Manual Focus Forum
Discuss how to buy, fix, clean, and use all the old manual focus photography kit you can find.
M42, Pentacon 6, Contax, Leica, Canon, Nikkor, Carl Zeiss Jena, Asahi Pentax Takumars etc!
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#1 2007-11-25 20:26:08
5D Mirror Mod: Success!
(Before you begin, yes this is the same topic that I posted over at FM, but many of you are not over there, so...)
Well, I finally found the courage to do it. My recent discovery and modification of the Minolta MC Rokkor-PG 58/1.2 pushed me over the edge.
I originally planned to use "Glad Press'n Seal" as masking material, but it did not "seal" the way I needed it too. Instead, I used green painters masking tape. I found it just flexible enough and just tacky enough to do the job. It is also just rigid enough to hold the mirror in place on its own, which was great because I was apprehensive about sticking something in the mirror box to prop the mirror up. I didn't want *anything* to touch the shutter.
I left about 1/8" of mirror sticking out beyond the masking tape. The mirror was about 2/3 to 3/4 "open".
I was too cheap to spend the $80 on a Dremel, so I bought some mini files of various shapes and a small "grinding stone" drill attachment. I stuck the grinding stone on my 850rpm cordless drill and went to work. It was slow going, as expected, but I didn't mind taking my time with this project
I used one of the files to work away at the plastic frame and then used the grinding stone to work at the mirror, alternating back and forth, because the plastic frame tended to gum up the grinding stone. I did not measure how much I took off (I just eyeballed it). When I thought I had taken enough off, I vaccumed everything thoroughly and kept vaccuming the area as I removed the masking tape carefully. Not much dust got inside at all and what was there was obvious and very simple to remove with a statically charged brush. There was no trace of dust or particles on the shutter.
Once complete, I immediately tried my Super-Takumar 50/1.4. I knew that it was just barely hitting before, so I figured it would be fine now. I was correct! No problem at all.
Next, I tried the Rokkor 58/1.2. Clunk! Uh oh. Hmmm... it certainly does protrude quite a bit more than the Super-Tak. So, I took my file to the back of the Rokkor and reduced the metal ring around the rear element so that it is nearly flush with the glass. Tried it again. Perfect. Click, click, click.
Not sure if this means I am home free with all the Leicas, but I can't afford them anyway. The mod was a bit nerve-racking, but I certainly wouldn't hesitate to do a bit more grinding if I fall in love with some lens that causes issues.
Time for a gin & tonic
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#2 2007-11-25 20:32:35
Re: 5D Mirror Mod: Success!
Oh, one other note:
I really should have taken photos of the procedure, but I was so "fixated" that I completely forgot. I only remembered a bit later, when my wife walked into the kitchen and asked "Is that the 5D ?!" It occurred to me then that I really aught to have taken a photo of the look on her face.
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#3 2007-11-25 21:34:24
Re: 5D Mirror Mod: Success!
cogitech wrote:
I was too cheap to spend the $80 on a Dremel, so I bought some mini files of various shapes and a small "grinding stone" drill attachment.
You´re a brave man...
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#4 2007-11-25 21:55:52
Re: 5D Mirror Mod: Success!
B. Ilktac wrote:
cogitech wrote:
I was too cheap to spend the $80 on a Dremel, so I bought some mini files of various shapes and a small "grinding stone" drill attachment.
You´re a brave man...
I've been told that before, but usually I ended up with an injury afterwards.
Luckily, no injuries involved here. Although, in hindsite, I really aught to have used safety gear.
The "grinding stone" was about the size of a Dremel attachment, so it was not unwieldy, and the 850rpm kept things to a dull roar. Very manageable, in fact.
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#5 2007-11-25 23:15:36
Re: 5D Mirror Mod: Success!
I have a vari-speed Dremel. Lovely tool.
Not a snowball's chance in Hell am I ever taking it to my 5D, though.
If you've got the stones for it, I guess...
Happiness is a loaded camera: Canon 5D+Grip | Nikon F3
Tamron AD2 90mm ƒ/2.5 | Canon EF 17-40mm ƒ/4L | Nikkor AIS 35mm ƒ/2, 85mm ƒ/1.4 | Minolta MC Rokkor-X PG 58mm ƒ/1.2 | Voigtländer Ultron 40mm ƒ/2 SL-II
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#9 2007-11-26 16:30:58
Re: 5D Mirror Mod: Success!
OK. Here's some quick shots I just took.
The masking material:
The grinding stone (you can see how the plastic mirror frame was gumming up the stone, but I was able to use the side to grind the mirror):
The file(s) (You can see the plastic from the frame still in the teeth):
The final product:
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#10 2007-11-26 17:35:07
- Flor27
- Focus: Way Over There
- From: Paris, France
- Registered: 2007-09-10
- Posts: 210
Re: 5D Mirror Mod: Success!
Oh man... that is a mod I would love to do! But so far I don't have a 5D... :-(
Mon matos: click here
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#11 2007-11-26 18:09:00
- 440roadrunner
- Focus: Infinity
- Registered: 2007-07-24
- Posts: 700
Re: 5D Mirror Mod: Success!
If you've seen some of my lens "modifications" then you know I'm not afraid to dig in. However, THIS would be a project that would give me pause........
Something that would bother me is that all the stress and vibration of filing and grinding would knock the mirror out of alignment, or tweak the hinge mechanism.
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#12 2007-11-26 19:09:05
- awldune
- Focus: Infinity
- From: NC, USA
- Registered: 2007-07-27
- Posts: 763
Re: 5D Mirror Mod: Success!
Congrats!
I am thinking about buying a 5D when the price is right, and will probably give this a go.
Do you see any difference when looking through the viewfinder, or is the shaved edge outside of the view?
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#13 2007-11-26 22:05:39
Re: 5D Mirror Mod: Success!
awldune wrote:
Congrats!
I am thinking about buying a 5D when the price is right, and will probably give this a go.
Do you see any difference when looking through the viewfinder, or is the shaved edge outside of the view?
Thanks!
Nope, no change to the viewfinder at all.
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#14 2007-11-26 22:58:33
Re: 5D Mirror Mod: Success!
440roadrunner wrote:
If you've seen some of my lens "modifications" then you know I'm not afraid to dig in. However, THIS would be a project that would give me pause........
Something that would bother me is that all the stress and vibration of filing and grinding would knock the mirror out of alignment, or tweak the hinge mechanism.
While using the file on the plastic frame, I held the mirror in position with my left thumb and index finger. It took very little pressure to remove the plastic, but I held it this way because the force of the action was perpendicular to the mirror and I wanted to avoid mirror movement (which would have pulled the masking tape away).
While grinding, I only applied enough pressure to slowly work away at the mirror. Most of the force here was parallel to the mirror edge, due to the rotation of the stone, and the friction required to remove the material from the mirror was not enough to cause damage to the mirror mechanism.
I alternated between these two methods, reducing each material separately, until it appeared that I had removed enough.
Also, I did not anchor the camera body to anything. I simply laid it flat on its back on my bench. A few times when I applied slightly too much pressure with the stone, it "grabbed" a bit and the camera body jiggled slightly. The slightly excessive force was distributed to the whole body, rather than the mirror taking the brunt of it.
It was nerve-racking, but overall it was simpler and less time consuming than the mount conversion I did on the Rokkor 58/1.2.
Also, in the back of my head I knew that it would only be a $300 repair if I completely screwed up. I could try it and mess it up many times with the money I saved *not* buying a 50/1.2 L.
Love the Rokkor even more, now! 
Last edited by cogitech (2007-11-26 23:05:56)
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