digital camera questions-

[tramp]

hello, everyone. questions-
1- if one makes a 4x6 [or 5x7] print from a 3.0mp,4.0mp,5.0mp and 6.0mp digital camera [such as the fuji film finepix line], can one VISUALLY see any quality difference in the prints?
2- i've understood that a 2.0mp and 3.0mp digital camera can produce a good quality print up to an 8x10 size and that going to a 4.0mp digital camera [ or higher megapixels] a larger quality print yet is achieveable. if all that one ever wanted in print size is a 4x6 or 5x7, is there any point in therefore going to anything any higher than a 3.0mp digital camera? or, like i asked in #1, is there VISUAL improvement in print quality [or other advantages] as one progresses up the ladder in mega pixel size camera's?
3- thank you-

tramp

[Clemmie]

I'm mainly a Film shooter, and prefer it for a number of reasons. But I also have a 2mp Kodak digital, and can tackle your question.

At 4x6 or 5x7, there is very little if any Visual difference as you go up the megapixel scale. This holds true for about 1/2 a megapixel on up, at this size.

For 8x10, you'll get equal print sharpness from 1 mp on up, in most cases. In my own experience, I've seen no visual difference between 1mp and 2mp from the same camera.

Beyond that, it depends on just how big you want to go. I know of a few services offering 40x60 prints now - for which you'd better be packing all the pixels you can carry, literally. (Highest pixel count I know of that's available right now, is a 14mp pro model from Kodak - which will soon be available from Nikon also. Those two work together on digital development.)

Where the higher-mp cameras will help you out, though, is in making sharper files at less than maximum resolution - and in that regard, the higher mp on the sensor, the better. All of the cameras let you choose from a range of file sizes to use. Regardless of your file size choice, the sensor is using all of its pixels to capture the scene.

If you're shooting at maximum resolution, you're getting pixel for pixel, and whatever interference or imperfection comes with it. You'll also find it takes longer to 'fix' the image, as it takes time to write all that information to the memory card.

Shooting at a lower resolution - say, half the sensor's capability - the camera is able to use multiple pixels of sensor information, per pixel of final file. This allows for faster 'write' time, and higher effective 'shutter speed' - both helping make your pictures sharper. As long as you're using a large enough file size to give the print equipment enough information to work with, the prints will be just as sharp on the low end of the range as on the high end.

So, if you get a quality 3mp camera, then routinely shoot 1mp files with it, for example, you'll be well covered for what is needed for prints up to 8x10 - with enough 'reserve capacity' to allow the camera to function pleasantly.

The current standard for photo prints, as done by the Fuji Frontier equipment used in many labs now (Wal-Mart is standardizing on them, nationwide), is a 300dpi Laser Print. Even when I have Film processed on that equipment, the prints I get are 300dpi laser prints from a scan, not the traditional direct enlargement from the negative. And since the machinery is all 'digitized' now, they can plug your memory cards right into the same machine, and make your prints with the same printer.

Here's a link to Fuji's brochure on the machine. Fascinating reading. Tells how they do both film and digital on one machine, and how it does it:
http://www.fujifilm.com/JSP/fuji/epa...ntier390_1.pdf

Printer dots per inch do not correlate 1:1 with Pixels in a picture file - so don't fall for the common misconception that the two are equal. A Pixel can cover several Dots.

Don't expect any current digital to match a good film camera in all situations. They just can't do it - yet. The two remaining major catch points are Low Light and Fast Action. Film still excels at both - but Digital is making progress.

[Roger Rowlett]

For 4x6 prints only, you would be hard-pressed to see any significant difference between a 3, 4, 5, or 6 Mpixel camera, at least in terms of sheer resolution. Keep in mind a 4x6 print at 300 ppi is 1800x1200 pixels, and even a 2 Mpixel camera will give you that.

What you may find is that the less expensive cameras may not have as sophisticated digital processing engines, and while that will not affect the native resoultion, it will affect noise, apparent sharpness, and color fidelity in the image. In addition, the lens affixed to the camera will also affect quality. Some digicam lenses are better than others, and none approach that of DLSR options. It pays to shop around, read the reviews, and take sample images before you buy.

Having said all that, most 3+ Mpixel cameras will make just fine 4x6 prints and reasonable letter-size prints, too. I just had a public display of prints in a local gallery (mostly but not all taken with a Nikon D100) and the most popular of these was a letter-size print taken with a 3 Mpixel Olympus C-3040Z. Nobody complained that it wasn't sharp enough.

Cheers.

[pentaxpirate]

WOW Clemmie !!

That's a fantastic machine.........Be great to have one of those in the house ( we can but dream i guess)

I have a question for you.

I have a HP Photosmart 715 3mp digital camera.........The files i get from it are 72dpi jpeg's, and are (on average) 1mb files.......I was surprised to find out that the files are only 72 dpi( as that file quality is usually used for web images etc...and i generally regard a 72dpi image as poor quality).yet when i view my pics( in photoshop)? Taken on the digital camera they look awesome.

Recently i decided to have some of them printed out at my local processers........I thought they might not print too good if they were 72dpi........ So i converted them to 450dpi tiff files and they printed out great.

My question is.

Does this machine convert the original pic to 300dpi, regardless of whether the original is 72 dpi or 450 dpi ??

In other words, am I just wasting my time converting my pics to 450 dpi?? Or any other size for that matter?

And- Does increasing the dpi just increase the actual size of the image, and not the actual number of pixels?

Many Thanks.
PP

[Clemmie]

WOW Clemmie !!

That's a fantastic machine.........Be great to have one of those in the house ( we can but dream i guess)

I have a question for you.

I have a HP Photosmart 715 3mp digital camera.........The files i get from it are 72dpi jpeg's, and are (on average) 1mb files.......I was surprised to find out that the files are only 72 dpi( as that file quality is usually used for web images etc...and i generally regard a 72dpi image as poor quality).yet when i view my pics( in photoshop)? Taken on the digital camera they look awesome.

Recently i decided to have some of them printed out at my local processers........I thought they might not print too good if they were 72dpi........ So i converted them to 450dpi tiff files and they printed out great.

My question is.

Does this machine convert the original pic to 300dpi, regardless of whether the original is 72 dpi or 450 dpi ??

In other words, am I just wasting my time converting my pics to 450 dpi?? Or any other size for that matter?

And- Does increasing the dpi just increase the actual size of the image, and not the actual number of pixels?

Many Thanks.
PP

Nice machine, indeed. I am told the top-line 390 version (what my local lab uses) is half a million bucks! So not exactly for home use - unless you've won the lottery.

My first digtal was also HP's first - a 'big brick' called the Photosmart 100, which I think was made for them by Konica. I remember its 'viewer default' was also 72dpi - and I think the largest file size was like 256k. All I ever did with it was web postings (mostly eBay ads), so I have no clue what the lab print quality may have been. I know that home printouts of the ads I did with it printed out nicely, though that would hardly be considered 'lab print' sharpness by today's standards.

I suspect, but don't know for sure, that your camera is producing quite a bit better file than 72dpi - and that the 72dpi (which gives a decent screen view) was simply the defaut on the viewer you were using. This is obvious from the fact you were able to make a 450dpi file.

The Fuji Frontier machine does more file conversions than we can shake a stick at - and neither I, nor most operators, know what its limits really are.

But since we do know that the prints it makes are 300dpi laser prints, regardless of the source material (film negatives or digital files) - then it would be safe to say a 300dpi file would be quite sufficient. Using 450dpi, of course, gives it extra source information to work with, which could be useful in overcoming any 'blips' within the data file. The more there is to work with, the better assurance we have of smooth print results.

The color photos in most glossy magazines, are printed at 100dpi - just to give you an idea of the relative print quality.

There is no correlation between dpi and pixels. Pixels don't equal Dots - and it is quite possible for one pixel to cover several dots. Print results are smoothest if the ratio is closer to 1:1, of course - but it doesn't have to be to get good prints. Adjusting dpi neither increases or decreases the number of pixels

If you want to do a "$2 experiment" that would thoroughly answer the question - take a shot from the camera and generate, say, half a dozen files from it. Each the same picture, and keep the size steady (in terms of pixels or inches), but use different resolutions - like from 72dpi thru to whatever the limit is. Run those files to the lab for 4x6 prints, and see if you can tell the difference in the final prints - or if there even is a visible difference. Let me know how they compare, for future reference.

[pentaxpirate]

Thnx Clemmie

[Photo-John]

PP-
That 72 dpi setting isn't relevent. It's only a default display setting for computer display. The only thing that matters for printing and image quality is the total number of pixels that your camera captures. When you print a photo from your camera, most printers will automatically change the dpi to match the print size you want. And they'll also usually "interpolate" to increase the resolution if your camera doesn't have enough for a given print size. That doesn't mean that printer software can make up for a low resolution camera - but it will try. The important thing is that the 72 dpi setting doesn't matter. It's how the total number of pixels are distributed on a print that determines print quality.