Why adjusting camera resolution X / Y works so strange way in Blender?

There probably is some reason for this, but I just have to ask.

So, if I change in render tab camera resolution X axis, the cameras Y is changing in view port. And if I change X axis, then Y is again the only one that is changing in view port.

Instead of working like that, I think it would be logical to only change with X-value the X axis and with Y value only Y axis in camera view. (then you could use those values for cropping your render without moving camera at all)

Or Is there something I did not understand of this feature?

https://dl.dropboxusercontent.com/u/5904620/Blender_aid/adjust.gif

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Think of the camera view as a square in the viewport (set by camera lens focal length setting). When you change the dimensions you cannot extend out of that square so if you change the x axis dimension the y axis may have to change to fit within that constraint

The dimensions are not for cropping the view so the X or Y size is always the longest it can be given the focal length

If you need to crop the render then that is the render border option. Either drag the border, use python to set the exact location of the border or use an addon to sett the border size to specific values

As Richard says you can’t change field of view so you are changing the aspect (vertical or horizontal) while increasing or decreasing the pixel density. Thus you are not adding to (existing height or width) it when increase the x or y values.

if iremember it is also function of the default camera pixel sensor ratio!

happy bl

So, am I ask something that is an impossible to do? I somehow think the camera as a “hole” to the 3d-world which size I’m changing and that made me having problem with this.

You can say that it’s impossible if you please so, although every other 3d package that I know works in the opposite way (EDIT: perhaps not every one, though just one example is enough to demonstrate that it’s possible.), that is the correct one from the point of view of the artist: when he wants to enlarge the view on X it enlarges the width and vice versa, and the same in Y of course.

Just another blender ‘peculiarity’.

paolo

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I tried to find some videos of those other software, but could not find any. So here is another gif from Blender. This is what I wish would be happening when I change the resolution (without that zoom effect that happens also sometimes in this gif).

https://dl.dropboxusercontent.com/u/5904620/Blender_aid/changingsize.gif

It keeps the target at the center and changes the frame size only from where I want to change it. It would be stupid if when trying to change X, it just makes Y longer.

I can understand your point. but when dealing with cameras in 3D, we must be clear which lens we are using, which aperture, etc.

What you’re suggesting will mix screen resolution with camera settings…That’s not good.

And as a side note… if you pay attention, to your first gif, everything is happening as you say you want… Blender only tries to fill the current view with the whole render… in other words, is no the axis that are shrinking or growing; is only your perception.

When you change the size of your shot you necessarily change some camera setting, it’s unavoidable, I assume it should be the size of the sensor.
Though, I don’t understand how this can be a problem; the software should do what requested, period, I can see by myself the result of my doing and judge whether it’s what I want or not.
The way it works in blender now actually forces you to move the camera backward to regain the correct view.

paolo

I accept that I’ve maybe lost this case, but I still tell only one thing. :smiley:

I work sometimes also a photographer for the company I work in, so I know quite a some things about photography. I always work with my DSLR camera in full manual mode. It means that I adjust aperture, shutter speed, ISO, focal length, EV, flash… etc. For my photos manually and those settings of course can change at almost every photo I take.

But I know Photographes who uses A S or P modes in their camera. Those settings are for those who don’t care to adjust all of the settings mentioned previously. For example A mode is an Aperture priority mode. It allows photographer to change the Aperture settings to what ever he wants to and camera will adjust shutter speed.

S Shutter speed priority mode is of course opposite version of that previous and lets the photographer adjust shutter speed while camera is changing aperture automatically.

P setting will give a photographer some of the combinations to choose of aperture / shutter where he will get the exposure the camera will see as optimal.

And then there is that full auto mode that will change even ISO automatically.

I would use it, if Blender changes automatically censor size to make sure that the render picture frames works as expected. Of course other people who loves to adjust the camera at every time, could keep doing it.

Imagine you have an animated camera. You do a first render and someone tells you we are now using another render size… i don’t think that changing only the render size should mess with camera positions, dollys, lens, etc…

And even in fotography, if you change the film from 35mm to 70mm… i doubt you can do it without changing your camera.

Let’s pretend that I’m your client and you’re created me this movie of the cube and camera that it rotating around the cube.

You’ve rendered the whole 100 frames animation with resolution X:2000 Y:1000 and I like it, but I need one more animation with exact same resolution, but this time it has to be X:1000 Y:2000. I like how the render border is following that edge of the hole in the cube, so I want you to also make sure that in the next animation the upper edge is following it. Nothing else matters.

This is how you do it: You type to X:2000 and Y:2000. Then you go to camera settings and type to that sensor size setting 16 instead of that 32 it had previously. That was 2 minutes work with that easy numbers and I wish the render X Y settings would be linked with that sensor X Y settings by some check box.

https://dl.dropboxusercontent.com/u/5904620/Blender_aid/cube.blend

I think they are link to sensor but only for the ratio of the X Y render
if I remember well

happy bl

Just last week while I was working over a scene, the studio told me to give more space in the image around the subject; given that the scene was already approved by the client, I had to accomplish that without changing the image at all, so I had to:
1 - take a shot of the viewport
2 - go backward with the camera
3 - put the screenshot as background image in camera view
4 lower the focal angle until the view matched the background.
All this just because of the odd way that blender uses.

In fact, that’s not unusual during still life shots in studio to change the back of the optical bench to change the format.

paolo

well…as anybody proposed this to the devs already?
it shouldn’t be hard to set the sensor size to ‘free’

Not yet. I just created this thread first to test the logic of this idea.

It would be soooo great if blender could do this. Time and time again I ran into problems, when I had created a scene (meaning an animated scene) and later came back to do some stills for printmaterials or the web, in all sorts of aspect ratios. And time and time again I found that upon changing the aspect ration some important parts were clipped or almost clipped. So I had to adjust the camera and adjust it again and again… When all I would have really needed was the y-axis to stay the same when adjusting the x-width.

The only workaround I found so far was to use the option “shift” in the camerasettings, which allows you to move the sensor position around without actually changing perspective. So I could shift to the right, render, shift to the left, render the missing area and compose both renders in an imageeditor. But thats a lot of handywork for getting a shot that really could be done in one render.

if you place a feature request please post a link so I can second it!