Why there are still no curves in Aperture?

Question

Just wondering.

Answer 1

there are parts of the image that are burned out to
255/255/255 but thanks to curves I can make this
"out" point 230/230/230, for example.
This is exactly what the Levels adjustment will do. It doesn't have the numerical feedback that you get from Adobe curves; I have asked for that and think that will get better in v2. For your example above move the Levels trianlgle all the way to the bottom right--sliding it to the left to get your 230RGB to 255RGB adjustment.
A slightly better adjustment IMO might be to have the 3/4 tone top triangle at 95% and the 3/4 tone bottom triangle further to the left. This avoids completely loosing the highligt details while compressing the highlights. Thus freeing up more of the tonal range for brightening the shadows and midtones or increasing contrast in that zone.
By adjusting the top triangles you set expansion/contraction of the tonal range. (Like Love/Marriage you can't have one without the other.)
You should see the 3/4 tone triangles as follows:
- 3/4 tone top triangle 100% of the way to the right
-3/4 tone bottom triangle a bit further to the left, maybe 85% of the way to the right
With this pattern as you move the bottom triangle--keeping the top triangle at %100 right position--you will control where in you image pixels start clipping to 255/255/255.
I think that Aperture's Levels is superior to curves because I can more easily see how much compression or expansion I am applying. I will get a feel for if I am compressing part of an image's tonal range by 10% or by 50%. Here is an example picture that compresses the highlights by about 50%. With Adobe curves unless you can see slopes values and convert tangent values in you head you don't get that kind of visual feedback for your adjustments.
Take a look here to see an example:
http://www.thomaswhitephoto.com/SubpageData/extras_content/levels/