Home Forums The Learning Center Computers and Technology for Artists What is 500 dpi in a jpeg file?

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  • #986065
    Westerngirl
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        OK, I’m pretty much a technical dummy, so please bear with me!

        A juried art show that used to require slides has switched to this entry spec:
        “images must be sent via cd as Jpeg files (500 dpi).”

        I’m confused, as I thought dpi had to do with printer resolution. Surely this does not mean that the artwork must be scanned?

        I have two digital cameras, a 5.0 megapixel Sony and an 8.0 megapixel Konica Minolta. What must I do settings wise to adhere to the entry specs?

        Thank you, and sorry to sound like such a dummy regarding this!

        Deb

        Deb
        The Lord reigns; let the earth be glad! :clap:
        My memory's gittin' so bad, I don't know whether I've found a rope or lost a horse!
        My website & My Art Blog

        #1077846

        dpi is indeed printer resolution. ppi is the the number of pixels to be used per inch when printing or viewing an image. Unfortunately dpi has come to be used for both printer resolution and ppi, and obviously 500 ppi is what is meant in the instructions. I don’t know why they would include this requirement, since the important thing is the pixel dimensions of an image, such as 3000 x 2000 pixels. Changing only the ppi (dpi) of a jpeg does not affect the true resolution (pixel dimensions) of the jpeg. If you really need to specify 500 ppi, a program like Paint Shop Pro or Photoshop will do it in a jiffy, and there are other programs too.

        Richard

        C&C is welcome.
        Richard

        #1077842
        Oldthumbs
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            Deb,

            What is the purpose of sending them a jpeg of your artwork? Is it to see if they will accept your artwork into their show, or are they going to judge your artwork using the jpeg file?

            Ray

            “The tragedy of life is not that it ends so soon, but that we wait so long to begin it.”- W. M. Lewis
            “It takes a lot of courage to release the familiar and seemingly secure, to embrace the new. But there is no real security in what is no longer meaningful. There is more security in the adventurous and exciting, for in movement there is life, and in change there is power.”- Alan Cohen
            #1077849
            Westerngirl
            Default

                Thank you, Richard! That helps alot; I was confused when they used the term dpi instead of ppi. I don’t trust my technical expertise at all, so thought I was really missing something.

                Yes, Ray, the purpose of the jpeg file is to jury the works for acceptance into the show. The actual award judging will be after the accepted works are submitted, and the show is hanging. This is the first time this particular show has used cd images instead of slides, so I imagine they are experiencing some procedure blips, as I am in getting used to this new way of doing things! :rolleyes:

                Deb

                Deb
                The Lord reigns; let the earth be glad! :clap:
                My memory's gittin' so bad, I don't know whether I've found a rope or lost a horse!
                My website & My Art Blog

                #1077843
                Oldthumbs
                Default

                    This is the first time this particular show has used cd images instead of slides, so I imagine they are experiencing some procedure blips . . . :rolleyes:

                    I might guess that. Like Richard said, specifying 500 dpi (or ppi) without specifying an image size (height X width – in pixels) is pretty useless. Not to mention that the images will probably be viewed on a monitor using a 72 ppi or 96 ppi resolution, which makes the 500 ppi spec even more ridiculous. Even the use of jpegs for judging artwork is questionable, in that it is a “lossy” file format where some of the image information is lost when saved as a jpeg.

                    Oh well, it will be interesting to see what they get.

                    Ray

                    “The tragedy of life is not that it ends so soon, but that we wait so long to begin it.”- W. M. Lewis
                    “It takes a lot of courage to release the familiar and seemingly secure, to embrace the new. But there is no real security in what is no longer meaningful. There is more security in the adventurous and exciting, for in movement there is life, and in change there is power.”- Alan Cohen
                    #1077847
                    Katherine T
                    Default

                        I have sat through a showing of slides submitted for a juried art show. I think maybe you’re making a few assumptions here which might be incorrect

                          [*]slides are often shown via a projector to a panel (they might be seen on a computer monitor but you can’t assume this)
                          [*]ergo they must be capable of being projected at an enormous size without losing definition
                          [*]500 dpi sounds a bit over the top to me – but it might be because they have had previous problems with people scanning at levels which meant images end up fuzzy
                          [*]there is absolutely no question that submitting the best possible slides makes a HUGE difference. I couldn’t believe the quality of slides that some people submitted.

                        There’s an article in this month’s Artist magazine about submitting slides to a juried show which you might find useful.

                        BLOG: [/COLOR][/COLOR][/SIZE]Making a Mark[/URL]
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                        #1077844
                        Oldthumbs
                        Default

                            . . . ergo they must be capable of being projected at an enormous size without losing definition . . .

                            I had thought about this, too. If they are projecting the images I might be able to understand the 500 ppi, but once again, without specifying an overall image size, the 500 ppi means nothing. Obviously a 35mm slide comes in a fixed size, so they never had to specify anything more than a 35mm slide in the past, so most likely no one even thought about the size (unless we don’t have all the info here).

                            Ray

                            “The tragedy of life is not that it ends so soon, but that we wait so long to begin it.”- W. M. Lewis
                            “It takes a lot of courage to release the familiar and seemingly secure, to embrace the new. But there is no real security in what is no longer meaningful. There is more security in the adventurous and exciting, for in movement there is life, and in change there is power.”- Alan Cohen
                            #1077848
                            Katherine T
                            Default

                                I think quite a few problems are emerging around communication as competitions switch from slide entry to digital entry. Mostly to do with the fact that people find it difficult to get their heads around how to specifiy the sort of image they want to get (oh for somebody to do a quick digest to formats and sizing and dpi/ppi!)

                                I guess the best suggestion is work on the principle that your image might be projected at some point.

                                BLOG: [/COLOR][/COLOR][/SIZE]Making a Mark[/URL]
                                SKETCHBOOK BLOG: Travels with my Sketchbook in......
                                PORTFOLIO: Pastels and Pencils[/COLOR][/COLOR][/SIZE][/B][/B]
                                #1077851
                                duene
                                Default

                                    Hi Deb,

                                    I bet I know which show you are submitting the images for! Cheyenne Frontier Days, right? It’s a small world!

                                    I just photographed some of my sister-in-law’s sculpture and put them on CD for her to send in. I couldn’t figure out the dpi requirement either, and finally sized the images to about 600 pixels on each side, and she sent it in. As far as I know, they were accepted.

                                    Duene

                                    #1077852
                                    duene
                                    Default

                                        I guess I only addressed part of your quesstions.

                                        Either camera should work fine for the photograph. After taking the digital image, you will have to resize it on your computer, using a graphics program. Then copy the image to a CD. I don’t know which program you use, so can’t help you any more there.

                                        Duene

                                        #1077839
                                        madster
                                        Default

                                            600px per side at 500ppi will give you an image of about 1 1/4″ by 1 1/4″
                                            PPI (for monitors) is for resolution quality. You are looking at images on your monitor at 72 ppi on macs, and 96 ppi.
                                            The detail lost is horrific.
                                            For a juried art show, the 500 ppi is to allow for enlargement and zooming in on an image to determine quality.

                                            More than likely, the submittal instructions give an “optimum” image size at 500 ppi, for uniformity. That is the size you reduce your image size to, with the resolution of 500 ppi.

                                            Look at these two photos of one of my works. The first is about 7″x5″ at 72 ppi, and is shown above the Image Size dialog box at 100%.

                                            The second is about 5 1/2″ by a bit overe 4″ at 500 ppi, and is shown next to the same dialog box as the first image, but it is at 33%…

                                            These are screen captures, just to show a fraction of the size and resolution difference between 72 and 500 ppi on a monitior.
                                            ~M

                                            Madster
                                            Change is inevitable, Growth is optional.

                                            #1077845
                                            kuzmal
                                            Default

                                                That is so frustrating. Before having digital requirements they really should at least consult a digital artist. There is no reason I can think of for an image to be over 300dpi. That is the standard for printing. If they are only going to view it through a monitor (that includes projection) I don’t know why it would need to be that high. As far as I’m aware, even projecting it the best you are going to get is 96. The image size should be an important factor. The important thing for you to know is. When shooting digital images of your work, keep the file as big as you can. If your camera has the option, set it to save your files as RAW or Tiff. RAW files have no compression, so you aren’t losing any data (they take up a huge amount of space but it’s worth it). I believe TIFF files have some compression but not like JPEG. If the only option on your camera is JPEG, then use the highest quality setting you can. Keep these original files and when you have to resize or change them, save them in an uncompressed format and only compress them once as your last step. Every time you save a JPEG it gets compressed (it drops data to save space), thus you don’t want to be saving them over and over again, it’s like making a copy of a copy. If I were you, I would call and see if I can find out more specific requirements, such as how they will be displayed so that you can make sure they see the best image you can give them. O.K. I suppose my New Media degree is worth something… ;)

                                                Malissa

                                                :D visit my gallery: Malissa Kuznicki

                                                #1077840
                                                madster
                                                Default

                                                    Requirements ask for 300 ppi for printing purposes.
                                                    You are making a rash assumption that an image will only be viewed through a 72ppi monitor.

                                                    Art shows print programs, catalogs, press releases, and the like.
                                                    500ppi is a bit extreme, but that could be a typo, or incorrect information, as dpi (dots per inch) does not even apply to digital files.
                                                    An e-mail to confirm the resolution and file size requirements shouldn’t be too hard to send if there are questions, such as the clarification of the specifications.

                                                    ~M

                                                    Madster
                                                    Change is inevitable, Growth is optional.

                                                    #1077853
                                                    Artslinger
                                                    Default

                                                        [FONT=Arial]500 dpi is a silly request.[/FONT]
                                                        [FONT=Arial] [/FONT]
                                                        [FONT=Arial]If the artwork will be reproduced in print the standard is 300dpi at actual print size, anything else is a waste of disk space. This size will also work fine if the file will be viewed in Photoshop for detail, you will see more than enough detail. [/FONT]
                                                        [FONT=Arial] [/FONT]
                                                        [FONT=Arial]More important than a higher dpi is a good scan or photograph that is true to the color of the actual artwork. Any color correction should be done by a professional on a quality monitor that has been color calibrated; otherwise the color and saturation can be seriously affected. [/FONT]
                                                        [FONT=Arial] [/FONT]
                                                        [FONT=Arial]A JPEG is just an industry standard compression file that can be opened in virtually all computer programs.[/FONT]

                                                        #1077854
                                                        TMeeks
                                                        Default

                                                            OK, I’m pretty much a technical dummy, so please bear with me!

                                                            A juried art show that used to require slides has switched to this entry spec:
                                                            “images must be sent via cd as Jpeg files (500 dpi).”

                                                            I’m confused, as I thought dpi had to do with printer resolution. Surely this does not mean that the artwork must be scanned?

                                                            I have two digital cameras, a 5.0 megapixel Sony and an 8.0 megapixel Konica Minolta. What must I do settings wise to adhere to the entry specs?

                                                            Thank you, and sorry to sound like such a dummy regarding this!

                                                            Deb

                                                            This is one of those things that drives me crazy!!! :lol:

                                                            YOU aren’t the dummy in this one. They are.

                                                            Unless they give you the precise size that they intend to print the image, the 500 dpi is absolutely MEANINGLESS!

                                                            I can set a 512×512 pixel image to 500 DPI. Of course, it would print out a 1″x1″ but it would match their requirements perfectly.

                                                            It tells me that they really don’t know what they are talking about and are simply upping the image resolution requirements to convey that they don’t want poor images.

                                                            If you have a 3mpx (megapixels) camera or better, you are going to be perfectly safe in sending in your images. THAT is a better way to define quality from a digital camera. The DPI is an artificial and outdated measurement of quality.

                                                            8×10 at 500DPI would be 4000×5000 pixels… or a 2,000,000 pixel image!!! That’s GIGA PIXELS!!! It would never even FIT on a CD. :wink2:

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