What are your settings when you convert to JPEG in DPP?

[ddt0725]

Awhile back, Joel had made this comment to me ..." I noticed that you are probably using "save for web" because the resolution was only 72 pixels/inch. That doesn't allow much to be done as far as reprocessing goes.


After processing, If you resize your image to around 800 pixels wide then save as a JPEG and adjust the quality so the image is just under 200kb the result will look better and if someone wants to work on it ,to help you out a little, it will be better as well."


Which brings me to my question ...What are your default settings in DPP when you Convert and Save to JPEG? I've never changed mine from when I installed the program so it defaults at Image Quality 10, checkmark in "Embed ICC Profile in Image", Output Resolution 350 dpi, and the Resize box is check but I never change what it defaults to. The photo I'm looking at now has Width 4115 x height 3086 pixels w/ a checkmark in lock aspect ratio.


Also, if I want to make additional changes in another program such as PSE on top of the changes I made in DPP, should I be saving as a 16-bit TIFF to make those additional changeselsewhere?


Sorry for the dumb questions but I figure, I can either ask the dumb questions and learn something or just remain dumb. [:P]

Denise

[tkerr]

What confuses people is Pixel Dimension vs DPI (or PPI). Viewing size vs Print Size


PPI effects the print size and not the output resolution when you view it on your computer monitor and doesn't effect your image editing or image quality during or after editing..


A picture with pixel dimension of 4115 x 3086 would be too large to fit on the average computer monitor so we resize the pixel dimensions to a more reasonable and easier to view size for the web, e.g. 800 x ? for this web forum. An image that size even my monitor which is a 1920 x 1080 is still way to large and I'll still have to scroll around when viewing it at 100%. But, an image with a resolution of 350 PPI, the actual print size of that picture is 13.226" x 8.817"


When you're editing pictures for the web don't get too concerned about the PPI Resolution, 72 is all that is necessary and is all most computer monitors can see anyways.


When you want to print then you want to adjust the PPI and not the pixel dimensions. However, having said that, When you use software such as Photoshop or DPP you probably still won't have to worry about adjusting the resolution. Most newer Printers do a fine job of managing that on their own so you don't have to worry about. If you use a print shop many of them will request something like 300 ppi or a specific pixel dimension to achieve good quality prints at whatever size you decide on.


Anyways, Maybe this can help better than I can.


http://www.rideau-info.com/photos/mythdpi.html


Or


http://www.photoshopessentials.com/essentials/image-resolution.php

[tkerr]

Additionally!

After processing, If you resize your image to around 800 pixels wide then save as a JPEG and adjust the quality so the image is just under 200kb the result will look better and if someone wants to work on it ,to help you out a little, it will be better as well."

Adjusting Image quality isn't adjusting the resolution. Instead it is adjusting the compression. Lower quality setting = higher compression.


Compression / Image quality setting will effect how your pictures look when viewed on the computer or printed. Depending on the compression method, to much can make a image look noisy as well as showing other artifacts.


Compression or PPI setting don't help when you try to re-edit a picture that you save from
the web. Eg. to help someone out a little. In fact you are losing IQ in a picture
each time you copy it and then open edit and then re-save and upload a copy of that to the Internet. Your saving a copy of a copy
and so on.





The color quality of your pictures and how well they look in print and how it looks on your computer monitor also depends on your Color Setting such as the working space and color management profiles of the image editing application that you're using. E.g. sRGB vs Adobe RGB or Pro Photo RGB etc.
That will make a visible difference to you when editing your pictures as well as when you print your images.You might not be able to see the subtle difference in the range of colors very good when you're editing them on your computer, but you definitely will when you print if you're not careful. If you edit using Adobe RBG or ProPhoto RGB and then save to Jpeg, and if you weren't careful or your monitor isn't properly calibrated you will suddenly notice a difference in how your colors as well as the brightness appear. Colors can look over-saturated and the overall picture too dark.

[neuroanatomist]

What confuses people is Pixel Dimension vs DPI (or PPI). Viewing size vs Print Size...When you're editing pictures for the web don't get too concerned about the PPI Resolution, 72 is all that is necessary and is all most computer monitors can see anyways

The 'most monitors are 72 dpi' statement is dated, as it applies to typical CRT displays, not modern LCD panels. Your monitor is 1920 pixels wide, right? Measure the horizontal dimension and divide. My 24" desktop monitor is 1920x1200 and ~22.4" wide, so it's resolution is ~86 dpi; my 17" MacBook Pro display is also 1920x1200, but only ~14.5" wide, so it's ~132 dpi.


However, it's true that you can ignore DPI/PPI for most editing purposes, since print drivers and photo labs handle that all behind the scenes, so it doesn't matter whether you print/send a 16x10.7" image at 350 dpi, or a 78x52" image at 72 dpi - the printer will size and scale the image appropriately for the output size. The only time it really matters is when designing page layouts or submitting artwork to a publisher, who may have specific requirements (for example, in scientific publishing, figures usually need to be submitted as TIFF format at 300 dpi for images, 1200 dpi for line art/text, and 600 dpi for combinations like images with text labels).

...defaults at Image Quality 10, checkmark in "Embed ICC Profile in Image", Output Resolution 350 dpi, and the Resize box is check but I never change what it defaults to. The photo I'm looking at now has Width 4115 x height 3086 pixels w/ a checkmark in lock aspect ratio.

As for the other parameters besides Output Resolution, Image Quality determines how much compression is applied to the final image. More compression means smaller files and lower IQ, you can see an extreme effect here:





The same 24.6 MB RAW file converted with the following settings result in the following file sizes:

• DPP, 16-bit TIFF - 126.3 MB
• DPP, JPG Quality 10 - 11.9 MB
• DPP, JPG Quality 9 - 8.9 MB
• DxO, JPG Quality 100 - 13.4 MB
• DxO, JPG Quality 95 - 3.9 MB
• DxO, JPG Quality 90 - 2.4 MB

So, it's pretty clear that DxO's 90% quality is not the same level of compression as DPP'squality 9. Personally, I left DPP at Quality 10 (but I no longer use DPP for routine processing). The file size decrement from 10 to 9 is pretty small. In DxO, I usually have Quality set to 95 - there's a substantial drop in file size, and for on-screen display the quality is excellent. For files I'm going to print at large sizes, I set the export quality to 100.


ICC = International Color Consortium. The 'Embed ICC Profile' checkbox adds metadata about the color space (sRGB or Adobe RGB) to the JPG file. Although previously this didn't matter much for web display since most browsers ignored the tags and just used sRGB as the color space. However, some current browsers (e.g. Apple's Safari 5) respect the embedded ICC profile and adjust the color to match your display, the idea being to represent the 'true' color (which really only works if you're also using a calibrated monitor). Click HERE for an example of the effect of embedding a profile (or you may just learn that your browser ignores the profile, if the image on the left changes as you mouse-over; clicking changes the gamma to match Apple's default 1.8 vs. Windows default 2.2). I think it's a good idea to embed the color profile - if you're having the image printed, it allows the lab to determine which color space was originally used relative to the color space of their printers, and if you're sharing it on the web, it will either allow the viewers' browser to correctly display the colors, or be irrelevant because the browser will ignore the tag, so no harm done.


The resize box just allows you to export the image at a smaller size, e.g. 800 pixels wide for posting here. If you're going to share photos, or keep them just for viewing on your computer, and you save the RAW files (as you should if you shoot RAW ;p ), you can consider exporting at a smaller size, e.g. 1800x1200, which means smaller files that are still large enough to fill most common displays (for now). Personally, I usually just export everything full size, and reduce using Photoshop for posting here or elsewhere. I would keep the aspect ratio locked, else you can independently change the width and height of the image, resulting in distortion.

Also, if I want to make additional changes in another program such as PSE on top of the changes I made in DPP, should I be saving as a 16-bit TIFF to make those additional changeselsewhere?

If you're going to make downstream changes to exposure (brightness, contrast) or color, etc., then using a 16-bit TIFF as a go-between from RAW to Photoshop can produce better results, as you'll have the full bit depth to work with (even though as Daniel has explained in his snake oil discussion, 'full bit depth' does not mean the 14 bits that Canon advertises, it's still more than the 8 bits of a JPG image). However, 16 bit images are large, especially as youadd adjustment layers - adding 3 adjustment layers to that 126 MB 16-bit TIFF file mentioned above resulted in a 762 MB TIFF file. Editing files that largecan be taxing on your computer's RAM and CPU - my Mac's Core i5 with 8 GB of RAM does fine, but my work laptop, a Lenovo Core2Duo with 2 GB RAM, struggled when working with that 4-layer 762 MB TIFF file. Also, when I say Photoshop I mean the full Photoshop CS - you mention working with the file in PS Elements, which makes it a moot point since PSE can't really do much editing of 16-bit images - they can be resized, cropped, and have brightness/color, etc., adjusted, but you can't add layers (which you'd almost certainly want to do for editing) or even use the magic wand selection tool on a 16-bit image in PSE.


Hope that helps...


--John

[ddt0725]

Thanks Tim & John for the information and thanks Tim for the interesting links! Both of you have been very helpful in answering my questions.


Denise