DTP


 
Lively discussions on the graphic arts and publishing — in print or on the web


Go Back   Desktop Publishing Forum > General Discussions > Print Production & Automation

Reply
 
Thread Tools Display Modes
Old 12-01-2006, 06:39 AM   #1
dthomsen8
Member
 
dthomsen8's Avatar
 
Join Date: Aug 2005
Location: Philadelphia, PA 19130
Posts: 2,158
Default 300 DPI Means What to Me?

My client wants to submit a photo. Their specs are here.

Now, if I have an interior house photo at 2592x1944 pixels, 1.25 Mb, 72 pixels per inch on the hard drive in JPG format, will that satisify their specs, or not?

I have been poking around on the web for an explanation of 300 BPI, and this is the best explanation I have found. Good, but I am still not quite clear about whether my 72 pixels per inch photo makes the grade or not. I think so, but I welcome the help of the print community here.
dthomsen8 is offline   Reply With Quote
Old 12-01-2006, 07:09 AM   #2
ktinkel
Founding Sysop
 
ktinkel's Avatar
 
Join Date: Oct 2004
Location: In Connecticut, on the Housatonic River near its mouth at Long Island Sound.
Posts: 11,189
Default

Quote:
Originally Posted by dthomsen8 View Post
My client wants to submit a photo. Their specs are here.

Now, if I have an interior house photo at 2592x1944 pixels, 1.25 Mb, 72 pixels per inch on the hard drive in JPG format, will that satisify their specs, or not?

I have been poking around on the web for an explanation of 300 BPI, and this is the best explanation I have found. Good, but I am still not quite clear about whether my 72 pixels per inch photo makes the grade or not. I think so, but I welcome the help of the print community here.
Have no idea what your first link shows — big Flash thing, then many, many words having nothing at all to do with image specs. [shrug]

Anyway, printed images need many more bits (pixels, sort of) than screen images do. A 72 dpi image is not printable (at least not without drastic reduction in size).

For magazine-quality printing, 300 dpi (at same size) is generally adequate. For newspapers, 180 to 200. Many digital images taken or adapted for the web will not have enough bits to make these resolutions.

   
__________________
[SIZE=2][COLOR=LemonChiffon]::[/COLOR][/SIZE]
[SIGPIC][/SIGPIC]
ktinkel is offline   Reply With Quote
Old 12-01-2006, 08:11 AM   #3
dthomsen8
Member
 
dthomsen8's Avatar
 
Join Date: Aug 2005
Location: Philadelphia, PA 19130
Posts: 2,158
Default Magazine quality printing

Quote:
Originally Posted by ktinkel View Post
For magazine-quality printing, 300 dpi (at same size) is generally adequate. For newspapers, 180 to 200. Many digital images taken or adapted for the web will not have enough bits to make these resolutions.
I attach the specs that this magazine provides. They also provide one interior photo for each luxury house advertised on the web. My client's listing is just over a million, a low price for this magazine.

Their specs say "Live Area 7 7/8" x 9 7/8" and also "All digital images must be at a resolution of 300 dpi at that the size they will appear in print." My images are at 2592x1944 pixels. That means 36" at 72 pixels per inch. Can I calcuate 2592/10 = 259 dpi and no good for their use? (I rounded the 9 7/8" to 10 for easy calculation, but precision doesn't make it to 300 dpi.)

It seems to me that only some quite expensive digital cameras make it to the level they are requesting, and consequently maybe film is the way to get a photograph of sufficient quality for their use.
Attached Thumbnails
Click image for larger version

Name:	specs.jpg
Views:	116
Size:	63.3 KB
ID:	781  
dthomsen8 is offline   Reply With Quote
Old 12-01-2006, 09:20 AM   #4
don Arnoldy
Curmudgeon
 
don Arnoldy's Avatar
 
Join Date: Oct 2004
Posts: 493
Default

Quote:
Originally Posted by dthomsen8 View Post
Can I calcuate 2592/10 = 259 dpi and no good for their use? (I rounded the 9 7/8" to 10 for easy calculation, but precision doesn't make it to 300 dpi.)
You have the calculation correct. A 300-dpi image that took up the entire 7 7/8 x 9 7/8 live area would need to be 2363 x 2963 pixels.

Quote:
It seems to me that only some quite expensive digital cameras make it to the level they are requesting, and consequently maybe film is the way to get a photograph of sufficient quality for their use.
The traditional way is to shoot medium-format slides, then scan them on a drum scanner. Not only do you get substatially higher resolution--you get a much larger dynamic range, and greater detail in the show areas.

   
__________________
--don
don Arnoldy is offline   Reply With Quote
Old 12-01-2006, 09:22 AM   #5
LoisWakeman
Staff
 
LoisWakeman's Avatar
 
Join Date: Jan 2005
Location: Uplyme, Devon, England
Posts: 1,402
Default

I find this page helpful:

http://hannemyr.com/photo/pixels.html

Basically, you need to upres the image so it's the right size at 300 DPI, (Qimage is very good at this) - I doubt they will notice!

Also, you need to make sure the file settings say 300DPI: lots of editors are really stupid and don't realise that it's the number of pixels that affect the print quality/resolution.
LoisWakeman is offline   Reply With Quote
Old 12-01-2006, 09:48 AM   #6
JohnC
Staff
 
JohnC's Avatar
 
Join Date: Oct 2004
Location: Seattle, WA
Posts: 124
Default

Does your image have to be the full 7-7/8 x 9-7/8? Your image is alredy at 6.5 x 8.5 inches (not quite the same proportion, so you would have to either crop your image or have some white space around it). If it does have to be the full size you will need to do a small bit of uprezzing.

For background, an image that is 2592x1944 pixels at 72 dpi is exactly the same as an image that is 2592x1944 pixels at 300 dpi. The only difference is the dpi number in the header of the file.

The important numbers are the pixel dimensions. If you uprezzed the 72 dpi one to 300 dpi it would become 10800x8100 pixels and the file would go from around 14 meg to 250 meg.

The DPI number does become important when you place the image into a page layout program. There it tells the program what size to place/print it at. The one at 72 dpi will print gigantic (36x27 inches) at 72 dpi, while the 300 dpi one will print at around 8.5 x 6.5 inches at 300 dpi. To fix that take the image into Photoshop and go to Image > Image Size. Make sure the "resample image" is __NOT__ checked, and change the resolution from 72 to 300.

When you do that you will notice that the pixel dimensions and file size are not changed. Only the "Document size" (print size) has changed.

If you had the resample box checked you would see the pixels change and you would most likely loose the quality of the image.

Just about any digital camera over 3 megapixels will be able to deliver the size they are requesting.

John
JohnC is offline   Reply With Quote
Old 12-01-2006, 10:02 AM   #7
dthomsen8
Member
 
dthomsen8's Avatar
 
Join Date: Aug 2005
Location: Philadelphia, PA 19130
Posts: 2,158
Default Medium Format Slides?

Quote:
Originally Posted by don Arnoldy View Post
You have the calculation correct. A 300-dpi image that took up the entire 7 7/8 x 9 7/8 live area would need to be 2363 x 2963 pixels.

The traditional way is to shoot medium-format slides, then scan them on a drum scanner. Not only do you get substatially higher resolution--you get a much larger dynamic range, and greater detail in the show areas.
Now I am not sure what you mean. Would a medium-format slide be taken with a 35mm SLR or rangefinder camera? My concern there would be that I don't have any wide angle 35mm cameras, and for interior shots of the town house we are going to photograph, we need wide angle photos. If by medium-format you mean larger than 35mm, I don't ahve such a thing.

My FujiFilm FinePix E510 camera doesn't seem to have any setting for the pixels per inch. I am supposing that 72 pixels per inch is a standard for many digital cameras, until the ones $1,000 and up are reached. I have not researched this supposition. Anyway, for one house, I am not buying or even renting a camera of any kind. I will decline the whole job.
dthomsen8 is offline   Reply With Quote
Old 12-01-2006, 12:12 PM   #8
don Arnoldy
Curmudgeon
 
don Arnoldy's Avatar
 
Join Date: Oct 2004
Posts: 493
Default

Quote:
Originally Posted by dthomsen8 View Post
Now I am not sure what you mean. Would a medium-format slide be taken with a 35mm SLR or rangefinder camera?
A medium-format camera would be a 2 1/4" x 2 1/4" or a 6 X 7 (cm) camera. Although these wouldn't produce "slides" in the normal sense, they would produce film positives for scanning.

As John suggested, the image you have will be 6.48" x 8.64" at 300 dpi. If you did not need to fill the entire live area with image --because there was type or border; or if you could arrange more than one image to fill the area, then you could use what you have.

Quote:
My FujiFilm FinePix E510 camera doesn't seem to have any setting for the pixels per inch.
Yup--cameras don't really know anything about dpi--only pixel dimensions. DPI doesn't exist until you decide what size you want to to print it at--even the default, 72dpi, is an unwarranted assumption on the part of the camera.

Quote:
for one house, I am not buying or even renting a camera of any kind.
If this house is listed for $1 million +, then somebody(ies) will be pocketing a $600K commission for selling it. You'd think they'd be willing to spring for an extra hundred bucks or so for you to rent a camera. <shrug>

   
__________________
--don
don Arnoldy is offline   Reply With Quote
Old 12-01-2006, 12:28 PM   #9
Franca
Staff
 
Franca's Avatar
 
Join Date: Oct 2004
Location: Monterey Bay area, CA
Posts: 2,203
Default Photoshop as Calculator

Whenever I get confused about this I fire up Photoshop and click File>New. I enter the specs for the image and get a blank document. Then I click on Image>Image size.... and make sure that Resample is unchecked. Now I can enter the desired print size of your image in whatever unit I like and I will see what DPI I have. Or I can enter the desired DPI and see how large an image I will get at that DPI.

Your image looks plenty wide enough to me. I'm not sure whether your image is intended to take up the entire alloted space or not; most times this will not be the case as there will be multiple images, or images and text, so each individual image will not need to be as large as the printer's specs for the space. In your situation it seems to me that the "live area" is for the entire ad and you are submitting just one photo which will form only a part of the ad. Unless I'm misunderstanding something, I can't imagine that your photo wouldn't be more than adequate.

The 300 dpi "rule" is also not hard and fast. If you are close to it, you are still probably OK.

   
__________________
..
..Franca

..
Franca is offline   Reply With Quote
Old 12-01-2006, 12:46 PM   #10
ktinkel
Founding Sysop
 
ktinkel's Avatar
 
Join Date: Oct 2004
Location: In Connecticut, on the Housatonic River near its mouth at Long Island Sound.
Posts: 11,189
Default

Quote:
Originally Posted by don Arnoldy View Post
If this house is listed for $1 million +, then somebody(ies) will be pocketing a $600K commission for selling it.
That’s some commission! How about $60K? (At most, these days.)

Still, enough to rent a camera for a day. And a photographer.

   
__________________
[SIZE=2][COLOR=LemonChiffon]::[/COLOR][/SIZE]
[SIGPIC][/SIGPIC]
ktinkel is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -8. The time now is 01:36 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Contents copyright 2004–2014 Desktop Publishing Forum and its members.