Thank you for your post and for your interesting question. I would like to share with you the experiments I've done with Samsung Galaxy S5 phone.
I sent a picture of 6.2 MB, the pop-ups on the phone says "picture too large, compressing" and "converting to multimedia message" and gets attach. The size got reduced to 459 KB
I tried sending a 19.2 MB video, similar popups but got presented with option to Resize or Cancel. I selected resize and the size got reduced to 407 KB.
Basically, regardless of the size of the picture or video the size gets reduced to allowed size which can be transmitted. I believe it has to do with the device as well. Based on my research HTC One M8 may compress the size to 300 KB, hope this helps.
Perhaps @Meowmix may have more insights to add.
Thank you for quick response. Same here, 3MB picture gets compressed to about 480 KB, so what I'm trying to find out is if rogers limit is let's say 600 KB or 1 MB, why doesn't compress to the limit, so 3 MB picture compressed to 1 MB would allow for higher resolution. I'm little suprised that nobody at rogers seems to know what the size limit is. Thanks again for your help.
Max size limit on each carriers varies.
Highest I have seen is 600kb (US carrier AT&T)
However, canadian carriers (including Rogers) run at 300kb size limit. (Video are generally slightly higher)...
Please note: You can receive bigger MMS file size based on another carrier.
However, File size are actually controled by your device ... so it can be modified if device is jailbroken/rooted but it isn't recommended if you aren't an expert on it.
File sized based on carrier are enforced by settings carriers implemented on their locked phones. (just a FYI).
300kb sent (slightly more due to LTE upgrade), I found all out dated info.
I'll do some more digging in the meanwhile...
Just double checked.
So my Note 3 allows me to do 955KB for video (Compressed) and 414KB of Picture (Compressed after taking full HD picture).
So definitely the info above I wrote is outdated; I guess most info you find these days are based on cellphones nor smartphones and on 3G not LTE network.
You have more room to play with, but it is still lower quality / compressed picture/video through MMS.
That's why thirdparty apps like Hangouts, whatsapp, iMessage and kik are usefull as they use pure data and don't compress (as much).
Thanks for going to all that trouble. I did some testing myself, sent 3MB picture that got compressed to 880KB, so I guess it's safe to say that anything under 1MB is fine. and my HTC One M8 stock app came preset to 1MB. Now it's just the question of finding the app that compresses the least. Thanks again for your help.
Wondering if someone out there knows what the MMS size limit is for Rogers (Android device if that matters)