GET THE CAMERA REPAIRED.

Hi ,
 
 
As  lots of other users , I have experienced problems in infinity using the tokina wide open , and also the samyang 8mm... wrote to blackmagic complaining and I got an answer that kind of shocked me.... summarizing they recommended me to change the tokina if that is the only lens I have problems with ( also with the samyang 8 mm) , blaming the lens not the camera , and that they do not recommend adjusting the tolerance of the mount since it can introduce problems to other lenses... This explanation does not convince me  at all, I've used the tokina in several canons and a Fs100 metabone adaptor with no problems at all. It sounds to me that they are slacking off their responsibilities..... am I wrong ?

Blackmagic is now telling me that if I send over the camera to get the flange prob fixed and then make my tokina 11-16mm working at infinity ( also had the same issue with the samyang 8mm) other lenses could be affected by that... Does this make sense? Has anyone had this problem?

It's kind of strange....

yes and no

the EF mount is proprietary to Canon. Everyone else that supports the EF mount are basically engineering their own version. The flange distance of the EF mount is "reported" to be 44mm. Unfortunately, a millimetre is a large enough unit of measure that there is still lost of room for high variation. You need a lot more precision that what's being given. So when Tokina, Tamron, Sigma or whoever make their lenses, they are designing to their own "version" of the EF mount with a 44mm flange distance.

The Tokina is a lens that seems to have far more issue with the EF flange distance than many other lenses. Reports of problem on the 7D and 5D have been reported for some time. This is why BM suggests you don't tweak the mount for one lens since it could/would throw hundred of other lenses out of alignment.

It's definitely one of the downsides of using stills glass on a cinema camera, especially one with such a high crop factor. There are not many lens options for shooting wide.

The only other comment I'll make is that while Tokina makes some very nice lenses, they (like Sigma) suffer from copy-to-copy variations. So while the Tokina you have is a problem, it's quite possible that another copy of that lens could be fine.

Has anyone had this problem?

Just search this forum...it's a well know issue.

He starts his post with 'As lots of other users'

He means the problem of Blackmagic not wanting to fix it.

Blackmagic is now telling me that if I send over the camera to get the flange prob fixed and then make my tokina 11-16mm working at infinity ( also had the same issue with the samyang 8mm) other lenses could be affected by that... Does this make sense? Has anyone had this problem?

It's kind of strange....

Call your local BMD Support Office: http://www.blackmagicdesign.com/company/
Demand they fix there Flange adjustment,
It helps if you have tested lenses that will not focus to infinity But it's not a given.

Tell them, I want my camera to have a tolerance that accepts EF Still lenses "PERIOD"
No If's, And's or But's, period.

Fix this borked flange mount, End of Argument!

If other lenses do not work, send the camera back for a refund, and if they bitch about that, then well...maybe they need a few reminders and about the law, and we need to band together and make
our discretion heard in a forum of Judges?

Firstly this is a real names forum.

Secondly, it's not really right to describe the flange as being broken. It's actually correct, and what you're asking for is a shorter than standard flange depth to be set when you want your camera "fixed"

What BMD will then do is deliberately shorten your FFD.

So now, low tolerance lenses that don't have accurate witness marks will hit infinity if they didn't before (some lenses do without a fix) and any cinema lenses will no longer have accurate witness marks.

Your BMCC will have a shortened FFD that means all lenses should hit infinity, but any lenses with accurate witness marks and hard stops at infinity will no longer be as accurate (assuming they are correct to start with)

JB.

Ok thanks DG FIlms and thanks John,


But i have a doubt.... the only side-effect I might get from getting it fixed is that the witness marks won't be as accurate? if so I do not mind at all, I focus myself and on the event of having a focus puller besides me he can always make new marks on the lens or follow focus ring, this is definetely not an issue, what it could be a major issue is not being able to focus to infinity the other lenses I have, or other lenses in the future... the ones I have now:

TOKINA 11-16 2.8 ( not working)
SIGMA 24-70 2.8
SIGMA 50 mm
CANON 70-200 2.8 L
HELIOS 44-2
LENSBABY

And I might get a complete set of samyang / rokinon in the future.

Blackmagic is telling me that I might have problems with other lenses , not being specific in what kind of problem,

John if that is the only problem ( witness marks) ...that's a relief...

And by the way !

Is the camera very very , I mean very sensitive to light that contaminates the fron lents ? I mean flares and things like that ?

Thanks!

Firstly this is a real names forum.

Secondly, it's not really right to describe the flange as being broken. It's actually correct, and what you're asking for is a shorter than standard flange depth to be set when you want your camera "fixed"

What BMD will then do is deliberately shorten your FFD.

So now, low tolerance lenses that don't have accurate witness marks will hit infinity if they didn't before (some lenses do without a fix) and any cinema lenses will no longer have accurate witness marks.

Your BMCC will have a shortened FFD that means all lenses should hit infinity, but any lenses with accurate witness marks and hard stops at infinity will no longer be as accurate (assuming they are correct to start with)

JB.

Dear John,
First, I regret to inform you that hundreds of forums members are not abiding by the real names forum rule,
Second, it is my/our right to describe the flange as being broken due to the fact BMD has admitted it,

Third, if it only breaks witness marks, and Canon EF lenses have a tolerance that BMD has gauged to be acceptable and have fixed hundreds of BMCC's thus far?? why are we discussing it?,
Fourth, And now you have mentioned it, What else do we not know? before we buy the Pocket or Production camera.. John?

Please explain how over 80% of BMCC purchasers are coming from DSLR's and how we can not afford to be guinea pigs so you can brood over BMD's accountability? and act like we know nothing about how camera manufactures do business.

It's more than you can deal with John, It's bigger than both of us, And no one advocate can fix it,
This is all about BMD dealing with customers here and now, or never, It's up to them.

One thing I will always confirm about BMD is they are doing what no others are,
They have faults, but the faults are few and far between, BMD is making history as we complain about the camera, Now that's funny!

Cheaper lenses have a lower build quality then the higher end "cinematic" lenses, the tolerance on the "affordable" lenses is larger in terms of measurements, than the professional (expensive) lenses. It is a cinematic camera for a reason, I only use Canon or Zeiss lenses, my Tamron lens seems to be soft compared to the others.

Dear John,
First, I regret to inform you that hundreds of forums members are not abiding by the real names forum rule,

Forum Rules:
You agree to use your real name including your location and job title if applicable. We believe people who post under their own name will be more respectful of others when posting as opposed to posting anonymously.


Maybe it should be enforced.... DGFilms

And by the way !

Is the camera very very , I mean very sensitive to light that contaminates the fron lents ? I mean flares and things like that ?

Thanks!

Flare sensitivity is an aspect of lens design, not camera design.

Most quality lenses have good coatings on the front element to limit flares...but accurately shading the front of your lens from oblique angle bright lights is still required. A matte box or lens shade helps a lot.

sean

Ok thanks, but it's wierd I did not have so much flares when using the same lenses on my 7D..... besides it's a strange flare , it's more a white vignette appearing on the same side of the light source...

can you post a still?

Not now, will do soon... thanks!

Even if this company is called Blackmagic, optical physics is not based on voodoo or any other mistery stuff
Solution is very simple
Take your Tokina lens to a camera repair shop in Barcelona
In 5 minutes they will get the lens to a collimator
if they say the lens is ok.. Blackmagic camera is wrong!
Simple as that

John Brawley!!
Do you remember being funny when i said cinematographers should have been involved in the design?
You called me Hommer! Just because i wanted a camera designed by cinematographers.. just like aaton, eclair, arri, movicam..
where is the back focus ring?
is there a shims solution like in other cameras?
yes.. very odd things for a CINEMA camera!!

As I previously said .... it also happened with an 8mm Samyang... may I think that is the ef mount not the lenses?

You think there´s something about the camera mount
Just take your tokina & samyang to a collimator.. and instead of thinking you will be sure

where is the back focus ring?
is there a shims solution like in other cameras?
yes.. very odd things for a CINEMA camera!!

Backfocus ring isn't a feature of EF mounts is it? (None on the RED EF mounts as far as I'm aware PL yes, EF nope)

Shim fixes I've always associated with lenses.

where is the back focus ring?
is there a shims solution like in other cameras?
yes.. very odd things for a CINEMA camera!!

Backfocus ring isn't a feature of EF mounts is it? (None on the RED EF mounts as far as I'm aware PL yes, EF nope)

Shim fixes I've always associated with lenses.

Alexa backfocus is fixed by shims in the mount.. just like any film camera

Once we have our mft cameras.. we can have letus pl adapter with backfocus ring
http://www.letusdirect.com/cart/micro-4 ... t-bmc.html

Dear John,
First, I regret to inform you that hundreds of forums members are not abiding by the real names forum rule,

Sure. But I follow the rules of this forum. It's a condition that you agree to when you sign up to this forum. I'm pointing out that this is a real names forum, most prefer real names. It's easy for you to change in your settings.

Second, it is my/our right to describe the flange as being broken due to the fact BMD has admitted it,

It's your right to call it whatever you want.

Third, if it only breaks witness marks, and Canon EF lenses have a tolerance that BMD has gauged to be acceptable and have fixed hundreds of BMCC's thus far?? why are we discussing it?,

Yes. You've nailed it. It breaks something. So how is it that a FIX can break something ? I'm making a point that goes to what the original poster was asking about and what BMD told him, which is in fact true. You seem more interested in scoring points and holding them to account. BTW, canon bodies also have shorter than standard FFD's and witness marks aren't accurate on their cameras either.

Having your FFD set to a shorter than standard FFD (which is what this "fix does) means that some lens functions break. They are checking that he really wants to forego infinity hard stops that stop at infinity and less accurate witness marks. They're making sure he makes informed decision.

Fourth, And now you have mentioned it, What else do we not know? before we buy the Pocket or Production camera.. John?

What are you asking ? What are you inferring ?

Please explain how over 80% of BMCC purchasers are coming from DSLR's and how we can not afford to be guinea pigs so you can brood over BMD's accountability? and act like we know nothing about how camera manufactures do business.

I really don't know what you're getting at.

It's more than you can deal with John, It's bigger than both of us, And no one advocate can fix it,
This is all about BMD dealing with customers here and now, or never, It's up to them.

Seems to me like they are ?


jb

where is the back focus ring?
is there a shims solution like in other cameras?
yes.. very odd things for a CINEMA camera!!

The canon EF mount design features a shim that's not a user serviceable thing unfortunately. It's deep in the back of the mount and is a special feature of the design.

jb

Alexa backfocus is fixed by shims in the mount.. just like any film camera

Once we have our mft cameras.. we can have letus pl adapter with backfocus ring
http://www.letusdirect.com/cart/micro-4 ... t-bmc.html

Um yes.

On a PL mount camera.

We're talking about an EF mount camera guys. You shim the mount, but it's very hard to get to.

jb

And by the way !

Is the camera very very , I mean very sensitive to light that contaminates the fron lents ? I mean flares and things like that ?

Thanks!

I do have a theory about this.

Because you're using 135 format lenses, they project a much larger image circle than what is required for the smaller m4/3 sensor size.

I think sometimes, you can get extra light and veiling flare from BEHIND the lens and before the sensor.

This used to happen when people put S35 lenses on some super 16 cameras. Light would sometimes bounce off things in the camera gate.

jb

Ok thanks DG FIlms and thanks John,


But i have a doubt.... the only side-effect I might get from getting it fixed is that the witness marks won't be as accurate? if so I do not mind at all, I focus myself and on the event of having a focus puller besides me he can always make new marks on the lens or follow focus ring, this is definetely not an issue, what it could be a major issue is not being able to focus to infinity the other lenses I have, or other lenses in the future... the ones I have now:

TOKINA 11-16 2.8 ( not working)
SIGMA 24-70 2.8
SIGMA 50 mm
CANON 70-200 2.8 L
HELIOS 44-2
LENSBABY

And I might get a complete set of samyang / rokinon in the future.

Blackmagic is telling me that I might have problems with other lenses , not being specific in what kind of problem,

John if that is the only problem ( witness marks) ...that's a relief...

Yes witness marks not being accurate is the main side effect.

To be honest, on the lenses you mention they aren't that accurate in the first place anyway. Most still lenses barely even bother with witness marks these days. It's only when you get to CINE lenses like the Zeiss CP's or some of the angenieux optimos that you would notice.

There is one other potential side effct and again it's lens dependent. Some lenses might not hold focus through their zoom range. Again, most STILLS lenses like the ones you've listed don't generally hold focus through their zoom range anyway. But that might be important to you as well.

If not then go for it.

jb

And by the way !

Is the camera very very , I mean very sensitive to light that contaminates the fron lents ? I mean flares and things like that ?

Thanks!

I do have a theory about this.

Because you're using 135 format lenses, they project a much larger image circle than what is required for the smaller m4/3 sensor size.

I think sometimes, you can get extra light and veiling flare from BEHIND the lens and before the sensor.

This used to happen when people put S35 lenses on some super 16 cameras. Light would sometimes bounce off things in the camera gate.

jb

Really? I would hope the entire inside of the housing would be a completely light absorbing, black matte finish. No?

sean

It's definitely one of the downsides of using stills glass on a cinema camera, especially one with such a high crop factor. There are not many lens options for shooting wide.

What this guy said. Using still lenses...and cheaper still lenses at that....on a cine/video camera is going to cause issues. The glass on front is the most important thing to invest money in, and I see from some of the posts, the cheaper lenses are the ones that are having problems.

I've a set of Rokinon Cine lenses, and have been using both Zeiss CP2's and Canon Cine EOS lenses....all manual aperture and focus, great glass and yes-more expensive. Not a single issue. Because the lenses are made to work not with a dslr, but a cine camera.

To many are looking at the low cost of buying a BMCC, and not looking at what you really need to have in order to get the most out of the camera. It's like trying to drive nails with a pipe wrench and then getting mad when half the nails get bent.

Richard Campbell
Tvshooter

Really? I would hope the entire inside of the housing would be a completely light absorbing, black matte finish. No?

sean

Of course it's all matte black inside, but even black still reflects light. Or else we couldn't shoot black objects

As I say, this is not an uncommon problem when you use lenses that have much larger image circles than the sensor or film size.

jb
(remembers the light baffle modifications to Arri 35-3's)

Really? I would hope the entire inside of the housing would be a completely light absorbing, black matte finish. No?

sean

Of course it's all matte black inside, but even black still reflects light. Or else we couldn't shoot black objects

As I say, this is not an uncommon problem when you use lenses that have much larger image circles than the sensor or film size.

jb
(remembers the light baffle modifications to Arri 35-3's)

I do recall a few years ago scientists being very excited about inveting a new 'blacker' paint, intended mainly for applications like space based telescopes and other very sensitive devices, that was deliberately rough at a tiny level to mean that any reflected light intially hit a few localised edges to increase the amount of light that is absorbed. not sure I'd want to have them over as dinner pary guests as anyone who's work conisists of making paint blacker doesn't bode well for their interesting dinner conversations.....

not sure I'd want to have them over as dinner pary guests as anyone who's work conisists of making paint blacker doesn't bode well for their interesting dinner conversations.....

Obviously you never saw Spinal Tap's Smell The Glove album.

"It's like, how much more black could this be? and the answer is none. None more black."
-Nigel Tufnel

Thanks guys for your help.


I'm sending the camera to the UK to get it fixed, will report as soon as I get it back.

Good decision, I'm really looking forward to your response, we need people to use the lenses they have and or the lenses they had problems with to come back and reply about how the FIX fixed the lenses
they have, and or are using.

I just finished my first job with the BMCC and had concerns with wide angle. I borrowed a Sigma 8-16 and had no issues. I only used it for two shots. The rest of the time I was on my 17-40L- no different from my 5D shoots.

I think the idea that a user can expect one third party manufacturer (Blackmagic) to make a product that works perfectly with other third party equipment (Tokina) with Canon EF mount is asking a bit much. Arri and Panavision require shimming for certain lenses. And we all know the quality of that equipment.

Moreover why force a square peg in to a round hole? The Tokina has problems with BMCC so why not sell it on Ebay, KEH, B&H and get a compatible wide angle?

I really do not know why you would have a 8mm prime as well as the Tokina 11-16. What is 2mm really going to buy you? Both lenses are 2.8 so it can't be the f-stop. I think your overly concerned about 'getting wide'. I shoot a lot in practical locations and really the only time I sweat not having the physical space to get a wide is a residential bathroom.

I have a tokina that doesn't hit infinity at less than f8. This lens on an epic is spot on.

And to address the "cheap lens" argument, I recently shot a music vid using the BMCC and an epic. We were loaned a set of Schneider Xenar III primes. These are cine lenses with a price tag of around $8000-$10,000 each. While they were all perfect on the epic, the 25 and 35 wouldn't hit infinity on the BMCC below f5.6. The 18 wouldn't hit at all.

I believe that this is a problem in camera due to canon's lack of official specs. However, this is the first I've heard of BMD not wanting to fix the problem. Is this real? The person I spoke to at BMD said it would be fixed under warranty and BMD covers shipping cost. I'm just waiting on things to calm down so the turnaround time is quicker.

[CaptainHook]

Flare sensitivity is an aspect of lens design, not camera design.

I noticed on my first 'outing' with the camera that our Canon L Primes flared MUCH quicker/easier than on our 5D3's. I do like flares though so try to induce them which is probably why i noticed so quick. John's theory as to the 'why' sounds good.

I believe that this is a problem in camera due to canon's lack of official specs. However, this is the first I've heard of BMD not wanting to fix the problem. Is this real? The person I spoke to at BMD said it would be fixed under warranty and BMD covers shipping cost. I'm just waiting on things to calm down so the turnaround time is quicker.

The issue isn't that canon haven't put out any official specs, it's the tolerances in the spec are causing issues. BMD's mount it appears falls within the requirements but the mount is too precise, so lenses that also fit the requirements can fall within the tolerances of the RF spec but not work on the BMD camera.

Fixing it properly is therefore tricky, as adjusting the mount is just moving this precise measurement around, meaning it's possible that by moving it into one lenses requirements you may shift it out of another's.