Testing upload size.

B

Blacktop

Senior Member
I've been playing around with my upload sizes to the forum (In posts, not the gallery)

I've been uploading straight from my folders on the hard drive with full size, letting the forum software do the resizing.
Here are two uploads of the same image.
The first is my normal way of letting the forum resize, and the second is pre resized at 1000 pixels on the long side.
Can anyone tell the difference in quality when viewing?

It's a pain in the butt resizing every time I'm uploading here, but if it does make a difference I will do it that way from now on.
Thanks.

_DSC3151.jpg

_DSC3151-2.jpg
 
hark

hark

Administrator
Staff member
Super Mod
Contributor
When they are right clicked and each one opened in a new tab and enlarged to its largest size, one is larger than the other; however, just comparing them as they are in the thread, no I cannot see a difference. :)
 
wev

wev

Senior Member
Contributor
At viewing normal size, they are close to identical; enlarged, you can see degradation and color shifting in the auto resized one. Probably not a concern in normal circumstances

auto
1.jpg


manual
2.jpg
 
A

aroy

Senior Member
Uploading a large 24MP image takes a lot of time, it is faster to upload a smaller jpeg. In my case it does not matter, as I export jpeg from Capture NX-D, I set it at 1000 pixels wide, so no extra steps required.
 
B

Blacktop

Senior Member
aroy said:
Uploading a large 24MP image takes a lot of time, it is faster to upload a smaller jpeg. In my case it does not matter, as I export jpeg from Capture NX-D, I set it at 1000 pixels wide, so no extra steps required.
Click to expand...

I'm not uploading NEF files.:D I'm uploading 4-8 MB Jpegs, which really takes no time. It would take longer to resize the files I want to upload then the actual time it takes to upload the original jpegs.

I save my edited NEF files on my computer to non resized Jpegs.
 
A

aroy

Senior Member
Blacktop said:
I'm not uploading NEF files.:D I'm uploading 4-8 MB Jpegs, which really takes no time. It would take longer to resize the files I want to upload then the actual time it takes to upload the original jpegs.

I save my edited NEF files on my computer to non resized Jpegs.
Click to expand...
I know, but even 8MP files take a long time here. The max upload speed is quite low. As I said I shoot RAW and have to export the files to get jpeg, so I export then to a smaller size. If I was shooting jpeg fine (as you seem to be), then resizing would take time.
 
W

wornish

Senior Member
I use Lightroom and export jpegs with the File Quality setting at 75 and sized at 2000 px on longest edge - 72 px per inch.
Some sites like Flickr allow you to post any size file and 2000 px looks great on a big monitor. This creates a files of about 350 - 450K in size.
The auto re sizing done on here works fine for me.

Here is a good article that shows comparisons at different quality settings.

Jeffrey Friedl's Blog » An Analysis of Lightroom JPEG Export Quality Settings

There is no observable benefit of going beyond quality 75 even at 100% crop in 99% of cases all you get are very big files that fill up your disk.
 
N

nickt

Senior Member
They look the same to me as they are and also when I click for the larger size. But on the second image, I am able to use my FireFox plugin, FxIF, to see the exif data. I get the forum pop-up exif on both though. Here is a clip of what I am able to get right clicking on the 2nd shot:

Camera Maker: NIKON CORPORATION
Camera Model: NIKON D300
Lens: 18.0-140.0 mm f/3.5-5.6
Image Date: 2014-08-03
Focal Length: 140mm (35mm equivalent: 210mm)
Aperture: f/5.6
Exposure Time: 0.0008 s (1/1250)
ISO equiv: 200
Exposure Bias: none
Metering Mode: Matrix
Exposure: aperture priority (semi-auto)
White Balance: Auto
Flash Fired: No
GPS Coordinate: undefined, undefined
Software: Adobe Photoshop Lightroom 5.3 (Windows)

(photographer name and copyright info usually shows up here too, but not in the case)


vs. this from the forum pop-ups for both images:

Model NIKON D300
Capture Date 2014:08:03 12:16:49
Shutter Speed 1/1250
Aperture f/5.6
ISO 200
Exposure Comp. 0.00EV
Focal length 140.00mm
Lens 18.0-140.0 mm f/3.5-5.6


So a little more info comes through on the shot you resized yourself. If you add your name and copyright info to the image, it may be desirable to not have the forum strip that out when it resizes for you.
 
S

Sandpatch

Senior Member
wev said:
At viewing normal size, they are close to identical; enlarged, you can see degradation and color shifting in the auto resized one. Probably not a concern in normal circumstances
Click to expand...

I was going to say that perhaps it's my aging eyes, but the pre-sized second shot is a tiny bit sharper to me.

I pre-size my submissions, going for something in the 500KB size range just for ease of uploading. It sometimes results in a small bit of blur, but that's okay because I know that my personal permanent large copy is fine.
 
B

Blacktop

Senior Member
wornish said:
I use Lightroom and export jpegs with the File Quality setting at 75 and sized at 2000 px on longest edge - 72 px per inch.
Some sites like Flickr allow you to post any size file and 2000 px looks great on a big monitor. This creates a files of about 350 - 450K in size.
The auto re sizing done on here works fine for me.

Here is a good article that shows comparisons at different quality settings.

Jeffrey Friedl's Blog » An Analysis of Lightroom JPEG Export Quality Settings

There is no observable benefit of going beyond quality 75 even at 100% crop in 99% of cases all you get are very big files that fill up your disk.
Click to expand...

Thanks for that link. I have it set at 100%, but I'm going to rethink this. Can't see any difference between 75 and 100%
 
A

aroy

Senior Member
jpeg is a lossy compression, so if you need to process the file further then 100% makes sense, otherwise if it is just for print/display 75% or even lower works. Just check the fine details at 75%, some times they are smeared, and in that case you may have to increase the quality.
 
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