550D- need a lens for panaromatic Videos (RAW) (EXAMPLE ONLINE!)

Started by dafassi, October 24, 2013, 01:24:46 PM

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dafassi

Hey there.

I use the 550D for filming.
Im NOT ASKING for a good recording resolution or aspect ratio!!

Im looking for somthing to get more image-material thru my lens ;)

The 18-135mm lens is great. But because of the crop factor (RAW-Video) a lot will be cutted while recording.

Im thinking about using a 8mm (fisheye) for filming, to get a panoramatic picture.

Any other ideas or tips? Maybe adapter, another lens or software?
May be a good deal with mm and dof?
A unwarper for fisheye-disortions?
Adaptor or anything else?
Or other good lenses for filming?

My hardware:
550D - ML lates build
Canon 18-135mm
Canon 50mm
80MB/s SDHC card

dmilligan

I love my Canon 10-22 EF-S. Its rectilinear, so you wouldn't have to 'defish'. The corners get a little soft @ 10mm, but that would be cropped out.

Malcolm Debono

Both the Canon 10-22 and the Tokina 11-16 should be fine for your needs, and both are excellent lenses
Wedding & event cinematographer
C100 & 6D shooter
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dafassi

Sounds intersting.
But im interedted in fisheye-material, too.
I just can pay around 400€- so im thinking ....

I did hear seomthing about 8mm and ML-DeFishing ... can someone give me informations- or better DEMOVIDEO about this?

a1ex

One of my early attempts (samyang 8mm defished): https://vimeo.com/23761162

of course, not raw.

TonyPitzicatta

Exactly my Problem.

If ML could be programmed to skip lines and pixels, it could use the whole sensor without producing a higher datarate. Thats the way the camera does it in the normal h.264 mode.

I wonder if the ML coders are thinking or working on that idea.

dafassi

Thank you a1ex.
Why didn´t you film in RAW? Because you need a  continous record?
But its a nice wide-angel. Not that much disortion or did you fix this a little bit in post?

Yesterday i bought a walimes 8mm lens. It will come next week, and i hope it will make me happy ;).

Whatevery- would like to see more examples.

glubber

Quote from: dafassi on October 25, 2013, 07:05:50 AM
Thank you a1ex.
Why didn´t you film in RAW?

Because Raw video was invented only 6 months ago and the footage is 2 years old.  ;)

As i use a 550D too i'm looking forward to see your results with the Walimex-Fisheye.
EOS 550D // Sigma 18-200 // Sigma 18-70 // Canon 10-18 STM

dafassi

Allright, got it, tested it, uploaded it :).
About 1minute 8mm-fisheye video:



Hope you like it!

jamesd256

While the subject of fisheye lenses is a live one...

I looked at getting a Zenitar 16mm for use on a 50d for video.  I was thinking of using it in cropped mode with some de-fishing action.  I read some suggestions (repeated in a few places) that on a cropped sensor, the 16mm lens becomes a 24mm non-rectiliear. 

This doesn't make sense to me because the full frame FOV of the lens is either 170 or 180 deg depending on what you read, so surely there would be more angle of view than a 24mm lens on the cropped sensor?

The centre sharpness of this lens is supposed to be excellent stopped down to f11, and they go for around £70-80 in the UK used on ebay.

5D3, 550D

dmilligan

16mm * 1.6 = 25.6mm

You are a bit confused: a 16mm lens on a cropped sensor would look like a 25.6mm lens on a FF.

NOT:
a 16mm lens on a cropped frame would look like a 25.6mm on a cropped frame (why would that make sense!?)

jamesd256

Quote from: dmilligan on November 04, 2013, 08:56:09 PM
16mm * 1.6 = 25.6mm

You are a bit confused: a 16mm lens on a cropped sensor would look like a 25.6mm lens on a FF.

NOT:
a 16mm lens on a cropped frame would look like a 25.6mm on a cropped frame (why would that make sense!?)

I'm not sure how you arrived at your interpretation of my comments, so sorry for not making it clear.  Maybe you thought it was a simple question about the crop factor?  I actually do understand this principle. It was more a question about the FOV of fisheyes in relation to their focal lengths vs the same for rectilinear lenses.

Yes I understand how the 24mm comment is arrived at.  But a 16mm lens on a full frame camera will have a viewing angle of 96 degrees.  The zenitar I read has a viewing angle of 170 degrees on a ff sensor, so simply put, what will be the FOV on a cropped sensor of the zenitar 16mm.



5D3, 550D

dmilligan

http://en.wikipedia.org/wiki/Angle_of_view#Measuring_a_camera.27s_field_of_view

FOV =  2 * arctan (frame size/(focal length * 2))
2 * arctan ( 35mm / (16 mm * 2) ) = 95 deg
2 * arctan ( 22mm / (16 mm * 2) ) = 69 deg

There are different types of fisheyes with different equations, here is common one:
Equisolid FOV = 4 * arcsin (frame size/(focal length * 4))

4 * arcsin ( 35mm / (16 mm * 4) ) = 132 deg
4 * arcsin ( 22mm / (16 mm * 4) ) = 80 deg

dmilligan

sorry, I was calculating on the sensor width, so those would be the horizontal FOV, for diagonal:
2 * arctan ( 43.2mm / (16 mm * 2) ) = 107 deg
2 * arctan ( 26.7mm / (16 mm * 2) ) = 80 deg

4 * arcsin ( 43.2mm / (16 mm * 4) ) = 170 deg
4 * arcsin ( 26.7mm / (16 mm * 4) ) = 99 deg

jamesd256

Quote from: dmilligan on November 04, 2013, 10:22:41 PM
http://en.wikipedia.org/wiki/Angle_of_view#Measuring_a_camera.27s_field_of_view

FOV =  2 * arctan (frame size/(focal length * 2))
2 * arctan ( 35mm / (16 mm * 2) ) = 95 deg
2 * arctan ( 22mm / (16 mm * 2) ) = 69 deg

There are different types of fisheyes with different equations, here is common one:
Equisolid FOV = 4 * arcsin (frame size/(focal length * 4))

4 * arcsin ( 35mm / (16 mm * 4) ) = 132 deg
4 * arcsin ( 22mm / (16 mm * 4) ) = 80 deg

OK, that's actually useful, thanks.

The 170 deg diagonal sounds like it might confirm the Zenitar has an equisolid mapping function.  I'm used to talking horizontal FOV, so:

I have a 50d, so the cropped raw mode will be using a multiplier of

4752 / 1920  = 2.475

That means my sensor size will be

22.3 / 2.475 = 9mm

So the angle I'd get from the lens is

4 * arcsin ( 9 / (16mm * 4)) = 32 deg

I'm guessing the distortion will be minimal using this centre portion of the lens, and certainly the sharpness will be excellent at f4-f11:

http://www.ephotozine.com/article/nikon-10-5mm-zenitar-16mm-fisheye-lens-comparison-interchangeable-lens-review-14651

I would think that with minimal de-fishing, you could have a reasonably sharp image, free of pixel binning induced moire and aliasing. 
5D3, 550D