# What is the Maximum Size I can enlarge a 12Mb (16Mb Nef) to before it destorts?



## popol22 (Jul 5, 2011)

Hello all,

I am working on a project to take photographs of a friends artwork (some of it is large, 2m by 3m) and to then reproduce this Art on Silk.. for making clothing items from.

Now the question is, if I use a Nikon D500 and set quality to max I will get a 12Mb Jpeg or 16Mb Nef file.. but how large is the actual image and how large can I magnify this before it becomes pixalated.

This is the basic question, in reality once I have the photograph I then work some magic in photoshop and edit the picture, however there is no point in me doing this if at the end of the day the maximum size of the image may end up 60cm by 60cm before it destorts.

SO does anyone know how I can get the maximum size enlargement (in metres) at good quality..? even if it means purchasing another camera and lens?

Many thanks in Advance.

Yours..
popol22


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## Robin Usagani (Jul 5, 2011)

for 60x60 cm, it will be fine.  Even the silk has threads where you are missing pixels.  Plus 60x60 isnt that big.

You should talk about files as in file size.  You need to provide the pixel by pixel.  2 photos with the same pixel size wont have the same file size.  But for printing it on a material, you shouldt be worried too much.


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## popol22 (Jul 5, 2011)

Hello, and thanks for replying..

Well it turns out 60cm by 60cm isn't large enough, to retain the quality of print (DPI) I need to be working at least with 1m by 1m at 720DPI if not 1m50 by 1m 50..

As people will be viewing the silk up close I have to keep high DPI, sure I could get away with an image 3m by 3m on a billboard seen from 40meters away, biut as this is a clothing item, people will want see this close up.. hence the high DPI..

It looks very possibly like a large format camera with Digital backing plate might be the way forward, the Nikon whilst great for the majority of shots people would want it for just does not have the definition required at large maginification, its a great camera but in this case a larger format is going to be needed I think..

Hmph, didn't want a holiday for the next 20 years anyway


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## The_Traveler (Jul 5, 2011)

The quality and type of the lens and the appropriate f stop are just as important and you could make a try at making several exposures and stitching them together.

and in regards printing at 720 dpi.  That is *not* the same issue as needing 720 pixels per inch.

read this link Getting Started Scanning - Printing Digital Photos and Scans


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## epatsellis (Jul 6, 2011)

I'd suggest spending some time on Better Light Large Format Digital Photography - The World's Finest Digital Camera System, then you will have a better idea of what is in store for you. Art repro work is extremely demanding of technique and skill, and if you're not comfortable with the basics, the more technical aspects will trip you up, guaranteed. A workable alternative would be to find a Betterlight user in your area and see what they would charge you to digitize the artwork.


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## analog.universe (Jul 6, 2011)

This is the best I've heard print size vs. resolution explained: How Big Can I Print by Thom Hogan


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## Derrel (Jul 6, 2011)

You are going to be shrinking the image DOWN, tremendously, from a large-size 12 megapixel capture. AND you are going to be printing the images on cloth!!!! Even though the original artwork might be 2x3 meters, the size reduction, and the output onto cloth means that there's absolutely no possible way that your output medium will stress the capabilities of even a modest lens and camera capture system. What is the thread count per inch on the silk fabric??? Whatever the thread count happens to be,it cannot even POSSIBLY begin to approach the pixel density found in a 12 MP d-slr capture. Furthermore, the transfer process onto the silk is going to be vastly more-coarse than the source file!

It would seem like some people did not read the entire thread before formulating a reply. Go ahead and shoot it with whatever you have.


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## analog.universe (Jul 6, 2011)

Derrel said:


> You are going to be shrinking the image DOWN, tremendously, from a large-size 12 megapixel capture. AND you are going to be printing the images on cloth!!!! Even though the original artwork might be 2x3 meters, the size reduction, and the output onto cloth means that there's absolutely no possible way that your output medium will stress the capabilities of even a modest lens and camera capture system. What is the thread count per inch on the silk fabric??? Whatever the thread count happens to be,it cannot even POSSIBLY begin to approach the pixel density found in a 12 MP d-slr capture. Furthermore, the transfer process onto the silk is going to be vastly more-coarse than the source file!
> 
> It would seem like some people did not read the entire thread before formulating a reply. Go ahead and shoot it with whatever you have.



12mp is 4000 pixels on the long side, 3m is a bit shy of 120 inches, you're lookin at mid 30's ppi....   quick google search found silk fabrics from 400 to 900 tpi.

Seems not big enough to me, I think you'd easily see an improvement going up from 35-40ppi to anything else, even on fabric


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## Mike_E (Jul 6, 2011)

Rent (or buy) a Mamiya RB67 with a normal lens (90mm-127mm) get a couple of rolls of Kodak Portra 160 and have the film drum scanned at max resolution.

6x7cm = 2.34x2.73 inches times 11000 dpi (about max for a drum scanner I think) =  25,740 x 30,030.

that ought to do.

Or listen to Erie ( a generally good idea)


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## epatsellis (Jul 7, 2011)

Let's take a look at it from the other direction, what resolution do you need to realisically print on your desired output medium? Let's ignore costs of capture equipment for this exercise.

The most popular sizes of silk for inkjet output (either direct or via dye-sub) is either 48-52" or 72". For the sake of argument, we'll say 50". Realistic dye sub and inkjet printing on silk requires no less than 300-360 dpi, we'll use the lower number, as most RIPs are far better at small interpolation than Photoshop, by a long shot. 

So we have a 50" substrate that needs 300dpi, for a required resolution of 15,000 pixels (width) x 22,500 pixels (for a 2x3 aspect ratio). 

Let's look at some capture methods to see which will be best suited for this project:

1.) DSLR- a 12mp sensor DSLR has a spatial resolution of approx 1800 pixels wide, due to the anti aliasing filter and Bayer pattern interpolation.[SUP]1[/SUP]
So, in order to utilize this capture method, we need to upsample 8.3X. _Quite likely not a desirable approach if image quality and faithfulness to the original is to be expected._

2.) MF/LF Digital Back-For this example I'll examine the use of a Sinar 54M multishot back, while not as high a resolution as many currently available backs, it's quality is far less dependent than the higher resolution digital backs on precise, sub micron alignment and optical quality.[SUP]2[/SUP] The Sinar 54m back achieves rather high spatial and color resolution by taking multiple exposures, shifting sub pixel amounts between exposures, in this fashion there is a significant increase in the real resolution captured, with the native 22mp resolution being increased four fold to ~88mp images, with 100% color resolution, as opposed to the typical single shot Bayer patter R25%/B25%/G50%. With a resolution on the short side of 4080 pixels, and in multishot mode, the same spatial frequency, it would only require an upsampling of ~3.5x to reach our target of 18K pixel width.

3.) LF scanning back- Typified by Betterlight or Phase One, these are nearly identical in operation to a flatbed scanner, but in miniature. The most common Betterlight back is the 6K, with a 6,000 x 8,000 pixel capture. Due to the unique nature of scanning backs, there is no interpolation and every pixel is captured with 100% color accuracy. Downsides are the need for continuous lighting and capture time often measured in minutes. However for art reproduction and high resolution digital capture, the advantages far outweigh the disadvantages. My own personal experience has led me to a maximum upsampling limit of 2.5-3x with my scan back, a number that will (just) attain our target resolution. Even at the 3x up sampling, the image is typically stunningly detailed and a virtual copy of the original. 

4.) MF/LF film/drum scanning-While this will give you the possibility of higher resolution than digital capture, for art repro work, there's no comparision, anything above ~4800dpi capture is just empty resolution, with no added detail whatsoever. Other's may argue otherwise, but I refer you to this comparison, draw your own conclusion.

I have extensive experience with all of the above capture methods, and had a Sinar 54m in my studio on loan for a month to compare with my current methods, quite simply my older Dicomed Field Pro scanning back (predecessor to the Betterlight), is by far the highest resolution option available to me, irregardless of price. 

In order to truly appreciate the amount of detail, here is an test image I shot in the studio (obviously down sampled from the 6,000x7200 full size capture):



(note the red outlined area)

Here's a 1:1 of the area outlined in red:




This is at actual capture size, not upsampled. (This was just a quick shot in the studio, with an enlarging lens I had lying about, for repro work, I use an APO copy lens for capture, with a significantly longer focal length to eliminate geometric distortion and it exhibits none of the CA apparent in the above image)

As I suggested earlier, your friend's interest would be better served by finding somebody (via a quick email to Betterlight) that specializes in art reproduction. I haven't even gotten into lighting, lighting spectrum accuracy needed (as well as proper profiling) and issues such as camera to art alignment, etc. It's a somewhat specialized field, and requires a tremendous investment in time, skills and finances to do it right.

Erie Patsellis

(And, yes I have printed numerous projects on silk, and the above numbers are reasonable approximations of the acutal resolution required to create a credible reproduction of a piece of art onto a silk substrate, with the 300 dpi figure for dye-sub and a much higher figure (think ~500-600dpi) for direct inkjet printing)[SUP]



1[/SUP]for a more detailed explanation on bayer pattern sensors and aliasing artifacts see here and here
[SUP]2[/SUP]Joseph Holmes elaborates in great detail here and here


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## Derrel (Jul 7, 2011)

This is actually amusing overkill, all in response to a simple question. Lots of math, and yet, the most-critical answers left to assumptions. Good Christ, this is not "art reproduction"....this is fabric art!


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## epatsellis (Jul 7, 2011)

Derrell, research the market, and look at market trends before you make statements like that. 

In fact it is art repro, onto a silk substrate instead of paper. It's a growing trend in the fine art world, high resolution artwork reproduced as wearable items. Silk is in many ways far more demanding than printing on paper, it took me and my printer nearly 3 days to get a working profile that wouldn't overload the silk, yet was rich and saturated. The same methods are used by custom textile manufacturers for custom "one off" samples for designers prior to putting the run into production.

"Lots of math, and yet, the most-critical answers left to assumptions." I could make the call, but alot depends on two things, the material the final image is ouput on and personal definitions of "good enough". Required resolution on fabric is limited to approximately 1/2 the mesh pitch, effectively the Nyquist limit. One persons idea of good enough is not another's. The artists I work with want exact digitizations, and are very, very demanding in terms of color accuracy and detail. I just try to remember the Golden Rule, he with the gold makes the rules....


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## Mike_E (Jul 7, 2011)

As I said...


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## Derrel (Jul 7, 2011)

epatsellis said:


> Derrell, research the market, and look at market trends before you make statements like that.
> 
> In fact it is art repro, onto a silk substrate instead of paper. It's a growing trend in the fine art world, high resolution artwork reproduced as wearable items. Silk is in many ways far more demanding than printing on paper, it took me and my printer nearly 3 days to get a working profile that wouldn't overload the silk, yet was rich and saturated. The same methods are used by custom textile manufacturers for custom "one off" samples for designers prior to putting the run into production.
> 
> "Lots of math, and yet, the most-critical answers left to assumptions." I could make the call, but alot depends on two things, the material the final image is ouput on and personal definitions of "good enough". Required resolution on fabric is limited to approximately 1/2 the mesh pitch, effectively the Nyquist limit. One persons idea of good enough is not another's. The artists I work with want exact digitizations, and are very, very demanding in terms of color accuracy and detail. I just try to remember the Golden Rule, he with the gold makes the rules....




Here you go, maybe this one billion pixel camera would be just the ticket?

http://www.thephotoforum.com/forum/photographic-discussions/249591-1-billion-pixels.html


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## Mike_E (Jul 7, 2011)

So, is the difficulty in printing on silk trying to make sure that you have a dot square on a thread and not have too many in a row in the spaces between?

If so I can see why you'd need pretty extreme resolution.

If not.. what?


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## epatsellis (Jul 7, 2011)

Derrel, 
I'm reminded of the adage often attributed to Mark Twain, "It's better to keep your mouth closed and be thought a fool than to open it and remove all doubt."


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## epatsellis (Jul 7, 2011)

> So, is the difficulty in printing on silk trying to make sure that you  have a dot square on a thread and not have too many in a row in the  spaces between?
> 
> If so I can see why you'd need pretty extreme resolution.
> 
> If not.. what?



The silks I've worked with have a pretty tight weave, I found after lots of experimentation that anything past 1/2 the weave pitch doesn't improve image quality and in some cases cause significant aliasing and moire. It makes sense, if you think about it and have some knowledge of sampling theory and the Nyquist theory specifically as it relates to aliasing errors.


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## Robin Usagani (Jul 7, 2011)

I am agreeing with derrel here.. however if you really think you need that high of resolution then just take several shots in segments and stitch them together using photoshop. There may be a slight distortion from the shooting angle but it will be on a silk that isnt laying flat.


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## Helen B (Jul 7, 2011)

Schwettylens said:


> ...just take several shots in segments and stitch them together using photoshop. There may be a slight distortion from the shooting angle...



If it is flat original artwork then you can keep the camera in one position and move the artwork in front of the camera, keeping it in the same plane, perpendicular to the lens axis.


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## Chris Stegner (Jul 7, 2011)

The very first thing you need to know is what the printer prints at. I have had images reproduced on commercial grade wallpaper quite often, and they print at 100dpi at 100%. That's pretty simple math in my book. Ask the service that's printing the fabric what resolution they need the files to be (at 100%). That will tell you if your image is good enough.


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## EchoingWhisper (Aug 15, 2011)

Try making panaromas. Maybe it will work.


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