Lens size to achieve depth.

General Forums Blender and CG Discussions
1

I am trying to achieve a better sense of depth with some of my environments. I understand color theory very well, and proper lighting.
Focal blur, dominant shapes, textures…
I have recently been experimenting with lens sizes. Are there any photographers here ? I really want to understand how to use the camera to my advantage.

btw…I did not put this in the questions forum because I am not just looking for an answer, but trying to open a discussion that could benefit other members of the community.

2

Lens sizes are directly related to focal length in cameras. For instance, a lens size of 35 in Blender would mean that the lens curves 35 mm on a real camera.
This way, when taking a scene shot from a video camera [when the camera is moving, for instance] and placing into Blender, it will be easier to mimick the motions in Blender. :o

3

How can you find the focal length of your video camera?

4

Here’s the theory:

http://www.panoramafactory.com/equiv35/equiv35.html

This discussion might be of interest:

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5

I have been doing some experimentation with lens size and camera distance (from subject). I have been studying art since I was seven
…or 30 years. I never really paid too much attention to camera angles, or any other photographic methods. I bought a Nikon 35mm camera today
to play around with. I am still curious if anyone has any suggestions as to wide angle vs. a 60mm lens to give my scene an illusion of real depth.

Strange, 94 views and 3 answers. Obvious that others are curious also.

6

sticks head out of bush

very.

rustle rustle

:o

7

yep, i sure am. thanks for the links, Fligh.

I also always wondered how to get a fish-eye lens in blender. Anybody any ideas on this?

d52477001

8

There is a tutorial somewhere amongst the CJs. You can always change your lens size to 1 and have the camera very close to the object.

Here is a snippet from that tut…much credit to the original author

The Display buttons

Ok, now that you’re all impress by that last pic (WP’s of course, not mine heh!), here’s How To:
-> Take any of your scene, preferably with something close to the camera (in front to be more precise).
The rest is a piece o’ cake!
-> Go into the Display buttons and locate the buttons with a red box around them (in the pic that goes with that paragraph, not in Blender of course!)
-> Press the Panorama button
-> Divide the SizeX value by a whooe number so that it gives another whole number (like 320 / 32 = 10 for example) and set the result as the new value.
-> Set the Xparts button value to the number you divided by (here: 32)
The divisor can be up to 64 only
-> and Render!

What happens?
Like a real panorama camera, Blender now renders in stripes (with a witdh equal to SizeX) and rotates slightly the camera each time (depending on the camera lens value).
So, if you set a specially calculated sets of parameters (Xparts, SizeX and Lens Size), you might get a 360 degree (though I never tried).

9

With a cammera lens the longer it is the more of a zoom lens it is(can see stuff further away), but also the more space is deformed and flattend out.
With a 35mm lens (or the equivlant on other cammeras) space remains as the human eye would see it (or very close)
And finally as a lens gets shorter (35mm-1mm) space is streched and lengethed (much greater sense of depth) but you have to be much closer to the objects.
Hopefully that helps :smiley:

10

I also always wondered how to get a fish-eye lens in blender. Anybody any ideas on this?

i was wondering that for a long time too!!! so far the only way i know of is post processing, but its not perfect

and changing the clip or using panorama does NOT give a fish eye effect, just a stretch… fish eye lens provides the “bend” of the objects as well, which is so sweet and i want it!

11

i remember sonix doing a fish eye lens on one of his cars…

12

rogerm3d wrote

With a 35mm lens (or the equivlant on other cammeras) space remains as the human eye would see it (or very close)

From the articles I was reading…it is more like a 60mm lens that would achieve that result.

13

FWIW…

Lens : Angle Of View : Lens Type
8mm : 139.4 degrees : true fish-eye
16mm : 107.0 degrees
21mm : 91.7 degrees
22mm : 89.0 degrees
28mm : 75.4 degrees : wide-angle
35mm : 63.4 degrees
42mm : 54.5 degrees
43mm : 53.4 degrees
50mm : 46.8 degrees : normal (perspective)
55mm : 42.9 degrees
70mm : 34.3 degrees : portrait
90mm : 27.1 degrees
100mm : 24.4 degrees
135mm : 18.2 degrees : tele-photo
200mm : 12.4 degrees
300mm : 8.3 degrees
400mm : 6.2 degrees
500mm : 5.0 degrees
1000mm : 2.5 degrees
2000mm : 1.2 degrees
2479mm : 1.0 degrees

14

I read somewhere [on Elysiun, not sure where] that if you set the camera size to a really low number, you can simulate fish-eye camera…
Of course, you might need to shrink everything down so that it doesn’t come out too far away.

15

i was wondering that for a long time too!!! so far the only way i know of is post processing, but its not perfect

and changing the clip or using panorama does NOT give a fish eye effect, just a stretch… fish eye lens provides the “bend” of the objects as well, which is so sweet and i want it![/quote]

The best way I know in blender to get a fisheye effect (or any other lens effect for that matter) is using good old EnvMaps.
http://webpages.csus.edu/~sac60363/Fish.JPG
Without turning the forum into a tutorial, here are the basic steps.

~1 set up the scene as usual (lens size makes no difference)
~2 replace your camera with an empty
~3 move the camera somewhere else (another layer, another scene, or somewhere out of view)
~4 Add a sphere (icosphere, uv sphere, it doesn’t matter, I used a subsurf cube). Put it in the same place as the camera.
~5 TURN ON SETSMOOTH in edit buttons for the sphere
~6 Place the camera inside the sphere, near one side, pointing directly at the center of the sphere
~7 Add a material for the sphere with ‘shadeless’ enabled. Add an EnvMap texture with the object set to the empty you created. Set the texture coordinates to ref.
~8 You need to set the texture coordinates scales. In this example, I used x=.30 y=-.30 z=1.

Depending on how your camera and sphere are oriented, you may need to move the camera around to find the scene and frame it properly.
If things are fuzzy, increase the resolution of your envmap.
Play around with the texture coodinate scale to find the amount of distortion you want, remember, negative values will flip the image like a mirror.

Hope this helped. EnvMaps are good for lots of stuff like this (I have a similar method for faking focal blur). If you make something cool with my method, send me an email or PM.

If there is enough interest, I may even write a tut on this and all the other fun stuff you can do with envmaps.

EnvMaps: They’re not just for chrome anymore.

quailman
[email protected]

16

Erm, I may be stating the obvious here, but select a camera, press F9KEY, and turn down the Lens control…

You can also do this for 3D viewports - SHIFTKEY+F7KEY, change Lens control, SHIFTKEY+F5KEY.

Is there a reason why this doesn’t work properly? Looks fine to me…