markngolf Loc: Bridgewater, NJ

Hi UHH ers,

My cousin presented a scenario to me and I'm not sure of a valid explanation. He claims (I'm Windows, he's Mac) that when an image is emailed, or even preparing an email with a photo attachment, the photo appears to lose (in his words, "sharpness") I think it may have something to do with an automatic resolution adjustment on a Mac when attaching a photo in an email, but I'm not really sure.

There are lots of knowledgeable dudes (and dudesess) out there. Anyone have some thoughts about this phenomena?

Thanks,
Mark

ebbote Loc: Hockley, Texas

Mark, tell your cousin he is full of it, I would compare the resolution on my
Windows monitor to anyones Mac monitor and I have a 34" monitor.

Rongnongno Loc: FL

I never experienced any loss when e-mailing an image whatever the format.

What can be experienced thought is a loss due to the difference in display quality but here the file has nothing to do with it.

See my post on color issues that seems to address the concern...

Dngallagher Loc: Wilmington De.

Not sure that this makes any difference, but on my Mac, using Apple Mail, when I send an image I have three choices - Original full size, large and small, of course reducing the size of the image greatly reduces the amount of pixels in the image and the mail attachment size.

I assume that more info is needed such as what "automatic" reduction? Not sure I know of any "automatic" reduction just because it is a Mac - Rather I think you need to look at what software is being used and what steps and options are being taken to send an email with image attached.

Rongnongno Loc: FL

If any software gets in the middle and changes the image anything goes so the cousin is probably right. The 'auto change' may have been selected which would explain the problem.

Dngallagher Loc: Wilmington De.

Auto Change? Not that I have seen with the built in software, of course, no telling what software is even being discussed at this point.

Apaflo Loc: Anchorage, Alaska

Everyone is missing your point and not discussing the question. :-)

When an image is down sized to send in an email, whether that is done automatically or manually, and regardless of the platform, it is a fact that you lose resolution and that means lower "sharpness".

For example, if you are shooting with a camera that produces 6000x4000 pixel images, an email attachment for the full sized image will be absolutely huge! Never mind sending half a dozen of them with one message...

So generally speaking people resize their image no more than maybe 2000 pixels on the longest side, and maybe down to as small as 800 pixels. They do that for the exact same reason that UHH resizes images to 600 pixels maximum, and it has the same effects too.

When an image is down sized obviously the "resolution" is less, but that may or may not be a big deal. It will be if the thumbnail sized 600 pixel image is then display in a window on your screen that is 1280 pixels wide! If the original 6000 pixel wide image were displayed, the display software would resample it to 1280 pixels. But that already down size 600 pixel wide image from email actually get up sampled from 600 to 1280 and will suffer significantly!

Another issue is that after any image is resampled it should also get a dose of sharpening. Your email program probably does not do that, and certainly a display program does not either. So the best way to send someone a 6000x4000 pixel image is probably manually resample it to 1200x800 and then, while looking at it in a 1200 pixel wide window, resharpen it with a UnSharp Mask tool by inspection to get the best possible results. Then send that image by email. It will look vastly better than one that was automatically reduced to less than 1000 pixels wide and then displayed at greater than 1000 pixels.

Note that none of this has anything to do with whether it is a Mac or Windows, other than any given software package for emailing images might have different defaults.

markngolf Loc: Bridgewater, NJ

I think you have missed my inquiry. He is not comparing Win with Mac. He seems to experience a differential of image sharpness when preparing an email with a photo attachment and has asked me if I can explain why.

Thanks, but I don't think I'll relay your "quote" LOL
Mark

markngolf Loc: Bridgewater, NJ

Thanks Ron. You are right, that is not the case here. It may just be his perception, too. Not sure. Only observable in person. I wonder if screen shots would show the difference?

Mark

ebbote Loc: Hockley, Texas

That's my point Mark, if we don't see the end result on our monitors how
else are we going to see it?

markngolf Loc: Bridgewater, NJ

I agree. I wonder if screen shots can reveal the difference?

Thanks,
Mark

rook2c4 Loc: Philadelphia, PA USA

I've emailed myself images many times, and I've never experienced loss of sharpness or any other alteration after the images were then downloaded. In fact, the size of image files were exactly the same as when uploaded. However, it may be that the images display different when viewing them directly from the e-mail; I'm not sure.

You can easily test this. Email yourself an image. Open the email from your inbox and download it back onto your computer - either renamed or to a different folder as the original. Then compare the original with the emailed copy, side by side.

CHG_CANON Loc: the Windy City

The person who referenced the full vs other email attachment option hit on a subtle difference that likely applies to our cousin's observation.

The two computing platforms do not change the attributes of a file. Otherwise, they'd be dropped as no one can have their files changed. Image files fall into this 'files' reference. Now, what an email program does to an embedded image rather than attachment, that's an issue with the email program (and / or the user) and not the operating system.

ABJanes Loc: Jersey Boy now Virginia

As stated, the email system compresses the large photo due to email size limits. I use Mac Photos Sharing and others use comparable websites where you can also post full HD Videos as well. This compression causes the issues you mention.

Bobbee

When I attach an jpg to an EMAIL, it shows up at the other end with the same byte count as when I sent it. I have never looked, but this might not be the same as when you embed pictures in an email. Something I do when I 'don't care'. If a program was altering my attachments, I would quickly stop using it.