Megapixel war

[Dusty]

Not to have everyone hash out the same old arguments again, this guy's blog is just talking about resolution the eye can see. He doesn't touch TR, DR, CA, noise or ISO. This is ONLY about resolution and how much we 'need' to see the finest details.

http://theonlinephotographer.com/the_on ... index.html" onclick="window.open(this.href);return false;

Dusty

[KevinBarrett]

That, my friend, is a very clever blogger. Great reading for anybody with an active mind. I particularly like his bleeping hypothetical questions.

[Greg Beetham]

Haw! that's a joke right, for a printer too print that fine it would almost have to spit individual atoms of ink...then most likely they would go clean through the paper
Greg

[KevinBarrett]

That's why they'll make quantum-printers next, to bundle with your quantum-computer from quantum-bankrupt quantum-Circuit City!

[Dusty]

Haw! that's a joke right, for a printer too print that fine it would almost have to spit individual atoms of ink...then most likely they would go clean through the paper
Greg

Well, Epson's R1900 can print at "5760 x 1440 optimized dpi". 5760/25.4 (1 inch = 25.4 millimeters) = 266.77

Assuming a line is printed 1 pixel wide, and, since it's a line pair, we have 2 lines, a blank line between, and a blank on one side, (we don't need on either side as that's taken care of by the pair/spaces combo next to it), then 266.77/4 = 66.69 line pairs/mm. (And only 14.17 lp/mm on the 1440 dpi side.)

I don't know what the highest resolution printer out there is, but it seems like it's fairly possible.

Dusty

[Greg Beetham]

I was sort-of pulling your leg a little Dusty, but the thing is, I read/saw somewhere that the human eye can not see detail beyond 90 dpi (so they say) so having a printer deliver 266 odd is probably an overkill, mind I'm taking at face value as meaning "dots per inch" not converting to lens line pairs per millimeter or such. I think the finest optics deliver about so called focussed 1/8th lightwave which as far as I know is a very very small diffraction dot, and then too construct a sensor with four pixels under that dot too record it properly is a tall order indeed, David or PT or someone with more optical knowledge than I (wouldn't be hard to do) could probably sort it out for us much better than I can.
Greg

[David Kilpatrick]

The human eye can certainly see more than 90 dpi - your laptop screen probably has 106-140 dots per inch, and you can clearly see all the dots! My iMac 24 screen has 106dpi and I can see every pixel clearly from two feet away. An A700 or A900 rear screen has about 250 dots per inch and I can see those clearly, from a little closer.

The accepted standard is around 300 dots per inch for human vision at reading distances, which is why the first laser printers were made this way (they actually used one solid black dot for each dot). Anything finer and you don't see dots. Inkjet printers do not really use 1440 or 2880 or whatever 'dots' per inch, they use no dots at all as they print using stochastic (random) pattern in which four to eight ink colours are overlaid. If you analyse the print to isolate the smallest cluster size which represents a point of density or colour in the image, it will be around the same 300 'dot' size but the dot is composed of tiny pulse droplets of all the colours.

Because the pattern is random, you can print with an image resolution of 200 dpi/ppi or finer and it will look sharp. For large prints (over 20 x 16) a resolution of 150 ppi is OK and for exhibition panels, even less.

David

[Greg Beetham]

This is the part I always get confused on, is a pixel dot a combo of R G B dots or is that three seperate dots?
Greg

[David Kilpatrick]

One pixel in an image is an RGB location. One pixel on your monitor is a group of three subdot, R G and B. One 'screen dot' in printing is a group of CMYK dots, ranging from three to hundreds depending on the process. In dye sublimation printing, each dot is a true RGB - overlaid transparent dye, diffused into the medium.

Here's one of my shots of an iMac monitor screen:



David

[Greg Beetham]

You have good eyes David, I can't see them on my monitor or my A100/KM5D screens I probably need my reading glasses....I just took a full extension 1:1 macro of the monitor (had too use a manfrotto sliding tube) and there they are, complete with lots of moire, HA! a pixel screen displaying an image of a pixel screen image, what a hoot.

I can also see them with a 10X loupe easily they look like one square with the red blue green stripes.
Greg

[artington]

You have remarkable eyes, David. The only way I get to see the individual pixels is by putting up a magnifying glass to the screen

[bfitzgerald]

What a dumb blog post!

So we need 8x10 large format for an 8 x 10-inch print, to meet his standards!

Wakey wakey! We don't look at prints with a microscope. I am so glad that some folks can worry about "what matters" and that is the final image. My best photos, are my lowest res, softest ones! Seriously, it's pointless talking about print quality, unless you talk about viewing distance.

I still have that big ISO 6400 DK print he sent me, from the A900. If you put your face up to it, it sucks! Viewed from a normal distance, it looks "pretty good" to me at least.

[KevinBarrett]

I think the author made the post as a purely academic exercise, and to demonstrate that we need not concern ourselves overly much with the megapixel wars right now. I thought it was a very sophisticated bit of writing (if technically useless).

[Dusty]

Not so useless. Most people have never worked with anything bigger than a 35mm camera. They don't realize the abilities you get when using large formats. Shoot something with an 8x10 view camera, and you can take a 1 by 1.5 inch section of the negative and make a decent 8x10 print. In fact, you can tale 53 such sections and make 8x10 prints!

Blowing a 35mm negative up to 8x10 is an 8x enlargement. An 8X10 negative blown up the same amount means a 64x80 inch print! Granted, most of us have no need for such print sizes, but the possibilities with cropping and the finer quality DO make a difference.

My very first use us my 4x5 view camera was to take some family reunion shots for our family. I also took the shots on my 35mm and 120 film cameras. The 35mm shots were good, the 120 better, but the 4x5 - WOOHOO! I could recognize individuals in the negative! Needless to say, prints showed 0 grain. Many times over the years I have found myself heavily cropping to get a small section of the scene I shot blown up. With 35mm. you're severely limited in your ability to do this. The same goes for a 12MP shot. If you had 80 or 100 MP to work with, your ability to take a piece of you shot and enlarge it of a good print is greatly increased.

Dusty

[bfitzgerald]

The problem with sweeping statements, is that they are just that..sweeping!

Is the blog useless? Well maybe not 100%, but back in the real world..there are more important things to worry about. Folks who make mega prints, have tended to head towards larger formats, the biggest I have is 120 roll film..though it has not seen film for a good bit.
So the discussion becomes more academic, than of great value to photographers.
There is also no doubt that more megapixels will be on the map, and for a long time. Though I have suggested before, resolution is only one part of the story.
The reason most people were shooting 35mm, and not large formats or even MF cameras (which were, and possibly remain popular with landscapers in particular, studio use etc), simply cost, and size. 35mm cornered the mass market, the larger formats the smaller specialist ones. FF digital has replaced that MF/LF desire, APS digital seems to be the new 35mm. Good enough for most. APS film was conspired by many as an unnecessary compromise, hence it's failure to grab the market.

The other problem with film remarks, is the wide variation of emulsions. It's simply not possible to say 35mm, MF = xyz resolution. In the same way high res APS sensors have more pixels stuffed in, low ISO film has more finer grains, and delivers higher resolution, across the formats this is the same. Go up ISO wise, and resolution drops, on film and digital too..though there is no doubt digital is a potent high ISO weapon.

I am sure some do want to make really big prints, hence their pursuit of very high megapixel cameras will appeal. I can only speak for myself..in that I am satisfied with 35mm for my average print size (let's say 18" x 12" would be common, sometimes a bit more..though not much), APS digital I tend to use for high ISO, even the 6mp KM does the job pretty well, for the tasks it is set.

35mm isn't severely limited if you seek sanctuary in the tech pans/adox world, and having seen some prints from those..you would indeed be impressed at the quality of the enlargements, albeit mono..few would want more.

As we all know things will get more with regards res, there comes a point where you reach a "satisfied" level, I am already at that. I honestly think, we hear too much luminous landscape style.."big print thinking"

For me at least, there are better things to talk about. I am now not concerned with "is my image quality good enough", but "are my photos good enough"

This is the most important factor for me, and I continue to try my best. I don't need 100mp, nor do most..and 100mp of not very good images, isn't the match of a great 35mm or lower mp shot. I don't cry myself to sleep worrying about it, so it really is mostly tech academic talk, and not that relevant to most photographers. Simply use what you have, if your needs are not met, get something better.