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Old January 16th, 2007, 03:55 PM   #1
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Wobbling vignette with XL H1 and Mini35!

Starting a commercial production next week, I have rented a P+S Mini35 (300 series) for my XL H1. When looking at the footage at a proper display (not the underscan EVF), it's small vignetting at the top corners (oscilating). Does anyone out there have any trick to avoid it? (I'm using Zeiss super speed T 1.3 primes)

Apart from the small vignetting, the footage is the best so far, coming out of mine XL H1!

But the weight... (see picture!)
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Wobbling vignette with XL H1 and Mini35!-where-my-xlh1.jpg  
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Old January 16th, 2007, 04:08 PM   #2
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Moved from XL H1 to our P+S Technik forum -- I think you'll get a better response here.
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Old January 16th, 2007, 04:20 PM   #3
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Yes, it may be. But I thought it also could have something to do with the setup (XL H1 and Mini35).
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Last edited by Jonas Nystrom; January 16th, 2007 at 05:03 PM.
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Old January 16th, 2007, 06:10 PM   #4
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Series 300 does not work well with HD, but from your picture that is not a series 300, it is a series 400.

Have you contacted the rental house - try another mini35?
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Old January 16th, 2007, 10:06 PM   #5
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Deleted - double post due to time-out during edit.
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Old January 16th, 2007, 10:25 PM   #6
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Firstly, I am in no way qualified on the Mini35. I have only played with one awhile.

The oscillation you describe is the groundglass motion strobing with the frame rate of your camera, something you would not normally be aware of and of little concern except in hostile lighting conditions when you might adjust the motor to maximise the motion difference between frames or attempt to synchronise the motion with the frame rate to make an unavoidable artifact motionless and less evident in a locked off shot.

The vignette suggests that the optical axes are not aligned due to incorrect assembly of the Mini35 to the camera, or the internal adjustments in the Mini35 are incorrect.


Some notions.

1. Has it been dropped in the past and the prism/mirror path bumped out of alignment. Has the hand of another messed with the frame adjustments.
(There are user adjustments for framing in the Mini35).

2. Has a quickfit tripod spacer been left on the bottom of your XL1. The Mini35 kit for XL1 has been designed specifically for that camera. Some of these spacers or wedges have another tripod hole in the bottom and can be inadvertantly left on the camera. If there is one there, take it off because it may leave your camera impossibly high beyond range of correcting adjustment for perfect match of the optical centres.

3. Related to 2. When you offered the Mini35 relay up to the Canon, did the lockring go on smoothly or has it jammed. There is enough compliance on the rod and camera mount structure that you can force the thing together. It will likely not work right because the optical axes will be angularly crossed. (If this is severe enough, you may also observe a soft edge in the relay image. Only a correctly centred and squarely adjusted test card with four rossettes in the corners will tell this truth. The motion of the lock ring takes a bit of getting used to but if it baulks or jams, likely something else in the assembly needs attention. The feel of the lockrings as they turn home is a sort of silky resistence which increases to a stop point. If they stop without any prior resistence they may be either worn or your assembly of the parts is not right. If everything else is right, then check the sequence or order in which you put it together which does affect how easily it assembles.

4. The vertical adjustment lock under the camera. If this cannot be screwed home firm to immobilise the vertical movement of the sleeve over the pillar, the little fingertip handle (or tommybar) may have to be screwed out and placed in another of the holes on the shank to enable it to be tightened correctly. If the camera is hanging on the relay mount and if the the relay mount is itself hanging on the back of the main body, when you tighten lockrings up, you may think they have tightened properly but they may have hit lug faces instead of end-stops and may not be holding the modules fully home in a face-to-face match. - Somebody may have done this in the past and then gone after the frame adjustment to compensate, then you may have come along, assembled it correctly and the it will be out of adjustment for you.


If you don't have the full operator manual, you can find it on the P+S Technik website. It correctly names the parts, which I have not done here and it is quite helpful.
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Old January 18th, 2007, 04:09 PM   #7
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Jonas, any luck?

Take it back to the rental house - try another mini35 just incase. There is really not much to adjust in terms of the mini35 with the XL cams. There is a very fine screen focus adjustment built into the relay lens, but this doesn't sound like it would help your problem.

Dennis
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Old January 18th, 2007, 08:10 PM   #8
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This may not be your model of Mini35.

Pages 6 and 7 of the Mini35 XL year 2002 manual. - Vertical and horizontal centering adjustments with a hex wrench (allen key) are found on the main case under a little hatch on the right and under the relay lens mount in the rear.

However, as Dennis sensibly suggests, if the rental house is conviently close, take it back to them swap another unit or have them adjust it themselves.
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Old January 20th, 2007, 10:22 AM   #9
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Thank you all for your input!

I called the rent house about Mini35, not about the wignetting, but i had some dust on the groundglass. When I received the second one, it had it's dust (or probably inhouse colour flake) but not on the groundglass this time. So the choice was moving dust or static - the rent house had to take both back and my assistent will to go Stockholm on monday (three hours with train) to get it the clean one for the shooting.

Anyway, the wignetting was not at all so obvious on the second one; and the wignetting were on all four corners. They only have on relay lense, and we are shooting 1,85:1, so I think it will do for this time.

I love the look of the footage - I think I have to buy a Mini35 myself. Hate to rent, these problems always come along.

We are starting shooting a three day production on tuesday, I will post asap!
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Old February 9th, 2007, 02:12 AM   #10
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We have Mini 35 along with a XL-H1...

Is great...I sugest you to get one instead of renting...

We own a Mini 35 series 300 and a XL-h1

Now, the vinegette effets is normal.

That come out because our setting is not like other cameras...
Other setting hook up directly from the front of the lens to the relay and they need to zoom in untill they get a full and nice image.
Our setting is deferent, the relay will go directly to the camera an de CCD will gett the image directly from the relay, and thats a little off set and the effects comes out.
Any ways keep in ming that if you close the aperture of the relay too much the blacj dots and the vinegette effect will show more...
Just try to keep the aperture full opend and adjust the back focus in the relay.

It does not bother me, we shoot int 16X9 for HDV and regular 4:3 SD.

Images are great.

Take care.

Carlos Quinones,

It's Written Productions, LLc.
Attached Thumbnails
Wobbling vignette with XL H1 and Mini35!-carlos-quinones-mini35-1.jpg   Wobbling vignette with XL H1 and Mini35!-carlos-quinones-mini35-2.jpg  

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Old February 9th, 2007, 07:23 AM   #11
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Carlos, how are you using the series 300 with the XLH1 without getting any grain in your image? I was almost quite certain if you wanted to shoot in HD you could not use the series 300 and needed the newer series 400 (ozzi) model?

Please let me know, I'm curious about this. Thanks.
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Old February 9th, 2007, 09:17 AM   #12
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Dennis.

If he is getting a vignette, it is almost certain the scale size of any grain relative to the frame is diminished and it may not be as apparent. If he eventually goes in closer by some means to eliminate the vignette, the grain may then become an issue.
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Old February 10th, 2007, 01:27 PM   #13
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His vignette is described as coming from the relay lens, thus keeping it open minimizes any vignetting. The grain however is a separate issue. It was orginally thought that the grain of the spinning GG would show up with HD cameras and therefore the vibrating GG of the series 400 mini35 would be better.

Carlos is clearly shooing with the mini35 series 300 adapter you can see in his photo. I'd love to see some video or frame grabs, Carlos can you please post some? Thanks.
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Old February 10th, 2007, 08:12 PM   #14
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From my playings with various groundglass grades on glass disks, my observation is the issue is not so much any observable grain but the resolving powers of a coarse finish versus a finer finish on a disk. The movement of the disk should deal with the grain itself unless the shutter speed is too high.

The trade-off with choosing the finer grind for the sharper resolution is aerial image creeping through as a ghosting effect.

If the groundglass texture of the 300 and 400 is the same and the image area seen by the camera on the groundglass is the same, there should be no observable difference other than the artifacts when either system is mismanaged, the "vortex" on the 300 and the "swirls" on the 400.

If the disk on the 300 has a coarser grind texture, then a replacement disk finished to the texture of the series 400 groundglass should bring it up to the same performance as the 400.
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Old February 11th, 2007, 01:35 AM   #15
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Mini Shot...Music Video...

Hello guys,

Here is a Music Video we shot with our Mini35.
Is in spanish, but tell me your critics...
www.myspace.com/itswrittenproductions
Is called Damian "Me Condeno"

We are shooting another video this coming week I will up load more info...

Take Care...

Keep Blessed,

Carlos Quinones
www.itswrittenproductions.com

Last edited by Carlos Quinones; February 11th, 2007 at 01:51 AM. Reason: Did not upload quick time file...
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