How many ppi for quality DVD jpegs

lisarhinehart

Hello

How many ppi do you suggest using for quality jpegs for wedding clients who want a DVD? I am exporting raw files from lightroom to format as jpegs and need to enter a number. I want them to be nice quality, but not take forever to upload to my website or burn. Thanks! --Lisa

Darren Troy C

300?

bike21

I have defaulted 300 but can't qualify it as to why. No complaints as of yet.

mmmatt

As far as I know dpi of the file doesn't matter. It is only the resolution that matters. To the best of my knowledge a 3000x2000 image at 72 dpi prints the same as one at 400 because the dpi is set on the printing end. Somebody can correct me if I'm wrong but that is my understanding.


Matt

Sam

Lisa,

It really depends on what the intended use of the images is. If your looking at just viewing the images on a computer and the image is in a 2X3 aspect ratio then you may want to size them at 800 X 533 at 72 ppi. This will yield a small file that will upload quickly and look good on a computer screen.

If you want print them, then I would not down size the image. I would save upload, etc the total amout of pixels available. The rule of thumb is 300 ppi, but you can print with more or less ppi and get good results.

Sam

Tim Kamppinen

dpi and ppi are meaningless unless you're talking about a specific print size. So something can be 300 ppi at 11x14" for example, and it will look great. 72 ppi at 11x14" will be low quality. But the only thing that's actually different about the files themselves is the resolution.

nikmolson

Tim Kamppinen wrote:

dpi and ppi are meaningless unless you're talking about a specific print size.

DPI (dots per inch) for print size yes.... PPI (pixels per inch) is detail in your digital file being displayed to screen which is your resolution so ppi i would say is not meaningless in this case

id agree 300 is a good default if your not to sure what they are being used for

lisarhinehart

My thought, and I am not tech savvy, is that inches are an actual measurement and attaching them to something virtual-- that can be enlarged to any size seemed to be irrelevant. Does that differ from your understanding?

At this point, customers can order up to 20x30 print, but most order 4x6, 5x7, 8x10. Since I do give them a DVD, I believe they do play it on their TVs, so I guess the more pixels the better for that?

I believe light room sets the resolution based on the mega pixels of my camera, and I just save them at 95%. Does that sound right to you?

nikmolson

at that point why not just go to 100%, shouldn't add to much time to the process id think?

Scott_Quier

lisarhinehart wrote:

My thought, and I am not tech savvy, is that inches are an actual measurement and attaching them to something virtual-- that can be enlarged to any size seemed to be irrelevant. Does that differ from your understanding?

At this point, customers can order up to 20x30 print, but most order 4x6, 5x7, 8x10. Since I do give them a DVD, I believe they do play it on their TVs, so I guess the more pixels the better for that?

I believe light room sets the resolution based on the mega pixels of my camera, and I just save them at 95%. Does that sound right to you?

As you concluded, DPI in a JPG file is meaningless. It's the resolution, the number of actual pixels, in the file that really matters. The DPI is a computed value .... dimension (number of pixels in one direction) divided by same dimension of the print.

My thoughts .... If you are supplying the JPGs to the client with the expectation that they are going to print them and you intend to provide them with limited use rights (personal printing, etc), then why not give them everything you have. Space isn't a function as your are providing them the data on DVD. For this kind of deliverable, I've provided a DVD of JPG files, the smallest such being in the neighborhood of about 6MB in size (the largest being circa 20MB - that's a HUGE JPG file). I process the image in LR/PS and export using LR at 100%. With the limited rights release, I give them the best I have and that means 100%.

Just my $.02 - FWIW

Crystal-Pixel

Actually....Being a Graphic and Print designer.. I know that DPI does make a difference. 72DPI is default for Web / On screen graphics. When doing any web design work I always work in 72 DPI it is the default. Even when saving for web you will see that Adobe auto converts to 72 DPI.

Now working with print files (brochures with photos) All the text and graphical items are usually in Vector format so DPI doesn't matter but all photos are preferably at 300 DPI. If you download stock photography you will see that the High Resolution (Print Ready Graphics) are set at 300 DPI. There is a reason for this. The print quality is significantly better for one thing. Also, the higher the resolution the bigger they can print. You can't take a 72 DPI 200x200pixel image and expect to get a 11x17 photo - the quality will be horrible.

Example from Wiki: For example, a bitmap image may measure 1000×1000 pixels, a resolution of one megapixel. If it is labeled as 250 PPI, that is an instruction to the printer to print it at a size of 4×4 inches. Changing the PPI to 100 in an image editing program would tell the printer to print it at a size of 10×10 inches. However, changing the PPI value would not change the size of the image in pixels which would still be 1000×1000.

Also I would suggest playing with Photoshop and seeing the difference for yourself. You can resample images by using the Image Size tab.

FYI - DPI is the same as PPI

Hope this helps! I would stick to 300 DPI..

Tim Kamppinen

Example from Wiki: For example, a bitmap image may measure 1000×1000 pixels, a resolution of one megapixel. If it is labeled as 250 PPI, that is an instruction to the printer to print it at a size of 4×4 inches. Changing the PPI to 100 in an image editing program would tell the printer to print it at a size of 10×10 inches. However, changing the PPI value would not change the size of the image in pixels which would still be 1000×1000.

...which means that DPI/PPI is meaningless, because people can and will get the file printed at whatever size they want. If you size a file for 300 dpi at 4x6", for example, it doesn't stop anybody from printing it as an 8x10 (with cropping of course) or an 11x14. If and when they do, it's no longer 300 dpi, but some lower dpi that is determined by whatever size they're printing.

So, if you just want to make sure that your file looks good at a certain print size (or not good, i.e. you want them to be able to print 4x6's but not 16x24's) then the ppi/dpi is useful information. But to say "___dpi at 400x600" doesn't tell you anything. You can print that file any size you want and each print will have different dpi. Saying "___dpi at 4x6" would have meaning and let you know if it's going to print with sufficient detail at 4x6".... but it's really just another way to interpret resolution, which is the only real variable that you have control over.

mmmatt

Crystal-Pixel wrote:

Also, the higher the resolution the bigger they can print. You can't take a 72 DPI 200x200pixel image and expect to get a 11x17 photo - the quality will be horrible.

yes but a 4368x2912 (full res for my 5d) image at 72 DPI prints the same as a 4368x2912 image at 300 DPI, and on a windows computer (can't speak for mac) shows the same on screen when using fax and picture viewer, or any editing program when you view as "fit to screen" and shows the same on a tv playing a JPG off a disk... only the resolution matters and the dpi is a printing spec. For us photogs it is meaningless. It is all about your resolution. Just don't shrink the resolution and you are golden. That being said I export at 400 DPI on the off chance that a client looks at it and has the same misconception about dpi that you do and they go "OOOOO 400 DPI! Thats extra good!"


Matt

Scoupe

The highest resolution any video format is going to display (in the US anyway) is 1920x1080. 720x486 is US standard def. That's less than 2Mb file size in jpeg for the 1920x1080.

The DPI or PPI is unimportant in video applications. They only come into play when printing. For example, a 1920x1080 image at 240 dpi would print 8"x4.5". If you lower the dpi to 72, it will print a 26.6"x15" image. Of course it would look kind of ratty, but the point is that video only cares about the size of the pixel map and print only cares about the dpi.

EDIT: Whew, I'm typing slow tonight. Topic well covered beofer I got around to hitting the post button.