Just curiuos if anyone can shed some light on an issue I have seen crop up a few times with my 5D when using a Contax/Yashica Focus confirmation adapter I bought from happypagehk off the auction site. On at least three to four recent occasions when using this adapter with both a C/Y Zeiss 28 2.8 AND the C/Y Zeiss 35-70 Zoom, the camera shutter seems to stay open way too long resulting in an extremely overexposed frame. My first thought was that somehow I might be seeing a mirror problem with the 5D and these lenses on this particular adapter but then why would that affect the shutter? Switching to a different adapter - the Fotodiox Pro - the problem seems to go away. I do recall that I was focusing near infinity which also gives some credence to a possible mirror issue(If for instance, that particular adapter allowed me to focus just barely past infinity and that was just enough to cause a mirror issue?). OR, is there any way that the focus confirmation chip could somehow electronically cause an issue with exposure?(which seems unlikely) Has anyone else seen this sort of behavior?

I haven't seen it. It sounds like you have mirror interference.

The funny thing is that the few times I have encountered mirror interference with other lenses, the opposite occurs. The frame is severly underexposed, not overexposed.

Some more testing and it is indeed a mirror issue. Apparently, the tolerances are so close with the C/Y Zeiss lenses when used with an adapter on a 5D that if the adapter just barely goes past infinity, there is mirror interference. So, the solution is to either be extrremely careful not to focus past infinity OR use an adapter which does not allow this. I guess the cheaper adapter used with the confirmation chip is made a little extra thin which is why I ran into this issue. Thank goodness the rear elements are recessed so that they were not scratched on these two lenses. They are both MM type lenses and I don't know if that affects this or not as it is actually the housing which holds the rear elements which causes the interference. They also work perfectly with no interference as long as infinity focus is not ever so slightly missed.

One last observation. The happypagehk confiramtion adapter will not work at all with the C/Y Zeiss 35-70mm MM regardless of the focusing distance! That adapter seems to always cause mirror interference with this particular lens and body and it has nothing to do with the distance of the rear element but rather the distance that adapter places the stationary inner barrel from the mirror which is where the interference issue is. No problem at all with that same lens using the Fotodiox Pro adapter on the same body(5D).

Happypage states that his newest Contax-EOS adapters are thinner than his previous adapters, and what many others sell. That's because many wide angle users have reported to him that a thinner adapter is needed for best performance (and proper regestration film to flange). If you use the Fotodiox Pro adapter on one of the wides you may find it's too thick and/or givesd poor perfomance across the frame. Adapters for the Contax CZ's seem to be a real pain. It's best to match each lens to a specific adapter an leave it there.

Yep. I did buy my happypage adapter recently and it was one of the newer, thinner ones I guess. The various C/Y lenses do appear to be very picky as far as adapters go. Wish I had a Zeiss 21mm to test your theory.

Hi Tariq,

I did have mirror clearence issues with my Distagon 21 and an extra thin adapter from Son. The same lense works perfectly with a very recent adapter from Rudolf (HapypageHK), which also seems to be exactly the right thickness for my 5D and Distagon 21 to go exactly to infinity. The adapter also works without a problem with my Vario Sonnar 35-70 but may actually be slightly to thick, at least I am not 100% positive if it goes all the way to infinity. The Distagon 28/2.8 seems to have a slightly better mirror clearence than the Distagon 21, at least the extra thin adapter from Son works with my Distagon 28, causing mirror hangs only very ocassionally.

If the mirror is sticking, it is the removable block at the top of the lens mount (on the lens). My 35-70 was causing the mirror to stick . . . which was confusing because the glass is deep in the mount. After removing the block (can be filed and re-installed) no more problem.

With the new happypage adapters, my 85/1.4 also needed the block removed/filed.

Not all lenses have this . . . the c/y on the left has a tab, the one on the right the offending block. Easily removed - two screws.

Thanks Lars and Kevin. Very helpful information.

Kevin, again, thank you, thank you, thank you. I removed the block you mentioned and the Happypage focus confirmation adapter works perfectly now with my 35-70 lens. What a great combination. I can't imagine using that lens without the "beep" for focus confirmation that adapter allows. What a great lens.

Damn—wish I had read this thread six months ago—my 35-70 hung on my 5D's mirror too, and I sold it. It is a great lens for the money, for sure.

Kit, these lenses are selling for even less than they did 6 months ago. Mine was a MM mint condition for just under $300. I bet you would have no problem getting one for between $250-$300 right now.

Tariq Gibran wrote:
Kevin, again, thank you, thank you, thank you. I removed the block you mentioned and the Happypage focus confirmation adapter works perfectly now with my 35-70 lens. What a great combination. I can't imagine using that lens without the "beep" for focus confirmation that adapter allows. What a great lens.

Hi Tariq,

Both my CZ 21mm & 28mm seem to overexpose on my 5D. I have the happypagehk adaptors but I don't have enough experience with this stuff to diagnose a mirror issue. I have never used Av mode until acquiring these lenses (a practice I adopted after reading many user posts), so I chalked it up the eccentricities of that mode. Also, I seem to remember reading posts from various Av users on other forums that they have to dial in some EC because thier 5Ds tend to overexpose (even with Canon lenses).

Anyway, I started bracketing a 1/3 stop with a -1/3 EC, and usually out of the three, I get what I need. Both of my CZ lenses (MM types) are absent of the block that Kevin mentioned. You removed the block from the 35-70, so just wondering if your 28mm had the same block and if not, is it still overexpsoing?

I know the Tariq's post is in reference to the 5D, but here's some additional experience with HappyPage's latest revision. So far they work very well on the 1Ds2 and I've not had any clearance issues with the newer (thinner) adapters. Infinity focus appears good too. I've used the 28/2 and 100/2; I'll try the 35-135 later this weekend. HappyPage has been excellent to deal with - he even zapped the AF chip with the appropriate lens information for each of my lenses. It took a bit longer to get adapters due to this customization, but now the EXIF shows the correct mm for each.

Unfortunately the actual aperture setting cannot be captured because the EOS metering system would compound the aperture calculation (ie F5.6 on the lens x F5.6 on set on the body) and shots would be grossly over-exposed. If you're going to use one of HappyPages adapters for a lens faste than F2 - you might want to let him know since he set the F2 as the aperture setting. I'm not sure if the F2 setting would compromise wide open metering on the 85/1.4, 35/1.4, etc.

John Black wrote:
Unfortunately the actual aperture setting cannot be captured because the EOS metering system would compound the aperture calculation (ie F5.6 on the lens x F5.6 on set on the body) and shots would be grossly over-exposed.

If you use manual exposure mode (vs Av mode), you should be able to set the aperture on the body and the lens to match and capture the aperture setting in the EXIF without overexposing. These are assuming that the chip's info on the lens' maximum aperture is accurate and that you focus and meter with the lens wide open with the aperture set on the body to the desired aperture and stop down just before taking the shot.

rfkiii wrote:
Tariq Gibran wrote:
Kevin, again, thank you, thank you, thank you. I removed the block you mentioned and the Happypage focus confirmation adapter works perfectly now with my 35-70 lens. What a great combination. I can't imagine using that lens without the "beep" for focus confirmation that adapter allows. What a great lens.

Hi Tariq,

Both my CZ 21mm & 28mm seem to overexpose on my 5D. I have the happypagehk adaptors but I don't have enough experience with this stuff to diagnose a mirror issue. I have never used Av mode until acquiring these lenses (a practice I adopted after reading many user posts), so I chalked it up the eccentricities of that mode. Also, I seem to remember reading posts from various Av users on other forums that they have to dial in some EC because thier 5Ds tend to overexpose (even with Canon lenses).

Anyway, I started bracketing a 1/3 stop with a -1/3 EC, and usually out of the three, I get what I need. Both of my CZ lenses (MM types) are absent of the block that Kevin mentioned. You removed the block from the 35-70, so just wondering if your 28mm had the same block and if not, is it still overexpsoing?

If your talking about HappyPages Focus Confirmation adapters, mine seems to be metering perfectly on both the 28mm 2.8 and 38-70 3.5 when using AV and Evaluative Metering. If your not using Evaluative metering OR a non chipped adapter(which cannot actually use the Evaluative metering), that could throw your exposure off depending on what is in the center of the frame. I recall that with a non chipped adapter on the 35-70, my exposre was off 1 stop. My 28mm 2.8 MM does not have the block by the way.

John Black wrote:
HappyPage has been excellent to deal with - he even zapped the AF chip with the appropriate lens information for each of my lenses. It took a bit longer to get adapters due to this customization, but now the EXIF shows the correct mm for each.

After reading this, I requested this service from happypagehk and he replied:

Yes we are capable of flashing the chip with different parameters and have done it for very limited cases. Unfortunately since we started doing so we received too many requests and our R&D staff is now overloaded. Yet we can do it for you because your Contax adapter is expected to send out some days later but not immediately. For other customers I am afraid we have to turn down their requests, so please do us a favour do not advertise the service on forums.