I have a 4MP camera. I am thinking of reprinting some photos to 16"x20"
At the Costco photo site, it recommends "1920x1536 pixels" to ensure quality for a 16x20.
Two of the photos I 'tested' on their site were flagged as 'not recommended' for 16x20.
One photo is 1536x2048 pixels, and one is 1704x2272. These numbers exceed their recommended pixels. So I can't figure what the problem could be :confused:
I may end up settling for 12"x18" and matting though, as I don't really want to wait a week for a mail order to arrive :rolleyes:
Thanks for any 'enlightenment' ;)
skofarrell
Jul 13, 05, 1:28 pm
For 16x20, you're looking at least 13 megapixels. Your 4mp camera is only good to 8x10.
Very interesting that their pixel requirements are so different than the ones at Costco's One Hour Photo :confused: Thanks for the link. Wonder how the prints would fare using Costco's list...
On a related note, I much prefer Mpix (http://www.mpix.com) to Costco, Wolfe, etc...
MatthewClement
Jul 14, 05, 10:51 am
I've had very good luck using interpolation to add extra pixels -- it may not be quite as sharp as a genuine 13 megapixel image, but it will be a lot smoother than a 4mp image printed at 16x20.
You could start with the interpolation in Photoshop (bicubic), but I prefer to use Ifranview (http://www.irfanview.com/) to resize my images as the interpolation algorithms are more sophisticated.
chaunceysf
Jul 14, 05, 10:51 am
Very interesting that their pixel requirements are so different than the ones at Costco's One Hour Photo :confused: Thanks for the link. Wonder how the prints would fare using Costco's list...
If Costco told you that you needed a 13 megapixel photo to get a decent 16X20 print, they wouldn't sell many 16X20 prints then, would they?? :p
Actually, you can probably get what Costco calls "decent" out of a lesser camera, but it will definitely not be of professional photographer quality. That may be all right for your needs - after all, I assume you want this picture enlarged for your own enjoyment and not for display/sale in a gallery. You may want to try just one at Costco to see if the results are acceptable, or find a place in your area that can show you the results in advance.
As a last resort, take some smaller prints and matte them together in an artistic arrangement. :D
ALadyNCal
Jul 14, 05, 11:02 am
I decided on 12x18 because they were available immediately instead of waiting a week for 16x20 (or two weeks if you ask WalMart). I increased the pixel size of my existing photos to approximately 4037 x 5383. The prints came out very well. I realized one glitch with the new Costco online (via snapfish) is that I didn't see the tiny box to upload the 'full quality' of the photo. Dumb that you have to tell it that :rolleyes: Thanks for the tips :)
CPRich
Jul 14, 05, 4:18 pm
It depends on what you are going to use it for and what your expectations are. See http://www.melbpc.org.au/pcupdate/2303/2303article4.htm
The Costco recommended minimum gives only about 1.8 lp/mm resolution, which is relatively crude if you are going to look at it up close. But if it is to be displayed/viewed from a distance, it may be OK (what kind of resolution do you think a billboard has? Get close and the dots are measured in inches).
The type of picture makes a difference too - a continuous tone picture with minimal contrast and edges can put up with a lot more enlarging.
I've very happy with the 8x10 out of my 6.3 MP 10D, and am ok with slightly larger, although I start noticing artifacts looking close-up.
It also depends on the camera. I know a MP of resolution on my large-sensor SLR is a lot better than a MP on a camera-phone, shirt-pocket camera, etc.
There are tools to do various types of mathematical interpolation and the like, but that's taking you down the hard-core camera-geek path. Typical 4MP compact camera photos of average content I wouldn't push past 8x10. But again, "it depends'.
pdhenry
Jul 14, 05, 4:34 pm
If you're blowing it up big you will probably be viewing it from further away. I don't have any problem with 20 inch x 30 inch images from Imagestation from my 4 MP Olympus camera. The image size is 2129 X 1704 pixels. The image may be a little grainy close up, but so is a 35mm image when blown up that much, at least in my experience.
bbkenney
Jul 16, 05, 12:59 am
If you're blowing it up big you will probably be viewing it from further away. I don't have any problem with 20 inch x 30 inch images from Imagestation from my 4 MP Olympus camera. The image size is 2129 X 1704 pixels. The image may be a little grainy close up, but so is a 35mm image when blown up that much, at least in my experience.
I agree. I am a total amateur. I have a 6+MP SLR Canon and can basically count on equal enlargements when compared to my 35mm SLR using Kodak Royal Gold 100. (Digital photos are shot in RAW mode). Excellent to 11x14, very good to 16x20. Never done larger on either camera.
Sam - DFW
Aug 28, 05, 3:15 am
For 16x20, you're looking at least 13 megapixels. Your 4mp camera is only good to 8x10.
Rarely will you know that you want to make an 8 by 10 while you're still framing the shot with your camera. It's only later that you discover you took a great picture and decide to make a print. If you have plenty of pixels, you're in good shape; if you capture the picture at a lower resolution, though, you might be out of luck.
That's why I don't recommend reducing a camera's resolution. For the most part, you should always shoot at your camera's highest pixel resolution.
Here's my question:
Do higher resoution pictures take up more space on the computer (are they larger files)?
I do not want to use a 2nd photo program unless absolutely necessary. Currently I plug my camera into my computer (via USB), and I can upload pictures to My Pictures (Windows XP). The files are about 1MB (w/ 3.2MP camera). I would like to get 5MP or more, but I don't want files that are 2MB+. I know that I can reduce size when I send in Outlook, and the resulting files are 30-40kb. However they don't look nearly as good.
What is the default size file for pictures taken with higher resolution?
Can people that are using larger MP cameras "maxed out" please provide insight?
Also, where should I turn for trustworthy reviews? CNET?
Thanks,
Sam
pdhenry
Aug 28, 05, 7:37 am
Do higher resoution pictures take up more space on the computer (are they larger files)?Absolutely. Quick example - on my old 1.3 MP camera at "good" compression an image file was about 250k-350k. On my 4.1 MP camera an image file is 850k-1 Meg at "good" compression and maybe 2 Meg at "high quality" compression.
Assuming that images are captured at 24 bits per pixel (a guess, but this equals 8 bits per red/green/blue and is generally the best color depth a PC displays) you can calculate the uncompressed (e.g. "RAW" or equvalent that a camera offers) file size in bytes as the number of pixels times 3. So a 6 MP camera would produce a raw image of around 18 megabytes.
What is the default size file for pictures taken with higher resolution?It depends on the level of compression. There's a tradeoff between compression and image quality (obviously) and some makers do a better job of optimizing this than others.
Also, where should I turn for trustworthy reviews? CNET?http://www.stevesdigicams.com
http://www.dpreview.com
It's been a couple/few years since I've seriously shopped but these sites were very helpful the last time I bought a camera.
Sam - DFW
Aug 28, 05, 10:03 am
Thanks for the helpful post! I never realized there were so many choices. It looks like I have some research to do.
Sam - DFW
Aug 28, 05, 10:43 am
I found a great resource - well I really like the format but have no way to determine the accuracy. You input numerous criteria and the site returns recommendations.
I found a few that look great, so I was hoping to get some input from others. I am more concerned with people that DISLIKE the following models for whatever reason.
Some of these do not optical viewer. What do you do when it is dark?
CPRich
Aug 28, 05, 11:20 am
What is the default size file for pictures taken with higher resolution?
Can people that are using larger MP cameras "maxed out" please provide insight?
On my recent trip to HI, I shot RAW+embedded Large/Fine JPEG and the files from my 6.3MP camera ranged from 8-14MB, averaging around 10. But unless you want to deal with a digital darkroom, RAW converters, custom white balance, gray cards/WhiBal, color spaces, etc., I wouldn't recommend it.
Just shooting high resolution JPEG averages about 2.8MB, with a range from 1.5 to about 3.8. This number should be directly proportional to the MP within the camera sensor, assuming each camera vendor implements the JPEG compression alogorithms in a similar manner.
Shooting lower resolution can save you space but, as the article said, CF cards cost me about $110 for 2GB just before I left, disk is about $0.25/GB, and CD's can be found free after rebate, so saving storage isn't much of a deal. And finding that you undersized that one magic shot that you want to enlarge would be a bummer.
Dpreview.com for FT-equivalent in photography. There are lots of other good sites, but that's where I tell folks to start.
pdhenry
Aug 28, 05, 11:22 am
If you're referring to cameras that may not have an "optical viewfinder," that refers to the film-type viewfinder where you hold the camera right up to your eye and frame that way. Just about every digital will let you set up the picture using the LCD viewer, but this takes more battery power to power the diplay and backlight and it's a little harder to hold the camera steady without bracing it against your face.
I use the optical viewfinder most of the time unless I'm setting up a special shot on a tripod.
I don't have any experience with the cameras you listed. Some considerations of mine:
the memory card type doesn't really matter much. You buy the card(s) and maybe a USB adapter once and then you're done.
max available card capacity matters more than type but there's not much difference between currently available formats in this regard
if you're mostly going to view on your PC and maybe print out a few 4x6 or up to 8x10, a 3 MP camera is plenty
ignore digital zoom. 3X optical is the minimum to consider; more is a bonus
in the long run portability trumps a larger camera with features you might not use often
there's value in a camera that can run off AA batteries but usually the smallest cameras use a proprietary battery
mcrt
Aug 28, 05, 12:01 pm
The rule of thumb that I use is 300 pixels/inch for premium quality prints. This is what you want if you are going to be doing family portraits or art prints. 100 pixels per inch will give acceptable prints. I have several 12 x 18 prints from Costco hanging on my wall that are about 150 pixels/inch and look great.
Another thing that is easy to confuse is the camera pixels and the printer dpi. The higher the dpi the smoother the color transitions will be and the better the overall print. A 150 pixels/inch file will look better from a 1200 dpi printer than a 300 dpi printer.
I shoot my digital camera maxed out. It has a 6 MP resolution with a 12 MP mode. I usually keep it in the 12 MP mode. You can always take a picture shot a 12 MP and make it into a 1 MP to e-mail it, but you can't take a 1 MP pic and turn it into a 12 MP.