# What Determines Maximum Final Print Size



## ray5 (Nov 18, 2015)

I am very ill educated on this subject. I have a unedited RAW image with these specifications:
22MP
240 ppi
5760X 3840

Though I am not looking to make it a billboard but trying to understand what determines the maximum final print size?
Thx
Ray


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## sanj (Nov 18, 2015)

Good question. I am waiting for replies to this...


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## sanfranchristo (Nov 18, 2015)

You do. 

It seems like you're asking what the maximum size at which you can print an image with those specs is but that is not nearly as strict of a guideline as you may think. There are many factors that would determine what the "maximum" is, but they really come down to your perception and satisfaction (e.g. how closely it will be viewed at, what the subject and style of the image is, post-processing and printing process, etc.). 24" x 16" is what those pixels at that resolution gets you to using a standard calculator but that is certainly not the maximum size that you could print that image at.


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## privatebydesign (Nov 18, 2015)

ray5 said:


> I am very ill educated on this subject. I have a unedited RAW image with these specifications:
> 22MP
> 240 ppi
> 5760X 3840
> ...



The total pixel number divided by the ppi figure. In this case the final print will be 24" x 16". If you change the ppi figure the print size will change. Send the printer 120 ppi and the print will be 48" x 32", send it 360ppi and the print will be 16" x 14.8".

As an aside I have found 240 ppi to be a printing sweet spot.

As another aside, I have found a 400% increase in area in Photoshop to be more than acceptable for most images from an IQ point of view, this would give you a 48" x 32" print at 240ppi.


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## mb66energy (Nov 18, 2015)

After printing a 36 x 24 inch poster from the "lousy" 12.8 MPix of 5D classic I am convinced that this number of pixels is sufficient for the job. At roughly 40 cm (16 inches) distance it is accepted as a well defined image which shows the textures with great detail.
I scaled the picture up by a factor 2 (linear) in DPP to avoid pixelization in the final product + I had some luck that everything went well: Focus, exposure and the choice of the EF 2.8 100 Macro which serves all the 12800000 pixels well ...

An idea came into my mind during reading your question: Maybe it is a good idea to print 4 x 6 inch cheapo photos which are crops of the desired poster size to get a feeling of the local quality at the corresponding resolutions / enlargements of the picture.

An additional remark: It also depends on the subject / function of the image. I am shure you can make a 6 x 4 METER print off a 5D classic file which hangs 5 meters above a counter of a companys entrance hall ... and it will be accepted as sharp - the "typical viewing distance" is another factor for max printing size.


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## tpatana (Nov 18, 2015)

I thought if you're using ppi (/dpi), you're already defining the print size (assuming you know the resolution).

Like many said, it's not that simple. If you plan to look it at 1 foot distance, it needs better resolution or smaller print. If you're looking it at 30m/100ft, you can make billboard.


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## AUGS (Nov 18, 2015)

The technical side first.
If I remember correctly, the average visual acuity of the human eye is about one arc minute. If the average reading distance is 1 foot (12 inches = 305 mm), 1 arc minute translates to a vertical resolution of about 300 dpi. This is why most magazines are printed at 300 dpi – most people can distinguish a printed pixel density of 300dpi at 1 foot reading distance.

If we use the 300dpi on your image size, we get about 19x13 inches (5760/300 is approx 19.2 inches) print size. You will rarely look at a “large” image at a distance of 1 foot, so a lower pixel density than 300dpi is usually okay. Further, you need to take the texture of the surface you are printing on into consideration. A glossy magazine cover or high gloss paper you will want as high as possible pixel density for the size you need. At the other end of the spectrum, if it is for a canvas print, a much lower pixel density can suffice.

Generally,
180dpi – for very large images, but may not withstand close-up scrutiny in fine details.
240dpi – good compromise of both print density and close-up scrutiny.
300dpi – if the absolute detail must be clear and sharp under scrutiny.

Ultimately, what determines the maximum final print size is a balance and really up to you, how you intend to display, the displayed visual distance and critique of your images.



mb66energy said:


> An idea came into my mind during reading your question: Maybe it is a good idea to print 4 x 6 inch cheapo photos which are crops of the desired poster size to get a feeling of the local quality at the corresponding resolutions / enlargements of the picture.


This is exactly what I do for large prints. I will crop small 6x4 sections of detail I want to check at the appropriate resolution and print them. This way I know my image will be okay before I spend too much on an extra-large image. It has saved me a few times.


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## Policar (Nov 18, 2015)

Totally subjective, unfortunately.

Talked with a great landscape photographer about depth of field and diffraction only to learn a lot of his work was f45 to f64 and held up at 40"X50".

Look at those "shot in iPhone 6" billboards.

Totally subjective.


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## YuengLinger (Nov 18, 2015)

I've saved a lot of ink and paper by carefully reading THE DIGITAL PRINT, by Jeff Schewe.

Regarding choosing a resolution for print in Lightroom, he strongly urges using the native resolution of the printer. For most Canon printers, that would be 300 dpi; for Epson, 360 dpi.

On page 132 he writes, "It's not optimal to send nonstandard resolution to the print drivers; it's far better to resample in Lightroom to arrive at the print driver's reported resolution."

So what *dilbert* says is right in my experience. Once you have Lightroom settings correct for your printer's driver, you just need to choose a paper size.

I've used 360 dpi for 3x5 and for 17x22, getting amazing results from an Epson 3880. Once I read the book and used the printer for a few weeks, I began to really trust the Lightroom print module. 

Also extremely important for me is the soft proofing option in the develop module, but that's for exposure and color. With a calibrated monitor, it gives a very accurate preview of what your print looks like on various types of paper.

The suggestions to use a detail section has also worked well for me.

If, on the other hand, you are sending your images out for printing, just be sure to use that company's recommendations. If you are making posters, ask them for advice.


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## LDS (Nov 18, 2015)

ray5 said:


> Though I am not looking to make it a billboard but trying to understand what determines the maximum final print size?



Actually, it depends on how far the final print will be looked at. There are tables around that tell what is the minimum resolution the human eye can see at a given distance. It can be calculated taking into account the average human eye angular resolution, remembering some people have better than average.

As long as the resolution is above that, the print size is OK. Of course, if the viewer get closer (as long as getting closer is possible), he or she will start to perceive the lower resolution images. Of course the higher the input resolution, the larger the print can be made before dropping below the required value.

It also means high-res print may be a waste if always seen from a distance where the little details can't be perceived.


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## Mt Spokane Photography (Nov 18, 2015)

dilbert said:


> ray5 said:
> 
> 
> > I am very ill educated on this subject. I have a unedited RAW image with these specifications:
> ...



And even then, you can do like billboard printers do and spread the print out over many sheets of paper. There is no theoretical maximum print size, software interpolates and increases the pixel count as you enlarge.

Perhaps you meant maximum native print size, that's a totally different thing, and is really meaningless since you can print much larger.


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## awinphoto (Nov 18, 2015)

There's a lot of good advise here... The old school method of thinking is 300 DPI is optimum for printing for all printer types... More DPI and you may not be able to tell the difference, less and in some instances, depending on how picky you are, you may. I know many print layout specialists (magazines, newspapers, et al) who has a rule of thumb that they are willing to print at double the native size with minimal loss of quality (so 150dpi). What it comes down to it, think of it like this, you can have a 20" and a 60" HD TV. 1080, not 4k lest anyone try to go overboard here. If you look at the same viewing distance, the smaller screen will look cleaner and better, all in all, than the 60"... But looking from farther away, they will look comparable. Moral of the story is you can print it as big as you want, just dont expect or encourage anyone to look at your print up close.


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## YuengLinger (Nov 18, 2015)

awinphoto said:


> There's a lot of good advise here... The old school method of thinking is 300 DPI is optimum for printing for all printer types... More DPI and you may not be able to tell the difference, less and in some instances, depending on how picky you are, you may. I know many print layout specialists (magazines, newspapers, et al) who has a rule of thumb that they are willing to print at double the native size with minimal loss of quality (so 150dpi). What it comes down to it, think of it like this, you can have a 20" and a 60" HD TV. 1080, not 4k lest anyone try to go overboard here. If you look at the same viewing distance, the smaller screen will look cleaner and better, all in all, than the 60"... But looking from farther away, they will look comparable. Moral of the story is you can print it as big as you want, just dont expect or encourage anyone to look at your print up close.



+1

And how many times do we see a 60" TV in a room that really only "fits" a 42"? You are right, the print has to fit the viewing space.


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## LDS (Nov 18, 2015)

Policar said:


> Talked with a great landscape photographer about depth of field and diffraction only to learn a lot of his work was f45 to f64 and held up at 40"X50".



That's why Ansel Adams group was called Group f/64... and it doesn't look his images suffer much from diffraction (although it's true he was also using large format lenses which are much slower and f/64 is not an uncommon value, IIRC some lense went beyond that as well).


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## ray5 (Nov 18, 2015)

WoW! A whole lot of informations, thanks. A few follow up questions:

-PPI is Pixels per inch, correct. So if I understood correctly if I reduce ppi I can get bigger prints at lower resolution? Shouldn't it be the opposite? If I reduce ppi I should get lower resolution pictures. Or does ppi have nothing to do with resolution?
- When I covert this specific image of the Delicate Arch straight from RAW to jpg it goes from 25mb to 6mb without any additional processing. Does that change the ppi?
- I hope to print for viewing at home on a wall, so about 20 by 30". I guess I can without the image appearing pixellated?
Thanks a lot!
Ray


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## privatebydesign (Nov 18, 2015)

LDS said:


> Policar said:
> 
> 
> > Talked with a great landscape photographer about depth of field and diffraction only to learn a lot of his work was f45 to f64 and held up at 40"X50".
> ...



An 8" x 10" field camera, of the kind used by several of the seven founders of Group f64 including Adams himself, though he used many different formats over his career, has a crop factor of 7.5, so f64 with their camera has the same diffraction and depth of field as f8.5 an a 'FF' 135 format camera. But Group f8.5 club doesn't sound as cool........


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## dak723 (Nov 19, 2015)

ray5 said:


> WoW! A whole lot of informations, thanks. A few follow up questions:
> 
> -PPI is Pixels per inch, correct. So if I understood correctly if I reduce ppi I can get bigger prints at lower resolution? Shouldn't it be the opposite? If I reduce ppi I should get lower resolution pictures. Or does ppi have nothing to do with resolution?
> - When I covert this specific image of the Delicate Arch straight from RAW to jpg it goes from 25mb to 6mb without any additional processing. Does that change the ppi?
> ...



When you resize your pic for printing, make sure you are keeping the number of pixels the same. So if you have 5760 pixels in the long direction, you divide that number by the ppi. So if you print at 300 ppi (or dpi), that's 5760 divided by 300 = 19.2 inches, 5760 / 200 ppi = 28.8 inches. If you want a 30 inch print that's 5760 / 30 = 192 ppi.

The only way you will be able to tell what resolution looks acceptable to you, is to try it out. Good luck.


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## privatebydesign (Nov 19, 2015)

dak723 said:


> ray5 said:
> 
> 
> > WoW! A whole lot of informations, thanks. A few follow up questions:
> ...



That isn't important for enlargements, the algorithms for resampled enlargements has improved dramatically in the last few years.

Here is an image I printed bigger than most, first the full image then a crop of the print file, if you zoom your viewer in or out so the crop is just under 3" wide on screen, that is what the print looks like. 

Guess how many of the cropped pixels are conjured up by PS? 

Believe me, this print holds up to very close, virtually nose on the canvas, inspection with zero pixelation and very good detail.


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## privatebydesign (Nov 19, 2015)

dilbert said:


> Consider that when you create images for the screen the typical PPI for the image is 72.



The 72ppi 'standard' for screen images died a long time ago, now screen resolutions are all over 100ppi, retina screens well over 200ppi.


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## neuroanatomist (Nov 20, 2015)

dilbert said:
 

> privatebydesign said:
> 
> 
> > dilbert said:
> ...



Yes, your repeated factual errors and lack of conceptual comprehension do get rather tiring.


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## rfdesigner (Nov 20, 2015)

I think we've all more or less covered most aspects.

My personal take on 300ppi is that at that resolution you can't see print artifacts. HOWEVER you are starting to lose detail in the print as well!

so if you upsample from say 200ppi to 300ppi then you are closer to being able to see all the information in the data, while also not seeing print artifacts. Yes Print at 300ppi, but you can create those from a coarser image... 200ppi original seems fine.. even for a wall print that people will look closely at... which means a 100ppi original scale would be fine viewed from a couple of feet away.

This all seems to tally with other sources where I've seen 8Mpix quoted as good enough for A3 printing.. it's even in the 6D manual that 5MP is good for A4 and ~9MP is fine for A3 (I was flicking through it yesterday, and noticed this)

As to Epson printers.. yes they're weird, I've tried all sorts and got best results on mine at 288ppi... 360ppi was also good, as was 240ppi.


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## privatebydesign (Nov 20, 2015)

dilbert said:


> privatebydesign said:
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> > dilbert said:
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And many mobile devices are over 300ppi now too


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## ray5 (Nov 20, 2015)

privatebydesign said:


> dilbert said:
> 
> 
> > privatebydesign said:
> ...


Though I understand that my file is good enough for a good sized print to be mounted at home I am still unclear about the ppi/dpi issue. How is it that reducing the ppi one can get a larger print but at a lower resolution and vice versa? Thx
Ray


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## rfdesigner (Nov 20, 2015)

ray5 said:


> privatebydesign said:
> 
> 
> > dilbert said:
> ...



ppi= pixels per inch

if you have 1000 pixels wide and print at 100 ppi you get 1000/100 = 10 inches, if you print at 200 ppi you get 1000/200 = 5 inches.. you it's 10 inches wide with "low" 100ppi res or 5 inches wide with "higher" 200ppi.

upscaling the image is generally desirable if you'd otherwise be printing at less that 300ppi.


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## risc32 (Nov 20, 2015)

i just hit print, or send it out. It always looks good, so either this doesn't matter, I'm blind(and everyone else who looks at the prints), I'm just lucky, or the software just does what needs to be done. I vote for the last option. I have never fooled with any of this. I've printed 15x10's from a 6mp cam a decade ago that look great.


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## Famateur (Nov 20, 2015)

To answer your question, as written in the thread title, you are only limited by the size of paper a printer can accommodate (hence Dilbert's answer). Having been in your shoes before, I'm pretty sure that's not what you're really asking.

There are really two aspects to your question about resolution and print size:

*1) Determining Physical Dimensions*

This is the easy part because it's just simple math: Take the pixel dimensions for height and width of the image and divide each by a chosen PPI (Pixels Per Inch).

Example: Image with pixel dimensions of 5760x3840


At 300 PPI: 19.2" x 12.8" Print Size
At 240 PPI: 24" x 16" Print Size
At 100 PPI: 57.6" x 38.4" Print Size

_* Note that changing PPI does NOT alter the image file or its pixel resolution. It simply tells the printer the physical dimensions to produce (i.e. How big should it print each pixel?)._

If you want to print at a finished physical size and don't have enough pixels for the chosen PPI, you'll need to first scale (resize) the image. See below for deciding whether to scale the image and print at higher PPI or simply reduce the PPI.


*2) Print Quality*

At a high level, and excluding the quality/resolution of the original image, print quality is driven by the relationship between pixel density of the printed image and distance from the viewer to the print. This is where it becomes more art than science because everyone will have a different opinion of what quality is acceptable (or even what detail is visible to their eyes).

Recommendations of printing at 240 or 300 PPI are helpful because they're a generally good place to start for typical print sizes and viewing distances. That said, you'll need to choose what works best for you for a given print job.

I second mb66energy's suggestion to print a cropped section (like the point of focus in the image) as a small print at various PPI choices to get a feel for quality at full print size and expected viewing distance without wasting the ink and paper of a full print for each.


*Extra Info...*

Part of the confusion is that people mistakenly say DPI when they should be saying PPI. They are not interchangeable.

PPI = Pixels Per Inch.

DPI = Dots Per Inch.

PPI is for display, like pixels in an image or pixels on a monitor. DPI is strictly a hardware specification of how many drops of ink a printer can/will cram into one linear inch when printing those pixels. When you print a 300 PPI image, the physical dimensions of the printed image will be exactly the same, regardless of whether the printer printed at 300, 600 or 1200 DPI.

In other words, when considering final print dimensions, you generally only need to concern yourself with PPI.
*
What I do...*

My printer's max capacity is 13"x26", though 13"x19" is more typical for my largest in-house prints. Uncropped resolution of my images is usually 3648x5472. The best quality I can achieve for my 13"x19" prints is about 280 PPI. With a sharply focused image, and to my eye, I find that 280 PPI holds up beautifully to nose-on-glass viewing distance.  Okay, more like six inches because I can't get any closer than that and still focus my eyes...


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## jrista (Nov 21, 2015)

I wrote this article years ago, but it should be helpful in determining the maximum print size you can go with for a given PPI and VIEWING DISTANCE (which is really key here):

http://jonrista.com/2013/12/16/generating-high-quality-inkjet-prints/

Viewing distance is determined by visual acuity, and for most people, you can get away with fairly significant enlargements at low PPI so long as a proper viewing distance is maintained.


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## rfdesigner (Nov 21, 2015)

jrista said:


> I wrote this article years ago, but it should be helpful in determining the maximum print size you can go with for a given PPI and VIEWING DISTANCE (which is really key here):
> 
> http://jonrista.com/2013/12/16/generating-high-quality-inkjet-prints/
> 
> Viewing distance is determined by visual acuity, and for most people, you can get away with fairly significant enlargements at low PPI so long as a proper viewing distance is maintained.



cracking write up there jrista, thanks for sharing


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## LDS (Nov 21, 2015)

Famateur said:


> Part of the confusion is that people mistakenly say DPI when they should be saying PPI. They are not interchangeable.



Also, the relationship between DPI and PPI depends on the printer (or any other output device) technology. Inkjet printers (and other half-tone technologies) need several dots in appropriate patterns to represent a single pixel color. Other technologies, for example dye-sublimation, and other continuos-tone technologies, may have a 1:1 relationship.

Thereby, while DPI for an inkjet printer *might* tell how sophisticated the pattern and its quality could be (number, quality of inks and the algorithm calculating the pattern are important also), when it comes to the actual output resolution what matter is the PPI.


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## ray5 (Nov 21, 2015)

Famateur said:


> To answer your question, as written in the thread title, you are only limited by the size of paper a printer can accommodate (hence Dilbert's answer). Having been in your shoes before, I'm pretty sure that's not what you're really asking.
> 
> There are really two aspects to your question about resolution and print size:
> 
> ...


Excellent explanation. I am going to save this for my files. Thank you!


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## ray5 (Nov 21, 2015)

jrista said:


> I wrote this article years ago, but it should be helpful in determining the maximum print size you can go with for a given PPI and VIEWING DISTANCE (which is really key here):
> 
> http://jonrista.com/2013/12/16/generating-high-quality-inkjet-prints/
> 
> Viewing distance is determined by visual acuity, and for most people, you can get away with fairly significant enlargements at low PPI so long as a proper viewing distance is maintained.



Very simple to understand. Thanks.


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## Famateur (Nov 23, 2015)

ray5 said:


> Excellent explanation. I am going to save this for my files. Thank you!



You're most welcome, Ray5! Glad I could help.


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## RGF (Dec 17, 2015)

Just an FYI -- I had a 1D M2 (?) which was 11 MP. I shot a bull moose shredding its velvet.

I cropped the image by ~50% and printed an 12x18 which really good. So out of an essentially 6 to 7 MP image I got an 12x18 print.


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## TexPhoto (Dec 17, 2015)

Maximum final print size? A good rule of thumb is smallest side of the print no wider than the width of the printer. 

Higher DPI is great, but there is no hard and fast rule. 300DPI images look great, 299DPI images? Great.

One of my images is displayed in an advertisement at my local airport. I's a 6MP image from my Nikon D70. (Back in the day) It's about 30 feet wide on the wall and starts about 10 feet up. Cropped to a Panorama. Looks great. Would a 50MP camera have produced a sharper image on that wall? Probably.


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