If you do the simple math, the A7s has 4240 pixels on the long side. If you simply converted that to 240 ppi to print (which I can't distinguish with my eye from higher resolution printing even on the best printer and glossy paper), then you can get at least an 18 inch print. Printing that large, if you don't crop and that is a big if much of the time, should be simple and IMO should produce excellent quality.
Now things are never that simple in real life, however. First, as suggested above some of us (and I would put myself in this camp) crop fairly often. Obviously when you crop having more resolution can really help. Second, printing is a skill that needs to be developed like all skills in photography. Those who have good skills at post processing, enlarging, and printing can print much better larger prints. Personally, I know I need to develop my skills a lot if I want to print bigger. I can do fine with my 13 X 19 printer, but if I were to print 40 inch prints I would need to significantly develop my skills. Third, the viewer and the viewing distance are critical to determining how a big print works. Others have highlighted this well above, but it sounds like you want big prints to sell and you think you will often have or worry you will have pretty critical viewers who will view it at close distances. That will require better prints of course.
So, can you make 40 inch prints with the A7s? There isn't a simple answer. You will be more likely to do so, however, if you don't crop and develop your printing skills, and print on more forgiving media. I am sure some can make some great 40 inch prints with the camera, but the question is whether you feel you can and to figure that out you will need to work with some 12 mp files and see what prints you can make from them. They might be what you are looking for and they might not be. I don't think anyone can answer this for you, but putting in a day of working with such files should.
chez wrote:
Sorry...you are wrong on your second point. Just go observe a gallery for a day and you'll see that your view of people not looking close at a print is wrong.
Actually you are incorrect on this one I feel. A very small minority of the general public ever goes to galleries. Just ask anyone who works in sales, fundraising, or memberships at public/private galleries and museums lol
For maybe every one person who actually goes at an art gallery or exhibit there are a few thousand standing in line to see the latest Keanu Reeve's movie.
Within a niche market they do, I'd love to be able to take my 4x loupe to Ansel Adams exhibits, but the OP doesn't seem to be asking about fine art printing, sales etc. I assume if that was his intended output he wouldn't really be asking such a question in the first place.
For the average photographer, taking average pictures, and putting them on walls in the normal family home, to be viewed by friends and family, there likely will be no nose prints on the photos.
In my house, the dog is the only one who's nose ever touches the frame
I use the calculations that Steve states above to get a feel for how large I can print, but behind my desk is a 16x24 print of a shot from my D30...3mp. Technically, it has all kinds of limitations, but, for me, it works for this particular shot. So my answer to the OP would be...it depends
I've posted this once before (sorry for the repeat, but it may be useful to some)
in researching this for myself (most of the frames in my house are 3' x 5'), I came across the following bits of info.
But before I share the formulas, I'd also agree that A *LOT* depends on your subject matter and how detailed it is to begin with. A shot of waves on a beach at sunset is unlikely to require as much resolution to portray as a close up of the scales of an creature, for example.
So, while I offer numerical ideas, please do not mistake my comments as gospel, but rather one piece to a complex puzzle.
In order to determine the required file resolution to print,
Step 1 is to establish the viewing distance. If you're printing something to hang on the wall, you're probably going to look at it from a greater distance than a 5x7.
Formula 1: Viewing Distance = 1.5 x diagonal of print. However, I tend to set a max viewing distance of 24 inches for anything indoors.
Formula 2: required print ppi = 3438 ÷ Viewing Distance
3438 is derived from the following formulas:
1 ÷ ppi = 2 x Viewing Distance x tan(.000290888 ÷ 2)
1 ÷ ppi = Viewing Distance x tan(.000290888)
ppi = 3438 ÷ Viewing Distance
.000290888 is the visual acuity angle, a measure of how much resolution the human visual system can perceive.
Example: if you are printing a large print for the wall, I'd use 24" for the viewing distance, so the required print resolution is:
3438 ÷ 24 = 143.25 ppi
Because my printer's resolution is 1440 ppi, I use 144 ppi to calc my target file size. So a 36MP file from a Sony a7r (4912 x 7360) could be used to print as large as 34" x 51"
I then use Genuine Fractals (now called Perfect Resize, part of onOne software) to uprez to 720 ppi (5x) and then let the printer uprez to 1440 (2x).
If it is a print that I really care about, I'll print small portions of the full rez file with various sharpening levels applied as well.
You can print a 12-megapixel file any damn size you want, and people can examine the print from any damn distance they want.
There is, however, only one viewing distance that renders the correct perspective for a given print size. Telephoto images are normally viewed from too short a distance, which gives a flat perspective. Wideangle images are normally viewed from too long a distance, giving rise to apparent distortion of three-dimensional objects in the peripheral regions. People blame these effects on the lenses, but they are really due to an incorrect viewing distances. A natural perspective is obtained when the angle of view from the eye to the print equals the corresponding angle of view of the lens/sensor combination.
This can be combined with the resolution of a normal human eye, which is about one minute of arc, to compute the required number of pixels for a sharp image from the viewpoint of correct perspective. In terms of a full-frame sensor, the back of my envelope says:
24 megapixel at f = 21 mm
8 megapixel at f = 35 mm
4 megapixel at f = 50 mm
I have posted this several times here on FM but here are the general, rule-of-thumb numbers that the late Bruce Fraser recommended, assuming a viewer with 20/20 vision:
Eyeball wrote:
I have posted this several times here on FM but here are the general, rule-of-thumb numbers that the late Bruce Fraser recommended, assuming a viewer with 20/20 vision:
I have read a few sources during my research that suggested using file ppi's that are whole number fractions/multiples of the printer's ppi help the algorithms that do the uprezzing. The printers that Bruce may have been working with may have had 360ppi (as many do) - as all those numbers can be divided by 60, then multiplied by a whole number to get to 360.
That's why i target 144, being 1/10th of my printer's 1440 and then doing even multiple's to get up to the full size.
I have 12MP prints that are 1.5 meters across. They look great. Clients still love them. What I don't have is a 36MP version of the same shot to compare it to sitting right next door. I've done the tests and if I put high rest and lower rest together I can tell which is which, even from 12 to 18MP of the same subject. However if I just have a print made then it still looks pretty good at the lower resolution.
It was also noted above that some subjects need more resolution as print size increases and some less so.
Ecarlino..... Bruce Fraser also uses Epson printers. The number 144 is a strange one. An injects actual visual resolution isn't the same as the dpi the printer head puts down ink. Simply using 1440 as the absolute resolution of the printer doesn't take into account the dithering pattern printers use to mix inks to make their colour palette. All the Epson 1440 printers max out at about 360dpi of usable resolution once this is taken into account. You might see a very slight improvement by working in lots of 180 (180, 360, 720) instead of 144.
Desmolicious wrote:
Some people claim that they have seen spectacular 40 inch prints from the Sony A7s. At ISOs over 10,000.
Is this possible from only 12mp? Or is this one person's idea as to what a high quality print is and/or depends on viewing distance?
I know you can upscale prints (my primitive method in LR asks me to define a print size, and then the files become HUGE!), but is that good enough to make super high quality large prints from not that many mp?
I was under the impression that one would need 24 or 36 mp from the A7 or A7r, otherwise what is the point of those cameras vs the A7s?
I've looked at Ming Thein's 'Ultraprints' and the quality of those are outstanding. But he says he needs a minimum of 36mp to make 12 by 16 inch prints. Which is why I am a bit confused to the 12mp/40 inch spectacular print claim.
This is a learning experience for me, so pardon my ignorance!...Show more →
ISO 10k and 12 mp. Hm.. I would say that it could hold to A3 size at best case scenario. Yes, A7s does have pretty good output, but I would print big from it only on really low ISOs. Which is where those big fat pixels can shine.
Otherwise point is you can print really big on base ISO. 36 mpix if you "nail everything" can be printed huge. Tho I would get D810 for that, not A7R.
And size of printing always depends from how far you will look on it and how tolerant you are to noise/lack of fine details.
Sorry...you are wrong on your second point. Just go observe a gallery for a day and you'll see that your view of people not looking close at a print is wrong.
Actually you are incorrect on this one I feel. A very small minority of the general public ever goes to galleries. Just ask anyone who works in sales, fundraising, or memberships at public/private galleries and museums lol
Pixel peeping, measurebating, and other such behaviors common to internet camera forums are not indicative of the general public.
Neither are noses to prints
But who actually stands less than 3ft away from a print that large?
Based on my own personal experience of having shown my printed work at a bunch of locations, a few in the gallery but mostly in places where the general public look at them, I can say that MOST people (non photographers based on asking them) get up very close and personal with the prints. They typically will look at the print from further back, and then move in right up close to study the detail. I certainly didn't expect this when I started showing, but that's just how it is.
Based on my own personal experience of having shown my printed work at a bunch of locations, a few in the gallery but mostly in places where the general public look at them, I can say that MOST people (non photographers based on asking them) get up very close and personal with the prints. They typically will look at the print from further back, and then move in right up close to study the detail. I certainly didn't expect this when I started showing, but that's just how it is.
That has been my experience too. Which is why I started this thread. And also why I use my Rolleiflex and Fuji GW690 much more than 35mm (when using film) for gallery printing.
I really don't want to tell people they are standing too close, it's up to them where they want to stand.
People may go up, but it doesn't mean they will turn their nose up at your work if they can't see super tiny details with their nose 4 inches from the print.
It's all personal. I admit that a large print with tremendous detail is pretty cool, but ultimately it's not a major factor. My largest traditional print that I have is a 40" print from a cropped 16MP full frame image, and it's a step too far. It looks OK at normal distances but falls apart as you get close. The same file looks great at 30" wide. I also have a 30" print from a Canon Digital Rebel that again, doesn't look 'great' up close, but the print still works quite well. I wouldn't use it at that size for a gallery presentation, but it's been on my wall for 8 years.
I also have a 36" print I made from a stitched photo in which the final file is 75 megapixels. That print looks spectacular at any viewing distance, with super fine detail.
However, 36 megapixels for an 18" print? That's going a bit far. I print a lot of 12x18" prints from my 16 megapixel cameras and they look fantastic, even up close. I think a 16x24" print from my 16 megapixel cameras also looks fantastic, while a 30" print is quite good in most circumstances at that resolution, but you start to lose the super-fine detail when you get really close.
For a really good print with an A7s, I'd think up to 18" would look fantastic, while 24" would be very good. Beyond you can still get good images, but things start to lose that 'fine detail' aspect up close.
For how I print and work, 16 megapixels is a sweet spot, though sometimes it's nice to have a little extra, which I notice with my 24 megapixel a6000, though it's not something necessary. I still bring my Fuji kit more often than my Sony kit because I prefer the lenses and the controls (and the file quality overall).
I have even printed 12 megapixel files from my Canon G9 Point and shoot camera to 30" long for display purpose and sales at Art Shows. The latest versions printed on Aluminum (metal). They look quite good and has been popular. But, no one would ever suggest that they hold up to the scrutiny and sharpness of some of my scanned 4" X 5 transparencies that have been printed 32" X 40" on Metal. But, the Canon G9 image is shot very differently and is a very different subject.
chez wrote:
Sorry...you are wrong on your second point. Just go observe a gallery for a day and you'll see that your view of people not looking close at a print is wrong.
I have to agree with millsart on this one.
The internet has been, in a good many ways, one of the worst things which has ever happened to photography. The reason being that it seems to have changed the very nature of what we do and why we do it. There are people out there whose sole measure of the success of a photo is how sharp it is. In more recent times it's been about "bokeh". Both can be contributory factors to the success or otherwise of a picture, Neither defines it absolutely.
What you find people doing in galleries is not a measure of anything beyond human curiosity. Photographers who shoot the sort of stuff you find there usually have a very specific idea of what they want the photograph to convey and viewing distance will be a major part of it. Resolution, sharpness and bokeh are probably not a very significant part of it. This is concept-focused and not gear-focused photography.
Sure, enlarging a photograph is as much a part of changing its impact as anything else we do and when we do it, we probably have a specific viewing distance in mind. How big do you have to enlarge an old B&W before the grain becomes so large that closer viewing is not worth it? I have a mate who shoots billboards with an original 5D. How close does the average member of the public go to that before it's no longer worth the effort?
If I enlarged something that big and people spent the whole time pressing their noses against it I would be pretty disappointed. The photo would be - for me - a failure.
flash wrote:
I have 12MP prints that are 1.5 meters across. They look great. Clients still love them. What I don't have is a 36MP version of the same shot to compare it to sitting right next door. I've done the tests and if I put high rest and lower rest together I can tell which is which, even from 12 to 18MP of the same subject. However if I just have a print made then it still looks pretty good at the lower resolution.
It was also noted above that some subjects need more resolution as print size increases and some less so.
Ecarlino..... Bruce Fraser also uses Epson printers. The number 144 is a strange one. An injects actual visual resolution isn't the same as the dpi the printer head puts down ink. Simply using 1440 as the absolute resolution of the printer doesn't take into account the dithering pattern printers use to mix inks to make their colour palette. All the Epson 1440 printers max out at about 360dpi of usable resolution once this is taken into account. You might see a very slight improvement by working in lots of 180 (180, 360, 720) instead of 144.
