How do you keep sharp photos sharp while decreasing file size for gallery specs (1 Viewer)

I'm exporting from iphoto on a Mac; I just can't get originally sharp photos to stay sharp for the gallery when I reduce file size to gallery requirements unless I am exporting a severely cropped photo (where file size is already reduced).... if you know how to do this please let me know.

What I usually do is to apply a little sharpening after reducing size. Additionally, I know there are different algorithms for the downsizing that might differ a little in output quality. Given that I use a PC and do not have any experience with iphoto, this is all I can say to help.

Niels

Neils thanks,
My windows laptop is a company laptop and I try to keep personal stuff off that. The only time I reduce file size is for the BF gallery; I'll work it out at some point!

Can't answer the question, but I do wonder, when price per megabyte of storage has dropped so low, and when high photo detail is often so important for identification, why the gallery size limits remain stuck in a 1990s time warp. Surely they be increased to say, 4000 x 3000 pixels and/or 5 megabytes per file?

Just for comparison, if one is uploading photos to Wikimedia Commons, the file size limit is 100 megabytes.

Would viewing on an average sized screen give you any benefit though with so many pixels? On the other hand if you are using zooming into a small area of pixels to help ID a bird, wouldn't that image be heavily cropped anyway?
For screen viewing I find that a 24Mb RAW image can look fine full screen size when less than 500kb in size as a cropped, resized & saved JPEG without a noticeable loss in IQ. My screen is 19" btw.

Surely by decreasing the file size, loss of sharpness is unavoidable?

My partner takes shots which are typically 7-8mb and this has to be reduced to a max 1mb for the gallery so I see no way to keep the sharpness. Best bet is to not zoom the image too much which IMHO is what happens too often.

Andy

Sorry Andy but I'm not sure I am entirely following you.

When processing images from the camera, by intention they will often end up looking sharper to the eye than the original yet can often be a fraction of the file size. Lack of sharpness in an image is not necessarily caused by reduction in file-size although this can be the case.

In terms of using zoom on the camera, this may just be reducing the IQ as a result of pushing the capabilities of the lens?

Robin Edwards said:

Would viewing on an average sized screen give you any benefit though with so many pixels? On the other hand if you are using zooming into a small area of pixels to help ID a bird, wouldn't that image be heavily cropped anyway?

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Yes, but on a large pic, you can zoom in to different parts of a bird to look at different details :t:

Nutcracker said:

Yes, but on a large pic, you can zoom in to different parts of a bird to look at different details :t:

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Indeed, the larger the better regardless of screen size.

Fugl, from the superb & sharp images on your Flickr link, typically, what would be the file size that you've uploaded for online viewing?

Robin Edwards said:

Fugl, from the superb & sharp images on your Flickr link, typically, what would be the file size that you've uploaded for online viewing?

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The only place I post photos to is my Flickr account where there are effectively no size limits and where, for that reason, I always go for the jpeg maximum. If I want to show a photo to someone I just post the Flickr link, not the photo itself, so I never have to worry about cutting the size down to meet the requirements of other sites (e. g., BirdForum).

If you reduce the size of the photo to a max 1024 width or 800 height it fits on the screen for viewing . I always save at maximum quality and don't seem to have any issues .... I don't think. I'll attach one then upload it to the gallery too.
Sent from my iMac but I don't use iPhoto.


Looks alright to me in the gallery. Incidentally I don't tend to sharpen my images very much if at all in PP.
http://www.birdforum.net/gallery/showphoto.php/photo/552835/limit/recent

Dave nice photo and sharp! I use iphoto as it's quick and easy to edit photos on a Mac (typically I only do a little editing). I think the problem is when I'm exporting and reducing from iphoto, if I export it as anything other than 'current' format it significantly degrades the image quality (even if I select maximum quality). No worries - I was only importing photos into the gallery for Opus only.. anyway I'll sort it out when I have time.

cassowary said:

I'm exporting from iphoto on a Mac; I just can't get originally sharp photos to stay sharp for the gallery when I reduce file size to gallery requirements unless I am exporting a severely cropped photo (where file size is already reduced).... if you know how to do this please let me know.

Click to expand...

You've spotted something alot of people miss: photos reduced for online viewing aren't quite as sharp or sometimes develop rough edges. There are a few factors at play:

• The JPEG file format is "lossy" and induces blur by it's very nature.
• If you upload something higher-res than 1024x900 for the Gallery, the system is down-rez'ing it for you. Even software as good as Photoshop isn't perfect at this, I just expect even less for a social platform (as Tumblr always reminds me, it's truly horrible there).
• Even if you carefully down-rez your own photos, the act of doing so induces a small amount of blur by it's very nature.

So your first line of defense is to downsize it yourself. As others have noted, don't downsize your only copy. Keep a high-res for yourself and create a downsized copy; that's what I do.

Second line of defense is to sharpen the image after you downsize it. But for goodness sake, if you have access to decent software don't simply use the Sharpen command: use Unsharp Mask or Smart Sharpen. I can even recommend settings for anyone wanting to try. For advanced users you can then dip-into plugins which offer even more control (which lately I have been exploring).

Third: always over-sharpen slightly when saving to JPEG. The JPEG lossy format induces slight blur, so slightly over-sharpen to compensate. This isn't 100% necessary, but is useful to keep in mind for the detail-oriented users.

Last: if you have software that lets you control how small to make the JPEG, always adjust it so you get as close to the max. file size (500kb for the Gallery) without going over. Less compression means less data loss and less induced blur. I fine-tune every BirdForum upload's JPEG compression, which runs from 65% (lower quality) to 95% (near-original quality) depending on the photo.

Does iPhoto let you do any of this? No idea; even as a Mac user myself, I'm a design/marketing professional so I've always had Photoshop around. I hear Lightroom is also very adept at this, and I am sure there are others I am unaware of. If iPhoto cannot resize, at least offer "Unsharp Mask", and control JPEG compression amount, my advice is to find software that does within your means.