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Thread: Compression

  1. #1
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    Compression

    I'm a newbie and still trying to get to grips with how to upload and indeed navigate my way around the site.

    In trying to upload entries for the competitions, I of course abide by the limits imposed - 1024 px longest side and file-size 250 kb. However that provides a problem because in reducing an image to as much as 1024 px on the longest side, the file-size limit compresses the resolution to what I deem as unacceptable levels - what I have already uploaded on this basis has presented quite insipid versions of my original image. The only alternative would be to reduce the dimensions to no more than say 600 px on the longest side but then that hardly fills the screen!

    My view, my humble opinion, is that for a maximum of 1024 px, the files-size should be at least 400 kb. The riposte from "Administration" may well be this is beyond the capacity of the site overall. Therefore, maybe there are only two alternatives: a) reduce the maximum dimensions or b) put up with it Thompson.
    Best wishes to all.

    Hugh Thompson

    www.doot.co.uk

  2. #2
    Moderately Underexposed I @ M's Avatar
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    Hugh, all members that are uploading competition images are following the same guidelines and I don't know about you but I would never call the vast majority of them "insipid".

    I would like you to try something for us, link an image at say 600kb and 1024px on the longest side and then attach the same image at 250kb and 1024px on the longest side so that we can see the degradation you are referring to.

    The main reason that the size was introduced was that when you have 50 + images in a competition many many people here that don't have a very fast 'net connection were finding that the competition pages took a very long time to load with large file sizes.

    Have a go at presenting the same image, both linked and attached in this thread and we will see if we can help.
    Andrew
    Nikon, Fuji, Nikkor, Sigma, Tamron, Tokina and too many other bits and pieces to list.



  3. #3
    Administrator ricktas's Avatar
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    Of course there is going to be degredation. The JPG format does that. But we had to set a limit somewhere. OK so you would like 400KB, what if someone else wants 600KB, maybe 1MB? Maybe we could decrease the pixel size to 600 on the longest side and keep it at 250KB?

    In the end the limit was set as a balance between fairly darn good image quality at 250KB, and site bandwidth usage, download times for those on slower internet speeds etc. Yes it is a trade-off, but we had to set a limit somewhere that was reasonable, and we chose 1024 pixels cause it is a standard for sites like Flickr and Photobucket, along with 250KB to create a balance between speed of download and image quality.
    "It is one thing to make a picture of what a person looks like, it is another thing to make a portrait of who they are" - Paul Caponigro

    Constructive Critique of my photographs is always appreciated
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  4. #4
    It's all about the Light!
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    Try removing all EXIF data (and thumbnails) first. It gives you a bit more file-size.
    In part the file-size limit is to help low-bandwidth users.
    Another reason is to keep images to a size where they are less likely to attract image theft.

    With the new system everyone has exactly the same constraints to at least it is fair.
    regards, Kym Gallery Honest & Direct Constructive Critique Appreciated! ©
    Digital & film, Bits of glass covering 10mm to 500mm, and other stuff



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    Administrator ricktas's Avatar
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    Oh, and just cause the limit is 1024 pixels on the longest side, you can enter smaller, it is a maximum limit, not a required size.

  6. #6
    It's all about the Light!
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    Quote Originally Posted by ricktas View Post
    Oh, and just cause the limit is 1024 pixels on the longest side, you can enter smaller, it is a maximum limit, not a required size.
    Just to amplify this point...
    12+ months ago the limit was 800 pixels - which was quite reasonable.
    So if IQ is a concern then even dropping to 900 makes a big difference.

  7. #7
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    During my sleeptime, you have all been rather busy !

    First thanks for all of your comments. From the tenor of what you say and how you say it, I reckon my original post has not been well received (incidentally I meant my photos looked insipid, not everyone's).

    Rather than my taking up "I@M"'s suggestion, I'll just pipe down. Thanks again for your suggestions and advices.

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