Blackmagic Forum

I actu­al­ly have a nag­ging feel­ing the mount of the Black­mag­ic Cin­e­ma Cam­era flex­es with heavy lens­es so if you have infin­i­ty focus issues (like with the Tok­i­na 11-16mm) it might be worth check­ing for this and using rails to sup­port the larg­er lens­es when­ev­er pos­si­ble.

Scott Pultz wrote:Is the front metal piece removable so that it could be replaced?

John Richard wrote:Don't think the weight of the lens is the issue. I and others are using a Canon 7-200mm (a.k.a. "The Magic Drain Pipe") on the BMCC with no barrel support and it infinity focuses fine. This lens is much heavier than the Tokina 11-16mm.

Wished you were right as that would be an easy fix.

Kristian Lam wrote:Hi,

If the focal flange distance is off, we can also adjust it under warranty.

Hang in there while we get to the bottom of this.

Malc84cine wrote:Greetings,
I wanted to take a moment to comment on this flange issue with some members. I'm probably one of the older members so please forgive me in advance of stating some of the obvious. Still lenses that we buy and mix and match are nowhere near the same quality as a true cinema lens you get from a rental house. I'm a fully professional cameraman I'm the union over 15 years and sadly have checked out lenses and found them to be off from Panavison ,CSC , and Clairmont. It is more common than we realize. As you handle the lenses put them in different temps it does force wear and tear on the mounts. The se holds true for our lens mounts. I check all of that carefully during a checkout. Now that your buying and commuting to the camera you will probably have to shim your lenses specifically to the BMCC for now. For my part I ordered a MTF version because the higher end mounts are adjustable to account for this potential problem. Take your camera to a rental house with a lens collimating and really check it out on the bench to be sure. The tech might have some great short term answers.

nilsonium wrote:Thanks for posting Malc84cine, great to have your input.

Could you elaborate on shimming lenses. How exactly do you do this? And, can this be done with consumer lenses like the Tokina 11-16mm?

Christian Schmeer wrote:To be honest, if cinema lenses are better quality than lenses made for still photography is irrelevant. The still lenses focus perfectly fine on Canon cameras, so they should work on the BMCC with Canon mount, too. I'm curious to see what BMD will offer to rectify this, especially if every camera produced so far has the issue...

Christian Schmeer wrote:Most of my lenses, also the ones that achieve infinity focus or go past it, do not hold focus after zooming on the BMCC (e.g. Canon 24-105mm F/4.0 IS L), whereas they do on my 5D Mark III. Why is that? This was also mentioned by someone else in another thread.

Christian Schmeer wrote:Most of my lenses, also the ones that achieve infinity focus or go past it, do not hold focus after zooming on the BMCC (e.g. Canon 24-105mm F/4.0 IS L), whereas they do on my 5D Mark III. Why is that? This was also mentioned by someone else in another thread.

wavalis wrote:HI Sean

My EF16-35 has the same problem as the non parafocal lens. With my BMCC any Canon L series lens I put on appears to not be parafocal.

Regards

Dave

Kristian Lam wrote:

MarshallHarrington wrote:

Kristian Lam wrote:Also if the problem is with the lens, is it possible for Blackmagic to be in contact with Tokina's engineers to find a transparent solution to the problem that all of us can rally to. No one is in a better position than you.

Yup, I'll see what I can do.

Felix Steinhardt wrote:Edit: Just ordered the Novoflex and the cheap Kiwi adapter. Let´s hope...

Kristian Lam wrote:Hi guys,

I want to give you an update about this issue.

The cameras are all shimmed and calibrated to 44mm as per the reported focal flange depth of EF mount. I use the term "reported" as Canon does not publish the specifications officially so the exact expected tolerances are not known.

When checked against a collimated cine lens, we expect the Blackmagic Cinema Camera to get accurate focus according to the witness marks on the lens. For example, at focus chart placed 6 ft from the camera sensor plane will be in focus when the witness mark on the lens is at 6 ft.

When I tried the same collimated lens on some 5Ds, 7Ds and even a C300, the witness marks fall short of the expected distance which indicates to me that there's some fair amount of tolerances built into the Canon cameras to cater for still lenses where the tolerances are not as critical as cine lenses.

To address this, we need to put in the same allowances. We have tested this with some of the cameras from customers reporting this and it works.

If you think you're encountering this issue, please contact your local Blackmagic Design support office and we'll sort you out.

Kristian Lam wrote:To address this, we need to put in the same allowances. We have tested this with some of the cameras from customers reporting this and it works.

If you think you're encountering this issue, please contact your local Blackmagic Design support office and we'll sort you out.

Graham Spice wrote:1) Will this fix be something we have to send our cameras in for?

2) Will this fix the problem with infinity focus on the Tokina 11-16?


Thanks very much for keeping us up to date on this problem, Kristian Lam. Much appreciated

Kristian Lam wrote:

Graham Spice wrote:1) Will this fix be something we have to send our cameras in for?
2) Will this fix the problem with infinity focus on the Tokina 11-16?

1) Unfortunately, yes. The camera will have to be sent back to be recalibrated.

2) Yes, it will. However, this is on the assumption that the copy of the Tokina 11-16 is good as I've read that there are some out there with issues focusing to infinity on other cameras as well.

Graham Spice wrote:Excellent, thank you very much for your responses. I have contacted Blackmagic Support USA to send the camera in for recalibration asap. I did a bunch of tests today with various lenses and really need to go with something really wide like the Tokina. I hope this fixes it!

Kristian Lam wrote:

Graham Spice wrote:1) Will this fix be something we have to send our cameras in for?
2) Will this fix the problem with infinity focus on the Tokina 11-16?

1) Unfortunately, yes. The camera will have to be sent back to be recalibrated.

2) Yes, it will. However, this is on the assumption that the copy of the Tokina 11-16 is good as I've read that there are some out there with issues focusing to infinity on other cameras as well.

Kristian Lam wrote:

Graham Spice wrote:1) Will this fix be something we have to send our cameras in for?

2) Will this fix the problem with infinity focus on the Tokina 11-16?


Thanks very much for keeping us up to date on this problem, Kristian Lam. Much appreciated

1) Unfortunately, yes. The camera will have to be sent back to be recalibrated.

2) Yes, it will. However, this is on the assumption that the copy of the Tokina 11-16 is good as I've read that there are some out there with issues focusing to infinity on other cameras as well.

nivou wrote:

Kristian Lam wrote:

Graham Spice wrote:1) Will this fix be something we have to send our cameras in for?

2) Will this fix the problem with infinity focus on the Tokina 11-16?


Thanks very much for keeping us up to date on this problem, Kristian Lam. Much appreciated

1) Unfortunately, yes. The camera will have to be sent back to be recalibrated.

2) Yes, it will. However, this is on the assumption that the copy of the Tokina 11-16 is good as I've read that there are some out there with issues focusing to infinity on other cameras as well.

Hi Kristian,

Another member here asked about the cameras that will be shipped from now on, and there was no answer if they will be factory recalibrated or they will have the same problem.

Scott Pultz wrote:Did you go through the BlackmagicDesign website or is there another link? I would like my camera calibrated, but I also don't want it gone for a month either!

Kristian Lam wrote:
They will be have the new calibration.

Kristian Lam wrote:When I tried the same collimated lens on some 5Ds, 7Ds and even a C300, the witness marks fall short of the expected distance which indicates to me that there's some fair amount of tolerances built into the Canon cameras to cater for still lenses where the tolerances are not as critical as cine lenses.

To address this, we need to put in the same allowances. We have tested this with some of the cameras from customers reporting this and it works.

danap wrote:@Kristian Lam I bought my camera new and unopened from a private customer in the US who had ordered one too much from a US based distributor. Now the camera is in Norway. Where should it be sent for re-calibration??

PS. My Norwegian distributor was utterly unable to deliver the camera I had ordered from them in August.The relative neglect of European customers by BMD (BTW, heard about Europe? 450 Million people) has been an added cost as I had to get my camera at a higher price than the advertized retailer price. And I am not alone in this situation.