BMPCC + Speed Booster = shifted focal plane?

[Axel]

I hope I can find a brick wall here in Graz...

 

And the Austrians also have no venetian blinds, colanders or patterned clothes? DSLR-heaven! Just tell me in general if you noticed more or less moire than with the Sigma, I am watching an ebay-auction ending this afternoon ...

[sir_danish]

And the Austrians also have no venetian blinds, colanders or patterned clothes? DSLR-heaven! Just tell me in general if you noticed more or less moire than with the Sigma, I am watching an ebay-auction ending this afternoon ...

 

The Lumix 14mm F2.5 doesn´t show as much moiré as the Sigma, not least because my Pancake is a rather soft lens. Mith my Sigma, I feel like I was in moiré hell.

[Axel]

Thank you. I am about to buy a diffusion filter for the Sigma, because it is too sharp. Moire means lower resolution. Resolution and sharpness are related, but you can have an overly sharp image with low resolution. Like in this case.

[sir_danish]

Thank you. I am about to buy a diffusion filter for the Sigma, because it is too sharp. Moire means lower resolution. Resolution and sharpness are related, but you can have an overly sharp image with low resolution. Like in this case.

 

That´s why I avoid shooting RAW when using the Sigma. It´s almost impossible for me to get a single moiré free shot. Look at this:

http://i1285.photobucket.com/albums/a588/sir_danish/moire3_zpsbd471ec6.jpg~original

 

Does this look like a streamlet? Purple and blue blotches everywhere, nobody would ever recognise this as sparkling water.

I´ve been advised to shoot wide open to soften the image a bit... LOL!! Well, I can´t because of the problem mentioned above.

I should try it with the pancake next time.

[Ken Aqua]

Sorry for this very slow response.

 

I'm a new user of BMPCC+SB and having the same problem with my Nikon 50mm F1.4 and Tokina 11-16mm F2.8.

Is this topic closed? and is this issue figured out already?

[sir_danish]

Ken Aqua, I couldn´t figure it out to this day... It´s rather frustrating. Do you habe exactly the same problem with the left side being slightly out of focus?

[Ken Aqua]

Hi Sir Danish,

 

Thanks for the reply.

 

Yes, I think I have exactly the same problem, but worse.

Most of the time the blurriness appears on the left side, but sometime it's on the right side as well.

 

I also replaced the product (SB for BMPCC) as soon as I found this problem, but the second one has

the same problem as well.

 

I have BMPCC, SB for BMPCC and several Nikon mount lenses but no MFT lens, so I borrowed SLR

magic F0.95 lens (MFT mount) from a friend then I had the similar problem with no Speedbooster.

 

Then I thought the problem is BMPCC itself and sent it to Blackmagic Japan for check the product.

Blackmagic Japan checked my BMPCC with Cosina Voigtlander 17.5mm F0.95 and could not find

any blurriness in any cases, and they said this is the problem of compatibility between Speedbooster

+ BMPCC or the SLRmagic lens + BMPCC.

 

The followings are the data which I found this problem at the very first time.

I shot this footage with my BMPCC, SB for BMPCC + Nikon AF50mm F1.4D at a Japanese shrine.

Those two images are 28th DNG and 555th DNG from the same sequence (with fixed focus).

 

28th DNG

https://drive.google.com/file/d/0B9fhU4X7bCLkNEFyMFNLWjVWRU0/edit?usp=sharing

 

555th DNG

https://drive.google.com/file/d/0B9fhU4X7bCLkc3h0LW1rbm1TUzg/edit?usp=sharing

 

I created those image for Blackmagic Japan, so the yellow charactor is Japanese and 

meaning 2x magnification.

I shot this sequesce panning stairs form the bottom to the top, so the 28th image is 

about 5m (15ft) away and the 555th image is about 8m (25ft) away from me.

 

As you can notice, the 28th image is soft on the right side, and the 555th image is 

soft on the left side.

From this result, I suspect the SB or BMPCC mount tilting, but the problem is not 

happening always.

 

If I set the focus infinity, the blurriness always appears on the left side as you mentioned.

 

At first, I thought this problem happens only extreme situation such as shooting at very

fast aperture like F0.8 (SB+NikonF1.4), but recently I realized this problem happens

not only at very fast F value, but also at the usual F value.

 

The following image is from a footage shot by setting F3 at Speedbooster with Nikon

50mm F1.4D.

 

https://drive.google.com/file/d/0B9fhU4X7bCLkaFcyaEp1RGdYZVE/edit?usp=sharing

 

Also please watch the following movie shot by setting F4 at Speedbooster with Nikon

50mm F1.4D. Sorry for the shaky movie because it was very windy.

 

 

For the comparison, the following link is the movie I shot at the same day with the 

exactly the same setting. I changed the angle a little bit and re-set the focus.

 

 

I shot about 6 movies on that day and only 1 movie above had the problem.

 

For now, I asked the Metabone's product distributer in Japan to borrow me the

new Speedbooster EOS mount for checking if it has the same problem.

 

I'll make a report of the test result here when I got the new SB EOS mount test

result.

[yanouche]

Hi,

I think I have the same problem with my BMPCC + Pocket dedicated SB + Sigma 18-35.

I'll do the grid test, similar to the one sir_danish did, to see how bad it is.

Another test I'm going to do will involve BMCC 2.5K dedicated speedbooster, as I own 2.5K + BMCC SB combo too, which works with Sigma 18-35 perfectly, the image is extremely sharp.

[sir_danish]

Ken Aqua, thank you for the test. What do you think causes the problem? A misaligned lens mount on the camera or the SB with a slightly skewed lens element?

[loosy1]

Hi,

I´m using a Sigma 18-35 1.8 with a Metabones Speed Booster on my BMPCC.
What I noticed is that the left side of the image isn´t perfectly in focus while the right side is spot-on.
If I try to get the left side as sharp as possible, the middle of the picture and the right side will be slightly out of focus.

Please take a look at the pictures below. Notice how the very left side seems to be quite blurry, while the right side isn´t that bad. The aperture was 2.5.
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I´ve tried two Sigma 18-35 and two different Speed Boosters, but the results were exactly the same.

Has anyone else noticed similar effects?

 

I would be very happy if someone with a Sigma 18-35 and a SB tried to shoot something outside with the lens wide open and focus set to infinity.

Recently I deleted all my files on my cell phone by mistake. There are many important photos on it. I want to recover them back. When searching on the Internet and find a web page which introduce WiseRecovery. I have no idea about I should try WiseRecovery(http://www.wiserecovery.com/articles/How-to-Recover-Deleted-Data-from-SD-Card ) as it says or anyone who have an useful way can help me? Thanks a lot.

 

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[richg101]

The problem is in the speed booster.  Almost certain of it.  

The adjustment screw on the back  (which allows adjustment if infinity is not able to be achieved), actually knocks the focal reduction optic off-centre when tightened.  - untighten the screw and sure enough the optical cell will wobble - meaning there is play.  as you retighten you'll see the lens cell move to one side.

 

the way to fix this is to use the speed booster without the screw tightened. (so the optical cell can rotate freely).  in order to keep the optic from rotating you can do a number of things, such as use 3 small blobs of blu-tack.  - im unsure what it's called in different countries, but it's made by bostik.  a bit like chewing gum, but blue and for attaching posters to the wall.  using 3 small blobs evenly spaced will prevent the optic rotating freely.  and will come off easily if you ever want to adjust it.

 

 

[Andrew Reid]

I also think the problem is with the Speed Booster. The shims aren't accurate enough in Metabone's PL adapters either.