Luminous Landscape Forum
Raw & Post Processing, Printing => Printing: Printers, Papers and Inks => Topic started by: kevs on May 28, 2009, 10:07:43 pm
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I have the 5D. Was not going to upgrade, but I am thinking of buying a wide format printer and was thinking images from a 22mil pixel camera might look much better than one from a 12 mil camera.
Am I right -- if printing very large?
I could upres in Photoshop, but what do others think? thanks.
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I have the 5D. Was not going to upgrade, but I am thinking of buying a wide format printer and was thinking images from a 22mil pixel camera might look much better than one from a 12 mil camera.
Am I right -- if printing very large?
I could upres in Photoshop, but what do others think? thanks.
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It depends on your subject and where you will display your prints. Try some 12mp blow ups. If you don't like those, you have some options...
1. print on canvas which is not so fussy about resolution
2. make stitched images if your subject allows
3. but a higher res camera
4. print even bigger, one of photography's best kept secrets is that images that don't look acceptable at medium sizes sometimes look OK at very big sizes. It is not logical, but it is often true.
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It depends on your subject and where you will display your prints. Try some 12mp blow ups. If you don't like those, you have some options...
1. print on canvas which is not so fussy about resolution
2. make stitched images if your subject allows
3. but a higher res camera
4. print even bigger, one of photography's best kept secrets is that images that don't look acceptable at medium sizes sometimes look OK at very big sizes. It is not logical, but it is often true.
Do you have an example of #4? I've got a few that just have a lot of detail that doesn't really show itself until you print them big. But that is more a case of having too much to resolve for the smaller size.
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Thanks guys. Well,, not printing on canvas -- you mean linen painters canvas? Printing on Epson paper, probably matte, maybe up to sizes 30x40. Shooting people and scenics.
Have you guys printed that big with 5D and compared to prints with newer 5D.
And have compared a 22mil SLR with a medium format digital?
I know what you are saying about artistic license, my fear is it just looking bad.. yes.. have to experiment.
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Thanks guys. Well,, not printing on canvas -- you mean linen painters canvas? Printing on Epson paper, probably matte, maybe up to sizes 30x40. Shooting people and scenics.
Have you guys printed that big with 5D and compared to prints with newer 5D.
And have compared a 22mil SLR with a medium format digital?
I know what you are saying about artistic license, my fear is it just looking bad.. yes.. have to experiment.
Going from 12 megapixels to 22 will indeed permit you to print to larger sizes, but the gain won't be as dramatic as you might think, and there are lots of "gotcha's" along the way. A rough rule of thumb is that you need a 50% increase in megapixels to get a noticeable jump in resolution in print. Nearly doubling megapixels will give you higher resolution, but you'll have to print bigger than 16x24" to see it easily. Furthermore, it won't be visible unless you apply perfect technique: solid tripod, mirror lock-up, best lens quality etc.
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I'm in the camp that believes that if you want big prints you should shoot with more megapixels. Yes, sometimes a small file can handle being considerably enlarged, but not that often.
I hung a show at my gallery this past spring consisting of my work done over the past 12 month. (The show is still up). Prints were my typical 24 X 30" size. There are 33 prints in all hanging.
Most images were shot with the Canon 1Ds MKIII, Sony A900, or Phase One P65+, all between 21MP and 60MP. Two, shot in Botswana on safari last October, had been shot with the 12MP Nikon D3.
The two 12MP D3 shots stand out like sore thumbs. Even though I printed them smaller than most of the others (because they couldn't handle my usual size) they still are seen as not having enough resolution. At 13X19" or smaller they are superb, but once one gets bigger than that they can't hold up.
Simply put, that's why a lot of landscape and nature photographers shoot with the highest resolution bodies and backs that they can. For publication this resolution is rarely needed, but for large display prints it really is.
Michael
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I recently went up from the 5D to the MK II just for the reason of more potential for big prints.
The 5D makes a very similar image and if printed at the largest size or smaller both look near identical. Yet if you go past the A3 size the 5D images don't look pure, whereas the 5D MKII holds up well at A3+ and beyond.
So for big prints, yes more pixels make all the difference.
A good sharpening applied by whatever favourite method you may have also helps a lot. I like what Qimage does, others like NIK products, some like their rip or what have you.
The only drawback with the 5D II is file size makes shooting slower, storage needs a lot more, but when you print big it's worth it. I can imagine a P65+ would be ideal for wall size prints.
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I currently shoot with a 12mp DSLR (D300). For my landscape work I've found that if I do everything right, I can get 16x24 prints that are generally quite good. By everything right I mean:
- Top quality lens shot at optimal aperture
- Sturdy tripod, cable release, and mirror lockup.
- Carefully composing in-camera to avoid cropping.
- Careful post-processing and sharpening.
Going any larger than 16x24 is very hit-or-miss, some images will still look decent if you don't get too close, others really break down. And even at 16x24", more resolution is advantageous. I was making some 16x24" prints last night, that were a mix of single-frame images and images stitched from multiple frames. The stitched images are noticeably superior, and you don't need a loupe to see the difference.
So I while I can't say for certain that you 'need' more pixels, it certainly can be helpful. I'm just waiting for a D700x or price drop on the D3x.
If I wrote this reply on certain other forums, someone would inevitably suggest that I must be doing something wrong, because they've gotten fabulous 40x60" prints from their 6mp cameras. To which I can only reply that different folks have different standards for print quality.
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Thanks guys, nice info.
I never use tripods, more handheld. Was hoping not to have to fork out another $2700.00, but then again I was not thinking of doing huge fine art prints either. So maybe I will get the 5D2, and keep the original 5D for consumer shoots I would never print fine art.
I may rent the 5D2 first and do a test. I think it would be fun also then to rent a medium format as well. Any recommendations on which one to try? I could never afford to spend 15 to 20k on a medium format system though. I read a review here that the 1DS2 performed basically as good as medium format.
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Thanks guys, nice info.
I never use tripods, more handheld. Was hoping not to have to fork out another $2700.00, but then again I was not thinking of doing huge fine art prints either. So maybe I will get the 5D2, and keep the original 5D for consumer shoots I would never print fine art.
I may rent the 5D2 first and do a test. I think it would be fun also then to rent a medium format as well. Any recommendations on which one to try? I could never afford to spend 15 to 20k on a medium format system though. I read a review here that the 1DS2 performed basically as good as medium format.
Ah.
Unless you use a tripod, the money spent on a higher resolution camera or (God forbid) a medium format digital system will be wasted. By the time you're talking about a 20x30" print, the degree of enlargement is such that any fault in technique will ruin the quality of the result. You can prove this to yourself easily enough; just take a hand-held photo of a brick wall at low ISO, with a lens around 100 mm and a shutter speed of 1/125th or 1/60th sec.; then take the same photo with the camera on a tripod and using mirror lock-up. Bring both images into Photoshop and zoom in to 100-200%. Yikes!
You'll see more improvement faster from using optimal technique than from buying more megapixels.
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Geoff,
that's interesting. As a longtime people, and occasional scenic shooter, I have always found tripods to be very annoying -- kind of like wearing a tie. But that's an interesting comment. I will have to test that out.
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Geoff,
that's interesting. As a longtime people, and occasional scenic shooter, I have always found tripods to be very annoying -- kind of like wearing a tie. But that's an interesting comment. I will have to test that out.
I go for maximum quality in results wherever possible.
But you can't always use a tripod or mirror lock up etc etc.
Does this mean these shots should not be printed huge?
No, prints are sized for effect as well and sometimes this is as important as resolution to the customer.
Dramatic prints or stylized prints don't always need to be pin sharp, just avoid digital artifacts which are worse than grain was.
Do I dismiss my 5D shots now that I have a 5D11, no way. Try looking at all those old photos we all have from way back when. Do they all have less value due to the processes at available at the time?
Anyway, buy more pixels but don't think that a perfect sharp print is the most important issue.
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Do a search for Jeff Schewe's article "The Art of Uprez".
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I go for maximum quality in results wherever possible.
But you can't always use a tripod or mirror lock up etc etc.
Does this mean these shots should not be printed huge?
No, prints are sized for effect as well and sometimes this is as important as resolution to the customer.
Dramatic prints or stylized prints don't always need to be pin sharp, just avoid digital artifacts which are worse than grain was.
You make valid points. I didn't read Geoff's reply as saying you can't print hand-held shots large, just that they aren't going to be as sharp as tripod shots, and there might be little or no advantage to moving to upgrading to a higher-MP camera if you're going to be shooting hand-held (which I happen to agree with).
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Do a search for Jeff Schewe's article "The Art of Uprez".
Took me a bit to find the link so I thought I'd post it here.
The Art of Up-Res (http://www.digitalphotopro.com/technique/software-technique/the-art-of-the-up-res.html)
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Thanks guys, I didn't know the tripod issue was so vital for the extra pixels to shine through.
What do you all think of medium format digital vs 22mp SLR?
Also, the wide body Epson printers: so dang expensive -- 5, 6k and there do not seem to be many good deals out there.
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I go for maximum quality in results wherever possible.
But you can't always use a tripod or mirror lock up etc etc.
Does this mean these shots should not be printed huge?
........
Anyway, buy more pixels but don't think that a perfect sharp print is the most important issue.
My experience is if you have good image stabilization, shoot at a reasonable speed for the amount of zoom you're using, and take 6-12 shots of whatever you need to be sharp, there's a good chance at least one will come out as sharp as the background noise will allow. There may be a few exceptions where the noise is so low and the resolution great enough that none of the shots will be visibly as sharp as a tripod shot at 100% viewing, but that's going to depend on your subjects and how much control you have over all other factors.
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You may want to consider shooting film, especially if you are working in B&W. I shoot 4x5 film, scan with a Polaroid Sprintscan 45 Ultra I picked up used, and regularly print 32x40 up to 40x50 inches on a z3100 and the results give me as good / better results than a $20,000 - $30,000 camera for a fraction of the cost. If most of your work is hand held you would want to use a medium format, maybe a 6x7 or 6x6. You can pick up excellent film cameras and lenses for cheap and again, if you shoot B&W and process your own film, the cost is negligible against a $30,000 digital camera that needs batteries and TLC (really hurts when that $30,000 camera falls in the creek, not such a big deal when I drop a 4x5 film holder!).
If you're shooting color, the cost goes up, obviously. I purchased the z3100 44" printer to print really large, but short of spending enormous sums of money ($15,000 and up), there's nothing digital that gets the sharp res I get from 4x5 film. A scanning back isn't an option for a portrait or any other subject that moves, and stitching really isn't either.
My system works really well. You can pick up really good film equipment and scanners for very little. The Polaroid Sprintscan 45 Ultra is as good as a drum scanner and you can find them on the used market for very little ($700 - $1,400). It is a SCSI scanner, so you would need a SCSI card. I think my system will work very well into the future. By the time they stop making film entirely, I'm sure 50-60mp cameras will be commonplace and affordable.
Might not help you. Might not apply to your situation. But another option to think about that I'm surprised more people don't consider. I know guys who are still making payments on now outdated $20,000 + cameras / backs that haven't come anywhere near justifying the purchase or saving even 1/3 of the cost of just shooting / scanning. There is a little work in processing / scanning, but I've got an old video based thingy that allows me to preview my negs as positives on a video monitor (not digital, just run the film over a light box / video camera and it appears instantly on the television). Primitive, but fast, efficient for previewing negs. Always hated making contacts, and I'm not about to scan every neg I shoot.
Good luck.
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Kev, I am not sure how "big" you really mean, if your "wide format" is talking about A2, and you are new to printing, my experience may be of use. I bought my first serious printer, the Epson 3800 an entry to wide format, last Christmas. When I browsed through the library looking for something worth printing big, (for me A3+ was pretty big) I found the reasons I dismiss a candidate were usually off focus, imperfect exposure and shaken image, but not resolution not high enough. One of my best A3+ print was taken with my old D70, 6Mp image. With the 12Mp of my D300, I am comfortable to go up to A2 (limit of the 3800), provided everything is right. It is not possible to use tripod, mirror all the time, but they really more critical then camera pixel count in real world.
My suggestion is you go get a good printer now and start printing. Print something big, look at the print, look at the image zoom to 200% or more, you will be able to tell you need more pixel or not. Everything being equal, higher pixel is better, but in real world, a camera is unlikely the most effective step to take. My experience is there is a lot money to spend after you get a printer, papers, ink, a faster computer, second monitor, software, hardware for colour management, reference books, sharper/ faster lens may be.
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Thanks guys, I didn't know the tripod issue was so vital for the extra pixels to shine through.
What do you all think of medium format digital vs 22mp SLR?
Medium format covers a pretty broad range, depending on whether you're talking about a slightly older used back, or the latest and greatest 'full-frame' MF back. The high-res DLSR's are no match for the latest MF backs. But if you're talking an older MF back in the ~20mp range, it's not so clear-cut.
Also, the wide body Epson printers: so dang expensive -- 5, 6k and there do not seem to be many good deals out there.
They're still new, and Epson is targeting them at a market for which the price tag isn't much of an issue. I would expect the prices to come down eventually, and/or some trickle down of the new technology into printer models aimed more specifically at photographers. In the meantime HP and Canon have some compelling offerings you might want to consider.
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I shoot with a D2Xs and D300 both 12mp cameras. I print everything on canvas for my gallery. The smallest canvas is 17 X 22 the average 24 X 30 and I have recently been printing 24 X 42. Everything goes through Genuine Fractals 6 for the uprez. The images are stunning no matter what the size. Printer is Epson 7900. I really wanted the D3Xs but the $8,000 price tag killed that. With the output as good as it is from GF6 I would save your money as well and get the software. I figure I saved $7700.00.
Dan Berg
Bergs Canvas Gallery
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Dan,
interesting.
I know GF was a hot things years ago, but from the reviews I've read, PS's bicubic smoother is just as good. Anyone dispute this with their testing?
The 7900 is an older model, mid size Epson right? Canvas you mean as opposed to photo paper?
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The D3x will print 24x36 and beyond on high detail landscape subjects (I'm not sure how much beyond, because I have a 24 inch printer - I've printed up to 24x48 by cropping the short sides to produce a wider ratio print, but haven't gone beyond that) really cleanly and with superb detail on Hahnemuhle Fine Art Baryta and similar papers, which even a 16 mp Canon EOS 1Ds mk II will NOT. I don't know the other 20+ MP DSLRs anywhere near well enough to comment on them, but the D3x has a great deal more resolution, even per pixel, than the older 1Ds mkII (a 16mp crop from a D3x will have MUCH more detail than a full 1DsII frame). I think the high per pixel resolutions due to the AA filter, but I can't prove this theory. A 5D resolves somewhat less than a 1Ds II, while a (much newer) D700 might be close to the 1Ds II. The medium format backs resolve more detail than even the D3x can, but I believe it would take a 44 inch printer to tell - a 24x36 off the D3x is stunning.
I start with the 140 MB D3x file, but I still use Genuine Fractals to uprez to the final print size (24x36 at 600 dpi - a 1.67 gigabyte file)! The iPF 6100 I use is actually a native 600 input dpi device (I've confirmed this from multiple sources including Canon, because so many folks say that no wide-format printer is higher than 360 DPI), and interpolates smaller files using a rather unsophisticated algorithm (bilinear?). I'd rather let Genuine Fractals handle all the interpolation work and let the printer concentrate on what it does best - putting ink on paper!
-Dan
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I shoot with a D2Xs and D300 both 12mp cameras. I print everything on canvas for my gallery. The smallest canvas is 17 X 22 the average 24 X 30 and I have recently been printing 24 X 42. Everything goes through Genuine Fractals 6 for the uprez. The images are stunning no matter what the size. Printer is Epson 7900. I really wanted the D3Xs but the $8,000 price tag killed that. With the output as good as it is from GF6 I would save your money as well and get the software. I figure I saved $7700.00.
Dan Berg
Bergs Canvas Gallery
I bought the Nikon D3X after selling my D3. The D3x is expensive, but because it is Nikon had the opportunity to make a very good camera and spend some more money on its parts.- like a good lowpass filter.
. It is not only resolution - the colour depth is amazing.
The images are very clear and the colour is beautiful. I use the PCE lenses and they add the optical excellence that can address every pixel- even shifted. The Nano coating makes a lot of difference.
For me it will be my little Hasselblad and fast dslr at the same time- i can do eveything with it. I do not agree that you need a tripod to see the difference - i find the opposite- even hand held it give me a lot more quality. and with my old and cheaper lenses it appears their optical centre can deal with the 24 mp; the corners are the problem but with some pictures that is not an issue.
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The D3x will print 24x36 and beyond on high detail landscape subjects (I'm not sure how much beyond, because I have a 24 inch printer - I've printed up to 24x48 by cropping the short sides to produce a wider ratio print, but haven't gone beyond that) really cleanly and with superb detail on Hahnemuhle Fine Art Baryta and similar papers, which even a 16 mp Canon EOS 1Ds mk II will NOT. I don't know the other 20+ MP DSLRs anywhere near well enough to comment on them, but the D3x has a great deal more resolution, even per pixel, than the older 1Ds mkII (a 16mp crop from a D3x will have MUCH more detail than a full 1DsII frame). I think the high per pixel resolutions due to the AA filter, but I can't prove this theory. A 5D resolves somewhat less than a 1Ds II, while a (much newer) D700 might be close to the 1Ds II. The medium format backs resolve more detail than even the D3x can, but I believe it would take a 44 inch printer to tell - a 24x36 off the D3x is stunning.
I start with the 140 MB D3x file, but I still use Genuine Fractals to uprez to the final print size (24x36 at 600 dpi - a 1.67 gigabyte file)! The iPF 6100 I use is actually a native 600 input dpi device (I've confirmed this from multiple sources including Canon, because so many folks say that no wide-format printer is higher than 360 DPI), and interpolates smaller files using a rather unsophisticated algorithm (bilinear?). I'd rather let Genuine Fractals handle all the interpolation work and let the printer concentrate on what it does best - putting ink on paper!
-Dan
I started a thread on Canon input resolution,
My first post.
Canon drivers and plug ins.
I did not get much response so am interested in your 600dpi method with the 6100.
I have one of these and see no advantage in printing at this input and fail to understand why it is default for the art media settings.
I also believe that the uprez used by the driver is now very good and my files at 300dpi are handled well by the printer when using said art medias.
I tested a trial version of GF this month, compared it to using PS.
If there was a difference at 200% it was my imagination. My thread also eluded to the value of some plug ins as dubious.
I am happy to be corrected on any of the above but not by whimsies, like that old dog, up rez in stages ha ha.
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The 16-bit printer plug-in for the Canon IPF's has bicubic interpolation as an option. I scale my files to 300ppi with the appropriate output sharpening, and then feed that to the plug-in and let it do the final up-rez to 600ppi using bicubic. I've tested and can't find any difference between this approach and scaling to 600ppi myself (except that the latter makes for a slower workflow and larger files).
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The 16-bit printer plug-in for the Canon IPF's has bicubic interpolation as an option. I scale my files to 300ppi with the appropriate output sharpening, and then feed that to the plug-in and let it do the final up-rez to 600ppi using bicubic. I've tested and can't find any difference between this approach and scaling to 600ppi myself (except that the latter makes for a slower workflow and larger files).
Exactly.
I occasionaly add a little sharpening at the plug in due to the prints out resolving the monitor (logic is that the screen may look over sharpened but the print will not). I also brighten a little depending on paper used as some papers have less shadow detail than others even when all else is profiling OK.
These changes are subtle only and depend so much on the photo in question, is the detail there to begin with!
In all, the supplied profiles, the iPF6100's ability to self calibrate, and personal preferences on paper performance work well. If I am wrong in my idea about extra sharpening at the print stage will someone tell me.
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Great comments guys. curious, those with wide body Epson, is anyone who used Colorbyte ImagePrint before and feels they don't need it now?
I know that my epson 2400 prints look horrible without it -- ie, just printing from PS software
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I have the 5D. Was not going to upgrade, but I am thinking of buying a wide format printer and was thinking images from a 22mil pixel camera might look much better than one from a 12 mil camera.
Am I right -- if printing very large?
I could upres in Photoshop, but what do others think? thanks.
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I would suggest buying the printer, then test some prints. Use good paper. To cut right to the chase, print the biggest size you would ever want; don't resample; just let the resolution fall where it will. If you like the print, you are done. If not, try resampling and upresing. If that doesn't work. Buy a Mk2.
Case: As I write this I sit between two 40x60 prints. They are different, but one was shot with a D700, the other with a 5D Mk2. The 5d mk2 is great in every way. The D700 shot is at dusk of a bridge with lights reflecting in the river. All is fine except the darkest parts of the water, where the continuity just isn't there. It actually looks kind of cool, but there just isn't the resolution for the shadows.
Think of it this way(and don't everybody argue using a bunch of numbers): with your 5d, you're shooting a 645 film equivalent; with a 5d mk2, you're shooting a 6x9. It shows in big prints,
OK, I'm done.
MAS
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I shoot with a D2Xs and D300 both 12mp cameras. I print everything on canvas for my gallery. The smallest canvas is 17 X 22 the average 24 X 30 and I have recently been printing 24 X 42. Everything goes through Genuine Fractals 6 for the uprez. The images are stunning no matter what the size. Printer is Epson 7900. I really wanted the D3Xs but the $8,000 price tag killed that. With the output as good as it is from GF6 I would save your money as well and get the software. I figure I saved $7700.00.
Dan Berg
Bergs Canvas Gallery
I would agree high quality image captures from a 12mp camera can produce outstanding results. I would point out that your frame of reference is within the confines of your own experience. I would strongly suspect some and perhaps most of those same images captured with a D3x would be remarkably different but you haven't experienced that to this point.
Uprezzing 'creates' data, higher rez cameras capture that data. Depending on the subject matter, final printed size, and how it is printed, it can make a big difference -even on canvas.
You never know what will present itself when shooting. I would always prefer to capture the image with the highest quality device I can afford/carry with me, just in case. There are no "do overs" most of the time, so I prefer to err on the side of great capture equipment as the priority. Personally I'd rather capture with a 20+mp Nikon, Canon, or Sony camera and make do with a used 9880 printer (or not even print it myself) than live with a 5D and print with a 79/9900, and I'm a big fan of the those printers. That's my take for the OP ... if you want to go wide format and print bigger, get the better camera.
Dan,
interesting.
I know GF was a hot things years ago, but from the reviews I've read, PS's bicubic smoother is just as good. Anyone dispute this with their testing?
The 7900 is an older model, mid size Epson right? Canvas you mean as opposed to photo paper?
I personally haven't used Genuine Fractals for some time. I think any differences are subjective and the overall quality of uprezzing depends far more on the quality of the original file than it does the software. PS does a fine job, as does most of the current printer drivers. However it certainly doesn't do a worse job and if you like the end results no reason to not use it. It doesn't matter what software you use, you can't make detail out of nothing so it can only work so well.
The 7900 is not an older model, it is the most recent and highest quality in Epsons current line.
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I have the 5D. Was not going to upgrade, but I am thinking of buying a wide format printer and was thinking images from a 22mil pixel camera might look much better than one from a 12 mil camera.
Am I right -- if printing very large?
I could upres in Photoshop, but what do others think? thanks.
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Sorry, you've probably made your camera choice months ago, but here's some experimental evidence:
Recently took 5D and 5DII into my studio with a still life setup. Switched bodies on tripod using same lens (24-70L), same focus, same settings, same lights, same everything.
Took images into Lightroom and corrected slightly (slightly different contrast due to different processor---very minimal). Images then looked the same (except noted after the fact that an ant had crawled on a leaf of one )
Then printed the images at different sizes and put them side by side. This is more important than pixel peeping.
At 11 x 16.5, no difference at all---needed to find the ant to tell them apart
16 x 24, barely visible difference with overlapped images to compare one spot and peering at closer than arms' length
20 x 30, can see a slight difference in certain areas of the image. didn't need to look for the ant
So up to 16 x 24 the 5DII doesn't make a significant difference. Larger than that, you can start to see a difference. BUT, now factor in how far people are going to be from large prints. Your clients and friends are rarely going to put their nose up to a 24 x 36 print---they'll be 2 or 3 feet away. When I stood back that far from my test prints the 20 x 30 were indistinguishable.
As others have mentioned, keep your technique pristine and for most purposes the 5D will be fine. Super-sized prints for galleries need more.
Good luck
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Sorry, you've probably made your camera choice months ago, but here's some experimental evidence:
Recently took 5D and 5DII into my studio with a still life setup. Switched bodies on tripod using same lens (24-70L), same focus, same settings, same lights, same everything.
Took images into Lightroom and corrected slightly (slightly different contrast due to different processor---very minimal). Images then looked the same (except noted after the fact that an ant had crawled on a leaf of one )
Then printed the images at different sizes and put them side by side. This is more important than pixel peeping.
At 11 x 16.5, no difference at all---needed to find the ant to tell them apart
16 x 24, barely visible difference with overlapped images to compare one spot and peering at closer than arms' length
20 x 30, can see a slight difference in certain areas of the image. didn't need to look for the ant
So up to 16 x 24 the 5DII doesn't make a significant difference. Larger than that, you can start to see a difference. BUT, now factor in how far people are going to be from large prints. Your clients and friends are rarely going to put their nose up to a 24 x 36 print---they'll be 2 or 3 feet away. When I stood back that far from my test prints the 20 x 30 were indistinguishable.
As others have mentioned, keep your technique pristine and for most purposes the 5D will be fine. Super-sized prints for galleries need more.
Good luck
I guess you never have to crop? And you only shoot still life's in a very controlled situation? And you can focus so well Live View is of no use? Personally, after shooting the first time with the 1DsMark3, the 5d hasn't seen the light of day. Finally gave it to my daughter. The differences would be observable in nearly every situation I use it in.
I'm assuming since the OP is considering buying a wide format printer, he wants to print pretty big prints... he says "if printing very large". True he didn't define very large, but 20 x 30 isn't that big ... in fact put it on a wall in many circumstances and it's actually kinda small. The 5D is a great camera and can deliver great results. You can always stitch, a great option some of the time. The 5D Mark2 is not an insignificant step up however, and I've got hundreds of images taken with 1Ds, 1Ds Mark2, and 5d's that just don't cut it when I get up to about 20x24". Maybe I'm just picky, but I also feel pretty strongly that people don't go up to images like you describe because doing so offers nothing ... just a bunch of fuzzy detail. From a few feet away there definitely should be an observable difference between a 20x30 image from a 5d and one from a 5d mark2 if printed on high quality media. ( I would agree with Dan, at this size on Canvas maybe not so much.)
I just don't see buying a big printer to print very large prints on makes much sense if all you have is a 5d, unless you are OK with stitching.