Large printing and DPI
 

I photograph my little boy and have prints developed using photobox. I always upload for 300dpi and the quality is excellent. I have some images I would like large and they average at 2400px wide. At 300dpi these images are good for and 8" maximum print width but could I stretch them to 12", this would mean printing at 200dpi, would I notice a difference?

I am thinking of a trial print of the same image, one at 8" the other 12" to see if I am happy with quality but I though I would seek opinions first.

What do you think?

I have printed borderless A4's (almost 12") from files even smaller than this with brilliant results. I do not think you will see much of a difference until you get up to around A3 size. I know 300 dpi is quoted as 'photo quality' but in practice you can get good prints from 200 dpi. I recently had a 3456 px wide image printed by photobox at 16" x 12" (216 dpi) and it came out great.

Stephen,

When you enlarge to 12 inches wide, resample to 300 dpi. This will not increase the detail but it will smooth the texture.

John

I was thinking about re-sampling to 300dpi, I assume I need to re-sample then apply sharpening for best results.

Stephen,

Yes, but don't apply to much sharpening or it will not look natural. Check sharpening at the size you intend to print at. I find it looks a bit sharper on the print than it does on the screen. For good skin texture set threshold to 5. Work on a copy so that you don't spoil the original. Alternatively:-

Subtle Sharpening

Duplicate the image.
Filter/Other/High Pass.
Adjust the slider until only the edges are visible.
Select the blending mode Overlay, flatten the image and save.
This method dose not sharpen areas of uniform colour such as skin tones, so there is no tendency for them to break up.

John

I agree, a touch of sharpening does wonders but there is a degree of natural sharpening when printing at 300dpi compared with viewing on monitor at 72dpi.

As a rule I apply 1/2 shaprening to print as I would to view on a monitor.

Stephen, please read my previous reply where I have now added a subtle sharpening technique which is useful for portraits.

John

If you want to make printing easy then try the software 'Qimage' it will do almost everything for you and produces outstanding prints - far better than can be acheived via Photoshop IMO (and just about everyone that tries it). There is a free try-out download which expires in 30 days. Here is the link http://www.ddisoftware.com/qimage/

I am new to this forum and have been browsing the postings. One thing I would like to say about this particular issue is that first I agree that 200dpi is fine for inkjet printing. In fact, I kind of think of it as the "rule of thumb."

But also, there is a lot of talk about "resampling" in this thread. If you have an image that is 2400 pixels wide, and you want to print it at 12 inches, you should definitely NOT resample it. There is no need to, since you can already print it at 12 inches by just changing its dpi to 200. You would only use resampling if you had to enlarge its dimensions (width or height in pixels), which in this case is unnecessary, because it is already large enough. Since resampling is unnecessary, there is no sharpening problem either. Just change the dpi (without resampling) and print it.

Hi RAH, noticed that this is your first post. I'd like to welcome you to WPF.

Thanks! I've been a member of Birdforum for several years, and this forum looks pretty nice too. :-)