do FD lenses connect to EOS bodies?

I just finished cutting the mirror out of my 550d. The reason being that it creates a bad gradient or I suppose you could call it a form of vignetting when I use fast lenses for astrophotography. I know that FD lenses usually require a specia adapter, like ED mika or the crappy magnifier adapters to be used with EOS bodies to achieve infinity focus, but can I just screw an FD lens onto my camera now that there is no mirror? And for that matter I may be mistaken, but I always thought that you could not use FD lenses on an eos body because the mirror would hit the lens. Any advice appreciated as I own no FD lenses but would love to have a reason to buy some of the older Fluorite champions.

IMAGE LINK: https://www.flickr.com …sunsetdeluxe/16​351251221/

Also here is the tutorial for removing the mirror, not for the faint of heart. http://www.markshelley​.co.uk …s/canon550mirro​rless.html It permanently eliminates the ability to look through the viewfinder so you have to figure out a way to block stray light from entering the viewfinder as well. I just painted the internal prism black and then covered it with a piece of black craft foam.

calypsob wrote in post #17397410
I know that FD lenses usually require a specia adapter, like ED mika or the crappy magnifier adapters to be used with EOS bodies to achieve infinity focus, but can I just screw an FD lens onto my camera now that there is no mirror?

No.

calypsob wrote in post #17397410
And for that matter I may be mistaken, but I always thought that you could not use FD lenses on an eos body because the mirror would hit the lens.

The reason the FD lenses won't work without an optical adapter is because the mount-to-focal plane (film or sensor) distance in EOS cameras is longer than the mount-to-focal plane distance in the cameras they were designed for.

Check out this article from Wikipedia to see mount-to-focal plane distances for a variety of camera types.

Some FD lenses that have been modified to fit EOS will hit the mirror, but this only applies to Full Frame cameras and only when focused at farther distances. Since you have a crop camera, it would not have been a problem at all.

Here is a sampling of which lenses may contact the mirror and at what focus distance they may start to contact the mirror. (all lenses over 85mm do not contact a FF mirror)

The chart comes form one of the EdMika ads on ebay: http://www.ebay.ca …er%2Fadapter+ki​t&_sacat=0

How come the mirror would cause a gradient on the image, when the mirror is folded away during exposure?

apersson850 wrote in post #17397697
How come the mirror would cause a gradient on the image, when the mirror is folded away during exposure?

I wondered why as well but the link from the 2nd post explains it well: http://www.markshelley​.co.uk …s/canon550mirro​rless.html

Well thats a bummer! Thanks for the input everyone.

Wes;

Apart from you said ways to attach FD lens to a EOS body, there are some other options too.

The cleanest, reversible one, with best IQ would be to use the Original Canon's FD>EOS adapter.
Unfortunately this thing is as rare if not more than Scandium and yttrium!
So you can understand why the price is also so high.

HERE IS LINK TO MIR
HERE IS A LINK BobAtkins
LINK to only deal I can see currently on ebay.

And only very rarely the show up on ebay or likewise but the prices I have seen are ranging from 2500 to 750$ depending on condition.
Nontheless they usually show up in the hand of sellers from Oversee specially Japan and you better be able to trust them before sending money.

The Ed Mike conversion as proposed by you ranged in vicinity of $90-200 and in a hard way, is reversible.

Now the interesting part.
Because I am familiar with you and your work and know the level of your capability let me share it here:

I have seen this being done by a seller from India on ebay.
Buy a 42mm to EOS adapter that should be about $1-10.
Remove the FD's metallic mount ring from lens (3 or 4 screws).
This should make your lens length shorter.
Attach that 42>EOS ring in any way you can. Either by drilling holes corresponding to original lens, using original screws or in case of that Ebay seller, just use Epoxy.... Yes don't underestimate Epoxy as if you follow news, it can hold things that History can't... And I am talking of Bear of King Tut of Egypt!
I haven't done it myself so can't give you a first hand opinion as to how steady setup is or how much weight it can tolerate but little I know of Epoxy, it is capable to the full extend, but unlike Ed Mika's method, here the procedure is oneway and the only way to get rid of lens thus made, is to sell it on ebay as that guy was doing... More over I assume F ring will not work any more, but not a deal breaker as for night deepsky shooting you need max light and therefore full open F. So may be worth to start first on a very cheap FD lens and see how it goes.

But then important point here regarding mirror and I have first hand experience here.
The bulk of problem with adapted lens and in camera mirror is with "FULL FRAME" camera bodies and not crop format as your 550D that the larger mirror of FF DSLR, hits the back of adapted (Longer that usual) lens and at times even sticks and you have to detach the lens to reattach and get rid of situation. I have this issue currently with may 5D and several of older lenses specially Zeiss and Contax mount lenses.
In any case by removing your lens box, you probably should save on battery significantly. Then reduce the vibration significantly for brighter objects and in essence if you know what you are doing (And I am convinced that you do) it is not a bad idea, though probably you will remain the last owner of that camera.

Please share you experience as you go down the path. I am sure it is going to be interesting and now the only other thing you should do is to find a cooling system for your sensor.

couldn't you mount FD lenses to an EOS M? and it already has the mirror removed, so no need to do any surgery to the camera

the main problem i see is if you want wide and fast, there really aren't any options for the crop sensor with FD lenses

Good to know, im going to try out the epoxy method on a cheap fd lens first and see where I can get with it. Thanks for the tip! Not worried about resale, it will go quick on astromart if need be.

Its funny you mention cooling, pretty soon I plan to buy another 550d, debayer the sensor to monochrome and add a peltier cooler. I am going to keep this one to shoot rgb.

Confused by this. A the camera is already de-mirrored. B, FD lenses were designed for 35mm film, which requires a much larger circle of illumination than the small aps-c. Lenses im interested in are fd 200mm f1.8, fd 300mm f4 fluorite variant, fd 500mm f4.5.

calypsob wrote in post #17399954
Confused by this. A the camera is already de-mirrored. B, FD lenses were designed for 35mm film, which requires a much larger circle of illumination than the small aps-c. Lenses im interested in are fd 200mm f1.8, fd 300mm f4 fluorite variant, fd 500mm f4.5.

i'm not sure what you're confused by?

if you're looking at longer lenses, then i'd say it makes a bit more sense to look at FD lenses...the reason i mentioned the mirrorless EOS-M is that i believe you can mount FD lenses with a glassless adapter, and still maintain infinity focus...which you wouldn't be able to do on your 550D with a lot of FD lenses...i think the only way you can is the ed-mika adapters

DreDaze wrote in post #17400009
i'm not sure what you're confused by?

if you're looking at longer lenses, then i'd say it makes a bit more sense to look at FD lenses...the reason i mentioned the mirrorless EOS-M is that i believe you can mount FD lenses with a glassless adapter, and still maintain infinity focus...which you wouldn't be able to do on your 550D with a lot of FD lenses...i think the only way you can is the ed-mika adapters

Gotcha, yes you are correct at this point an Ed mika adapter is the only way. The eos m is an interesting camera but unfortunately it cannot be tethered and controlled by astronomy software so it was never able to really take of astronomy wise. Also my 550d is already modded, so I am trying to avoid having to have another camera modded for full spectrum. I will post up results on a modified fd lens soon.

might as well adapt to a mirrorless camera, rather than perform surgery.

A7r, A7, EOS-M in that order depending on how much money you've got.

Dont take this the wrong way but did you read my first post and see the picture? I already removed the mirror, the picture is a mirrorless 550d. The purpose of this thread was to establish what I need to do to use an fd lens at this point. Thank you for advice on alternative camera bodies I am well aware of these choices.