What is the minimum size sensor to print an A3 ?

[nico_bouchi]

<p>What is the minimum size sensor to print an A3 ? How much MP does I really need at least ?</p>

[bob_sunley]

<p>How sharp do you want the print, are you shooting handheld in a dark night club or in sunshine with a tripod? Type of paper makes a huge difference as well.</p>

[geoffs1]

<p>Well, a "back of the envelope" calculation would say that for 300 dpi resolution you would need about 18.4 Mpixels. If 180 dpi is acceptable then all you need is 6.6 Mpixels.</p>

<p>In reality Bob's comments are the most germane. You really need to determine what resolution you need for the print to look good in your application. I've gotten very nice (near pixel-peeping) 16x20" prints of very sharp images from my 8 Mpixel Canon 20D.</p>

[bruce_rubenstein]

<p>Sensor size and mega pixels are independent variables. A P&S sensor (6.16mm x 4.62mm) can have 12 Mp and so can a full frame 36mm x 24.3mm sensor. What really counts is the viewing distance of the print, which determines what resolution the capture system has to have. Again, that's the system resolution.</p>

<p>Back of the envelope calculations always assume the xxx dpi contains xxx dpi of information, but that's a baseless assumption. A tiny 12 Mp sensor in a $150 P&S camera will only capture a fraction of the data that a ff 12Mp DSLR with a 100mm macro lens (just about all of them are very sharp at any focus distance).</p>

<p>Since this has probably left you dazed and confused, since you're just looking for that one, magic number, a m4/3 camera (even with the kit lens) is the starting point of of what cameras can give files that that will print well at A3.</p>

[philip_wilson]

<p>For A3 i would go as big as I could. Low ISO will help a lot as will careful post processing. As others have said MP is not a key variable - my old Canon 1DIIN (APS-H or 1.3x and 8.2MP) can make very good A3 size prints but it helps if you use an interpolation program such as genuine fractals. My Panasonic G1 can make quite acceptable A3 prints with its M4/3 sensor but you need to be ISO 400 or below and nail the exposure.<br>

From my experience a good sensor or *MP or above will make very good A3 prints. In general the bigger the sensor the better the image although the technology generation of the sensor is a big factor (as processing and sensor design has revolved a lot of late). I would suggest that with current technology M4/3 or bigger will be great - smaller sensor will be more challenged.</p>

[Spearhead]

<p>Some friends of mine just had a show of 20x20 prints from iPhones. It got reviewed in the big city newspaper (SF Chronicle) and had incredible response at the opening. </p>

[frank_skomial]

<p>A lot depends on the quality of lens, as well and your luck to take that "perfect" picture that will look great at large size.<br>

This seems to defy any reasoning, but I got few lucky shots with the fabulous 180/2.8 Nikkor and D70 camera printed at 24 x 36", something that I have less luck to match with with D700/D300S and any of 14-24, 24-70 or 70-200 Nikkor zoms.</p>

[jcuknz]

<p>Back when I was using a 3.3Mp camera I made A3 prints using interpolation in editing to maintain 300dpi when all else was good. It was a Canon P&S. Then I got a 5Mp Nikon and was able to crop just a little bit.<br>

I gather that the interpolation available in current good editing programmes is as good as any, the main point is not to push the process too much.</p>

[Dave Luttmann]

<p>What show Jeff? I was just down in San Fran and would love to read about it. Do you recall the date of the printing in the paper?</p>