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p.1 #11 · p.1 #11 · Infinity focus with FD lenses


Asim, I think if we get one for cheap especially the 85mm F1.2L or the 55mm F1.2 aspherical we can converted and just shoot it at f1.2. I was told that the old 85mm F1.2L FD is actually optically better than the autofocusing one from folks who shoot films. I love to test them side by side and you know how good the EF 85mm F1.2L is.

Thanks I am now a married dude

Oh yes, I am regaining some lens back now and I will wait until the 22 megapixel 1Ds Mark III to come out before I put the money on these camera. I promise myself when it get to 22meg I will not trade camera anymore for a long time no matter how many more meg they come out after that.

-Son



Jun 30, 2005 at 12:37 AM
astrolucida
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p.1 #12 · p.1 #12 · Infinity focus with FD lenses


jrs915 wrote:
My question is, based on the internal focusing, it appears that the lens could focus past infinity, but there is just some sort of stop at the focusing ring which doesn't allow it to go any futher.

Never seeing the inside of the lens, I'm not really sure if I could just take it apart or have a camera repair place take it apart and put the stop someplace further to allow it to focus past infinity, which should give me infinity focus


I think this depends on the lens internals. Some lenses might have room available for the internal focusing mechanism, while others might already hit the limit. If there is room, then adjusting the relation between the focus ring and the mechanism would work. It is also possible it works only partially.



Jun 30, 2005 at 01:05 AM
Kyle Yates
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p.1 #13 · p.1 #13 · Infinity focus with FD lenses


Roy NN7DX wrote:
Hama Lens Mount Adapter - Canon FD & FL Lenses on Canon EOS Bodies
Mfr# HA30845 B&H# HALACFDCAF B&H Price: $ 119.95

This adapter allows for Canon FD and FL type lenses to be mounted onto a Canon EOS body.

Unlike other simple mount adapters, this is an optical adapter which is actually at the same time also a short teleconverter, which increases the focal lenght by a factor of 1.25x, and reduces the lens aperture by approx. one f/stop. This adapter allows for focusing at infinity.

Here


These adapters are HORRIBLE.

You need the proper adapter which has a 1.2X factor and you lose 2/3 a stop but it works very well indeed --I use mine on a FD 2.8 'L' 400 MM ==brilliant Lens.

These will omnly work on specific telephoto lenses ( I think the 500 is one of them) .

Note --the difficulty is due to the long protruding piece so the optics have to be VERY accurate -- a simple piece of glass won't do.

You CAN use Av on the camera --the camera will adjust the exposure -- set of course the aperture manually on the Lens and of course as well Manual Focus.

Here's what a proper one looks like

http://www.1kyle.com/converter.jpg

You can see the protruding piece which fits into the Lens and makes a proper fit unlike the other adapters.

Cheers

-K



Jun 30, 2005 at 01:16 AM
Pham Minh Son
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p.1 #14 · p.1 #14 · Infinity focus with FD lenses


Kyle, that is one expensive piece that has been discontinued and very difficult to get extender-adapter.

-Son



Jun 30, 2005 at 01:46 AM
Pham Minh Son
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p.1 #15 · p.1 #15 · Infinity focus with FD lenses


astrolucida wrote, "I think this depends on the lens internals. Some lenses might have room available for the internal focusing mechanism, while others might already hit the limit. If there is room, then adjusting the relation between the focus ring and the mechanism would work. It is also possible it works only partially."

I believe that if you change the mechanism of the rear focusing element you will change the optical performance of the lens. It will no longer be optimized for its design.

-Son



Jun 30, 2005 at 01:48 AM
astrolucida
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p.1 #16 · p.1 #16 · Infinity focus with FD lenses


Pham Minh Son wrote:
I believe that if you change the mechanism of the rear focusing element you will change the optical performance of the lens. It will no longer be optimized for its design.


You are quite right there: lens aberrations are bound to increase. Whether that is acceptable, depends on the application area and how good the lens was before the modification.



Jun 30, 2005 at 02:04 AM
Kyle Yates
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p.1 #17 · p.1 #17 · Infinity focus with FD lenses


Pham Minh Son wrote:
Kyle, that is one expensive piece that has been discontinued and very difficult to get extender-adapter.

-Son



As an old Pro I got this when Canon introduced the EOS line --very glad I kept it.

It was only ever issued to accredited professionals --never on the open market BTW and are VERY difficult to get -- I've been offered over 500 USD for mine --but I'm Keeping it.

A 400MM EF 2.8 'L' lens is NOT cheap so I'm glad I can continue to use my 400 FD 2.8 'L' Lens --still a fantastic piece of glass.

Cheers

-K



Jun 30, 2005 at 02:43 AM
Wesnofske
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p.1 #18 · p.1 #18 · Infinity focus with FD lenses


I've always wondered if the Canon 35mm T/S (tilt shift) lens would be a great candidate for having its mount adapted to EOS. I've heard it's a great lens, and Canon doesn't presently offer a 35mm TSE.


Jun 30, 2005 at 01:20 PM
Pham Minh Son
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p.1 #19 · p.1 #19 · Infinity focus with FD lenses


Kyle, that is one great investment you got there and a professional you are.

Wesnofske, the Canon 35 T/S is an interesting lens. This lens could be modify from the physical appearance and you wont loose aperature function but you may loos the shifting mechanism in order to compensate for the new EF bayonet mount.

-Son



Jun 30, 2005 at 02:17 PM
jrs915
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p.1 #20 · p.1 #20 · Infinity focus with FD lenses


Pham Minh Son wrote:
The only way to get infinity focus without loosing optical performance is to have the lens altered so that it will focus to infinity with a new built in EF rear bayonet. You will have to sacrifice the aperature ring in doing this alteration. Thus, you must shoot wide open in which is fine for the FD 500mm which is already at F4.5.

The way to alter the lens is to cut into the barrel and sacrifice the aperature ring. Use the neutral density filter as your stop down f stops when you need it.
-Son


Do you have any information on this procedure? I would definately consider it if it weren't next to impossible



Jun 30, 2005 at 04:41 PM





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