Lens Focal Length vs S.U.8 (pro)

For all the users of Twilight Render (V1 & V2), to ask questions and get started
Fletch
Posts: 12897
Joined: Fri Mar 20, 2009 2:41 pm
OS: PC 64bit
SketchUp: 2016-2023
Contact:

Re: Lens Focal Length vs S.U.8 (pro)

Post by Fletch » Thu Mar 24, 2011 9:31 am

Thanks Gaieus, it is exactly as Chris described above - The number is simply being reported differently because the "film" size for Twilight is different than the film size for SU.
But the rendering result is identical to the view in SketchUp.
Chris wrote:Twilight's camera editor is the focal length based on a 25 mm film width. In SU, if your camera is expecting, say 36 mm (the default value in SU), the displayed focal length would be 72. But in Twilight, using 25 mm film width, the focal length would be 50.

The resulting image, however, is identical. :)
Why doesn't Twilight use the same film size as SU? Because it was originally conceived to serve the many people that use it to export and render with Kerkythea. And the so it matches the default film size of Kerkythea.

res08a7k
Posts: 42
Joined: Sat Sep 24, 2016 9:29 pm
OS: windows 10 - 64 bit
SketchUp: 2017
Contact:

Re: Lens Focal Length vs S.U.8 (pro)

Post by res08a7k » Mon Oct 25, 2021 6:51 pm

I have read the previous responses concerning this issue but they are from 2011? A lot has changed perhaps.

I have SU 2021 on windows 64bit and just checked Twilight render is up to date.

am trying to get the best render settings for a 360 panorama to be used in a program called 3D vista tour where you can also control the scope of the panorama to show how far up, down, right, or left to view cutting out what not wanting to show around the edges during the tour.

When using a TR spherical projection with a constant 35MM film size, and experimenting with different size focal lengths from 5 to 20 to 100 (see images) I found the SketchUp view changes, prior to the rendering but the resulting renderings appear the same?

Please advise what's the best way to determine settings, mostly if not for all interior shots using spherical projection settings for a 360 panorama.
Thank you for your time,
Billy G
Attachments
Twilight Test Pic.jpg
Twilight Test Pic.jpg (323.63 KiB) Viewed 3102 times

Fletch
Posts: 12897
Joined: Fri Mar 20, 2009 2:41 pm
OS: PC 64bit
SketchUp: 2016-2023
Contact:

Re: Lens Focal Length vs S.U.8 (pro)

Post by Fletch » Tue Oct 26, 2021 6:29 am

res08a7k wrote: Mon Oct 25, 2021 6:51 pm...to be used in a program called 3D vista tour ...
Great program - I know it well. Have used it with Twilight Render many times.
res08a7k wrote: Mon Oct 25, 2021 6:51 pm When using a TR spherical projection with a constant 35MM film size, and experimenting with different size focal lengths from 5 to 20 to 100 (see images) I found the SketchUp view changes, prior to the rendering but the resulting renderings appear the same?

Please advise what's the best way to determine settings, mostly if not for all interior shots using spherical projection settings for a 360 panorama.
Thank you for your question Billy G.

Render spherical images at 2:1 ratio width to height. So, 2000 px wide and 1000 px high, or 4000 px wide and 2000 px high (probably the maximum I would go with rendering something for display via the internet)

If you change focal length you MUST right-click your Scene Tab in SketchUp and choose "update" for the scene, otherwise the change will not be registered. If you want to try different focal lengths, may I suggest creating several different scenes with different focal lengths?

But for rendering spherical interiors, since it is a spherical image, you will most likely, at least in architectural situations, keep your FOV at around 50. The only exception could be for a very narrow space such as a small bathroom or narrow entry hall. Then you could maybe venture to 60 or 70. But I would try to keep it around 35-55. (35 is similar to the "catch-all" lenses of old point-and-shoot basic cameras that were sold everywhere before digital cameras were popular. 50-55 is similar to the basic lens that came with a little bit higher end mid-range cameras like your basic decent Canon or Pentax or what have you.

Since you are rendering the image as a spherical image, it will result in that you are seeing the entire interior space in spherical format, only the FOV will make the spherical image appear to be either zoomed in or zoomed out when you open it to take a look on the web when it is set up by 3D Vista.

Post Reply

Who is online

Users browsing this forum: No registered users and 17 guests