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Appropriate Camera/Megapixels for Poster-Size Prints?

Hi guys,

I am in the market for a new digital camera, and definitely want to do poster-size prints (20x30). Hoping to get some input:

A) I was wondering how many megapixels would be ideal for such a purpose?

B) Are there any particular models that you guys would recommend? I'm looking for a compact, pocket-size unit, capable of taking fast shots, and ideally selling for less than 250.

Thanks in advance for the help.

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20 x 30 inch poster

That is quite large and you do need more megapixels.

I would say, 7 or 8 megapixels.

But $250 will not buy such a camera.

There are three 7 megapixel cameras selling for $300 (plus or minus $10):

Casio Z120
Nikon 7600
Olympus SP-310

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The Canon SD 550

The Canon SD550 is ideal for that purpose. It has a 7.1 megapixel. and 3X optical zoom. However, priced around $400. To be honest, it is teh cheapest and best ultracompact camera so far. Has a nice screen and for posters (I am into doing those also) it is perfect. Check it out. You cannot go wrong.

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OK, what am I missing? Photoshop is telling me that

I need about 44megs to print a 20x30 at 150dpi. Are you assuming a lower resolution for printing at this size?

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I'll Be Using Commercial PhotoG Websites

Hi,

I was actually going to do my printing using one of the commercial photo websites (choosing between shutterfly or yahoo photos), and they can do 20x30 prints for $19.99 a pop.

Oh yeah, shutterfly also does prints on canvas...anybody have any experience with this?

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Snapshot?

Actually, sending your image to a commercial printer does not alter the need for sufficient resolution. Sometimes folks will accept a higher degree of pixelation in a larger output since they think the image will be viewed at a distance. I am just wondering what Snapshot's reasoning in this case is.

I tried it again and am getting a lower size. In this case, I set up a new image. 20x30 with rgb 8 bit color, and 150 ppi. Photoshop is saying that image size is 38.6 megabytes. If I drop the resolution to 65 ppi, then the size is 7.25 megabytes which is in the right ballpark. However, pixelation at 65ppi is going to be very obvious.

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Large Photo Printing

He stated a price for the camera.

The largest mexapixel camera within that price limit is 7 megapixel.

7 megapixels will not give the results needed for an excellent photo, but it may be acceptable.

The most megapixels you can buy for under a thousand dollars is the new Sony R1 - at 10.8 megapixels.
It is supposed to sell of $999

38 megapixels would be the best choice, but it is not available.

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Since we can not achieve perfection here, there is one tricks worth trying:

Use Adobe Photoshop and use interpolation to increase the size of the photo. This will degrade the photo some. But it should eliminate some of the blocky appearance that the 7 megapixel photo could present when printed at such a large size.

You would have to do the increase in size in several steps with some Photoshop touchup between steps.

It is something that has been done before.

Anyone have the time and money to spend on such a test?

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That is exactly

What you do to get a poster sized pic out of a standard camera! What is Kidpeat talking about. I thought that he would know that. They have been using interpolation for a long time now. Even with lower pixil cameras like Kodak.

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Actually, interpolation is the last choice. It degrades

image quality, and is only done when there is no other choice. By 'standard camera', I assume you mean some sort of low resolution digital camera. The best way to get a large image out of small cameras is to merge several shots into a single image.

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OK. I was just checking to see if there was something I had

overlooked in my thinking about the problem. I have seen many mistakes made in the sizes needed to produce a particular output size.

The other way, of course, to approach the problem is to photograph sections of the desired image and merge the result for a larger output.

Actually in Photoshop CS2, there is no need to do the increase in several steps. The task can now be done in one step with the same results that several steps would produce. Photoshop now has choices for resampling with bicubic smooth being the preferred way to increase an image's size.

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Bicubic Smooth

I remember reading that, but forgot which one was for enlarging.

I'm going to give it a try.

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I finally figured out what is wrong with my calculations.

I am confusing pixel counts with megabytes. Of course they're not the same. I'm thinking that, for many images, 1/3 of the megabyte size is the pixel count. That's assuming that a pixel includes all of red, green, and blue.

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poster sized prints

I work with 20 by 30 as my standard print and file size. A 7 megapixel camera is sufficient though not ideal...the ideal is a camera beyond any pixel count one can imagine. That is the key. Infinite res is what one wants but what one can afford is a different issue but let me say that the way one should determine what pixel count is necessary is decidedly NOT to simply divide pixels per side by the print res such as 150 or 240 or whatever. This simplistic and common method does not consider that modern software both available either in the printer itself or in computer software allows for essential re-sizing and thus, decreasing pixel sizes to make them invisible. I work with an 8 megapixel Canon and as well a Sony. Both are equally sharp but the former has a quieter image due to its larger sensor. I can print considerably LARGER than 20 by 30 with fantastic results after resizing and some modest sharpening. It is far superior to any 35mm camera film image. Remember, one does not stand two cm from a poster and analyze its micro structure. That is not the point of an image and surely, not that of a poster. There is very little visible difference between a 7 and and 8 megapixel sensor...Remember, its relationship is the square root of the sensor. If there is a good lens and a good steady image and if you judiciously use sharpening and resizing algorythmns such as bicubic ( sharper) than the results will be fine. I recommend whenever possible, that RAW files be the choice if that is possible but if not, the finest JPG file needs to be created to make less visible any artifacts of the compression ( jpeg) process.

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20X30 prints

You can think about Nikon Coolpix S2 with 7 MP with 10X optical zoom.

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Confusion is rampant

Regarding poster prints (22X28'?)I've successfully printed these on a nearly daily basis for quite some time. Frequently, 75ppi is all the resolution you need. Who looks a a poster from 12-18" away? Usually, 3 feet or more is more likely. Trust me, at 75ppi at a distance of as little as three feet, try and find any pixilation. As a matter of fact, you can even knock it down to 50ppi if you absolutely HAVE to, and still get a pretty good damn print, if you have a good printer. (I do.)

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poster sized prints

I have a Canon Powershot A470, which is 7.1 megapixels and sold at Walmart for just over $100.00. I don't know about the poster size prints it is capable of though, I haven't tried.

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Locked by the Forum Moderator

This thread was created in the year 2005.

The information is dated, since camera cost and megapixel size has greatly changed in the past four years.

The thread is now locked.

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