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View Full Version : How to Match virtual camera lens (mm) with real camera lens?


Halduke
03-16-2009, 11:13 PM
Hello,
it could be a silly question but ill give it a try.
Ok... so I have a real (photographs) camera.
I see a lot of written tiny numbers arround the lens that says: 4.7 - 84.2 mm 1:2.8 -4.5 (it is an Olympus SP-550UZ) with a big 28mm number at the top.

I want to build (in 3D) the "same" scene/picture that was taken with this camera. So the question is, how can I match the values of the camera with a virtual camera on a software like 3Ds max? Is 84.2 mm the Lens mm?? is 28mm the value that im looking for?

thanks in advance.

beaker
03-30-2009, 02:47 AM
here are some tech specs for that camera:
http://www.dpreview.com/news/0701/07012507olympusp550uz.asp

MegaStas
04-24-2009, 02:02 PM
You should find an advice in bojou 4 tutorial

Doerge
05-05-2009, 05:28 PM
Basically your perspective depends on the following:
Focal length
Film size (chip size)
Lens distortion.

The chip size is somewhere in your camera manual or online.

The focal length used is the "zoom" expressed in mm. Check the Exif-data of your image-files and see if its there.

Lens distortion is funny-ness introduced. It is a more comp related issue, but reaches into 3D as well. Look up: shooting distortion grids.

Hope that helps

-Aske

SeaJackal
05-06-2009, 10:15 AM
Hi,

How is the film/chip size related with distrortion?

cheers

sundialsvc4
05-13-2009, 02:44 AM
Basically, every film-size (or image-sensor size) has some "normal lens." This is the lens focal-length that, according to some agreed-upon standard, produces "about what the human eye would see." For a 35mm film size, that's about "50." Each film-size has its own version of "normal."

CG programmers have done the same set of calculations, and their "cameras," too, have a "normal lens." Most likely, that's what they have set their "cameras" to by default.

The easiest way to handle this situation, both in CG and in "real life," is to simply ignore the numbers and instead consider "the relationship to 'what is normal.'" When you do this, "all films are comparable to one another," regardless of image-size, and "CG is directly comparable to film."

aesnakes
05-13-2009, 04:56 AM
Check out this Maya 2 Nuke video, It talks about lens distortion and how to fix it using a grid and squeezing it out. I think if you look at this and maybe you can translate some information to maya or max. Use a grid in maya and adjust your settings in the camera or take a photo where you can notice the distortion and adjust the camera accordingly.

link: http://www.thefoundry.co.uk/dl_file.aspx?ui=61A27EA7-0CC0-461C-BA84-A2C88B0D2B84

jfrancis
05-13-2009, 10:29 AM
Matching a Horizontal Nikon D200 to a Maya Lens (http://www.digitalartform.com/archives/2009/03/matching_a_hori.html)

Matching a Vertical Nikon D200 to a Maya Lens (http://www.digitalartform.com/archives/2009/03/matching_a_vert.html)

jfrancis
05-13-2009, 10:34 AM
Not quite what you asked for (see post above) but may shed some additional light

Matching Poser and Maya Cameras and Scales
(http://www.digitalartform.com/archives/2009/04/matching_poser.html)
Matching DAZ Studio and Maya Cameras and Scales (http://www.digitalartform.com/archives/2009/04/daz_studio_-_ma.html)

Halduke
05-13-2009, 02:17 PM
Hey guys, thanks a lot for your answers.
I was out of reach for a while (and thought that nobody answered this post). Ill take all your advices and see what I can come up with (also see what is the film size/chip size of this camera and lear to apply it for any camera). (Last test I did, I just had to match it manually through trial and error).
Again. Thank you very much.


Technical Details

Image Sensor:Effective Pixels:7.1 Megapixels
Filter array:Primary colour filter (RGB)
Full Resolution:1/2.3" CCD sensor
Lens:Optical Zoom: Wide 18x
Aspherical Glass Elements:4
Filter Diameter:48.4mm Use CLA-10 to attach conversion lens
Focal Length:4.7-84.2mm
Focal Length (equiv.35mm):28-504mm
Structure:14 Lenses/11 groups
Maximum Aperture:2.8-4.5
Digital Zoom:Enlargement Factor:5.6x/100x combined with optical zoom
LCD:LCD Type:LCD
Pixel Number:230000 pixels
Monitor Size:6.4cm/2.5"
Viewfinder:Electronical viewfinder
Focusing System:Method:TTL iESP autofocus with contrast detection
Spot Focusing:Yes, 143 AF areas selectable
Predictive AF:Yes
Manual Focus:Yes

jfrancis
05-13-2009, 05:05 PM
Focal Length:4.7-84.2mm
Focal Length (equiv.35mm):28-504mm


The quickest, 'laziest' way to fairly closely match would be to take your camera, multiply the focal length x 6 and plug that number into Maya's default camera, since Maya's default basically matches an 8-perf 35mm SLR (http://www.digitalartform.com/archives/2009/03/matching_a_hori.html)

beaker
05-13-2009, 06:16 PM
The quickest, 'laziest' way to fairly closely match would be to take your camera, multiply the focal length x 6 and plug that number into Maya's default camera, since Maya's default basically matches an 8-perf 35mm SLR (http://www.digitalartform.com/archives/2009/03/matching_a_hori.html)that is the worse idea in the world. Why would you just arbitrarily multiply it by 6? That makes zero sense.

Find the dimensions of the sensor and then put that into Maya's film aperture. Simple as that.

jfrancis
05-13-2009, 07:49 PM
that is the worse idea in the world. Why would you just arbitrarily multiply it by 6? That makes zero sense.

Find the dimensions of the sensor and then put that into Maya's film aperture. Simple as that.

It wasn't arbitrary at all. It was derived from his specs.

Focal Length:4.7-84.2mm
Focal Length (equiv.35mm):28-504mm

28 / 4.7 = 5.957 (http://www.google.com/#hl=en&q=28+%2F+4.7&btnG=Google+Search&aq=f&oq=28+%2F+4.7&fp=ICVP5FShbzg)
504 / 84.2 = 5.986 (http://www.google.com/#hl=en&q=504+%2F+84.2&btnG=Google+Search&aq=f&oq=504+%2F+84.2&fp=ICVP5FShbzg)

The Maya default camera is, as I laid out in tedious detail in my links above, equal to a standard 35mm SLR (http://www.digitalartform.com/archives/2009/03/matching_a_hori.html) (not a standard 35mm 4-perf movie frame)

So, like I said. If you want to be quick and lazy, multiply by 6. That is a very accurate answer.

jfrancis
05-13-2009, 07:55 PM
Find the dimensions of the sensor and then put that into Maya's film aperture. Simple as that.

And if you want to go that route, I explained that process in detail in post #8 of this very thread.

jfrancis
05-13-2009, 07:59 PM
that is the worse idea in the world.

What exactly is a 'Forum Leader,' anyway?

Is it common for a 'Forum Leader' to use that kind of language in a professional forum?

beaker
05-13-2009, 07:59 PM
Woops, my bad, I was looking at that link and it was talking about film aperture and thought you we're talking about multiplying the film aperture by 6. Of course you we're talking about the FL.

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