I have recently realized that some people have been having difficulties to obtain the depth-of-field effect on their pics in Second Life. Although this blog doesn’t intend to cover technical aspects of SL, I resort to photos in order to show the sims that I visit, the buildings that I refer to, the avatars that I comment on, etc. So, I decided to dedicate a post to the question of depth of field.
It seems that some photographers in Second Life haven’t been able to transfer the depth-of-field effect that they see on their screen to their pics. In other words, when they are taking a photo in SL with their viewer’s tools and hit the snapshot button, the depth of field seems to disappear from their final pics. It seems to me that this is the very same problem reported by Strawberry Singh back in 2012 (4th paragraph on). In order to correct the problem, some photographers that I have contact with started making their own depth-of-field effect, manually, during post-production (i.e., while enhancing the snapshots on Photoshop or on The Gimp, for instance). This method may require a lot of work, though, and it’s not absolutely necessary. You can actually capture depth of field directly on your snapshots, though you have to keep in mind that you won’t obtain exactly the same amount of blur that you see on your screen if you opt for a high res photo. Let me explain what I mean by actually showing some photos.
For the following pics, in order to obtain a depth-of-field effect, I basically played with two settings: “CameraFNuber” and “CameraFocalLength”. If you want to learn further about them, you can check this page on Second Life Wiki (where you can also learn how to enable depth of field, in case you don’t know). Depending on the viewer you are using, those items can be accessed on the Advanced menu, by clicking on Debug Settings, or via alternative ways, as on Firestorm, which has those settings on the DoF/Glow tab of the Phototools floater that appears when you click on World, Photo and Video, Phototools. There are other settings that contribute to the depth-of-field effect, but for what I’d like to show here, CameraFNuber and CameraFocalLength are the ones that matter. And to make things even simpler, let’s set CameraFNumber to 3 and vary only the CameraFocalLength value.
The principle is this: when you save a photo to disk, the amount of blur that you see on your screen, resulting from depth of field, will only directly translate to your pic if your resolution matches your screen, i.e., if you set size for “Current Window”. If you choose a higher resolution, the amount of blur will reduce. So, remember, our CameraFNumber value will always be 3. Now, let’s set CameraFocalLength to 90. Under those settings, when I take a photo on my viewer with the size set to “Current Window”, I get the following result:
Nonetheless, when I increase the resolution of my photo to, let’s say, 3200 x 1676, I get this result:
None of the pictures shown here were edited, they are the raw result of pressing the snapshot button of my viewer with the settings that I described above. Notice that on the 3200 x 1676 photo, the depth-of-field effect (i.e. the blur on the background) disappeared almost completely. So, what can I do about it? Well, I can increase the CameraFocalLength value. Let’s set it to 120 and try again. Now, for the “Current Window” sized photo, I get this:
And for the 3200 x 1676 photo, I get this:
As you can see, the second photo now has some blur on the background. But I’d like to increase it, so I’ll set CameraFocalLength to 160 now. This is my new “Current Window” photo:
And this is my new 3200 x 1676 photo:
The first photo of the pair has now more blur than I’d like to see, but the high res pic is what I expected. Anyway, I’ll still try to increase CameraFocalLength to 200. By doing so, I get the following “Current Window” photo:
And the following 3200 x 1676 photo:
On the latest pair of photos, the blur effect is getting too close to my foreground, so, for the photos used in this example, I’ll stay with the third high res pic. Notice that if, nonetheless, I wanted a photo with more blur, I could keep CameraFocalLength on 160 and start playing with CameraFNumber. But I’ll stop here, I think I already showed what I intended to.
So, what we can see here is that, if you want to create a depth-of-field effect directly from your SL photo camera, you either have to opt for a “Current Window” sized photo or go for a high res photo with more blur on your screen than you’d like to see on your final result. I, myself, prefer the high res photos, because they are more flexible and, so, support more options on the post-process phase.
The pics for this post were taken on the Catznip viewer. Nonetheless, from the tests I performed, the same mechanism described here seems to work for the Firestorm viewer and the Linden Lab official viewer – and I would risk to say that the situation is the same with other graphical viewers.