Cropping and printing

JamesJWeg

I have looked and have not found a guide to min cropping sizes for a usable print at X size, is there one floating around?

James.

ImageMapper

JamesJWeg wrote:

I have looked and have not found a guide to min cropping sizes for a usable print at X size, is there one floating around?



James.

[url=""]http://www.ezprints.com/help/ResolutionGuide.asp[/url]

JamesJWeg

Thanks, just what I was looking for. SM staff, you need this available in your help if it is not already. If I can believe that chart I was overly worried about croping.

James.

Bodley

Chart?

JamesJWeg wrote:

Thanks, just what I was looking for. SM staff, you need this available in your help if it is not already. If I can believe that chart I was overly worried about croping.

James.

Where's the chart? I've been wondering if I need to up-sample after cropping if PPi is less than 300.

Bodley

Bodley wrote:

I've been wondering if I need to up-sample after cropping if PPi is less than 300.

Found my answer in the thread http://www.dgrin.com/showthread.php?t=10845 but would still like to see the chart

JamesJWeg

Bodley wrote:

Found my answer in the thread http://www.dgrin.com/showthread.php?t=10845 but would still like to see the chart

I have no idea where that chart went, someone replied with it, and I guess they came back later and deleted thier post.

James.

Baldy

ImageMapper wrote:

http://www.ezprints.com/help/ResolutionGuide.asp

There's the chart.

Bodley

Is this what I should do?

Baldy wrote:

There's the chart.

Thanks for the chart link:D

This is what I've been doing:

1. Shooting digital photo 8mp
2. In PSCS - Process and crop at 5x7 ratio no resolution adjustments (seemed to be the best fit for 4x6,5x7 & 8x10's)
3. Upload pix

The way I understand it I'm uploading pixels at a ratio of 5x7. The print size will determine the PPI. From the chart I'm seeing the min PPI for an excellent print appears to be 94-100 PPI.

Questions?

If my 5x7 crop shows less than 94 PPI then should I can the photo if I'm expecting to sell 5x7 prints?

If someone attempted to purchase a 11x14 print of a 470x658 (5x7 * 94PPI) photo would the system let them? Would they get a warning?

I thought I had all this figured out until I figured out what I thought

mercphoto

Bodley wrote:

If someone attempted to purchase a 11x14 print of a 470x658 (5x7 * 94PPI) photo would the system let them? Would they get a warning?

I believe the system will let them, and will not warn them. In my opinion, Smugmug should not be in the business of dictating what items should be sold from my images. That is my business. And that is exactly the way Smugmug is currently setup.

Further, I don't want Smugmug popping up a window saying "image may be too small for requested print size". All that does is confuse the buyer.

You need to remember, I'm the guy who is a big fan of personal responsibilty and not having someone else hold my hand. Witness my remarks about whether Smugmug should be automatically adjusting the color space of people who upload images in something other than sRGB.

So, if you end up cropping so much out of a 8 mega pixel image that you are left with a 309K pixel image (as in your example of 470x658), then you should manually adjust the pricing to disallow anything larger than a 5x7 for that image.

mercphoto

Bodley wrote:

1. Shooting digital photo 8mp
2. In PSCS - Process and crop at 5x7 ratio no resolution adjustments (seemed to be the best fit for 4x6,5x7 & 8x10's)

When you say "no resolution adjustments", what do you really mean? In PSCS, you select the crop tool. You put in a width of 5 in, a height of 7 in. Do you leave the resolution the same, or do you make it blank?

And are you making the largest possible crop you can? Or do you sometimes crop a small part out of the middle? (in other words, how many pixels are you throwing away?)

If you do the largest possible 5x7 crop of a 4x6 image starting with 8 million pixels, you should end up with around 6.8 million pixels. Suitable for poster size prints.

Bodley

mercphoto wrote:

I believe the system will let them, and will not warn them. In my opinion, Smugmug should not be in the business of dictating what items should be sold from my images. That is my business. And that is exactly the way Smugmug is currently setup.

Seems like I've read where the cart would only show items which had an acceptable print resolution. This could have been on another site, although, EZ-Prints has a warning box.

mercphoto

Bodley wrote:

Seems like I've read where the cart would only show items which had an acceptable print resolution. This could have been on another site, although, EZ-Prints has a warning box.

Dunno. But, I would prefer there not be a warning box myself.

I'm still concerned about your comment of taking an 8MP image and cropping to 5x7 "without changing the resolution". Consider a Canon 20D at 3504 by 2336 pixels. If I make the largest possible 5x7 crop of that, I will have 3270 by 2336 pixels, or approximately 7.6 million pixels. And it will be 467 dpi at 5x7. By default, the 20D is a 72dpi camera.

If you use the crop tool incorrectly, however, you could end up with substantially fewer pixels than that. For example, if you truly are leaving the resolution alone, lets see what happens.

With a Canon 20D, it defaults to 72dpi. So my 8 million pixel image is about 48 by 32 inches. If I crop to 5x7 and leave it at 72 dpi, I will end up with an image of only 180,000 pixels.

Bodley

mercphoto wrote:

When you say "no resolution adjustments", what do you really mean? In PSCS, you select the crop tool. You put in a width of 5 in, a height of 7 in. Do you leave the resolution the same, or do you make it blank?

I select the crop tool with a 5x7 ratio and crop existing pixels out of the file without up-sampling to a particular PPI. Just use pixels as they are in a 5:7 ratio.

mercphoto wrote:

And are you making the largest possible crop you can? Or do you sometimes crop a small part out of the middle? (in other words, how many pixels are you throwing away?)

Cropping to suit the photo. I shoot as tight as I can but sometimes just can't get as close as I need to be. It's a dilemma - Don't shoot little Johnny in left field because it may require excessive cropping and get a tongue lashing for leaving him out.

Really don't think I have a problem with any photos I'm submitting, just trying to find a minimum PPI recommendation.

Bodley

mercphoto wrote:

Dunno. But, I would prefer there not be a warning box myself.

I'm still concerned about your comment of taking an 8MP image and cropping to 5x7 "without changing the resolution". Consider a Canon 20D at 3504 by 2336 pixels. If I make the largest possible 5x7 crop of that, I will have 3270 by 2336 pixels, or approximately 7.6 million pixels. And it will be 467 dpi at 5x7. By default, the 20D is a 72dpi camera.

If you use the crop tool incorrectly, however, you could end up with substantially fewer pixels than that. For example, if you truly are leaving the resolution alone, lets see what happens.

With a Canon 20D, it defaults to 72dpi. So my 8 million pixel image is about 48 by 32 inches. If I crop to 5x7 and leave it at 72 dpi, I will end up with an image of only 180,000 pixels.

I don't think I'm screwing up but heres what I'm doing:

View the entire photo - all available pixels - then select the crop tool and set my desired ratio (5x7, 4x6, 8x10) depending on what in intend on printing. Click-and-drag in the photo to set corners - adjust corners and alignment - hit enter to crop. I should have the highest native resolution for the photo in the area which was selected.