5x recording from sensor center, not left-center- very important for UWA lenses

Started by kgv5, November 09, 2013, 10:41:48 AM

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kgv5

Is there a possibility to make an option which will allow 5x crop to record from sensor center? Now it records left-center which makes the footage looks blurry and distorted (when moving camera) on the left side when shooting with UWA lenses like tokina 11-16. I assume, that such recording with one huge margin on the right is more efficient and gives better writing performance but when shooting say 2,5K (which gives about 2,3 crop factor) we often have to use UWA lenses. One can use tokina 11-16 @11mm with no vignette when shooting 5x but distorsion on the left side only cause that it looks weird. Option to turn OFF/ON shooting with the exact center would be great even if this will cause some performance loss (i believe there was such an option in the early stage - called "force left" or so. I dont know if it worked also with 5x crop recording - if it did - please, bring it back). Thanks

EDIT: 5d3, tokina 11-16 set @ 11 mm with variable ND with 2,5K recording with current settings makes very strong vignete only on the left side. Recording from the exact center probably would give clean 2,5K crop picture with quite wide field of view (about 24mm ).
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kgv5

Yes, but reframing with joystick is giving strong left or right vignette/distortion. You cannot move crop frame exactly to the lens center, it just skips from left to the right.
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kgv5

Quote from: kgv5 on November 09, 2013, 10:41:48 AM
Is there a possibility to make an option which will allow 5x crop to record from sensor center? Now it records left-center which makes the footage looks blurry and distorted (when moving camera) on the left side when shooting with UWA lenses like tokina 11-16. I assume, that such recording with one huge margin on the right is more efficient and gives better writing performance but when shooting say 2,5K (which gives about 2,3 crop factor) we often have to use UWA lenses. One can use tokina 11-16 @11mm with no vignette when shooting 5x but distorsion on the left side only cause that it looks weird. Option to turn OFF/ON shooting with the exact center would be great even if this will cause some performance loss (i believe there was such an option in the early stage - called "force left" or so. I dont know if it worked also with 5x crop recording - if it did - please, bring it back). Thanks

EDIT: 5d3, tokina 11-16 set @ 11 mm with variable ND with 2,5K recording with current settings makes very strong vignete only on the left side. Recording from the exact center probably would give clean 2,5K crop picture with quite wide field of view (about 24mm ).

Would it be possible to implement? Shooting crop mode from exactly sensor center?
Shooting 2,5K with 24mm equivalent (tokina 11-16 @11) is very tempting. I think this is one of the widest and fully usable lens options for full frame combined with crop mode. Now its not looking very good because of strong distortion on left or right side.
I know that this would probably have some bad influence on overall performance and record time but please, make such thing as an option, please :)

Please bring back "force left ON/OFF" option from the old days :)
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g3gg0

i dont understand... raw_rec and mlv_rec record from the center..
why do you think it doesnt?
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kgv5

g3gg0, yes, 1920x1080 definetelly is. But say 2560x1090 it is not, i think that more than half of the picture is left or right, depends of cursor setting, i mean seems like those additional pixels are on one side. It is very visible when dealing with UWA lenses with much distorsion on the sides.
I might be wrong with this but lets say in 1920x1080 we have 960 pixels on the left of the sensors center axis and 960 pixels on the right. Its OK and looks right. In 2560 seems like 960 pixels on one side but 1600 pixel on the left or right which makes 640 additional pixels are going into distorted area. It is getting more and more visible with increasing horizontal resolution, i will try to post some pictures. Could we set the crop to have its center always on center axis of sensor? In this case 1280 pixels on the left and 1280 pixels on the right? 2880 would be 1440 on each side etc.

EDIT: Moving crop area with joystick is possible but limited, helps a little bit but i am unable to put 2560x1090 area exactly in the middle.

Here is the picture of what i mean

https://www.dropbox.com/s/7tqryncz04o3lcc/feature%20request.JPG

Thanks
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Andy600

Quote from: g3gg0 on December 26, 2013, 05:17:43 PM
i dont understand... raw_rec and mlv_rec record from the center..
why do you think it doesnt?

They don't in crop mode
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kgv5

g3gg0, A1ex, devs, please take a look at this:

https://www.dropbox.com/s/h9n14iy5ihndtf0/raw%20crop%20factor%20tokina%2011%2016.jpg

I hope this explains what i am asking about. Tokina 11-16 gives beautiful wide angle for cropped image. Distortion is a huge drawback.

Thanks
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g3gg0

yeah remember how it was done on 5x zoom.
this is a canon issue mainly.
ml just doesnt give you a chance to properly select the center.

iirc we cant know how much of the real sensor is captured in total.
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kgv5

Ahhhh... well... thank you for the answer, so we will probably have to stick to 1920x1080 3x after all, i mean mainly with wide lenses. Its a pity, because 24mm is wide enough for stabilizers like glidecam, using narrower  lens is much more tricky. 2,5 k became quite useful, with current builds i can record up to 45 seconds so it is enough in most situations (but in 2,35:1 aspect). Rescaling it down to 1920x818 gives beautiful, razor sharp picture.

But I still hope for resolving this matter :)

Thanks
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core_32


kgv5

For anamorphic it would be best to shoot in full frame mode but with higher vertical resolution - 1920x1280 with 1,5x anamorphic it would give 2880x1280 =2,25:1 aspect. But this is something else. Anamorphic requires  narrrower lens like 50mm and it will not be usable with glidecams.
The main reason of my request is to get the widest view as possible with large crop fractor (2,3 to 3x). Shooting 2,5k with 24, 35 or 50mm lens is possible without much distortion but is unusable handheld or with stabilizers (those requires widest lens possible to look smooth) because it would give telephoto equivalent.
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