HTTP 500 error

[Bruno Schroder]

After posting 25 images in 5 posts in the "NG Get Together Maastricht 5 June 2016"http://nikongear.net/revival/index.php/topic,3723.msg56688.html#new , I'm now getting HTTP 500 errors when posting with images. I can still post in the thread but without images.
A refresh is now showing 2 of the 3 pictures I wanted to post.

[Bruno Schroder]

working fine now.

[Bjørn Rørslett]

Check for illegal characters in file names. SMF does not like apostrophes, for example.

[Bruno Schroder]

I thought about that after the previous post from Rosko but all filenames had the same structure:  _6050XXX.jpg and all files ended up uploaded. The strange thing is when I got a 500 error but the post finally appeared but with only 2 or the 3 files.

[Andrea B.]

If you send me via Dropbox a copy of the photo which would not upload, I will investigate further.

[Bruno Schroder]

PM sent.

[Andrea B.]

Hi Bruno -

My test of your files was OK. However I noticed that the files were very large (in dimension) and not downsized prior to your posting. So I am thinking that you perhaps stressed the forum software when uploading multiple large files at one time? The forum software will itself downsize your photos for display on web pages. Thus it is usually better for a member to perform their own downsizing prior to posting here so that their photos may be touched up after the downsize with appropriate re-sharpening or other edits. You can perform much better downsizes than can the forum software!

Hope this helps. Do let us know if you should again encounter the 500 error. I try to track them down as best I can.

Cheers -
Andrea B.

[Bjørn Rørslett]

Keeping the fine line of distinguishing the concepts of a "large" file in terms of its pixel dimensions (MPix count) and file size (MB required for its storage) is essential.

The forum software will downscale uploaded images to an initial display size of 1200x800 pix (approx). When the user clicks on the file, its original pixel dimensions re-occur (it might take a click on a + symbol to make this happen). Rescaling causes more server strain and if a user has to compromise image quality by selecting a high degree of jpgs compression in order to make the physical size fit inside the allowed limits, one usually has forgotten the pixel dimensions. A jpg file say 2000x1300 pix or smaller can be uploaded with very low jpg compression (jpg levels 10-12) and thus retain its high level of quality, and still be well within the current storage size limit of 2.5 MB.

[Andrea B.]

I just induced some stress on the forum software by uploading a large dimension 4948 x 3280 px file. I did not get the 500 error, but I got a kind of "hiccup" thing. The page disappeared, and I had to reload twice to see the uploaded image -- which was, of course, downsized by the forum software.

So something somewhere does not like pixel dimensions to be too large even though it can struggle through.

[Bjørn Rørslett]

Which more or less was my point. Apparently the forum software cannot *directly* reject a file because its pixel dimensions are excessive. However, it can fail or time out on the downscaling, which shouldn't be necessary if the user did a first downscaling on their own. This way they can relieve server stress and concomitantly get their images displayed with a better quality. A win-win scenario.

[Andrea B.]

I added one sentence to the guidelines to emphasize that resizing pixel dimensions is a good thing. So maybe that will help.

I do wish we had a place to enforce pixel dimensions. That would be useful to prevent this kind of thing. There might be something in the CSS files somewhere. I've been through those a couple of times, but I don't really recall where to find it.

[Bruno Schroder]

That's what I assumed too. It happened after I had uploaded 25 files in a row and disappeared when I uploaded at a slower pace.

I'll warn Martine as the files were from her, she asked me to post them while her computer was fixed, and she got another issue today when posting 5 of her files in the same post. See #362 here http://nikongear.net/revival/index.php/topic,3723.360.html. Personally, I'm usually resizing everything to 1000 pixel on the largest dimension.

Thanks for the support.