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Author Topic: Which Canon combo?  (Read 17733 times)

Mark D Segal

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Which Canon combo?
« Reply #40 on: September 14, 2006, 09:34:12 am »

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Your right, I have Photoshop CS2 but until know I am not very familiar with RAW image shooting and image processing. The same is true for using Adobe RGB or sRGB. I don't have a Photo printer yet, so I depend on a store that basically only processes sRGB.
...by the way, does RAW shooting increase the dynamic range (a little) ? During daytime, I continously have to pay attention, not to get blown out highlights.
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Even though you do not yet have a photo printer, if you think that sometime later you will buy one, and if you intend to print some of the images you are now making, it would be advantageous to keep them in a format that will give you the potential for maximum quality at that time. As well, it is not clear that the service where you get your pictures printed is using a technology whose colour space mimics the size and shape of sRGB, therefore it is likely preferable to use RGB. Your camera can make both RAW and JPEG files simultaneously, so even if you do nothing with the RAW captures yet, you can save them.

One of the areas where a RAW capture can be advantageous is for exposure correction. To some extent the RAW converter in Photoshop CS2 can "correct" blown highlights by reducing exposure in the converter before converting the RAW file to a normal TIFF or PSD file. The best however is to try to avoid blown highlights by making your exposures with the histogram values pushed up as close to the right-side end of the scale without clipping. You can see whether you've succeeded with this immediately after the image is processed by examining the histogram. If you have blown highlights or the exposure is positioned further down the scale than it can be without clipping, you can make exposure compensation adjustments and retake the picture. There is a considerable amount of material on this website about optimizing digital exposure (essays and tutorials). Bruce Fraser has written a very good, compact book on using Adobe Camera Raw which would be worthwhile reading.
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Eric Myrvaagnes

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Which Canon combo?
« Reply #41 on: September 14, 2006, 11:07:57 am »

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Even though you do not yet have a photo printer, if you think that sometime later you will buy one, and if you intend to print some of the images you are now making, it would be advantageous to keep them in a format that will give you the potential for maximum quality at that time. As well, it is not clear that the service where you get your pictures printed is using a technology whose colour space mimics the size and shape of sRGB, therefore it is likely preferable to use RGB. Your camera can make both RAW and JPEG files simultaneously, so even if you do nothing with the RAW captures yet, you can save them.
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In the three years that I have been shooting digital, I have now on numerous occasions gone back to an earlier raw file to reconvert it, just because my skill at using these (*&^$#) converters has improved a lot since I first tried it. I'm just pleased that some of my earlier pictures are worth redoing (in my humble opinion       .)

-Eric
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Mark D Segal

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« Reply #42 on: September 14, 2006, 11:48:18 am »

Rene, I forgot to mention in my previous reply that with RAW images, when you convert them in 16 bit mode and into ProPhoto Color Space (which Adobe Camera Raw supports) you will have the widest gamut colour working space and bit depth (i.e. capable of accommodating very highly saturated hues accross the visible colour spectrum) that most of our current computers can comfortably process. While the gamut considerably exceeds that of all our current photoprinters, it does have the benefit of INSURING (providing you expose properly) that you have for any image the maximum amount of image data your printer can possibly handle - plus most likely what the next several generations of printers will probably handle. You cannot have this file quality and assurance with JPGs.

Eric - I just plugged into your website - what wonderful imagery - and it provided me an excellent reference source for creating the web content - I've downloaded the program you are using and will give it a try. I've been looking for exactly such an animal (effective, cheap and easy) as both my wife and I need to create web sites with image files.
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Mark D Segal (formerly MarkDS)
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AdrianW

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« Reply #43 on: September 14, 2006, 02:32:31 pm »

My choice would be 5D + 24-105 IS USM. Although the 24-105 also suffers from fairly bad CA it's a good lens otherwise, and if you're shooting RAW then it's correctable.

Choose the other lens based on your preferred activities. Say the 100-400 IS USM if you're into wildlife and/or headed to Africa.
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Eric Myrvaagnes

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« Reply #44 on: September 14, 2006, 08:49:24 pm »

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Rene, I forgot to mention in my previous reply that with RAW images, when you convert them in 16 bit mode and into ProPhoto Color Space (which Adobe Camera Raw supports) you will have the widest gamut colour working space and bit depth (i.e. capable of accommodating very highly saturated hues accross the visible colour spectrum) that most of our current computers can comfortably process. While the gamut considerably exceeds that of all our current photoprinters, it does have the benefit of INSURING (providing you expose properly) that you have for any image the maximum amount of image data your printer can possibly handle - plus most likely what the next several generations of printers will probably handle. You cannot have this file quality and assurance with JPGs.

Eric - I just plugged into your website - what wonderful imagery - and it provided me an excellent reference source for creating the web content - I've downloaded the program you are using and will give it a try. I've been looking for exactly such an animal (effective, cheap and easy) as both my wife and I need to create web sites with image files.
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Mark,

Thanks for the nice comments. I had been hoping to design my own website, but I had an exhibit opening that I was eager to get a site up for, so looking for (cheap!) gallery software seemed the best way to go.

Please let us all know when you and your wife have your websites up.

-Eric
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Mark D Segal

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« Reply #45 on: September 14, 2006, 09:02:54 pm »

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Mark,

Please let us all know when you and your wife have your websites up.

-Eric
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Will do! I appreciate the interest.
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Mark D Segal (formerly MarkDS)
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RedRebel

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Which Canon combo?
« Reply #46 on: September 15, 2006, 05:06:18 am »

Thanks for the usefull comments...

Mark,
The way you describe to use the histogram is a bit diferrent then the way I have used it until now. I checked the image if it indicated blownout highlights (black blinking area's) and stopped down if needed.

Indeed the 24-105 shows some CA, but it is neglectible compared to the EF-S 17-85 I have owned. But I will have a closser look to RAW processing to improve image quality further.

Another thing to pay attention to (for me although   ) is the vignetting of the 24-105 in the 24-35mm range. On occasions that the sky is over exposed, the vignetting causes the sky to turn into blue...   During daytime I didn't notice it, because the LCD monitor is often hard to view in bright sunlight, but back in my appartment I saw it on my Epson P2000. In these narrow Italy citties (Siena, Florance etc..) you often have to strugle between blownout skies and shadows in the streets.

...but that makes life fun, otherwise it would be to easy offcourse...
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Mark D Segal

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« Reply #47 on: September 15, 2006, 08:40:59 am »

Rene, you can either stop down without changing the shutter speed (means you are off automatic) or you can do negatve exposure compensation. When lenses are stopped-down too much they may deliver inferior image quality. As a rule of thumb one hears that the optimal optical performance of a lens is about two stops above its maximum aperture - but that's a general guide.

My 24~105 f4 L has extremely little CA and very little vignetting. Both are correctible in Photoshop - the CA more successfully than the vignetting in my opinion. It may be a good idea to verify that the lens hood is on correctly - an incorrect placement of the lens hood could cause excessive vignetting. It may also be useful to have Canon check your lens to make sure it is performing within their quality assurance standards.

Regarding the exposure dilemma - this is where working with RAW files in a good image editing program can be very advantageous. By "exposing to the right" as I discussed several posts ago, and making sure there is no or minimal clipped data at the ends of the histogram, in post-processing you can create two separate versions of the same raw file, one adjusted for the brighter areas and another adjusted for bringing out the detail in the darker areas, then blend the two using layers and layer masks in Photoshop. There is much more information in those shadow areas than you will see on your Epson P2000 once you start bringing-out the data in Photoshop using Levels or better still Curves. There are articles about this on this website. As well, if you send me your email address in a private email I'll send you an article (unpublished) I drafted on the same topic.
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Mark D Segal (formerly MarkDS)
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