Document Raster Effects Settings in AI10.0.3

John Slate

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Apr 25, 2003, 3:51:42 PM4/25/03

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I was at an Adobe service provider seminar yesterday, and at one point the presenter suggested that suppliers should consider changing Effect>Document Raster Effects Settings on a supplied file from a customer, stating that it is non-destructive.

I raised my hand and questioned that practice based on the fact that doing so would change the appearance of art, by virtue of raster effects being applied a certain number of pixels in width, so that a higher resolution setting produces smaller widths on all effects.

The presenter in turn indicated that the change would only happen when an object was selected.

I furrowed my brow over this, but let it go.

Today I played with this, and I find that not to be the truth.

In fact it appears to be a document-wide setting that affects all vectors to which raster effects have been applied.

Am I correct about this or is there a setting/preference that I have not got right?

Additionally, changing this setting is somehow seen as a rasterization of some sort, since the undo for the move is “undo rasterization”.

This is curious since no rasterization takes place... no new embedded links... vectors are still vectors.

In fact, if you open a new file and change the setting before putting anything in the file at all, you get the same “undo rasterization”. Strange.

Teri Pettit

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Apr 25, 2003, 4:56:59 PM4/25/03

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John,

You are mostly correct, in particular you are correct that it does not matter whether the objects are selected or not, they will still get rebuilt if they are using the default Document Raster Effect Settings.

However, it does not truly affect all vectors to which raster effects have been applied, just all of those to which raster effects other than Rasterize have been applied that are not preceded by an explicit Rasterize effect. That is, the Document Raster Effect Settings control the default rasterization that will be done if the in-progress object is still in vector form when it hits an effect that needs a raster as input.

By explicitly including a Rasterize effect before other raster effects, you can shelter the object from the document raster effect settings, and make different objects in the same document use different resolutions or other settings. In practice, few people do this, so as a practical matter almost all raster effects will be affected by the Document Raster Effect settings.

As for the Undo string, it says "Undo Rasterize", not "Undo Rasterization". This is because the Rasterize plugin handles the setting of these options and the undo recording for it, and it somewhat cavalierly uses the same undo string regardless of why the plugin was called. The Rasterize plugin should probably be more descriptive and record it as "Undo Rasterize Settings" instead of "Undo Rasterize".

John Slate

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Apr 25, 2003, 5:30:07 PM4/25/03

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Yes, thank you Teri, I see. You apply Effect>Rasterize and then Blur or what ever, and then it is not subject to being recreated upon changing the setting.

I'm not sure I understand Effect>Rasterize as it does not create an embedded raster the way Object>Rasterize does.

The rasterize effect must also apparently be above the other effects in the appearance palette in order to shelter the item.

I also can't see that alot of people would include the rasterize effect in their work, so playing with that setting could get a supplier in trouble. Unless you selected all, applied effect>rasterize, and then dragged the rasterize command above the other effects in the appearance palette on every effected object. That could be a daunting task.

Probably best to leave things alone. My theory is, that even for high resolution imagesetter output, the program default of 72ppi for these effects is sufficient since they are usually very soft images that do not require high resolution.

Do you agree?

Teri Pettit

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Apr 25, 2003, 8:25:35 PM4/25/03

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Re: "I'm not sure I understand Effect>Rasterize as it does not create an embedded raster the way Object>Rasterize does."

It creates an embedded raster inside the "styled art", just like vector effects create new vector objects inside the "styled art". The styled art is what gets previewed and printed. Expand Appearance elevates the styled art to editable status, but it exists in the art tree all the time. (Expand Appearance does not create any new objects, it just deletes the old editable art and moves the existing styled art into its place.)

If you set a real low resolution like 20 on a pattern-filled object you will maybe get a better feel for what the Rasterize effect does.

Re: "The rasterize effect must also apparently be above the other effects in the appearance palette in order to shelter the item."

That's what I meant by "including a Rasterize effect before other raster effects". You think of it as the location in the palette display, and so call it 'above', I think of it as execution order, and so call it 'before'.

Re: "Probably best to leave things alone. My theory is, that even for high resolution imagesetter output, the program default of 72ppi for these effects is sufficient since they are usually very soft images that do not require high resolution.

Do you agree?"

I agree with you that a service provider should not be changing the designer's Document Raster Effects settings, at least not without discussing it with them. I hope the "presenter" who spoke to you wasn't from Adobe, because they're passing around bad advice.

I don't think I agree that a default setting of 72 dpi is generally adequate for print work, though.

There are over a hundred raster effects when you count all the Photoshop variations, and they have many different purposes. Not all of them are "soft". A setting that works well for Blur might not be very good for Craquelature.

Basically I think there are too many variables to be able to come up with a "one size fits all" recommendation, and therefore that anyone using raster effects for print work should become familiar with how the particular effects they use are impacted by the Rasterize settings. If the performance is acceptable, the safest thing to do is use a fairly high resolution (probably not over 300 even for an image setter, though) and then set the pixel-based options in the specific effects (Blur radius, etc.) to match that resolution. If that causes unacceptable performance, then in many cases the designer should bump up the resolution before sending the document out to print, and then make any necessary compensating adjustments to the options on specific raster effects.

This is really the same kind of issue you have to deal with in Photoshop all the time. Raster effects and filters tend to have resolution-dependent options. If you work in your final resolution, you can avoid changing the options when you're ready to go to print, but you pay a performance price while you're working. If you want to work in a lower resolution and then bump it up when you're "done", then you may need to go through your effects and change some of their distance-related options that will be too small, close or crisp at the higher resolution.

Which is a design decision that I wouldn't think a service provider should be getting into, unless it is is the kind of combination service that takes rough art and does the final design work.

Doug Katz

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Apr 26, 2003, 8:22:19 AM4/26/03

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Jeez. Talk about enlightenment.... I'll take this over Baba Ram Dass anyday.

John Slate

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Apr 28, 2003, 11:10:44 AM4/28/03

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I hope the "presenter" who spoke to you wasn't from Adobe, because they're
passing around bad advice.

Unforunately they were.

"Tools for the New Work" seminar, Denver, CO 4/24/03