Strictly speaking there is no such thing as depth of field. If the camera is focussed at, say, EXACTLY 20 metres, then only objects at EXACTLY metres will be in focus; anything nearer or further away will not; at these distances a point on the subject will be rendered as a circle on the image. The diameter of the circle will be very small at 19 and 21 m. and will become larger and larger nearer or further away. The idea behind the concept of depth of field is that when the circles are very small they will still be seen as dots. An arbitrary decision has to be made about how large the circle has to be to be noticeable. The depth of field lies between the nearest and furthest acceptable circles. The problem is that what is acceptable varies according to circumstances such as how big the print is, how far away you stand to look at it etc. Hence depth of field tables are really only guide lines, useful but not infallible.
GHK

The fact that a RAW file cannot be printed (see my earlier post) does not mean that the only alternative is JPEG. In my view, the best method is, after opening in Adobe Camera Raw (and probably doing some image adjustment), to save the image as a PSD and print from that.
GHK

I don't really think that you made a mistake. The raw file is all that is necessary.
GHK

You should have no problems. If you sized the 7D image to 180 ppi and printed, the width would be over 30 inches. That would give you plenty of opportunity to crop away some of the image and still get 24 inches.
I have ultra sharp images printed at 180 dpi;indeed it is possible to print quite a lot lower than this and still get sharp images. For reasons I won't go into here, 180 is an ideal resolution for printers that print at 2880 or 5760 dpi such as Epson.
There is a lot of nonsense talked about the need to print from a high res image. The often recommended 300 dpi is derived from the requirements for printing with large press printers; ink jets can cope with much lower figures. In fact, 300 dpi is not a good res for use with an Epson; 320 or 288 would both be better.
GHK

HOORAY! HOORAY! HOORAY!

GHK

If you have Photoshop you will also have Adobe Bridge.
Just click on the 'Br'square to the right of 'Help'.
When Bridge opens, go to the file which contains your images. The stuff for this is located just below the string of symbols at the upper left.
Open the file and all the images should display as thumbnails in the CONTENT block. It is possible to set up the Bridge display to suit yourself: I have CONTENT on the left as a column, and PREVIEW to its right. You can make them wider or narrower by dragging the border.
If the thumbnails aren't big enough to form a judgement, then double clicking on one will open it up in PREVIEW.
To see two previews (or more) side by side, hold down Ctrl and click on another thumb - etc.
If any thing is clear or doesn't seem to work , feel free to send me a private mail.
GHK

I have just come across this. I think that some of the material in the response that I posted into the thread "How Much Sharpening is Enough?" may be of use here. One thing that I didn't point out is that when I "open" a DNG file it automatically opens into Adobe Camera Raw (ACR).

If you wish to ask any further specific questions, please feel free to send ma a private mail. You may not have used private mail before, but it's quite easy; there are instructions on the site.
GHK (from UK!)

[quote=JohnSwanda]Re: Saving layers. You don't have to flatten the file to save it. PSD files are saved with the layers intact.

This is what I inferred; it is one of the benefits of saving as PSD. (You can also save TIFF layers). You can re-edit saved layers without loss, but there are other processing tools which do cause losses. Saving layers is a way to avoid some problems, but, unfortunately, not all.
GHK

Welcome.

Yes, they do.
DNG has all the advantages of a RAW file because IT IS a RAW file. Processing a RAW file does not cause any loss of imformation; it merely changes vector parameters which are readily reversible. It is worth noting that when you "open" a RAW file, that is not what you see on the screen; the RAW file (which contains linear relationships between its parameters) must first be converted to a bit mapped file, which has exponential (logarithmic)relationships. If you open into Photoshop you will get a Photoshop file which is a working format. When you come to save the image , it is saved in a saving format (again - exponential). You have the choice of what format you use for saving.
I always use PSD because is closely related in structure to my working Photoshop file as well as other advantages. When I reopen the file in Photoshop it again becomes a Photoshop working file.
Files may be saved as JPEG, TIFF, and others.
JPEG has many disadvantages and I only ever use it for internet transmission and screen projection (which is what it was invented for).
TIFF has less disadvantages than JPEG, but there is no positive reason today for using it. In the past, press printing houses used to demand that files were submitted as TIFFs, but they are much more flexible nowadays.
Unlike RAW, all the other files suffer loss of digital information content when saved. PSDs can prevent this to some extent by saving some information in recoverable vector form on layers but this is only the case when the layers are saved. Flattening the image for saving destroys this availability.
In brief, do all the processing you can before you "open" the RAW (DNG), then refine after opening in your working format and save. The processed DNG will also save automatically and if you want to modify (or reverse) your changes to the RAW there is no problem.
GHK

Sharpen an image to your satifaction, then apply a lot more to a duplicate. Compare; you will soon learn to spot when an image is ovrshapend.
GHK

For casual work, sharpen until it looks right at 100% viewing, and recognize that changing image size on screen or in print will require a different sharpening setting(s).[/quote]

I trust that 100% means an on screen image which is the same size as the print, and NOT 100% in the bar at the top of the on screen image!
GHK

Agreed, but some of you might be interested to learn that the old masters, right back to Goya, made their images look sharper by painting THIN white lines along important boundaries.
GHK

The Kelby suggestion, as it stands, is pointless. It all depends on the image resolution. I am not familiar with 'Detail' but the figures given for Amount and Radius would, very likely, be OK for a 160 dpi image, although this is lower than I would really like for printing.

Local sharpening is certainly to be recommended. Each image has its own needs, but a common use is for land/skyscapes; it is almost invariably that the land area needs more than the sky (which may not need any at all).


But there are better ways of doing it than with a simple brush.
I use soft edged masks and USM or another of the more controllable methods. I may have a number of masking layers, each sharpened independently.
GHK

True enough, but it isn't of much help to someone asking how to achieve.
GHK