Way2slk Loc: Bluffton SC

I Have a pretty good question. When I shoot a photo, it is 65x42 and 72dpi. My question is when I save it in post process.....what format is best quality, size, do I save as a png or tiff file? What size is best to upload to uhh?

Some of the old pros can really assist and I am willing to always learn new things.

rmalarz Loc: Tempe, Arizona

I'm assuming that the 65x42 is inches. That would give you an image size of 4680X3024 pixels. The next question is saving it for what purpose? If you are saving it to post, here for instance, .jpg is fine. If you are saving it to work on it at a later date, tif. If you are using photoshop, save it in psd format for additional work.

It's best not to save a file for future work in jpg format. This is due to inherent characteristics of that particular format. However, for a save and post, jpg is just fine. I hope I interpreted your question correctly, along with the numbers you provided.
--Bob

Way2slk Loc: Bluffton SC

Should I save at 300 dpi or 72. What gives me the sharpest image when enlarging. I read where no compression and saved in tiff format is the best for display.

Plieku69 Loc: The Gopher State, south end

For posting in the Photo Gallery, and for print publication, I always save a 5x7, 300dpi out of Photoshop. I have found that is the near perfect size to download in Gallery.
Ken

rmalarz Loc: Tempe, Arizona

Again, it depends on what you are going to do with it. For posting 72 dpi will work just fine. If you are planning on printing the image, then I'd open from a RAW file at 300 dpi. Do your processing and save it as a psd, if using PS, tif if some other processing application. That image should be saved, again as a psd if you plan on further processing. If you are going to print it, save it at the size you intend to print, jpg and 300 dpi.

There's nothing magic about 72 for posting, it's just a long time practice. Most printers, with whom I've dealt, require a 300 dpi full size image in jpg format for printing.

Enlarging a digital image can result in some very ugly images. They tend to pixelate if you try to make an image bigger. That's why I suggested starting with the image size you want to print with a resolution of 300 dpi. You can always make the image smaller by reducing the 300 to 72 and adjust the overall size accordingly.

Just for information, my standard print sizes are 12x18, 24x36, 16x20, and 32x40.
--Bob

TheDman Loc: USA

It is completely irrelevant. Digital images don't have a DPI.

blackest Loc: Ireland

kind of the dpi of an image is really related to the file size and the use you are putting the image to. for example my screen is 1280 Pixels by 800 pixels so if an image was scaled down to 1280 by 800 then that's going to fill the screen at that size. for a retina display they have a dpi of around 300 dpi which coincidentally is the dpi used most often for printing.

https://en.wikipedia.org/wiki/Retina_Display
"Raymond Soneira, president of DisplayMate Technologies, has challenged Apple's claim. He says that the physiology of the human retina is such that there must be at least 477 pixels per inch in a pixelated display for the pixels to become imperceptible to the human eye at a distance of 12 inches (305 mm).[28] The astronomer and science blogger Phil Plait notes, however, that, "if you have [better than 20/20] eyesight, then at one foot away the iPhone 4S's pixels are resolved. The picture will look pixelated. If you have average eyesight [20/20 vision], the picture will look just fine... So in my opinion, what Jobs said was fine. Soneira, while technically correct, was being picky."[29] Shortly after Soneira's challenge, the Boys of Tech podcast published their own analysis[30] and concluded that Soneira's claim was invalid and that Jobs' claim was correct. This was primarily because Soneira misinterpreted the manner in which the acuity of the human eye can be tested. The retinal neuroscientist Bryan Jones offers a similar analysis of more detail and comes to a similar conclusion: "I'd find Apple’s claims stand up to what the human eye can perceive."[31]
Apple fan website CultOfMac stated that the resolution the human eye can discern at 12 inches is 900 PPI, concluding "Apple’s Retina Displays are only about 33% of the way there."[32] On the topic of 20/20 vision, they said "most research suggests that normal vision is actually much better than 20/20. In fact, people with normal vision usually won't see their eyesight degrade to 20/20 until they are 60 or 70 years of age"[32] (confirmed by vision testing experts Precision Vision).[33] CultOfMac also noted that people do not always view displays at a constant distance, and will sometimes move closer, at which point the display could no longer be classed as Retina."

900 DPI well i think i'm too old to appreciate that level of detail.


If you want to print an image at 8 by 10 300dpi then you need 3000px by 2400px to get an 8 by 12 printed that looks pretty good at a normal viewing distance. To look good on my screen full size around 100 DPi is grand for me (roughly 1/9th of the pixels required for the print) but if I wanted to print that photo it would look poor at much above 3 by 2, but thats fine you probably don't want me making prints of your photo's.

Anyway what looks good on screen doesn't necessarily look good in print if there isn't enough pixels to print at the size you want.
If a picture is for screen use or email you can reduce the resolution and even optimise the sharpening for screen, but don't use that version for print.
by reducing resolution for screen use it means smaller files and faster load times.
dpi is pretty much only use as a guide to what size your image can be displayed at. You need to be careful embedding pictures in documents especial documents that can be going to print. If you're viewing a word doc and embed an image on the page it usually scales the image down in the document If i'm making a print document from what you sent me the image files are now tiny and i can't make them any bigger for print use. For editing a doc to produce a printed document i really need a larger image...

Way2slk Loc: Bluffton SC

Thank you for the interesting read. I appreciate the feed back and will continue to save as a psd or tiff. Printing for sharpness and the color variation are the next step in my growth as a photographer.

Way2slk Loc: Bluffton SC

Thank you Ken. That makes perfect sense.

Jim Bob

tiff will do nicely.

TheDman Loc: USA

DPI has no bearing on file size at all. Your confusing monitor DPI (how dense the pixels of a screen are) with that DPI value embedded in the meta data of a photo. The two are unrelated. You could save your 1280x720 image at 9,000 DPI or 1 DPI and both would fill your screen, look exactly the same, and be the same file size.

blackest Loc: Ireland

Oh it does have bearing if i am going to print your image and require 300 dpi then your going to get a 2 by 1 inch photo if you send me a 600 by 300 image on the other hand a 600 by 300 px image would be likely fine for an email or posting on a web page. There is no need to send a high resolution for display on a web page or an email. If you send a 6 Megabyte image for a web page one of two things happens If the website is hand rolled then your image may be downloaded and then rescaled in the browser. Or as is more common in most cms systems a smaller version is generated which might be 60 Kbyte in size. Your original full size image may never be displayed. This makes the server load less as less data needs transferring (around 1% of the original file). Now when the server resizes your image how it does so is generic, while if you do it yourself you can optimise for the size it's being displayed at.

DPI is more of a guideline than a requirement and there is no real such thing as a 300 dpi image or a 72 dpi image but if an image has been optimised for display at 72dpi and scaled down to a smaller file with less pixels it is going to look lousy if you want a print around the same size it is on screen as it needs more pixels.

TheDman Loc: USA

Now you're confusing pixel dimensions with DPI. In all the examples you mentioned pixel dimensions were the important factor. DPI played no part in anything. If I order a print from a lab they're going to print whatever size I order no matter what my image's DPI says. Pixel dimensions are all that matter to digital images. DPI does not.

via the lens Loc: Northern California, near Yosemite NP

Computer screens are not capable of showing a photo at 300ppi, they show it at 72ppi or I think there might be some screens that are in the 80ppi range (I may not have said this technically correct and I'm sure someone will find fault with it!). For web work save at 72ppi in most cases and around 700-1200 pixels across. For printing use 240ppi to 300ppi in most cases, depending on the size of the print, sometimes even 360ppi. Larger size print means you can use smaller ppi (i.e., 240ppi) and a smaller size means you can use a larger ppi. Adobe Lightroom uses a standard of 240ppi. I normally print at 300 ppi, which is a standard in the industry in general, for example, a Blurb book requires at least 300ppi. And it is ppi not dpi, dpi is used for the CMYK printing process, although they do seem mostly interchangeable. If you save an image for the web at 300ppi the web program that you are loading to converts it to 72ppi so it's better to keep control over it and convert it yourself in many cases. I never convert and save my photos until I need one as I use Lightroom, when needed I simply export at the needed size and conversion required. Tif is a good format if you do need to save and work on a photo and have a reason to save it in that format. I only use jpg for email and web work. Otherwise, all photos simply stay put as taken in RAW format, or if worked on in a plug-in program in a tiff or Photoshop format (using the word "format" loosely).

blackest Loc: Ireland

erm yes the retina displays are higher
http://www.pcadvisor.co.uk/buying-advice/apple/what-is-retina-display-on-ipad-3491035/
"What are the benefits of a Retina display?
What difference does the Retina display actually make? That depends on what screen resolution you're comparing it to. The iPad 1 and iPad 2 both have a resolution of 1,024 x 768 pixels and a pixel density of 132 ppi (pixels per inch). That compares to the 2,048 x 1,536 pixels at 264 ppi on the Retina-class iPads. In other words the pixel density is twice as high. (There are actually four times as many pixels in the same amount of space, but that's a function of area whereas pixel density is a function of length. Try to keep up.)
The difference between the iPad mini and the iPad mini 2 with Retina display is similar. The iPad mini 1 has a screen resolution of 1,024 x 768 pixels at 163 ppi, while the iPad mini 2 has a Retina screen at 2,048 x 1536 pixels and 326 ppi - twice the pixel density."