I thought it important to state here that Aperture won't run on the first generation of the all-in-one-unit iMacs. For example, the iMac 20" uses the Nvideo FX 5600 graphics chip set which is not supported by Aperture, a fact that I have verified with Apple, regardless of the fact that it was released only last year.
Be sure to verify your hardware before you purchase this software.
Submitted by Mike Manzano on Tue, 11/15/2005 - 10:30.
-->As a long-time silver-based photographer, with some digital photo experience, I'm confused by this description. Perhaps it's because the phrase "expose for the highlights" isn't defined well.
A RAW data file is linearly encoded. So say you have a camera capable of 6 stops of data and it's producing 12 bits per color or a total of 4096 bits. The first stop of highlight data has half of all the data (2048) while the last stop of shadow data has only 64 bits. You want to expose to put as much data in the shadows as possible or you introduce noise. Get yourself a copy of Bruce Fraser's Real World Camera RAW and check out chapter 1 (he's got very good illustrations of this).
So expose to the right (expose for highlights) isn't about over exposure, its about proper exposure with linear data. There's no H&D curve like we saw in film.
Andrew Rodney
Author "Color Management for Photographers"
http://www.digitaldog.net/
Submitted by Andrew Rodney on Tue, 11/15/2005 - 07:26.
> Also, because Raw files preserve all original camera data (which is usually
> 10- to 12-bit data), you can output an image with much more dynamic range than
> you'd find in a JPEG file, which is limited to 8 bits.
Well bit depth doesn't equate to more dynamic range! One defines the steps between the range, the other IS the range (from shadow to highlight). Now you do have far better control over rendering highlights in a good RAW converter like Adobe Camera RAW as it can build highlight data if one of the three color channels hasn't been clipped to 255. You mention is unique feature later and apparently Aperture has something like it.
> Apple's stance is that Aperture provides 90% of what professional
> photographers need for most of their images. For the other 10%, Apple includes
> a menu item that opens the file in another image editor.
Has Apple said that (90%)?
> Aperture's Raw conversion tools look fairly simple, offering sliders for
> Exposure, Saturation, Brightness, Contrast, Tint and White Balance adjustment.
How's that much different from say Adobe Camera RAW (certainly version 1 of that fine product)?
> (Speaking of non-destructive editing, Apple has made a big deal about
> Aperture's non-destructive editing capabilities. Though Aperture's versioning
> system looks very well-implemented, there's nothing unique about
> non-destructive Raw editing -- Adobe Camera Raw and most other Raw converters
> leave original Raw files untouched.)
Excellent point, I'm glad you've made this (as have I). The RAW data is never touched. What IS cool is the ability to produce multiple iterations more easily from that data.
> It's also not clear what color spaces are supported by the program.
For output, any you have a profile for. For input floating point HDR. Bad news IMHO is it's histogram doesn't reflect the output space for encoding that data. I find the Histogram in Adobe Camera RAW indispensable for viewing based on the four working space options which I'll use based on what clipping I see. That's not an option in Aperture. Hopefully in future releases it will be. Then you could, like ACR, toggle from say Adobe RGB (1998) to ProPhoto RGB and select which to use based on the saturation of the scene data as it is rendered and then encoded into these spaces.
Andrew Rodney
Author "Color Management for Photographers"
http://www.digitaldog.net/
Submitted by Andrew Rodney on Tue, 11/15/2005 - 07:08.
What a great article Ben. It's clear, complete and right on the money. Your suggestions and criticisms certainly seem tempered by 'Pro Level' involvement along with a lot of experience using the tools we have today.
What a horrible experience it would be to pre-order the program with the idea that it was a 'Photoshop Killer,' and find you couldn't create a marque selection or lasso select an area. OUCH!
I'm looking forward to seeing the first reviews on Aperture.
Submitted by artist_david on Wed, 11/09/2005 - 07:13.
I enjoyed your article, but I have a question about this passage:
"For the best results when shooting Raw, you want to expose for highlights, to capture as much data as possible in the areas of the image where the camera records the most information. The danger of exposing for highlights, of course, is that you run the risk of overexposure."
As a long-time silver-based photographer, with some digital photo experience, I'm confused by this description. Perhaps it's because the phrase "expose for the highlights" isn't defined well.
In silver-negative photography, "expose for the shadows" means "expose the film sufficiently to permit the thinnest/weakest part of the negative to develop with usable detail, but no more than it needs."
In silver-positive photography (slides/transparencies) we say "expose for the highlights," which similarly aims at properly exposing the thinnest/weakest parts of the image.
In both negative and positive silver film, it's possible to adjust the chemical development of the darkest/strongest parts of the image (the negative's highlights, or the transparency's shadows) to restrain them from developing to the point where they "mush" together.
I'm wondering if, by "The danger of exposing for highlights, of course, is that you run the risk of overexposure" you mean "averaging exposure tools don't provide enough information to help you expose a scene's highlights accurately?"
With the general-reading (averaging) exposure tool in most cameras, you need to expose more than the automatic exposure algorithm indicates. For example, auto-exposures calculated for images that contain large amounts of sky, sand, or snow, tend to underexpose ("average") them towards a middle brightness. Manually overexposing from this average isn't really "over" exposing - it's correctly exposing for the subject.
How much more to give, is a guess that you can improve with tests and experience, or by using a camera's "spot exposure meter" mode, if it has one, or using an external spot meter, or by reading a standard exposure surface, such as a photographer's gray card.
This has always been a difficult area of photography to describe simply. One reason is that the photographer has to work against the averaging exposure tools that usually work quite well in a wide range of subject types, in these specific cases.
Thanks for mentioning the ability of these software tools to help recover some lost detail.
Regards,
Peter Gold
KnowHow ProServices
peter@knowhowpro.com
Submitted by peter gold on Wed, 11/09/2005 - 07:58.
Make sure it works with your machine!
I thought it important to state here that Aperture won't run on the first generation of the all-in-one-unit iMacs. For example, the iMac 20" uses the Nvideo FX 5600 graphics chip set which is not supported by Aperture, a fact that I have verified with Apple, regardless of the fact that it was released only last year.
Be sure to verify your hardware before you purchase this software.
Linear Encoded data
-->As a long-time silver-based photographer, with some digital photo experience, I'm confused by this description. Perhaps it's because the phrase "expose for the highlights" isn't defined well.
A RAW data file is linearly encoded. So say you have a camera capable of 6 stops of data and it's producing 12 bits per color or a total of 4096 bits. The first stop of highlight data has half of all the data (2048) while the last stop of shadow data has only 64 bits. You want to expose to put as much data in the shadows as possible or you introduce noise. Get yourself a copy of Bruce Fraser's Real World Camera RAW and check out chapter 1 (he's got very good illustrations of this).
So expose to the right (expose for highlights) isn't about over exposure, its about proper exposure with linear data. There's no H&D curve like we saw in film.
Andrew Rodney
Author "Color Management for Photographers"
http://www.digitaldog.net/
A few points to clarify
> Also, because Raw files preserve all original camera data (which is usually
> 10- to 12-bit data), you can output an image with much more dynamic range than
> you'd find in a JPEG file, which is limited to 8 bits.
Well bit depth doesn't equate to more dynamic range! One defines the steps between the range, the other IS the range (from shadow to highlight). Now you do have far better control over rendering highlights in a good RAW converter like Adobe Camera RAW as it can build highlight data if one of the three color channels hasn't been clipped to 255. You mention is unique feature later and apparently Aperture has something like it.
> Apple's stance is that Aperture provides 90% of what professional
> photographers need for most of their images. For the other 10%, Apple includes
> a menu item that opens the file in another image editor.
Has Apple said that (90%)?
> Aperture's Raw conversion tools look fairly simple, offering sliders for
> Exposure, Saturation, Brightness, Contrast, Tint and White Balance adjustment.
How's that much different from say Adobe Camera RAW (certainly version 1 of that fine product)?
> (Speaking of non-destructive editing, Apple has made a big deal about
> Aperture's non-destructive editing capabilities. Though Aperture's versioning
> system looks very well-implemented, there's nothing unique about
> non-destructive Raw editing -- Adobe Camera Raw and most other Raw converters
> leave original Raw files untouched.)
Excellent point, I'm glad you've made this (as have I). The RAW data is never touched. What IS cool is the ability to produce multiple iterations more easily from that data.
> It's also not clear what color spaces are supported by the program.
For output, any you have a profile for. For input floating point HDR. Bad news IMHO is it's histogram doesn't reflect the output space for encoding that data. I find the Histogram in Adobe Camera RAW indispensable for viewing based on the four working space options which I'll use based on what clipping I see. That's not an option in Aperture. Hopefully in future releases it will be. Then you could, like ACR, toggle from say Adobe RGB (1998) to ProPhoto RGB and select which to use based on the saturation of the scene data as it is rendered and then encoded into these spaces.
Andrew Rodney
Author "Color Management for Photographers"
http://www.digitaldog.net/
Fabulous overview on 'Yet to be, Aperture'
What a great article Ben. It's clear, complete and right on the money. Your suggestions and criticisms certainly seem tempered by 'Pro Level' involvement along with a lot of experience using the tools we have today.
What a horrible experience it would be to pre-order the program with the idea that it was a 'Photoshop Killer,' and find you couldn't create a marque selection or lasso select an area. OUCH!
I'm looking forward to seeing the first reviews on Aperture.
Exposing for the highlights?
Hi, Ben:
I enjoyed your article, but I have a question about this passage:
"For the best results when shooting Raw, you want to expose for highlights, to capture as much data as possible in the areas of the image where the camera records the most information. The danger of exposing for highlights, of course, is that you run the risk of overexposure."
As a long-time silver-based photographer, with some digital photo experience, I'm confused by this description. Perhaps it's because the phrase "expose for the highlights" isn't defined well.
In silver-negative photography, "expose for the shadows" means "expose the film sufficiently to permit the thinnest/weakest part of the negative to develop with usable detail, but no more than it needs."
In silver-positive photography (slides/transparencies) we say "expose for the highlights," which similarly aims at properly exposing the thinnest/weakest parts of the image.
In both negative and positive silver film, it's possible to adjust the chemical development of the darkest/strongest parts of the image (the negative's highlights, or the transparency's shadows) to restrain them from developing to the point where they "mush" together.
I'm wondering if, by "The danger of exposing for highlights, of course, is that you run the risk of overexposure" you mean "averaging exposure tools don't provide enough information to help you expose a scene's highlights accurately?"
With the general-reading (averaging) exposure tool in most cameras, you need to expose more than the automatic exposure algorithm indicates. For example, auto-exposures calculated for images that contain large amounts of sky, sand, or snow, tend to underexpose ("average") them towards a middle brightness. Manually overexposing from this average isn't really "over" exposing - it's correctly exposing for the subject.
How much more to give, is a guess that you can improve with tests and experience, or by using a camera's "spot exposure meter" mode, if it has one, or using an external spot meter, or by reading a standard exposure surface, such as a photographer's gray card.
This has always been a difficult area of photography to describe simply. One reason is that the photographer has to work against the averaging exposure tools that usually work quite well in a wide range of subject types, in these specific cases.
Thanks for mentioning the ability of these software tools to help recover some lost detail.
Regards,
Peter Gold
KnowHow ProServices
peter@knowhowpro.com