PDA

View Full Version : Little Megapixels & Huge Crops



Bill McCrystyn
02-11-2008, 11:36 AM
I hate to cross swords with the masters, but, the story that a 2.7 MPX camera can make 13x19 images of relatively high quality I think needs to be qualified. I wouldn't proclaim "on guard" save for the fact that basic math and PP reality dictates otherwise.

I will quote a D215 INC. article:

"Notice that as the print size doubles, the megapixels required increases geometrically. You can make nice 8" x 10" prints with a 6 or 8 megapixel camera, but to make a true photo quality 16" x 20" print, you need between 24 and 30 megapixels. Don't be fooled by manufacturers' claims that say you can make 16" x 20" prints from an 8 megapixel camera. While you certainly can make a print that size, it will not be true photo quality.

Here's why:

A megapixel is 1 million pixels. It's an area measurement like square feet.
A typical 8 megapixel camera produces images that are 3266 x 2450* pixels.
If you multiply 3266 by 2450, you get 8,001,700 or 8 million pixels.
To find the largest photo quality image you can print, simply divide each dimension by 300:
3266 / 300 = 10.89 inches
2450 / 300 = 8.17 inches
If you are not publishing your images in a book or magazine, and you're just making prints for yourself or your friends, you can "cheat". Good quality inkjet printers can make a nice looking print at 250 or 200ppi. At 200ppi, the maximum print size becomes:
3266 / 200 = 16.33 inches
2450 / 200 = 12.25 inches
If you know how to use image editing software like Photoshop, you can "cheat" even more by increasing the image size, and even doubling the number of pixels in the image. The quality of the camera and lense becomes more important at this point bacause any loss of detail or sharpness is magnified. If an image is enlarged too much in this manner, it will look "fuzzy" or "pixelated". [end quote]If Megapixels beyond, lets say, 8 didn't matter, then someone has been wasting several thousand dollars on 16 and 21. When someone says they produced film quality (approx. 20 megapixels) with 2.7 then I must ask what the crop factor was and how far were you standing away from the print?

Glass of course will play a part in it, especially how close you are able to get to your subject to avoid a large crop and consequential, deteriation.

I find with 8 MPX that a 12x18 crop out is about on the ragged edge. I run my screen up to 100%, crop out the full screen and size to 12x18, which that is close to begin with. If you can do that with 2.7 megapixels and maintain any quality at all something is very wrong with my 20D. Any more and noise and loss of resolution rear their ugly head. I am using 300ppi for referance.

When people say 2.7 MPX is all you need for a quality print, I think some qualification is wanting.;)

john crookes
02-11-2008, 02:15 PM
The attached picture was taken with a Nikon D1H camera which is a 2.7 megapixel camera

If the print is done on fine art paper a resouloution of 180 to 160 ppi can be used with fantastic results depending of course on the printer and the person using the appropiate software to print from

I have seen images from Moose Peterson from the same camera printed to an astonishing 30x and the result was stunning

another issue is you did not multiply the resoulution of your camera by three which is what happens when you open it up in photoshop and through the new camera raw you can double that without a lot of loss of detail

John

Bill McCrystyn
02-11-2008, 03:16 PM
QUOTE - another issue is you did not multiply the resoulution of your camera by three which is what happens when you open it up in photoshop and through the new camera raw you can double that without a lot of loss of detail.

Thanks for your reply John. I'm not sure you took into account a 100% blow up to print as an issue or that the above example (as breath taking as it is) is anywere near that, which once again, would explain the clarity.

john crookes
02-11-2008, 03:20 PM
The above image has been printed to a 16 x 24 full size crop on a fiber base fine art paper then framed and hung in a gallery for a year with no issues

all from a 2.7 megapixel camera

Bill McCrystyn
02-11-2008, 05:01 PM
John, pardon me if I am missing something.

Again, are you saying you cropped the F/F out of the camera to leave a 16 x 24 image by which to print? If you wouldn't mind, I would love to see the full frame of this. Printing at 100% blow up above super B size with 8MPX and achieving even this Jpeg quality would be amazing to me, and many others I might add, regardless of the paper used.

john crookes
02-11-2008, 05:12 PM
What I said was this was printed at 1 16 x 24 print which is the same crop as was captured at the time i tripped the shutter

john crookes
02-11-2008, 05:17 PM
also an image will never look right if sharpened while being viewed at 100 percent in photoshop

according to dearly departed Bruce Fraiser we should be viewing our photos at 50 or even 25 percent when sharpening according to the resoulution of our monitor

Bill McCrystyn
02-11-2008, 06:15 PM
Ok, now I think we are on the same page. It has not been cropped or blown up, if you will, at all. It is indeed full frame. BTW it is one of my favorite images I have seen on this site. Arizona Magazine would probably use it except they only accept 12 MPX images or better last I checked.

john crookes
02-11-2008, 06:32 PM
No it ia full as out of the camera here

but to make a 16 x 24 the image was about 70 megs whisch was a lot of blow upsince the original was only opened as a 7 meg

BillPelzmann
02-11-2008, 07:08 PM
Based on my printing experience - not 100% screen views, I feel the article that you cite which uses (sensor resolution / 300 ppi) is FAR too restricitve on what they consider "photo quality". It is the equivlaent of limiting 8"x10" negatives to contact prints. Yes, that may be the "ultimate", but they sure do hold their own when enlarged. :D

I have 20"x30" prints from a Canon 10D (6MP) which I still proudly display along with my 1DsMkII prints.

I certainly do not consider the higher MP sensors a waste of money, but to say you can't get more than a 8"x11" "photo quality" print out of a 8 MP camera is simply wrong.

Bill McCrystyn
02-11-2008, 08:34 PM
Well actually Bill, I didn't. I said anything over 12x18 was pushing it. Apparently I am not making myself clear at all. If you print what you see on the screen at 100%, hows that, then any enlargment beyond 12x18 will lack in quality of resolution AND have considerable more noise to deal with. If you think they are being too restrictive with "photo quality" call around and see what the magazines require for publishing, you may be surprised at what your told and why.

Lets go this way, why did you buy a camera with more than 8 megapixels? If one reason is so you could make bigger enlargements and crop tighter without loss of resolution and less noise, I have made my point.

john crookes
02-11-2008, 08:46 PM
mmmmmmmmmmmmm Most editors I deal with now just want the image at 300 ppi as long as it makes the grade they do not care how you geyt it there

You can open a image as a smart object and it has tremendous capability to meet almost any image size within reason as long as it was a clean image to begin with

There are still some editors that think only certain sizes will do but a lot of them are starting to realize that with todays software and photographers learning how to use the software better all the time then you will see the file size requirements go down

It was not that long ago that you could not photograph any quality images for a mag without it being done with a 4x5 or a least medium format for most of the commercial stuff

times change
and editors do too

Bill McCrystyn
02-11-2008, 09:56 PM
Your right of course John but the reason for more megapixels won't. I whine allot about only having 8 because I do not always have good access (close proximity) to my target so to get the subject near full frame I must heavily crop or enlarge the image considerbly. This of course take its toll on IQ in the form of noise and resolution loss. If it were not for that, 8 megapixels would be fine. As it is, dispite the math in the article, 12 should be fine for up to 16 x 24 properly processed as you suggest.

BillPelzmann
02-11-2008, 10:24 PM
Yes, you did state that 12"x18" was at your "ragged edge".

The source that you cite as an authority claimed that "photo quality" for an 8MP sensor is limited to 8"x10".



To find the largest photo quality image you can print, simply divide each dimension by 300:
3266 / 300 = 10.89 inches
2450 / 300 = 8.17 inches


I will take as many pixels that are available because I like BIG prints.
The largest print that I have sold is 40"x60" from a 16.7MP source file.
Everytime I see the client he tells me how much he likes the image and how many compliments it has received.

My objection is the concept, in your quoted article, that uprezing in Photoshop produces non "photo quality" prints.
Starting with a critically sharp image, and proper post processing, the limits are FAR beyond the (sensor size/300) forumla suggested above.

What magazines require is of no interest to me. What people find pleasing on their walls is. :)

john crookes
02-11-2008, 10:36 PM
I would rather spend the money on getting the glass needed first as if everything remains the same you will still be cropping the 12 meg camera and falling under the specs that you talk about.

I got my big glass before i made the move up to higher megapixel cameras and the move up was not solely for the higher res but for all of the features of the camera.
in fact my last move went down in pixels and also moved from a 1.5 factor to full frame as i movede from a D2x to theD3

I feel I canalways use the techniques to get closer to my subjet and that is more important than to have the convenience of photographing and then being able to crop afterwards

by that theory the cameras some day would take a huge megapixel photograph and the person would be able to crop out what they want from the image.

I hope I never live to see such a day as it would take all of the art out of photography

James Shadle
02-12-2008, 12:56 AM
Ok, now I think we are on the same page. It has not been cropped or blown up, if you will, at all. It is indeed full frame. BTW it is one of my favorite images I have seen on this site. Arizona Magazine would probably use it except they only accept 12 MPX images or better last I checked.

So far not one photo editor (not even National Geographic) has specified an original file size.

All they say is "send me a X x X at 300dpi"

It just better look good.

I had a 20x30 from my 4mp D2H printed on a HP 130 auctioned off.
It was well received.

James

Richard Kowalski
02-12-2008, 01:32 AM
Bill,

Please stop dissing our 20Ds and their 8 point >>2<< megapixel sensors!

As for Arizona Highways, their digital photography submission guide (http://www.arizonahighways.com/images/default/Downloadable%20Docs/DigitalGuidelines.pdf) clearly states a minimum of 8 megapixels...

Alfred Forns
02-12-2008, 08:49 AM
Bill I stand by my statement A 2.7 MP camera .... not a point and shoot with a tiny sensor... makes fine large prints Have seen them 20X24 looking great

Remember you will be viewing these prints froma distance Also I am assuming you start with an excellent RAW file and your processing skills are up to the task

Fabs Forns
02-12-2008, 09:31 AM
Just to chime in, my nature's Best winning image was made with an 8.3 MP camera, It is cropped a little bit for composition, Let's say, image is 90% of original, putting us at roughly 7 1/2 MP
If you look in my website, you can see the size of the print....museum quality.

I made iit easier. Here is the size compared to a tall human.

Bill McCrystyn
02-12-2008, 09:52 AM
Well ladies & gentlemen, all I can say is, when I go to 100%, I see alot of noise/grain looking stuff. Anything over 100% and resolution/sharpness starts falling apart. PP will take care of a allot of it - BUT - it just never looks quite as good/clean as one of Arties shots with 500mm & 21 megapixels. Maybe I need to step to f/11 and down to ISO200 from f/8/400 but I am not happy with that much noise and less than tack sharp res. and feather detail. I have a feeling that when all I have to do is pluck out 25-50% instead of 100+ I will be allot better off.

John
I am about to get a 2.8/300 with a TC based on the opinion of many here, as well as more pixels.

Richard/James
Thanks for bringing me up to date, it has been a while. AZ Hwy used to require 12MPX/RAW minimum.As John says, things are changing.

Fabs
That's my point. Your shot is 90% of the oringinal - mine are 10% blown to kingdom come. Way big differance.

Alfred - I"ll talk to you later - boy! :)

john crookes
02-12-2008, 10:24 AM
Bill
If you are using only 10 percent of your image there are numerous problems with that
going to a larger megapixel camera and still using only 10 percent of an image is not going to work either.

There must be a way for you to get more of the image to use.

I think that there is not a person in here that wants to use only 10 percent of what they photograph in the viewfinder.

John

Fabs Forns
02-12-2008, 10:29 AM
I see what you all mean now.

I'm not a pixel techi, but MP for MP, a full frame of the 2.8 pm camera will look better than a 10% crop of a 21mp imo.
using only 10 or 20% of your original capture will bring out heavy pixelation for sure.
I think investing in a longer lens will be healthier than buying another camera with more room to crop.

Bill McCrystyn
02-12-2008, 11:09 AM
Ahhhh a breath of fresh air. Thanks Fabs & John, I intend on getting both. Didn't mean to get everyones knickers in a knot. :)

Fabs Forns
02-12-2008, 11:12 AM
Ahhhh a breath of fresh air. Thanks Fabs & John, I intend on getting both. Didn't mean to get everyones knickers in a knot. :)

Quite the contrary, a very interesting conversation :)

Richard Kowalski
02-12-2008, 12:45 PM
Hey Bill,
I'm not sure just where you got the 12MP for Az Highways. AFAIK, they refused ANY digital submissions until October of last year. Once they changed over, the 8MP was in their guide from day 1...

Now , depending on what your subjects are, you might consider, GASP! A film body. I just purchased a used EOS-3 in excellent condition for $185. I am not using it for anything but my landscape images, for a few reasons. One is to regain a full sized frame and the other for longevity. The slides I make now will still be visible to anyone who looks at them 100 years from now. I figure unless I (or someone else after I'm gone) migrate my digital images to new media every 5 - 10 years or so, most of my digital images will be lost in short order...

But that's another thread.

Bill McCrystyn
02-12-2008, 12:59 PM
Hey, Richard. I called AZH a couple of years ago and was told that they were considering digital images BUT only if they would be 12MP or better. I will admit I am a bit out of the loop. The last time I was published was by Avanti Greeting Cards some 15 years ago. I just got back into photography in "05 when digital looked like it was gonna go. Been fighting my way back to normal since then. Thanks for all the advice. I actually did give some thought to my old A1 but I really think that digital is the way to go assuming you have the right setup for what your doing.