How many MP for a 20x16 or 20x30 print?

[RadioNate]

I friend just had some made and they are awesome. A photographer friend took them with his 5D so I know they are probablly at 12MP. But how low can you go and still get a decent print. I'm redecorating DH's office and there are some NBA and AHL shots I've taken that I'd like to have made.

 

[boBQuincy]

Would you believe 3 MP?

An image from a Canon D30 can be enlarged to 20" x 30" and still look very good. The loss of sharpness is there if you get close to the print but that's not how prints that size are meant to be viewed anyway.

It takes a lot of care, a tripod, ISO 100, RAW, and a sharp lens to start with. Then careful upsampling and sharpening before sending the image off to be printed. One of the files I did was a 98 MP PSD after all the work was done, then I converted it to a 13 MP jpg, the final file that was sent off to the printer.

Of course it can't be done, at least if you listen to the pixel counters who say it won't have enough resolution, but it works and very well at that! The D30 has very large pixels and that helps it to do better than the specifications would indicate.


boB

 

[Tuffcookie]

RadioNat:

The picture I took of the gazebo (see my thread about selling photos) was taken with the Canon Powershot S2 IS, which is 5 MP. I had that one made into a 16 x 20 and it looks awesome!!!

TC

 

[Kelly Grannell]

6 MP will make 20"x30" no problem. Of course, you don't look at the print at the same distance as a 4"x6". If you look at it at the distance your eyes can take all of the image in, then it will be as gorgeous 4"x6" at the distance you can take all of the image in.

Also, if you have a 6 MP camera, you can extrapolate the image up to be 60 MP using Genuine Fractals Print Pro. (I've used a 6MP image, iterpolated to 60 MP for a roadsign billboard size)

 

[RadioNate]

I have an S2IS. and I've been taking everything at the highest res. I think that the 20x30 will be too large anyway for what I want to do in his office anyway. Maybe I'll spend the $20 and try one out.

 

[Kelly Grannell]

this where a real photofinisher vs Wal-mart type differs. Wal Mart will only enlarge your photo. Real (pro) photofinisher will upconvert your picture to the required resolution using Genuine Fractals Print Pro or other programs similar in function.

 

[webshark3]

Mega-pixels aren't as important as Sensor Size. Any DSLR will do it flwlessly. High end point and clicks might work, but cannot compare to the DSLRs.

The Mars Rovers can do HD on IMAX. They have 1MP cameras, but huge sensors, and lenses manufacutred without flaw...

 

[Kelly Grannell]

uhm... HD is approximately equivalent to 1 MP anyway.

Regardless, webshark3 point is correct. It's more about the lens resolution, sensor size rather than merely MP count.

 

[manning]

Here is a perfect example on how the eyes can be fooled

Has anyone seen the picture "Sunday Afternoon on the Island of La Grande Jatte" by Georges Seurat? Painting was finished in 1886 It is a 7 foot by 10 foot painting hanging in the Chicago Art Institute. This is a perfect example on how the eyes can be tricked. From a distance it looks like a normal picture. Get on top of it you see dots. He didn't use brush strokes. He used dots.

I guess you could say it was the first famous megapixel picture.

http://www.answers.com/main/ntquery...ekey=Sundayafternoon.JPG&sbid=lc08a&linktext=

Also processing was slow then. It took two years to finish.

 

[Anewman]

According to signindustry.com
"Did you know that the average size of a billboard is 14 feet in height by 48 feet in length and that the resolutions of a billboard print ranges between 2 to 20 dots per inch..."

link


But I expected it to be in the 40 DPI range.

 

[Charade]

this where a real photofinisher vs Wal-mart type differs. Wal Mart will only enlarge your photo. Real (pro) photofinisher will upconvert your picture to the required resolution using Genuine Fractals Print Pro or other programs similar in function.

I wouldn't want them to do that. I would do that myself. The only thing I would want them to do is make sure the color is right (profiled).

 

[Charade]

According to signindustry.com
"Did you know that the average size of a billboard is 14 feet in height by 48 feet in length and that the resolutions of a billboard print ranges between 2 to 20 dots per inch..."

link


But I expected it to be in the 40 DPI range.

We used to make w i d e (72 inch!) printers that were used in the billboard industry. They were only 100 dpi. And that was plenty for the viewing distance.

 

[Kelly Grannell]

I wouldn't want them to do that. I would do that myself. The only thing I would want them to do is make sure the color is right (profiled).

You can always ask them not to. Regardless, GF Print Pro is the industry standard just like Photoshop is the industry standard.

 

[Charade]

You can always ask them not to. Regardless, GF Print Pro is the industry standard just like Photoshop is the industry standard.

I don't know about that. I've been semi-associated with the graphics business for years and have never seen anyone use GF. There are much more powerful (and better) RIPs out there than GF for making large prints. Really LARGE prints!

 

[Kelly Grannell]

Dunno about the US, since the first inception of GF, every print house I've dealt with (whose clients include Yamaha Motors, Ford, GM, Pioneer Electronics) they all use GF.

 

[Anewman]

While I agree that a print labs raster image processor(RIP) has better and more specialized(for that specific machine) algorithms for upsizing. RIPs = thousands of dollars.

BUT to me the main benifit of upsizing myself(with GF) is not the actual quality of the resampling. When I upsize I apply EXACTLY the amount of sharpening that my upsized image requires(it is my image). If a photographer allows the RIP to do the upsizing you must also allow the RIP to decide how much sharpening to apply after that upsizing.

 

[AZ JazzyJ]

RadioNate,

The point everyone is trying to make is that there are software and printing solutions that will allow your photo files to be manipulated so that you get a good quality print at 16x20 or 20x30. Start with a good quality photo that you've taken then find a finishing lab that you trust and whose work you have seen at the size you are looking for. The key will be to ask the right questions of your lab to make sure they have the capability to do what you are asking. Good luck with your redecorating project, I am sure your husband will love the photos once they are done. Also don't forget the photos will last longer and the colors will remain vibrant if you consider the framing and mounting. Low-e and antiglare glass will help as will keeping the print out of direct sunlight. You'll have to take a picture of the room when you are done and show us how it turned out.

Jeff

 

[webshark3]

uhm... HD is approximately equivalent to 1 MP anyway.

Regardless, webshark3 point is correct. It's more about the lens resolution, sensor size rather than merely MP count.

Closer to 2MP

 

[Kelly Grannell]

DOH! You're right, HD 1080P is equivalent to 2 MP. HD 720P is the one equivalent to near 1 MP Thanks for the reminder.

 

[webshark3]

DOH! You're right, HD 1080P is equivalent to 2 MP. HD 720P is the one equivalent to near 1 MP Thanks for the reminder.

np your point well taken too.