If you take the table of @Joanna and look at the first first line, 0.6m/300dpi, and you multiply them you get 180. Now you can calculate easy any combination, by example 37m needs minimal 180/37=4.9 dpi or just 5 dpi.
And with 225dpi you can view the image at a distance of 180/225=0.8m.
George
My D3 is in the ācamera hospitalā for a week or two. After reading the firmware instructions three times, and downloading the appropriate software, I decided to let my camera repair shop do this, along with cleaning the sensor. Unfortunately, during the software update, the camera apparently tipped over, interrupting the update process, resulting in a dead camera. The shop will order the parts, and the camera should be ready in a week or so. Either I go back there to get it (most likely) or they will ship it to me.
Regarding the recent posts, if weāre talking both color and B&W, and I settled on 16"x20" for the size, Iām not sure what I could buy, and since I make trips every so often, it would usually sit unused, which probably means the inks would dry up? Then there is the issue of how to show the prints to family and friends. The way I reach everyone now, is email.
Then there are finances, which I need to be careful about. The top of the list is a new Apple display, like what @Joanna uses. Being retired makes buying new things much more difficult.
If the conclusion is that people will mostly see my images on a digital display, watching images they downloaded over the internet, I suspect that they wouldnāt be able to see the difference between photos from a D3, D780, or D850. But if the photos are intended to be made much larger, from what Iāve learned up above, a D850 might be my best choice.
This lengthy discussion has clarified a lot of things in my mind.
The biggest problem with this article and many others, is that they confuse dpi with ppi.
Most modern printers create a great many more dots than you could dream of for pixel resolution. For example, my Canon Pro-1000 lays down 2400 x 1200 dpi, whereas the ideal resolution for printing for viewing at armās length is 240 ppi. This allows for dots of multiple colours to make up a single pixel to āmixā those colours.
Epson printers always used to state their resolution as being a multiple of 300 dpi but folks misinterpreted this and set the resolution on the printer dialog to multiple of 300 ppi, which was, and still is, totally unnecessary.
The only real difference pixel resolution for printing makes is that it determines the finished size.
Personally, I calculate the pixel dimensions for the size of print I require at 240ppi and then export the image to a TIFF file of that size. then I use the Canon Professional Print and Layout utility to position the correctly sized image on the paper.
What I never do is to use the PL print dialog, which I find to be neither accurate nor convenient.
To print up to 20" x 16" you would need a 17" printer, which is not going to be cheap.
After previously owned (one after the other) two Epson A3+ printers (13"), which are now sitting dead in storage due to blocked jets or air ingress, I decided to switch to the Canon Pro-1000, which prints up to just over 17" wide in a quality that is far superior to anything I could achieve with the Epsons. I have left the Canon unused for a couple of months and it just resumed printing without any problems at all.
What is more, if things do get bunged up, the head can be replaced for far less than the price of a whole printer.
The Pro-1000 is not cheap - mine cost around ā¬1200 and a set of 12 inks is around ā¬500, but they also do an A3+
Err, no! Epson printers work in multiples of 360 dpi. Itās other brands, HP, Canon etc. that are typically considered to be 300 dpi.
Ah well, almost right. At least more right than confusing dpi and ppi 
Iād love a 17" printer but @Joannaās right such devices are not cheap, in the UK that means a minimum of not a lot of change from ~Ā£1100. Such machines usually use pigment inks, which are also not cheap (>Ā£600 for a complete set of cartridges). Plus pigment inks are more prone to causing clogged the nozzles if the machine is not used regularly.
Meanwhile back in the real world, my lowly and now several years old, Epson Expression Photo XP-960 prints up to A3 (11.7 x 16.5 inches) and does the job for me.
Guessing it is something you would not reccomend though. Whilst not ever touched one, Iāve read that a lot of PRO-1000 users* leave the printer on and let Qimage do some printing at regular intervals. Mostly to prevent automatic cleaning cycles from using up ink. Have you looked at Jose Rodriguez on YouTube?
*not just Pro-1000 owners
@Joanna, after reading what you wrote about prints, and print size, I think I realize that I have visualized a lot of things incorrectly. The size of the print, and the viewing distance are also key things to consider.
I now imagine a small e-mailed photo from a Nikon D40, will probably look just as good as had a D850 or Z9 been used. Up until a certain image size, a person looking at them wonāt notice the difference. (Of course, viewed on a huge monitor, or printed at 16x20, the quality (or lack of) will be obvious.)
If I took an identical photo with a D40, D750, D2, D3, D780, D850, or even your LF cameraā¦
ā¦as a very small image on a normal computer monitor, they will all look about the same.
Using a standard display monitor, viewing the screen while seated at a desk, and with the image up to ten inches or so wide, when will the difference become obvious?
I guess the camera doesnāt really matter, itās the number of megapixels in the image being viewed (along with the lens). I remember struggling to get images that looked sharp on-screen with my older Nikons, up to and including the D2. With images from the other cameras, I suspect the sharpness (or lack of) may not show much difference.
Of course, is no longer relevant, if the images are cropped.
I remember how nice your photo of an amusement park looked, until you zoomed in. In that case, the limit was the camera and camera specifications.
I know with my D3, that images look fine to me on my 21" display, but they fall apart if I crop. So thatās about my limit - I need to fill the frame with image).
All of this is ignoring stuff like ādynamic rangeā, which can limit how good an image someone can make with their camera, and their choice of subjects.
I can simplify this whole post into one question:
In your estimation, how many megapixels does a camera need to create a good looking image on other peopleās video monitors, at a normal viewing distance?
Thanks for this link - it also helped me understand things better:
You should be able to answer this yourself. ā Set your cam to jpeg, reduce the resolution, use your telezoom and focus on something static with details. Your can go down to about 5 MPix and in DX mode even lower.
That answers my question, as asked, but it does not answer what Iām thinking.
A better question might be why do each of us take photos?
My answer - because I enjoy doing so.
I mostly use cameras I enjoy.
I try to capture images that I enjoy.
And then, I enjoy sharing them.
Iām no longer earning money.
Iām not entering contests.
Iām not āworkingā at it.
PhotoLab is a ātechniqueā that I have been learning, and will continue to learn.
Lots of technical gobbly-gook about photography I donāt understand.
The sheer joy of capturing photos for me, is like the āhighā a druggy might get.
Sharing with others is also something that gives me pleasure.
Learning how to use my camera machine, and get it to do what I want - ditto.
ā¦and there are lots of things to stumble on, and get frustrated, and struggle with, such as that silly pelican that was so āalmostā, but is less than I want.
I learn so much more just from reading these forums, and asking questions. Iāll never get as skilled as you and Joanna, but Iāve certainly benefitted. The beautiful photos āthe mastersā created came from them, not their cameras. I certainly will never become āa masterā, but I can try, anyway! 
If you want to know the necessary resolution as you asked for, you need to check this yourself on your monitor. And that gives you then an idea by how much you can crop pics taken with your D780.
Hi all!
@OXiDant is walking in to the livingroom completely dizzy from all the posts in this topic. 
which are lately about colorspaces rawfiles and cameraās
mildly confused about @mikemyers his postās and the answers
i thought we grinded this in serveral posts when Wide Gamut started to pop up back a few years/months?
Some very kind people with exelent knowlegde about colorspaces and behaviour in applications posted a lot on this matter in serveral topics. ( quick search on ācolorspaceā and āwide gamutā will do the trick i think to raise those out the quicksand of time.)
i keep it simple because my images are simple:
@mikemyers think in flowcharts: (small blocks and yes/no and IF=> then.)
exposure and composition => gets a rawfile.
Hopefully within the DR of your cameraās capabilityās. 
Open DxOPL and set all preferences to your liking considering what your learning and findings are wile reading the manual of DXOPL.
create a personal preset and working space in this settings.
date this to say today.
"mikes workingspace 28032024"and make a āimage import presetā like mikeās preset v7 28032024 which applies all settings you want when first open your imagefile.
this is your baseline.
your workhorse.
every time you change something in this settings because you learn something or think it would be better you create a new one working space xxxxxxx version 2 or preset version 2
this way you should be able to keep track on your improvement or maybe decline of ācalibratingā dxopl. throw away those which you arnāt using anymore for sure. Keep those inorder to see if your progressing the right way: to a better first preview image and startingpoint.
@platypus small structured flowchart post above looks great as startingpoint.
me i am forgetting more then i like after a wile in colormanaging but in the base itās what @Joanna showed: starting wide and softproof your way down. keep it simple.
No use to go all the way and donāt calibrate your screen once. ( and also your printer or viewing device ( 4K smart tv?) itās all connected. Every change can break something else if you donāt keep track of your changes.
Me i stopped bothering too much about color realness and colors to be true of the original scene. If i like it itās ok. i donāt need to sell my images or be foodcolorreal. i donāt calibrate my devices. to much of an hassle.
yes for my work i calibrate printers, office printers not proprintingdevices so i know that wrong calibration can be a pain in the bu. But if you canāt understand completely what you need to do keep off the fasttrack aka keep colormanangement as ādefaultā as possible in DxOPL because often the default is about in the ballpark near the hole.
( often when my users have printing problems of colors, they where stumping about in settings without realizing what they change so few weeks later something else comes out wrong. And they donāt remember they changed something to correct an color mismatch in the end wile the problem was in the beginning so it looked good on paper.)
best fix is throw away the driver, calibrate the printer and reinstall driver from scratch
owh shoot! itās already too late for me, have to get up at 06:45 6 hours sleepā¦ argh.
have fun!
Thank you for that - itās what Iāve been doing, with several of my cameras. The D780 and D750 allowed me to crop quite a bit (for images to be viewed on the monitor). The D3 means I pretty much need to fill the viewfinder with what I want - not possible to crop very much. I imagine with the D850, for my purposes, not Joannaās, I could probably crop more than I ever imagined.
I have been trying to mostly fill the screen with what I want, but to always leave room around the sides in case my camera wasnāt level.
I do try to use the ālevel indicatorsā when/if I have time. Thatās one of my own limitations, I donāt always find the time to check this for every shot. I know āwhat to doā, but I donāt have the time to do it. I try to leave āgridlinesā on whenever possible, as that helps me a lot.
Peter, I love what you wrote, for taking āfun picturesā (not work), but with one exception. Until @Joanna convinced me to calibrate my ASUS monitor several years ago, neither of us were seeing the same thing.
Photos I take, or am involved in taking, at the Eye Hospital I volunteer at in South India MUST be as accurate as possible. But, my own personal photos donāt. Now that my display is calibrated, I donāt see any reason to worry about so many of those things.
On the other hand, I donāt like blurry, and/or pixelated images, meaning I should fill my image with what I want to show, and I should STOP thinking I can always crop the image later - several people here have beat that into my brain permanently. (ā¦birdsā¦) That, and be aware of my shutter speed, and how steady my hands are, or are not.
Me too. In my case, itās because Iām too ignorant. Iām learning that nothing I now think is sure to be right - even posting links from the internet. I never knew I was supposed to try to check them for ātrackingā. I never do that.
So many of you are way, way above my head, but itās been that way since I first joined this forum, and I love it. It seems like every day Iām learning new things. Maybe Iām just too old, or maybe I donāt āthinkā as well as I did years ago. Iām going backwards, I think. I used to think I knew a lot. Not any longer. Everything I think I āknewā now has question marks. Maybe I donāt belong here.
When I got my Nikon D2x twenty years ago, I thought it was the absolutely perfect camera, that would serve me for the rest of my life. I thought digital had caught up with film.
(ā¦and ten years from now, everything we now think of as being so good will be looked down on as antique junk, compared to whatās available in 2034. Geez, I look over my web site at m.smugmug.com and wonder why most of those photos are as good, or better, than what I take todayā¦maybe thatās part of why part of me wants to just enjoy my photography nowadays, and not get so seriously involvedā¦)
Death by customising. Art is not about what one can do, but to know when to stop. 
Moreover, the streets of India and yet another shot out of your window have different powers to capture interest.
Very easy to work out. a 2019 iMac 27" screen measures 5120px x 2880px, which is just under 15Mpx. Therefore, as long as you use a full frame image from a camera with that image size, you should get a reasonable rendering at a 100% zoom. Bearing in mind that the camera aspect ratio is 3:2 but the screen is 16:9, which means, to get a full height 3:2 image on screen, you will end up with an image that would only be 4320px x 2880px or 12Mpx, with wide vertical bands of nothing on the sides.
But, if you want to know how large a print that would equate to, you have to take into account the difference in pixel density, which for the 2019 iMac 27" is 218ppi, whereas printing resolution is 240ppi, so a print will be around 90% of the screen size.
I print A2 size prints (23.4" x 16.5") which, at 240ppi, means I need an image that is 5613px x 3969px to fill the paper without any enlargement. My D850 gives me 8256px x 5504px, so plenty of room to spare. Your D780 gives you 6048px x 4024px, which is also large enough to produce an A2 print without enlarging. However, your D3 only gives you 4256px x 2832px, which is not large enough for printing without enlargement, but is almost large enough to fill the screen height at 100% zoom.
However, your Asus display is a whole different game, where the resolution is only 2550px x 1440px, which is half that of the iMac, so you are only ever going to be able to see images at 50% of the zoom that would fit on the iMac.
An other very important thing is viewing distance.
Nowadayās every one is used to sit close on 4k screens.
(@Joanna you know al this thus the following text is for @mikemyers
Example:
My father 93 eyesite very poor needs 1200 euro glasses to see and uses a loop to read with glasses together. (to set the specs of visual perception)
His sister 94 has got a 4k screen and he was stund by the sharpnes and visual details.
So my brother in law bought him a 4k smart tv because his old one was 10 years plus and only FHD not UHD (4k)
I instal this because well i am the tech in the family, and the first thing he stateās: Itās not as sharp as my sisters tv.
I point out that source file of internet TV is only FHD aka 1080p so the tv has to invent 3/4 of the pixels and then the processingchip which recalculates the pixels comes in play.
Start up Youtube and select a 4k Afrika animal clip in the Savanne to proof my pointā¦
Answer ok i need to change my abonnement of itv?
Nope could be but most itv streaming is 1080p or upscaled 2k. So problem is stil interpolation of the tv it self.
Then i say letās play a movieclip by usb on both wile both are side by side.
Start walking backwards to your sofa where you 90% of the time watch tv.
Which is better?
The new oneā¦
Well problem solvedā¦
Pc screen of 2k or 4k means much more expensive camera with 24Mp or more in use because everyone crops and viewing very closeup sitting just infront means almost viewing 1:1
My G80 is 1:1 4k output. Sort of.
So cropping means always enlargment on 4k tv. And in the future 8k tvās
A 50 inch 4k vs a 70inch 4k means you have the same amount of pixels but bigger and you can stand further away and still see all the details.
If you recall, I brought this to your attention over a year ago. You have many really excellent photos on your site. Maybe you need to rethink what youāre capturing these days and why. Maybe youāre missing the spontaneity that you had when you were using your Leica. Itās possible that you are just overthinking things.
Mark
Iām reading this post using my Safari browser on my ASUS. From reading the above, I had an idea - slide this window to my left, so the left half is on the Mac screen, and the right half is on my ASUS. Did that, but didnāt notice any major change in the text size. Maybe I did something unusual five or so years ago, as having things set this way makes it easier to use my computer. Let me check:
Aha! I guess this explains it. But for now, I will leave it as it is.
Need to think about this some more.
I use the ASUS for image editing, and the iMac for messaging, email, and most āordinary stuffā. I guess things will likely change a lot when/if I buy the 21" Apple display.
My eyes do have issues, but with my progressive lenses, I can still see reasonably well, but maybe nothing like when I was younger. They tell me I still have 20:20 vision.
The website is for two purposes - to try to post good photos that I am happy with, and to serve as a āphoto albumā for places Iāve been to. I really need to bring it up to date.
Peter - I never thought about whether or not my images are āsimpleā, but I will say sometimes I just take āsnapshotsā and other times I do everything the best way I know how.
Part of that is āsimpleā, but I just export as ājpegā images I can post.
I need to be careful, and try not to take photos that I would get laughed at, should I post them here - but in the choice of āimage interestā vs āimage qualityā, itās sometimes a difficult choice. All images go through PhotoLab, as I hardly ever shoot in ājpegā (unless itās give-away photos).
Other than shooting in sRGB, and hardly ever taking jpeg images, and exporting for screen viewing, I do try to keep things āsimpleā.
