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Resolution


Lee

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I have been testing my new digital camera and trying to understand resolution (trying being the operative word in that sentence).

I did three test shots of the same subject. One in RAW mode (3072X2048), one in LG (3072X2048) and Medium (2048X1360). Enlarging each in PS I can tell the difference between the LG and Med images although it is very slight. I did notice that all were at 180 resolution. As all this will be print work don't I need to change that to 300 dpi? I tried that to see what would happen and the images obviously got larger but on the monitor but I could not tell the difference just by looking at them.

My question - I'm still trying to do what gare told me yesterday (to have approx. 4BM per 5X7 image). That's easy at the size of these images. I also want to have 300dpi resolution for printing which makes a HUGE file, what do I do? I am totally lost at this point. Do I shoot in LG mode, increase the resolution to 300 once in the computer and then just reduce that to 5X7 for printing???

Please HELP. I'm dying here. [confused]
 

Erik

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What is important is the number of pixels, and the file size. Multiply height with width and then multiply by three and you get an idea on the uncompressed filesize. If, for the same image size, the filesize is noticeably smaller, then the file has been compressed which means less quality.

As for the resolution: pixels have no fixed size, so you can decide how many there will be in every inch. For printwork, 300 per inch is very good. Often you can have less without seeing the difference. It depends on the print size you want:

3000pix, 300 per inch is 5 inch. at 150 per inch you get 10 inch.

If you want to change the filesize in PS, it's always better to make it smaller than to enlarge it. Best is to do it in several steps, and to avoid simple cheats like 50% (one out of two pixels): better let PS do some calculation.

o, and BTW: you don't die that easily. It's a tough job to die!
 

Lee

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Erik,
I understand what you said but am still not sure what to do. If you could walk me throught the steps I can figure it out from there.

Do I shoot in LG mode, transfer image to computer, change the resolution to 300? At that point I obvisouly have better print resolution but a huge file. After making any adjustments in PS I want I select print with preview and reduce the size to 5X7 (or whatever size) and then print?

And why is RAW mode so much better? I did my test shots and could not tell the difference between the RAW image (TIFF) and the Large jpg image (both were 3072X2048).

Thanks
 

Lompoc42

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Check the resolution in RAW mode. It could be that the camera is shooting at 300 DPI in raw mode or higher. Your best is shooting in the highest quality setting you can and then beefing up the resolution afterwards. With the highest res shots, you'll notice very minimal loss in quality when you blow up the resolution ;) Also. Being the wonderful program it is, you can change the print size without changing the display size. Yes, the files will be quite large, but if you're going to print them it's absolutely necessary. Then again Lee, are you using these prints for professional stuff? Because if you're only going to be home printing these, then 180 DPI probably won't look that bad. Check out the print size before anything else, because if your print is size is nice and small but the display size is incredibley large that means you're packing in lots of pixels into that print size and therefore the print will probably look pretty good. Fuddle around a bit, if you can't print at 300 dpi don't fret, you may not even notice much of a difference! :perfect: :D :D :rofl: B7
KOP
 
G

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Lee, if you're an experienced photographer, which I know you are, then you also know it's best to shoot in the highest resolution, uncompressed, period!

But hey, if you want to able to shoot more shots with your camera, then you always have to turn to a compressed format or buy more storage.

Gare's 'Megabytes' rule works if you know what you're going to shoot or scan, but hey, photography can be unpredictable. I had shots that I wasn't satisfied with, until I cropped a certain area....et voila! Suddenly I had a great shot. But where does that leave you if you shot the image in a low resolution? ;) Also, maybe now your target is a 5x7 print, but what if someone comes to you one day who wants a larger print of that same file?

Personally I never shoot with TIFF. I don't see enough difference between TIFF and the highest quality Jpeg that urges me to buy an extra 200GB hard drive or to archive my images on 150 CD?s.

Just a simple example of what it means to shoot and archive in TIFF;

2,000 JPEG images of let?s say 2M take up 4 GB of CD storage
2,000 TIFF images of 50 MB each, that?s 100GB! You?ll need a lot of CDs/DVDs for that!

And we DO need to archive them or don?t we ;)

Ok, back to the subject... my suggestion

- shoot in the highest resolution
- select the quality (raw/tiff/jpeg etc) that suits your storage
- transfer your images to your computer and make the necessary adjustments
- most of the time you can leave the 180 dpi intact if you?re printing on a home inkjet and that?s it

There are many other ways to do it, but this one is quite straightforward.
 

wbiss

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[stuned] 3072*2048 @ 180 ppi, will give you a very good quality 17"x11" print! I can't buy photo paper that size! [confused]

Under Image->Image Size, uncheck the "resample box", Lee, and see what happens when you change your print size to 10" x 6". You'll have over 300 ppi. ;)

My advice to you... do some 'test prints' and compare various settings from 150-300 ppi. Your printer may be throwing away extra information (pixels) that it doesn't need and it's always better to let Photoshop do that for you by resizing the ppi before you send it to your printer.

Unless you're shooting "studio quality portraiture", I see no noticeable benefit to shooting in a TIFF format. I've run enough tests myself to know this! And, as Gaussian has pointed out, these files are "massive" in size!!!!
 

Lee

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Thank you Erik, Gaus and Wendy. I've just spent the morning taking pictures in the top three size options, comparing them on the monitor and then in print. Maybe it's just me but I can not tell the difference between an image shot in RAW mode from one shot in high rez jpg/fine (3072X2048). Maybe an expert can but if it's that close then I'm not going to worry about it. And yes, these are for business, not personal, but, like I said, only 5X7 99.9 percent of the time and if someone wants and 8/10 I'm quite confident the jpeg/fine will work [he says crossing his fingers].

Problem with RAW is file size. I got a 256 Flash Card and that will record 101 of the highest rez jpeg images. If I shot RAW it would only be 19 (according to the Canon owners manual). Then there is my 80G H/D. Bottom line, I did not plan on getting back into photography on a digital level and none of my equipment is going to handle hundreds of RAW images. Cost to upgrade......."fa get a'bout it." Maybe if my little business grows THEN I can look at upgrading all my computer stuff.......and if I do that I'm going back to Mac. :D

ANyway, thanks again. I'm still not sure I understand but I'm a lot further along then I was this morning. 8}
 

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