LOG IN    OR   REGISTER TO FORUMS


How many pixels are there in 4 MB?

FORUMS Post Processing, Marketing & Presenting Photos RAW, Post Processing & Printing
Thread started 27 Oct 2012 (Saturday) 10:10   
LIST NEARBY THREADS
 
KeyserSoze1
Senior Member
Joined Oct 2010
525 posts
[MORE/SHARE]

I couldn't find a calculator and the few ones I googled were contradictory to each other.

If these are the size of resolution

Focal Plane X-Resolution 2796.43591501028 dpi
Focal Plane Y-Resolution 2839.248434238 dpi


Have I exceeded the 4 MB requirement?

Post #1, Oct 27, 2012 10:10:08


Canon 5DM III, 35 1.4 II 50 1.2L
Canon 6D/// RX1

LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as registered member)
Colorblinded
Goldmember
Colorblinded's Avatar
Joined Jul 2007
2,325 posts
[MORE/SHARE]

We have no way of knowing from that information. If it were a three color 8 bit per pixel image and it had no compression or header information it could be just under 1.4 million pixels.

The dpi is meaningless without knowing how many inches large the image is (and outside of printing it's a pretty useless number).

That and the number of megabytes an image file takes up depends on more than just pixels. 4MP could be a very low resolution TIF file or a very high resolution JPG that's been heavily compressed. You need to look at the images pixel dimensions to determine pixel count and then at its file size to determine how many MB it requires to store.

Post #2, Oct 27, 2012 10:24:07


http://www.thecolorbli​ndphotographer.comexternal linkhttp://www.thecolorbli​ndphotographer.com ...ter-of-performance-specs/external link

LOG IN TO REPLY
tzalman
Fatal attraction.
tzalman's Avatar
Joined Apr 2005
12,598 posts
Gesher Haziv, Israel
[MORE/SHARE]

Dpi is actually ppi which is pixels per inch; so how many inches are we talking about? Where and how did you get those numbers? Citing dpi alone is like saying, "My car went 60 mph so how far did I travel?"

Post #3, Oct 27, 2012 11:17:57


Elie / אלי
I look at the world and I notice it's turning, while my guitar gently weeps.
With every mistake we must surely be learning, still my guitar gently weeps.
Paul Harrison
Siteexternal link

LOG IN TO REPLY
KeyserSoze1
THREAD ­ STARTER
Senior Member
Joined Oct 2010
525 posts
[MORE/SHARE]

For example. I uploaded 21 MP from a 5DmII raw file. Does this mean the file has 21 MB file as well?

Post #4, Oct 27, 2012 11:19:00 as a reply to Colorblinded's post 54 minutes earlier.


Canon 5DM III, 35 1.4 II 50 1.2L
Canon 6D/// RX1

LOG IN TO REPLY
KeyserSoze1
THREAD ­ STARTER
Senior Member
Joined Oct 2010
525 posts
[MORE/SHARE]

tzalman wrote in post #15175431external link
Dpi is actually ppi which is pixels per inch; so how many inches are we talking about? Where and how did you get those numbers? Citing dpi alone is like saying, "My car went 60 mph so how far did I travel?"

Thanks. Well, I will be sending some online submissions and the rule is each image must not exceed a 4MB weight. How can I tell how many MB does my image have? I use a PSE9 for resizing.

Post #5, Oct 27, 2012 11:20:40


Canon 5DM III, 35 1.4 II 50 1.2L
Canon 6D/// RX1

LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as registered member)
KeyserSoze1
THREAD ­ STARTER
Senior Member
Joined Oct 2010
525 posts
[MORE/SHARE]

What information should I post to know how many MB a picture has?

Post #6, Oct 27, 2012 11:27:53 as a reply to KeyserSoze1's post 7 minutes earlier.


Canon 5DM III, 35 1.4 II 50 1.2L
Canon 6D/// RX1

LOG IN TO REPLY
mjkubba
Senior Member
mjkubba's Avatar
Joined Oct 2012
270 posts
Chicagoland
[MORE/SHARE]

What I do is: resize by x% if it's under that xMB requirement then i'm done if it's not i'll resize it again by another x%.

Post #7, Oct 27, 2012 11:39:29


Canon AE-1, Canon 60D, Fujifilm JX400
Canon 35-70mm, Canon 18-55mm IS, Nifty Fifty, Tamron 70-300 VC
http://folding.extreme​overclocking.com ...ge.php?un=mjkubba&t​=37726external link

LOG IN TO REPLY
tzalman
Fatal attraction.
tzalman's Avatar
Joined Apr 2005
12,598 posts
Gesher Haziv, Israel
[MORE/SHARE]

KeyserSoze1 wrote in post #15175432external link
For example. I uploaded 21 MP from a 5DmII raw file. Does this mean the file has 21 MB file as well?

No, an uncompressed 8 bit tif from a 5D2 is around 60 MB. I have never output a jpg from my 5D2 (only Raws) but I'd guess that a Fine jpg is around 10 MB and a Medium jpg might be down around 4 MB. But I'm not at home right now to try it.

Post #8, Oct 27, 2012 12:01:15


Elie / אלי
I look at the world and I notice it's turning, while my guitar gently weeps.
With every mistake we must surely be learning, still my guitar gently weeps.
Paul Harrison
Siteexternal link

LOG IN TO REPLY
sandpiper
Cream of the Crop
sandpiper's Avatar
Joined Aug 2006
7,000 posts
Merseyside, England
[MORE/SHARE]

KeyserSoze1 wrote in post #15175432external link
For example. I uploaded 21 MP from a 5DmII raw file. Does this mean the file has 21 MB file as well?

Raw files are compressed, so will vary in how many Mb they contain, even at the same pixel dimensions. An image containing a large area of blue sky will use less Mb than an image containing mostly leafy foliage, which contains much more fine detail.

KeyserSoze1 wrote in post #15175461external link
What information should I post to know how many MB a picture has?

Too many variables to make a simple calculation, regardless of what information you post. But you only need to look at your image, open the image properties and see the size in front of you. If it is too big, simply go back to the original and make a smaller version.

Post #9, Oct 27, 2012 12:20:57




LOG IN TO REPLY
Colorblinded
Goldmember
Colorblinded's Avatar
Joined Jul 2007
2,325 posts
[MORE/SHARE]

tzalman wrote in post #15175431external link
Dpi is actually ppi which is pixels per inch; so how many inches are we talking about? Where and how did you get those numbers? Citing dpi alone is like saying, "My car went 60 mph so how far did I travel?"

Just to point out, DPI and PPI are not the same thing. In this case if we're talking strictly about the digital file the PPI might have relevancy (although usually it's meaningless unless you are scanning something). DPI has to do with printing.

Post #10, Oct 27, 2012 14:19:35


http://www.thecolorbli​ndphotographer.comexternal linkhttp://www.thecolorbli​ndphotographer.com ...ter-of-performance-specs/external link

LOG IN TO REPLY
mjkubba
Senior Member
mjkubba's Avatar
Joined Oct 2012
270 posts
Chicagoland
[MORE/SHARE]

tzalman wrote in post #15175431external link
Dpi is actually ppi which is pixels per inch; so how many inches are we talking about? Where and how did you get those numbers? Citing dpi alone is like saying, "My car went 60 mph so how far did I travel?"

Colorblinded wrote in post #15175935external link
Just to point out, DPI and PPI are not the same thing. In this case if we're talking strictly about the digital file the PPI might have relevancy (although usually it's meaningless unless you are scanning something). DPI has to do with printing.

just to clarify :
DPI = dots per inch which is used mostly to determine the printer print quality
PPI = pixel per inch which is used to state a screen resolution or a digital file resolution before printing.

http://en.wikipedia.or​g ...PI_in_digital_image​_filesexternal link

Post #11, Oct 27, 2012 14:32:56


Canon AE-1, Canon 60D, Fujifilm JX400
Canon 35-70mm, Canon 18-55mm IS, Nifty Fifty, Tamron 70-300 VC
http://folding.extreme​overclocking.com ...ge.php?un=mjkubba&t​=37726external link

LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as registered member)
Rimmer
Goldmember
Rimmer's Avatar
Joined Nov 2010
1,383 posts
[MORE/SHARE]

KeyserSoze1 wrote in post #15175437external link
Thanks. Well, I will be sending some online submissions and the rule is each image must not exceed a 4MB weight. How can I tell how many MB does my image have? I use a PSE9 for resizing.

If you don't mind doing a little trial-and-error work, this is pretty easy.

Start by doing a Save As in PSE. That will give you a dialog box where you can adjust the amount of compression (Quality) and the box will tell you how big the image will be. If, at the quality level you want you can't get the file size low enough, then cancel out and back up. (See attached image for example, note that it says 942.7K.)

Then, go into Image > Resize > Image Size... and make the image smaller. How much smaller? I don't know -- make a guess, maybe cut the dimensions in half.

Now, try the Save As procedure again and see what you can get, trading off compression (Quality) with file size.

You'll soon get enough experience to be able to move through this procedure pretty quickly.

But... I assume you are submitting JPGs -- have you checked the size of the files that you already have? They may be OK already, and if not then just a bit of compression may help.

Final note: If you're starting out with a JPG, then when you do the Save As be sure to give the file a new name (maybe add a number or letter) so as not to overwrite your original.

HOSTED PHOTO
please log in to view hosted photos.

Post #12, Oct 27, 2012 15:33:05


Ace Rimmer -- "What a guy!"
"Smoke me a kipper, I'll be back for breakfast." ;)

LOG IN TO REPLY
tzalman
Fatal attraction.
tzalman's Avatar
Joined Apr 2005
12,598 posts
Gesher Haziv, Israel
[MORE/SHARE]

Colorblinded wrote in post #15175935external link
Just to point out, DPI and PPI are not the same thing. In this case if we're talking strictly about the digital file the PPI might have relevancy (although usually it's meaningless unless you are scanning something). DPI has to do with printing.

mjkubba wrote in post #15175959external link
just to clarify :
DPI = dots per inch which is used mostly to determine the printer print quality
PPI = pixel per inch which is used to state a screen resolution or a digital file resolution before printing.

http://en.wikipedia.or​g ...PI_in_digital_image​_filesexternal link

Nevertheless, throughout the industry the term dpi is commonly used even though another term would be more accurate - scanner software UI has scan resolution in dpi although it refers to spi, scans per inch; the EXIF standard uses dpi for both images (pixels per inch) and sensor resolution (sensels or photo sites per inch); monitor and TV resolution in ads or spec lists is given in dpi; and every art director, graphic designer or non-photographer client asks for dpi. They are all wrong, but trying to change them is quixotic tilting at windmills.

Post #13, Oct 27, 2012 17:32:01


Elie / אלי
I look at the world and I notice it's turning, while my guitar gently weeps.
With every mistake we must surely be learning, still my guitar gently weeps.
Paul Harrison
Siteexternal link

LOG IN TO REPLY
RDKirk
Cream of the Crop
RDKirk's Avatar
Joined May 2004
11,579 posts
USA
[MORE/SHARE]

They are all wrong, but trying to change them is quixotic tilting at windmills.

Fortunately, they aren't on this forum, so we can wallow in technical correctness while here and ignore the windmills.

Post #14, Oct 27, 2012 17:51:14 as a reply to tzalman's post 19 minutes earlier.




LOG IN TO REPLY
Colorblinded
Goldmember
Colorblinded's Avatar
Joined Jul 2007
2,325 posts
[MORE/SHARE]

RDKirk wrote in post #15176451external link
Fortunately, they aren't on this forum, so we can wallow in technical correctness while here and ignore the windmills.

I do my best to not perpetuate misuse of terms since they do still have functional differences. If and when those differences are no longer relevant then the differentiation in terminology will become meaningless. I'll just roll my eyes every time they're misused until that happens :lol:

Technically correct is the best kind of correct anyway!

Post #15, Oct 27, 2012 19:29:48


http://www.thecolorbli​ndphotographer.comexternal linkhttp://www.thecolorbli​ndphotographer.com ...ter-of-performance-specs/external link

LOG IN TO REPLY


LIST NEARBY THREADS
6,542 views & 0 likes for this thread
How many pixels are there in 4 MB?
FORUMS Post Processing, Marketing & Presenting Photos RAW, Post Processing & Printing



NOT A MEMBER YET? CLICK HERE TO REGISTER TO FORUMS

CHANGE BODY TEXT SIZE FOR ALL THREAD PAGES
POWERED BY AMASS 1.0version 1.0
made in Finland
by Pekka Saarinen
for photography-on-the.net


SEND FEEDBACK TO STAFF  |  JUMP TO FORUM...  |  FORUM RULES


Spent 0.00085 for 4 database queries.
PAGE COMPLETED IN 0.02s
735 guests, 497 members online
Simultaneous users record so far is 3341, that happened on Dec 11, 2014
Latest registered member is johntorcasio

COOKIES DISCLAIMER: By using this site you agree that some cookies will be stored on your browser. For unlogged users we store one session id cookie. For registered members we store (in addition to login session cookie) only cookies that are essential for required functionality, we do not store any personal tracking data in cookies or other browser's data storage methods.