Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
06-05-2020, 08:43 AM   #16
Site Supporter
Site Supporter




Join Date: Jun 2008
Location: Idaho
Photos: Gallery
Posts: 1,107
Something to note, it's not the number of megapixels in your camera that count. It's the number that are in the print. If you crop your original shot, you've reduced the total megapixels. Most editing tools will show the horizontal and vertical pixel counts for a given file and you can go from that (divide by the size of the print you're after and you get pixels/inch or pixels/cm). Then you can judge if that is sufficient from experience or from what has been said previously in this thread. Also note that a lot has to do with the lens you use and in some cases a 100 megapixel file can look bad if the lens is bad. On the other hand, a really good lens will exceed the capability of your sensor and then it comes down to the number of pixels in the print, print size, distance its viewed from, the actual content of the print, and how picky the viewer is.

06-05-2020, 09:14 AM - 1 Like   #17
Otis Memorial Pentaxian
Loyal Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 39,140
With any luck @TonyW will happen along and set this thread straight. He has shown great insight in the past in regards to pixel dimensions and print size.


Steve
06-05-2020, 09:32 AM   #18
Site Supporter
Site Supporter




Join Date: Aug 2018
Location: Arkansas, USA
Posts: 583
There have been a lot of studies done that conclude the human eye can only resolve a print, when viewed at the proper distance, up to about 180 dpi. I have printed (on a Canon Pixma Pro 100) the same images on A3+ luster paper anywhere from 200 dpi to 450 dpi and can't see any differences, whether viewed extremely close or futher away. I normally print now at 240 dpi, which I believe is the default level in the Lightroom print module.
06-05-2020, 10:37 AM - 4 Likes   #19
Site Supporter
Site Supporter




Join Date: Feb 2016
Posts: 628
First off it is worth saying garbage data in garbage data out and no amount of messing with print resolution is going to help get a well resolved print. The only cure is to stand further back, far enough and many soft images will appear well resolved.


The human eye is certainly capable of being able to percieve much greater than 180 ppi (note not dpi this is a very different animal) it is entirely possible to percieve differences in a print made (with enough pixels!!) over 800 ppi. Again the detail must already be there in the image data as well as a sufficient pixel count.

You may want to quote viewing distances of 1.5 - 2x the print diagonal and assume that your prints will be viewed this way but what if the viewer is forced closer (narrow hall for display of a large print, viewer want to get closer than ideal to see more detail etc.).

There is a quick rough and ready way to calculate ideal PPI based on how close you are likely to want to view. Take the figure 3438 and divide by the viewing distance (in inches). EDIT: Note, these figures are for "average" viewing conditions. For "optimal lighting conditions" e.g. exhibition work, the figures could easily be doubled

10" viewing distance = 344 PPI
36" viewing distance = 96 PPI

But if you have enough pixel count then a 10" viewing distance may see improved resolution by printing at your printers native resolution e.g. 600 or 720 ppi (or possibly higher). In any case you should always aim to print at your printers native resolutions to get the most out of your print workflow e.g. Canon 300, 600, 1200 ppi with Epson 360, 720 ot 1440 ppi


Last edited by TonyW; 06-05-2020 at 12:12 PM.
06-05-2020, 11:01 AM - 1 Like   #20
Site Supporter
Site Supporter
Alex645's Avatar

Join Date: May 2015
Location: Kaneohe, HI
Photos: Albums
Posts: 3,076
QuoteOriginally posted by BruceBanner Quote
For example, could we print a K-1 shot at 36mp to A2 with acceptable results, yet the KP at 24mp to A2 will start to show its flaws?
The answer is truly subjective and mainly depends on the viewing distance, the image itself, and the viewer.

I print most everything from 16x20" to 40x48" using everything from a 12MP smartphone to APS-C to FF to a scanned 645 MF. Can I see the difference? Absolutely. Can others and do they care? Usually not. One of my most popular poster sized prints was a jpeg from an iPhone 6s. The technical quality is mediocre but everyone that loves it doesn't care or even notice it.
06-05-2020, 01:18 PM - 1 Like   #21
Pentaxian




Join Date: Feb 2015
Photos: Gallery | Albums
Posts: 8,281
I would add: If the photograph is one of a center subject in focus, with everything around out of focus (e.g background), corner + edge sharpness of lens don't matter. I define photographic quality as sharp detail when viewed at 16 inches (~40cm) since this is (sorry...) the distance when my eyes can resolve the highest detail, closer to 16 inches I see less detail, further away from 16 inches I see less details. For me it is impossible to see any sharpness flaw on a print from a K1 at 16x24" (300ppi), I can only distinguish drop of crispness below 250ppi, for me photographic quality is already there at 200ppi, very good between 200 and 300. I consider lower end photographic print quality (at 16 inch viewing), below 200 ppi, but since pixel pitch is the same accross the same print lower pixel pitch isn't catching attention as much as CA or fuzzy corner (as if the image detail is stretched in the corner according to a pattern of lens optic, distorsion of shape). Of course, 8 mega pixel with a low quality lens can be printed 20 feet wide looking good from far away, but I do not consider this as photographic quality, and because you can doesn't mean that the result is good. I was told that "you can print 10 feet wide from a Fuji X-T3", but the language here is to be taken word for word, "can" means it is possible to do so. Even 150 ppi would be Ok, at the condition that the lens is super-sharp, each pixel given a contribution to detail and contrast: David Yarrow / london exhibits gallery prints 150 cm to 180 cm wide (less than 150 ppi), from images captured with a D800E/D810 with Nikkor 28mm 1.4, 35mm 1.4 primes, aperture f4...f5.6 (wide angle give more DoF and no diffraction), large subject (animal) filling the frame, so a lion's face if defined by lots and lots of pixels.., exceptional lens sharpness and very low CA edge to edge, he wouldn't be using a 24-120 kit zoom for this type of enlargement.
06-05-2020, 03:17 PM   #22
Site Supporter
Site Supporter




Join Date: May 2014
Location: Minnesota
Photos: Gallery
Posts: 1,721
Usually when my customers order prints, I send them a copy of this printing chart Megapixels vs. Print Size – How Big Can You Print? | Digital Photography Live along with the maximum # of megapixels of the camera I used to take the picture they want printed. This gives them an idea on what can and can't be done. I haven't tried up-sampling, or down-sampling yet, I just go by this chart and leave it at that ?
06-05-2020, 03:25 PM - 2 Likes   #23
Site Supporter
Site Supporter




Join Date: Feb 2016
Posts: 628
At 16 inches viewing using the rough formula above you would ideally be looking at around 200 ppi to give an impression of continuous tone.

Regardless of how many ppi you think you are using in actuality the printer will interpolate to its native resolution. If either 300 or 360 PPI

06-05-2020, 03:29 PM   #24
PDL
Pentaxian




Join Date: Oct 2006
Location: PNW USA
Photos: Gallery
Posts: 2,014
I will only add the following, which I have said several times here and on other forums.

My next to favorite print is a 20x30" image of Aoraki taken with my old *ist Ds printed on Fuji film paper by Costco. I have another copy, again 20x30", hanging on my wall by Costco on canvas.

Both are great prints and look just fine.

So for 6MP (uncropped) 2008x3008 pixels to 20x30" at 300 dpi. Remember, your software will upsize a low pixel count to meet the image dpi. And, inkjet paper does not just absorb the ink so the dots will merge. (Just look at a inkjet print with a magnifying glass or good loupe. You do not see distinct dots, you see blurred, merged colors.
06-08-2020, 08:24 PM   #25
Pentaxian
BruceBanner's Avatar

Join Date: Dec 2015
Posts: 5,201
Original Poster
QuoteOriginally posted by pschlute Quote
I tend to use 300 ppi (pixels per inch). This is what the commercial printer I use specifies and seems to be a standard. So the max recommended from a K1 file is 24*16 inches.

If you want larger you can:

1 Upsample the image to a larger pixel resolution. or

2. Print at a lower ppi.
Thanks Peter.


QuoteOriginally posted by house Quote
There are rules of thumb but the true aswer is that its complicated. Upscaling algorithms are quite good now. The following are some things that might affect what resolution is appropriate.

- Printer
- Paper
- Viewing distance
- Type of photo
- Detail level of photo (not strictly resolution but how important the details are to the image.)
Good points, I perhaps needed to word my initial post better (but lacked the knowledge to better ask the question). For my purpose the image would need to hold up for reasonably good close inspection, such as exhibition work. The sort of image one can enjoy from afar but also walk closer towards and enjoy the details without flaws becoming very revealed.


QuoteOriginally posted by Rondec Quote
I think house has the basic answer. Printing at 300 dpi you would get a 24 by 16 inch image with 36 megapixels. Of course you can print larger than that if you want -- most people view large prints from a bit of a distance and so they won't notice. Of course there is software that can help up-resing your image too.
Do you know of any upresing software for this specific purpose that is recommended for print?


QuoteOriginally posted by Sandy Hancock Quote
I have made quite a few prints at home at 300dpi on A3 paper from KP files. I can't see any problems with even close inspection, and I can't really tell them from the K-1 images.

I'll let you know if that changes when I get my A2+ printer
Noice! Please let me know how you get on with that. Good to know about the 300dpi/A3 K-1 vs KP, thus far I've only printed A3 and K-1 (but been satisfied with the quality). Sounds like I am (yet again) following in your footsteps and thinking A3+ is not large enough and am going to start researching printers that can surpass this size restraint, but before I can do that I kinda need to know what the limit for megapixels to print size is generally accepted as being.

Did you do much research on your A2+ printer u finally decided on?


QuoteOriginally posted by acoufap Quote
Since different aspects have to be considered in the equation, it‘s not really possible to answer in one or two sentences.

Some years ago I had a closer look at this topic and wrote a blog post on my website about it - in german language. If you’re interested in reading it, maybe google translate helps and you may find an appropriate answer to your question?!
Thank you, I'll have a look at that later.


QuoteOriginally posted by noelpolar Quote
I seem to do ok with 150 dpi on canvas.
Ah yes, so we have to consider different mediums of print. Ok, so canvas... that's not something we can do at home right? That's more specialist equipment? Can Canvas even be printed beyond 150 dpi or is there a limit for that source material?


QuoteOriginally posted by texandrews Quote
Let me amplify several things from his and other posts:
  • the scene itself dictates a great deal. You can "get away with" lower ppi output, maybe much lower, if it's a low contrast, foggy scene that's very atmospheric. The reverse if it's a scene of high detail. Also, content (different from subject matter) may also allow for leeway or not.
  • viewing distance is very relevant
  • context is very important. For art prints meant to be seen by viewers in galleries, they may be scrutinizing the prints pretty closely. For casual things that are over the couch viewers may be much more forgiving, or even unable to view closely. Don't expect people will not look closely if a scene is inviting close inspection and there are no barriers to such, however.
  • intended impact is a subset of context. The marvelous RC aircraft images above have such impact, combined with a specific context and audience, plus existing in the action genre, that all of that would mitigate or even evaporation printing detail niceties.
I should have been more thorough with my initial post. I realise billboards for example are not meant to be inspected closely, for this post I was referring to something that would be inspected closely (such as exhibition work).


QuoteOriginally posted by DWS1 Quote
There have been a lot of studies done that conclude the human eye can only resolve a print, when viewed at the proper distance, up to about 180 dpi. I have printed (on a Canon Pixma Pro 100) the same images on A3+ luster paper anywhere from 200 dpi to 450 dpi and can't see any differences, whether viewed extremely close or futher away. I normally print now at 240 dpi, which I believe is the default level in the Lightroom print module.
Interesting, so what is 'the proper distance' that these studies concluded? It sounds a bit like 'The Emperors New Clothes'. Previous to photography I was quite into the world of mp3 players, as phones started to kill that market we saw the birth of HD Audio whereby these players would output music files and play them at bitrates higher than MP3 320kbps. Flac and Wav files etc. However, when actually testing users if they could ascertain any audible difference between HD and non HD source files the evidence showed more often than not the users could not differentiate. I wonder if DPI/PPI or whatever is behaving similarily and that to exceed a certain DPI/PPI for that frame size is just unnecessary and possibly wasteful?


QuoteOriginally posted by TonyW Quote
At 16 inches viewing using the rough formula above you would ideally be looking at around 200 ppi to give an impression of continuous tone.

Regardless of how many ppi you think you are using in actuality the printer will interpolate to its native resolution. If either 300 or 360 PPI
So wait, are you saying that some printers will spit out 300 or 600 (whatever their native is) despite you telling PS or LR to print lower? Just because they're made that way and can't behave any other way?

Thanks everyone for your input.
06-09-2020, 01:56 AM   #26
Site Supporter
Site Supporter
JensE's Avatar

Join Date: Dec 2015
Location: Leipzig
Photos: Gallery | Albums
Posts: 1,181
QuoteOriginally posted by BruceBanner Quote
So wait, are you saying that some printers will spit out 300 or 600 (whatever their native is) despite you telling PS or LR to print lower? Just because they're made that way and can't behave any other way?
Sure the printer can't change the spacing of the nozzles on the printing head, resulting in a number of discrete resolutions that can be printed.
06-09-2020, 02:23 AM - 1 Like   #27
Site Supporter
Site Supporter




Join Date: Mar 2009
Location: Gladys, Virginia
Photos: Gallery
Posts: 23,020
QuoteOriginally posted by BruceBanner Quote
Thanks Peter.




Good points, I perhaps needed to word my initial post better (but lacked the knowledge to better ask the question). For my purpose the image would need to hold up for reasonably good close inspection, such as exhibition work. The sort of image one can enjoy from afar but also walk closer towards and enjoy the details without flaws becoming very revealed.




Do you know of any upresing software for this specific purpose that is recommended for print?




Noice! Please let me know how you get on with that. Good to know about the 300dpi/A3 K-1 vs KP, thus far I've only printed A3 and K-1 (but been satisfied with the quality). Sounds like I am (yet again) following in your footsteps and thinking A3+ is not large enough and am going to start researching printers that can surpass this size restraint, but before I can do that I kinda need to know what the limit for megapixels to print size is generally accepted as being.

Did you do much research on your A2+ printer u finally decided on?




Thank you, I'll have a look at that later.




Ah yes, so we have to consider different mediums of print. Ok, so canvas... that's not something we can do at home right? That's more specialist equipment? Can Canvas even be printed beyond 150 dpi or is there a limit for that source material?




I should have been more thorough with my initial post. I realise billboards for example are not meant to be inspected closely, for this post I was referring to something that would be inspected closely (such as exhibition work).




Interesting, so what is 'the proper distance' that these studies concluded? It sounds a bit like 'The Emperors New Clothes'. Previous to photography I was quite into the world of mp3 players, as phones started to kill that market we saw the birth of HD Audio whereby these players would output music files and play them at bitrates higher than MP3 320kbps. Flac and Wav files etc. However, when actually testing users if they could ascertain any audible difference between HD and non HD source files the evidence showed more often than not the users could not differentiate. I wonder if DPI/PPI or whatever is behaving similarily and that to exceed a certain DPI/PPI for that frame size is just unnecessary and possibly wasteful?




So wait, are you saying that some printers will spit out 300 or 600 (whatever their native is) despite you telling PS or LR to print lower? Just because they're made that way and can't behave any other way?

Thanks everyone for your input.
I thought that Gigapixel-AI did something of this sort. Gigapixel AI – Topaz Labs
06-09-2020, 02:42 AM   #28
Site Supporter
Site Supporter
Alex645's Avatar

Join Date: May 2015
Location: Kaneohe, HI
Photos: Albums
Posts: 3,076
QuoteOriginally posted by TonyW Quote
Regardless of how many ppi you think you are using in actuality the printer will interpolate to its native resolution. If either 300 or 360 PPI
QuoteOriginally posted by JensE Quote
Sure the printer can't change the spacing of the nozzles on the printing head, resulting in a number of discrete resolutions that can be printed.
The resolution is going to be a combination of your file and the printer setting. For example, I use a DNP DS80 dye sublimation printer. In the printer setting software, I can opt for either 300 or 600 dpi output.

DNP DS80

However if you are printing an image at a given size is 300ppi, you will not see a higher res if the printer outputs at 600dpi. The only benefit is if your image size and res are 600ppi for printing at 600dpi. And for what it's worth, the subjective difference between 300 and 600 at normal viewing distances is barely perceptible.
06-09-2020, 02:43 AM - 2 Likes   #29
Site Supporter
Site Supporter




Join Date: Feb 2016
Posts: 628
QuoteOriginally posted by BruceBanner Quote
Ah yes, so we have to consider different mediums of print. Ok, so canvas... that's not something we can do at home right? That's more specialist equipment? Can Canvas even be printed beyond 150 dpi or is there a limit for that source material?
Unless your printer cannot accept the medium there is no reason why you cannot print on canvas. Due to the generally coarse nature of the canvas there may not be much point exceeding half your printers declared PPI e.g. 150 or 180ppi.

QuoteQuote:
I should have been more thorough with my initial post. I realise billboards for example are not meant to be inspected closely, for this post I was referring to something that would be inspected closely (such as exhibition work).
Stand far enough away and the dots that form the image from the screen print will not be apparent.

QuoteQuote:
Interesting, so what is 'the proper distance' that these studies concluded?

....... I wonder if DPI/PPI or whatever is behaving similarily and that to exceed a certain DPI/PPI for that frame size is just unnecessary and possibly wasteful?
The "proper distance" for viewing is often quoted as 1.5x - 2x the image diagonal:

10" x 8" image the viewing distance would be 19" - 25".

6" x 4" image the viewing distance would be 11" - 14"

The PPI (amount of pixels in the image data) is the important figure. That plus the printers native resolutions 360/720/1440 ppi (Epson). If your image data has been resolved high enough and has important detail then ideally you should send that data to the printer at one of those resolutions. It may be considered wasteful to print an image that has a ppi count of say 600 ppi at 360 ppi, as you should be looking at upsampling the data to 720 ppi before sending to the print driver.


QuoteQuote:
So wait, are you saying that some printers will spit out 300 or 600 (whatever their native is) despite you telling PS or LR to print lower? Just because they're made that way and can't behave any other way?
Short answer yes


Bear in mind there are two resolutions that a printer deals with. The first is the PPI (pixels per inch) which is the printers native resolution related directly to the number of nozzles in the print head. To generalise a professional Epson printer will have a print head with 360 nozzles per inch, whereas a Canon or HP printer will have 300 nozzles per inch - note that some may have half 150 or 180 nozzles per inch. They will also have a finer resolution of 720 or 600 ppi and possibly one other of 1440 or 1200 ppi. These other ppi resolutions are achieved by a very fine stepping of the motor moving the paper over the print roller.
The second is the the DPI (droplets or dots per inch) this is a measure of volume of ink laid down on the paper and will normally be a multiple of the nozzle count of the print head. Quite often print drivers quote print quality such as Draft, Standard and High rather than actual DPI figures

---------- Post added 06-09-20 at 02:55 AM ----------

I posted some printed images as a quick and dirty example of printing resolutions here What PPI to send to printer for best IQ - PentaxForums.com


This to give some ideas of the difference that you may observe. In all cases view from far enough away and the resolution lost.

Last edited by TonyW; 06-09-2020 at 02:57 AM.
06-10-2020, 06:14 PM - 1 Like   #30
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 37,104
I wonder how many people have actually printed so large, they didn't like the image. It's never happened to me. I've printed images with as little as 72 pixels per inch that were fine for 4x6 images. I've heard so many theories about what folks need to do I'm immune now.

I print the image I have at the size I want it to be.
Maybe others have display spaces that mean they need some sense of an upper limit. My largest is 42x30, a K-3 image. A k-1 could be 20% bigger.
So I almost feel like turning folks into guinea pigs. Why not just have everyone upscale their images to 300 DPI, and print the size they want. Eventually someone will be unhappy and let us know.

Corners and edges limit the enlargement only when in focus. Out of focus areas upscale quite nicely and for many prints the edges are out of focus.

This painting sold for 240 million.....


The resolution is terrible. Until photographers start to come to terms with this, this will be a topic of endless debate. I ask, would the painting be better if you could read the cards in the players hands? Are you really going to second guess the appeal of a 240 million dollar painting? What is it that's important here?

Check this one out....


3 million dollars.Do you think someone went up with a magnifying glass and pronounced it worthless? Does anyone care what that person thinks? Why?

I see very little evidence that Richard Prince spent much time pondering the resolution.

Gursky on the other hand has sol for more and is incredibly detailed, but if you'll read about Gursky, you realize the kind f detail that makes him the big bucks isa combination of scanning and combining 5x7 film images of different focal lengths, creating 100 MP fplus files and then printing. None of us shooting Pentax are Gurskys.



This is what really impressive high res looks like. You aren't going to do that with your K-1. Neither could Gursky.

If you have a great image, print it at the size you want.
I place absolutely no value on print resolution.
My issue is," is it a compelling image?"

I know one of my favourite images was a 35mm of myself and my kids walking through a forest of tall birches, done as a 36x24 poster, (the limit for 35 mm was supposed to be 11x14.) The grain was awful, the image was delightful. I'm kinda starting to think of the resolution based print guys as fitting in with those who know the measurement of everything and the value of nothing.

I know, what the reaction will be. Probably insults and outrage. But I'm on the team of the guy with the 3 million dollar print, who are you guys with?

There will alway be those for whom the numbers build their confidence to feel they've done a good job. I see little evidence that it's necessary to pay much attention to the numbers. My advice would be, if you think I will work, go for it. Find out. No one giving you advice here has sold a print for 3 million dollars, but other less critical people have.

I'm a photographer, not an accountant.
Take chances with your printing, you might creates something special. Those successful in the world of photography didn't get there following rules and mathematical formulas.

Last edited by normhead; 06-10-2020 at 07:01 PM.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
a2, data, image, inch, k-1, kp, megapixels vs, photography, photoshop, ppi, print, printer, printers, resolution, resolutions, shot, size, terms, vs
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Flickr Pro to increase maximum photo size to 6K aslyfox General Photography 20 10-19-2019 02:46 PM
K-5 vs MZ-S vs LX vs PZ-1p vs ist*D vs K10D vs K20D vs K-7 vs....... Steelski Pentax K-5 2 06-28-2017 04:59 PM
Print size vs. megapixels of camera fevbusch Pentax K-30 & K-50 29 12-18-2013 09:21 AM
Image Size vs Document Size vs Resolution vs Resampling vs ... AHHHH! veezchick Digital Processing, Software, and Printing 13 08-02-2010 03:57 PM
Maximum Printed Image Size vs ISO - Successful or Not? Sideways Digital Processing, Software, and Printing 6 08-08-2007 11:00 AM



All times are GMT -7. The time now is 05:55 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top