Advice Wanted How big will these print?

Brownie

Top Veteran
A recent mistake has me a bit concerned. I shot a bunch of photos that were supposed to be 33MP but they ended up around 14MP. The guides for printing on the internet all seem to err on the side of caution. In the past I've had excellent results from 20MP M-4/3 at either 24" X 30" or 24" x 36" (can't recall) with excellent results. I've enlarged 6MP to 8" x 10" no problem, never tried larger. My experience is that keeping the file @ 300DPI is important.

There's a chance someone may want some of the 14MP images. If they do, I would like to recommend that they go no larger than X" x X". Any thoughts on what that would be? 11" x 14"? 16" x 20"?
 

WhidbeyLVR

Top Veteran
Location
Whidbey Island
Name
Lyle
So if your image has about 2/3rds the pixel size in each dimension, the simple answer would be 2/3rds of whatever you would have done with the larger image. The more complicated answer would involve intended viewing distance and underlying quality of the image and whether the image lost any significant detail in the downscaling.

The modern answer involves new scaling algorithms which allow upscaling without losing much sharpness (Gigapixel AI, etc.).
 
Location
Finland
My experience is that keeping the file @ 300DPI is important.

If you have built your portfolio -- and made a good name for yourself -- with this guideline then you need to deliver 300 DPI, is it not so?

If this is the case your limit is about 10x15", simple as that.

Now, I don't think 300 DPI is a hard requirement but everyone's level of standard is different so it's out of scope.
 

WhidbeyLVR

Top Veteran
Location
Whidbey Island
Name
Lyle
So if your image has about 2/3rds the pixel size in each dimension, the simple answer would be 2/3rds of whatever you would have done with the larger image.
So, if you have had good results printing a 20 MP (5200x3900) at 30" x 24", that's about 180 ppi.

On the 14 MP image (4500x3000), that would be about 24" x 16".

I would say 300 PPI is important for viewing distance of 18" or less, but probably not much of an issue above that.
 
Location
Vancouver BC
Name
Graham
I have a 30" x 30" smooth canvas print above the fireplace that is from a 3030 x 3030 pixel crop. It has no obvious signs of poor resolution despite it being only 101ppi. Sharp focus, good exposure, contrast and color saturation are more important to producing a great print.
Here's the 2/3 scale version:
52005684522_22cc25d9bd_o.jpg
Subscribe to see EXIF info for this image (if available)

GBH Rookery Outbound by Graham Moore, on Flickr
 

bartjeej

Hall of Famer
I replied in the "mistake" thread, in which I mentioned upressing to 300 PPI.

Indeed as others have said here, 200 PPI is enough for a really nice print; the upressing to 300 PPI for me is more of a "why not" thing, since I'm usually working with a given absolute print size that should fit a specific frame or place on the wall. The native PPI follows from that, and I can upres that to 300 just in case, won't make the image worse (if you do it right) and might prevent some jagged edges for large enlargements.

And as Graham noted above, on certain print media (canvas in particular) you can get away with significantly lower PPI still.
 

Brownie

Top Veteran
I'm probably overly concerned.

I've always used 300DPI because that's the Darktable default.

When someone wants one of these it's almost always sent digitally, which means I have no control over what they do once I send it. Canvas, metalic, linen, whatever. Given that, my safest bet is to send the highest quality file I can.
 

Iron

All-Pro
Location
New Zealand
Name
Tímo
No upscaling programs, never really needed it. I process in Darktable, I think there may be a module in the Lightable section, will look.
Yes, there is an upscaling mode in Darktable and it's in the Global Options section.
1655951242934.png

I've used this and it's pretty reliable.

Regarding maximum PPI/print size, 40"x30" is not a problem for me even with GF1's 12MP sensor. It really depends on the viewing distance. Some exhibits have 1 metre barrier from the printout, so usually, people will stay 1 metre more. Cheers.
 

John King

Member of SOFA
Location
Beaumaris, Melbourne, Australia
Name
John ...
Tim, I've printed 16x20" from my 5 MPx E-1 without any problems. Examined for defects or artifacts with a 4x magnifying glass before framing and glazing. My 5 MPx 2/3" sensor Nikon Coolpix E5000 will not go past about A4 size without significant and noticeable degradation.

Since any glass is a very fine anti-aliasing filter, glazing will very, very slightly degrade any image anyway. Just enough to conceal any tiny problems you might see in the bare print.

And canvas will hide a multitude of sins ...

I use Photoshop to uprez a ProPhotoRGB 16 bit TIFF or PSD to whatever final print size I want. I find it does a better job than any of the dedicated uprez programs I have seen or used. Much underestimated IMO.
 

Iron

All-Pro
Location
New Zealand
Name
Tímo
Tim, I've printed 16x20" from my 5 MPx E-1 without any problems. Examined for defects or artifacts with a 4x magnifying glass before framing and glazing. My 5 MPx 2/3" sensor Nikon Coolpix E5000 will not go past about A4 size without significant and noticeable degradation.
Ah the E-1. I can only imagine the colours yours produced with ProPhotoRGB.
 
Location
Finland
@Brownie,

One thing I would definitely do here is to use Rawtherapee (FLOSS) to make demosaic and their excellent capture sharpening. Then the file can be taken to Darktable for the rest. The results will be staggering. It's just a clever algorithm that takes Bayer mosaic better into account.

Hopefully this comes across uncompressed PNG to show the difference. Processed from the same shot, one is Darktable's default processing and the other is Rawtherapee

comp.png
 

OldRacer

New Member
... Any thoughts on what that would be? 11" x 14"? 16" x 20"?
As American humorist H.L. Mencken once told us: "To every complex question, there is a simple answer. Usually wrong."

Really, your question has little to do with size and everything to do with viewing distance and subject matter.

If you're going to hold the print a few inches from your nose, that's really pixel peeping and probably only a smaller print will satisfy. If the print is to be hung high on a shopping center wall over the escalator, any size is probably acceptable.

Re subject matter, if the print involves a bunch of sharply focused detail smaller might be better. OTOH portraits with out of focus backgrounds and traditionally-post-processed faces really do not include -- deliberately -- a lot of sharply focused detail. So they can go bigger.

An ounce of data trumps a pound of theory and a hundred pounds of SGOTI opinions. Just buy a few prints of various sizes, including at least one that you are sure will be too big. See what you think. Even though you can't control your customers, it's still important for you to counsel them if necessary. Getting some data is a big step on that path. If you're in the US, Costco is a very cheap place for experiements and, actually, a pretty good place to buy the final prints.
 
Last edited:
Top