Aperture 2 Quick Tip – Managing Previews

RB | 03 January 2009 | Apple Aperture, Articles | Aperture, Aperture 2, Apple, work-flow, Workflow | 22 Comments

This entry is part 11 of 27 in the series Aperture Work-flow

Previews are one of the most misunderstood and notoriously undocumented things in Aperture. A couple of weeks ago I wrote a post about what you can and cannot do when you have referenced masters that are off-line, as in all of your masters are on external drives and your library with previews happens to be on your laptop while you are away. Previews make some of the functionality that I mentioned possible. Understanding how to manage previews within Aperture is essential to effectively managing storage, performance, and functionality. Unfortunately most of the documentation supplied with Aperture focuses on Aperture preferences and really does not connect the dots on the rest of the preview picture.

Let’s start at the beginning, in the preferences window preview tab. Here there are a couple of options that are pretty self explanatory. The options that are important are “New projects automatically generate previews”, “Share previews with iLife and iWork”, and “Limit preview size”.

The “New projects” option has nothing to do with turning previews on and off for projects already in Aperture, it merely does exactly what it says – sets the preview options from projects created going forward (after changing it) to either on by defualt or off by default at a project by project level. You can turn it on and off until you are blue in the face and it will do nothing to previews already out there. More on this in a second. “Share previews” pretty much makes the OS X media browser connect with images within Aperture that have previews, there is not any great reason that I can think of to turn this off, if you know one please share it. When turned on you can get at the JPG previews from pretty much any other Application running in OS X, not just iLife and iWork. “Limit preview size” in combination with the quality setting is pretty important depending on your intended use of the previews as well as managing the size of the actual Aperture Library. I happen to use a 1920 pixel limit because that happens to be the full resolution of HD flat panels and projectors that I routinely display my images on when traveling with my laptop – very convienient without having to resort to lugging around a ton of RAW files or PSDs with me that I am not currently working on.

Moving on to the next peice of the preview puzzle take any selection images from any view, incuding the all photos view, in both the right click context menu or the image menu take a look at “Update preview(s)” and “Delete preview(s)”. These will either create JPG preivew images or get rid of them respectively with no regard to the “New projects…” option setting in preferences. There is also a shortcut for either generating or deleteing previews for an entire project. You can get to this shortcut by looking at the context menu for a project in the inspector.Â These two simple menu items in combination with the next (and probably the most overlooked preview related function) are the keys to beating Aperture previews into submission.

The next and probably most important piece of preview generation functionality happens to be hidden in a place that few rarely venture. Take a look at the drop down menu up in the corner of the project pane in the inspector. Down at the bottom of the menu there is the magical “Maintain previews for this project” option. If you select this Aperture will generate previews for every image verison in the project. Aperture will also generate previews every time you make an adjustment to an image or lift and stamp a bunch of adjustments. This is the option that gets set on new projects if you check “New projects automatically generate previews” in the global Aperture preferences. Many Aperture users are driven to the brink of insanity by trying to turn previews off by turning the “New projects…” option in preferences on and off to no avail. If you are on a laptop or other machine that doesn’t have unlimited resources you may want to turn this off while you are working on your RAW images it will free up a lot of computing juice for the task at hand. You can even set this on or off for every project in your library by clicking on the “Library” in the project inspector – pretty cool huh.

So what to do with all this new found preview goodness. Let’s pretend that your Aperture previews are in a state of chaos and you want to start over from scratch. Easy – Turn off the “New projects…” option in Aperture preferences, click on the Library item – use the gear menu to un-check “Maintain previews for all projects”, and last but not least go to the all photos view – select all the images – use delete previews. Now everything is clean and fresh, just like new. Now using your new found tools you can choose what projects exactly you want to maintian previews for or control them down to the image level and don’t let Aperture generate them for you – I personally hate having Aperture startup processes to generate previews while I am trying to do image adjustments – especially on my laptop. Now you can generate previews for just certain albums or smart albums if you wish. You can do pretty crazy OCD kind of things as well by generating previews using different “Limit preview size” settings but there is no great way to automatically do this.

One word of warning. If previews are off Aperture will slow down when doing certain things to certain images that have no preview because it may have to render what you are looking at from the RAW master but that is what “Quick Preview” is for. The point of this article is not that previews are bad or that having Aperture automatically deal with them is bad, it is that knowing how to manage them for the task at hand is good. In reality I get rid of previews for old projects and turn off the manage previews for project – images that I care about show up in smart albums that i manually generate previews for. I also turn of the automatic generation of previews for a project while I am actively working on that project in terms of adjustments and/or using an external editor – especially on my laptop.

As usual feel free to question or contribute.

22 Comments

Mark says

03 January 09 at 3:25pm

Very cool article – thank you thank you thank you. I have been going nuts with the cconstantly regenerating previews. Can I buy an Aperture book from you?

Also very nice background photos.
Dave says

04 January 09 at 5:01am

This was very very helpfull. Thank you!
RB says

04 January 09 at 9:02am

Dave and Paul,

You are welcome – I am glad that I could make your photographic life just a little bit better.

RB
Craig says

07 January 09 at 4:17pm

Excellent article!

I recently found this site and very pleased i did too.

if i reset all my previews and start over, will i lose all the adjustments I made to my raw files ?

Thanks
Craig
Craig says

07 January 09 at 4:30pm

oops i mean ones that Aperture has also created versions for.

Thanks
Craig
Pedro says

07 January 09 at 7:05pm

Great tip.
Fit like a glove to a problem that i have.
I use a Imac with a 800fw Lacie 2TG Raid0, for all the referenced files, and a Macbook Air, with a small disk and a low processor only with previews.
There are a lot of previews of the referenced files that i don’t really need to carry around, and now i can fix that.
The solution i was thinking about was to transfer the Air library to a external drive, but now it is a solved problem.
Thanks, RB

(don’t you know a way to export a preview?)
RB says

07 January 09 at 10:46pm

Craig,

You will lose nothing in Aperture at all. The only side effect will be that stuff outside of Aperture will not be able to see things inside Aperture that have no preview. You can rebuild one or more previews at will and they will be exactly the same as last time (unless you change your preview prefs).

RB
RB says

07 January 09 at 10:47pm

Pedro,

Let us know how it works out.

RB
Craig says

08 January 09 at 7:30am

Thanks Rob.

Will you be writing anything up on versions ? probably my biggest issue. and when are apple going to do some kind of reversible history state like lightroom to save constant version image creation

Regards

Craig
RB says

08 January 09 at 8:16am

Craig,

There is a bunch of stuff covering versions throughout the Aperture Category and in the Organization PDF – give me a some more specifics on what you would like to see.

RB
Peter Sidell says

20 February 09 at 9:39pm

Your insights are very helpful. You mention the maximum pixel setting you use for preview. what is the quality setting that you use, and how do you choose that?
Thanks
RB says

01 March 09 at 8:52am

Peter,

Sorry for the delayed response – got a little busy. I use something in the middle like 6 for my purposes. In my mind the only reason to use higher (bigger) is if you have noticeable compression artifacts when using the previews for your purposes. If you don’t stay with the smaller sizes, if you see compression artifacts that bother you when using previews then up the quality.

RB
Adrian Harvey says

30 March 09 at 1:58pm

Portrait format preview fuzzy.
Hi RB
You seem to be a preview expert, so I wondered if I could ask you about a problem I am having, which no Applestore bod has managed to solve.

I set my previews to 1680, so I can whizz through them on my monitor. However, I’ve noticed that the portrait format shots are not as sharp. I press z to see them at 100%.
I tried a workaround; turning off autorotate in camera, then manually rotating images after the preview has been created. Doesn’t work because Aperture just generates a new preview.
I did a screengrab of the same image before and after rotation, and there is a big difference.
Any ideas?
best regards Adrian
cubemann says

09 September 09 at 6:11pm

My SBODs have greatly diminished. Thank you very much!
Phil Culhane says

13 September 09 at 1:46pm

Thanks for solving a troublesome problem. I shoot onsite at sporting events; often 20-30K images a day – previews were killing me.

Greatly appreciated!
Cheers
Merlin71 says

22 October 09 at 2:05pm

And yes, anything getting more people to crochet is good, but really, what do you DO with them. ,
David Farquhar says

09 November 09 at 10:57am

Excellent page, great tip about “Maintain previews for project”. My workflow now if I want to do lots of editing of files is switch this off, make the edits with nothing else in the background (so much easier) and then switch it back on again once complete. While Aperture goes away generating previews for a while I can then do something else off the computer. Less frustration, less time spent editing. Hooray!
larry duff says

02 December 09 at 1:34am

Excellent article, I wish I had found it 2 days ago… Spent a few hours trying to understand why my previews are not shared with iLife. That said, the solution (“maintain previews”) was right there in the Aperture User Manual, p. 202….

LD
RB says

07 December 09 at 12:15pm

Larry,

That’s how it usually goes – the manuals are okay but I find that somethings are not documented at all but even the things that are documented have no dots connecting them on how to use them together.

RB
Iain MacDonald says

10 February 10 at 6:23am

Thanks for the article – very useful. I was just looking to move from iPhoto to Aperture 3, and was trying to get my head around the difference in library size compared to the size of the original images.

All to do with Previews. Although having said that – I’ve been trying out a folder with around 500MB of photos.

Initially this gave me an Aperture Library of around 1GB.

But I don’t think I necessarily need previews, as I just have one machine etc.

So I switched off previews, and reimported.

That still gave me a library of around 900MB though – with the thumbnails folder in the library weighing in at around 400MB.

400MB worth of thumbnails for 500MB worth of photos seems an awful lot.

If that’s how it is, that’s OK – it would just be good to get my head around why it is!

Many thanks for any light shed.
Veronica says

30 March 10 at 4:23am

Enjoyed the post and learned some things. Thanks for taking the time! Also…sorry to be a sourpuss, but women use Aperture, too, and the girly screenshot examples undermine your credibility for me (all I can think is gwc!), and in any case probably aren’t the best choice for a general audience interested in Aperture’s quirks. Just one opinion. Thanks for the post, keep up the good work.
RB says

30 March 10 at 4:49am

Veronica,

Thanks for the feedback but I would like some clarification.

What exactly is it that you found off-putting about the photos that are the background of the illustrative screenshots? Was it the lighting? Out of focus? Bad color? Bad Framing? Lack of compositional integrity? Poor lens choice? Horrendous shutter release timing? Did I do some kind of hack “GWC” hack job that just “screams” I use my camera and lack of skill to trick unsuspecting women into things they don’t want to do?

Actually I have toned down some of the images over the last year and a half because I believe that sometimes it does get in the way for some segment of people interested in the stuff I publish here and decided I should not exclude them.

That being said – You might get a sense of my political and moral set of though processes if you have been following along for a while. I can assure you they probably line up with yours closer than you think but… I “grew up” in a very different environment than the typical extremely hypocritical US thought process that I consider very backwards on this type of thing.- I can explain that if you don’t know what I am talking about.

RB

Ps. If these get your dander up I am sure glad that I did not choose to use some of my commercial fashion images as a backdrop – European publication of course.