Printing questions: Can anyone tell me what the minimum requirements are for printing an image as large as 24"x36"? What are the determining factors: PPI, file size, combination...

steve_stoneblossom Loc: Rhode Island, USA

Can anyone tell me what the minimum requirements are for printing an image as large as 24"x36"? What are the determining factors: PPI, file size, combination thereof, something else? And is Lightroom Enhance effective at increasing the size at which an image can be printed?

I've not had reason to print any of my images prior to this, but a need has arisen. Thank you.

rcarol

steve_stoneblossom wrote:

Can anyone tell me what the minimum requirements are for printing an image as large as 24"x36"? What are the determining factors: PPI, file size, combination thereof, something else? And is Lightroom Enhance effective at increasing the size at which an image can be printed?

I've not had reason to print any of my images prior to this, but a need has arisen. Thank you.

Please take a look at this YouTube video by Canadian photographer Simon d'Entremont. He explains things far better than anyone I've heard before. Here is his YouTube link.
https://www.youtube.com/watch?v=ThpQWhOfKO4

steve_stoneblossom Loc: Rhode Island, USA

rcarol wrote:

Please take a look at this YouTube video by Canadian photographer Simon d'Entremont. He explains things far better than anyone I've heard before. Here is his YouTube link.
https://www.youtube.com/watch?v=ThpQWhOfKO4

thx

CHG_CANON Loc: the Windy City

steve_stoneblossom wrote:

Can anyone tell me what the minimum requirements are for printing an image as large as 24"x36"? What are the determining factors: PPI, file size, combination thereof, something else? And is Lightroom Enhance effective at increasing the size at which an image can be printed?

I've not had reason to print any of my images prior to this, but a need has arisen. Thank you.

PPI and colorspace are the only considerations for printing a JPEG, a pixel-based digital image.

PPI - pixels per inch - is a calculated value. Start with the finished image, how many pixels 'wide' and 'tall' is the current file? Will it print as-is to a 300ppi 'gold standard'? The math is simple: 36 x 300 is 10,800 pixels, probably larger than your typical 24MP camera. What if you achieved 200ppi, as in 36x200 = 7200?

With the math analysis performed, do you need to up-size the pixels to a minimum of 200ppi or higher? You can generate the up-sized file and inspect the "created" pixels at the 1:1 pixel level. How does that candidate up-size file look on your monitor? That's the level of detail (or fuzzyness) you'll get in the printed file too.

You should be using sRGB colorspace JPEGs as the output print file, unless you've found a printer who can accept other file formats or colorspace. Even then, you'll likely not find a tangible difference in the more complicated workflow of not using sRGB JPEGs.

bsprague Loc: Lacey, WA, USA

rcarol wrote:

Please take a look at this YouTube video by Canadian photographer Simon d'Entremont. He explains things far better than anyone I've heard before. Here is his YouTube link.
https://www.youtube.com/watch?v=ThpQWhOfKO4

That's a very good video. I watched it last week!

PPI, DPI and megapixel math is nearly useless for me. The only thing that counts is looking at a print from a normal viewing distance for that size print. My standard size is 13x19 from a Canon printer using Lightroom Classic. My cameras have sub "full frame" sensors and I get very viewable results, even after cropping away some pixels.

I've never been able to figure it out, but there is some magic in Canon's print driver with Lightroom Classic's print module. Prints that flunk the math look great.

BebuLamar

If you have the printer supports that size of paper and you print it yourself you can use just about any image files you have. If you use a printing service you have to check with them if the files have too few pixels they may refuse to print them to that size.

steve_stoneblossom Loc: Rhode Island, USA

CHG_CANON wrote:

PPI and colorspace are the only considerations for... (show quote)

That all makes sense. My printer says they can work with JPEGs or TIFFs. Am I gaining anything by using TIFFs, in particular when the TIFFs are being created from JPEGs and not the raw files?

Longshadow Loc: Audubon, PA, United States

bsprague wrote:

That's a very good video. I watched it last week!

PPI, DPI and megapixel math is nearly useless. The only thing that counts is looking at a print from a normal viewing distance.

I don't count pixels at all, no math, I just use the largest file I have, the one with the most data.
The printer driver will reduce/compress/adjust as needed for the size printed anyway...

CHG_CANON Loc: the Windy City

rcarol wrote:

Please take a look at this YouTube video by Canadian photographer Simon d'Entremont. He explains things far better than anyone I've heard before. Here is his YouTube link.
https://www.youtube.com/watch?v=ThpQWhOfKO4

LOL - that demo at 4:17 is how I look at the 1:1 pixel level details of my monitor and any print I where I can get that close. When the video author gets to 8:48 showing an R6 vs R5, that's the type of pixel-level inspection I suggested (earlier) that you perform on an up-sized image file vs the original. To the author's point: is 300ppi of 'invented' pixels better / same / worse than the original image printed at a lower ppi?

CHG_CANON Loc: the Windy City

steve_stoneblossom wrote:

That all makes sense. My printer says they can work with JPEGs or TIFFs. Am I gaining anything by using TIFFs, in particular when the TIFFs are being created from JPEGs and not the raw files?

A TIFF is an uncompressed JPEG, possibly at a higher-bit depth, storage that contains no data that wasn't also contained in the 8-bit JPEG original. The specifics of how the TIFF file was created are relevant, where most uses of TIFF have no positive relevance. Creating a TIFF from a JPEG is a waste of time, specifically if just for the purpose of an output print file.

Creating a TIFF from an edited RAW into a non sRGB colorspace might be relevant for specific situations. Specific like highway billboards or instore displays or a canvas wrap of a motor vehicle. A print to frame and hang, probably not.

CHG_CANON Loc: the Windy City

BebuLamar wrote:

If you have the printer supports that size of paper and you print it yourself you can use just about any image files you have. If you use a printing service you have to check with them if the files have too few pixels they may refuse to print them to that size.

My experience is the opposite, if you don't have enough pixels for the requested size, they won't accept the order.

rcarol

CHG_CANON wrote:

LOL - that demo at 4:17 is how I look at the 1:1 pixel level details of my monitor and any print I can't get that close to. When the video author gets to 8:48 showing an R6 vs R5, that's the type of pixel-level inspection I suggested (earlier) that you perform on an up-sized image file vs the original. To the author's point: is 300ppi of 'invented' pixels better / same / worse than the original image printed at a lower ppi?

I think that most of us realize that print resolution is a function of viewing distance. My take away from his YouTube video is that he attempts to put some quantitative values to the print resolution as a function of viewing distance. I recall seeing some tables that gave recommended resolutions as a function of print size and viewing distance but I have not been able to locate them.

CHG_CANON Loc: the Windy City

rcarol wrote:

I think that most of us realize that print resolution is a function of viewing distance. My take away from his YouTube video is that he attempts to put some quantitative values to the print resolution as a function of viewing distance. I recall seeing some tables that gave recommended resolutions as a function of print size and viewing distance but I have not been able to locate them.

The video has a short table of these values. I don't have the timestamp, but it's after his pixel peeping at 4:17.

What the higher megapixel cameras offer is an upending of these rules of thumb, where 100 ppi maybe fine from a distance, but it really is amazing when you can walk up next to the print and see the level of detail 300ppi delivers from a 40+ MP sensor. That is: 300ppi of original pixels, not upscaled / invented pixels.

My oft-repeated suggestion of 2048px 'wide' images for digital display is the same idea. If you're only going to see the image on a screen full-sized around 2000px wide, you don't need an original 6000px image, as that image looks exactly the same on the full screen as an image that matches / nearly matches the exact pixel-resolution the display device. The video from about 9-minutes on looks at this idea for digital display of digital pixel-based images.

BebuLamar

CHG_CANON wrote:

My experience is the opposite, if you don't have enough pixels for the requested size, they won't accept the order.

That is exactly what I said. Read again. The first part I said if the op own the printer for that size then he can print image that size regardless of how many pixels he has. The second part is that if he has to use a printing service they may refuse to print if his file has too few pixels.

CHG_CANON Loc: the Windy City

BebuLamar wrote:

That is exactly what I said.

Sorry, I read too many pixels, or thought I did ...