Photoshop title jump

[Bill Lee]

OK, I set up a multi-layer Photoshop file (.psd) 720 x 486 (D1) and imported this into a D1 8-Bit uncompressed sequence to do some tests. I think I may have discovered why you are getting the results you have been getting.

A multi-layer photoshop file is storing the layers as a set of the smallest bounding boxes for each layer. This is true for both raster layers and for text layers.

If you have a 10 x 10 pixel square on your 720 x 486 D1 frame, then it is stored as a 10×10 box with an offset from the origin of the D1 frame. You can see this when you import this multi-layer psd file into FCP, drop it in the timeline, then double click on it to see the layers. If you turn on ‘Image and Wireframe’ in the Canvas view, clicking on each layer will show the bounding box of each layer. Since each bounding box is not centred on the frame, each bounding box will likely have a different offset from the centre of the frame and thus show a different set of values for the centre point in the Motion tab. The same is true for text layers, the text being stored with the bounding box for the text and the centre point of that bounding box.

Text layers are somewhat special, since you have to be careful about font metrics and rasterisation when moving to other applications or machines. When you move a text layer to FCP, there may be some subtle differences in the way the text is rasterised for compositing into the frame. Photoshop gives you the ability to anti-alias text and these have an effect on the way the text is displayed. These anti-aliasing settings will have an effect on the size of the bounding box when it is imported into FCP, and this is why your text may be changing position.

The test that I did:

[Bob Cole]

First, thanks for the fantastically informative test. It’s a real service, and I hope Apple sees it. Your suggestions for a work-around are excellent, but what a PITA! Looks like I need to use one of the other ways to handle text graphics for FCP that you suggested (Motion or Live Type).

[billlee] “A multi-layer photoshop file is storing the layers as a set of the smallest bounding boxes for each layer. This is true for both raster layers and for text layers.”

That little vertical smear that I referred to, just grazing the right side of my text, is probably the edge of this bounding box.

I think it’s very odd, still, that when I import a wrong-sized graphic (720×540), FCP handles it fine (except for needing to render).

Thanks again for the great research.

— Bob C

[Bill Lee]

I’ve been doing some more thinking on this, and in the Photoshop help for CS2 there is the following note:

By default, type is displayed with the fractional widths option on. This option allows the spacing between characters to vary using fractions of whole pixels. In most situations, fractional character widths provide the best spacing for type appearance and readability. However, for type in small sizes (smaller than 20 points) displayed online, fractional widths could cause type to run together or have too much extra space, making it difficult to read.

Turn off fractional widths when you want to fix type spacing in whole-pixel increments and prevent small type from running together. The fractional character width setting applies to all characters on a type layer