How to crop an image without adding canvas

[Gerald McClaren]

I've had a 4X6 photo that was enlarged to an 8X10. I had used photoshop and Bicubic Smoother to enlarge this photo. After the photo was enlarged, I cropped it to 8X10. I had noticed that I had to add some canvas to this photo to complete the enlargement to 8X10.
I would like to know if there is a method that I can use to help me in this situation. I would like to avoid adding canvas everytime I enlarge and crop a photo. Am I using the wrong technique?


Gerald McClaren

[Gary Richardson]

Because the aspect ratio is different between 4x6 and 8x10, it's always going to be necessary to either lose part of the image, or add canvas, if you want to retain an undistorted image.

Where the aspect ratio is the same 4x5, 8x10, 16x20 etc. you'll find a straight enlargement is all you need.

[Gerald McClaren]

Gary thanks for replying to my thread. Can you please explain how to do a straight enlargment of a 4X6 to an 8X10. Thanks.

Gerald McClaren

[Gary Richardson]

Hi Gerald,

Think we may be at crossed purposes.

If you do a straight linear enlargement x2 of a 4x6, you will NOT get a 8x10, you'll get an 8x12.

That's what I meant by the aspect ratio being different.

A 4x6 image is a different shape to a 8x10, and can only be made so by distorting the image.

If you don't want to distort your image, you can only crop or add canvas.

Crop if there's some detail you don't mind losing from the picture, add canvas if you want to keep the picture complete.

If it was the latter, I'd enlarge the 4x6 by a factor of 1.5 which will give you a 6x9, and set it in a Matt.

If it's just technical details you need about how to enlarge, and I'm mis-reading your post, let me know and I'll be happy to post details.

[Gerald McClaren]

Hi! Peano, That's exactly what I'm talking about. The vertical blue line on the 8X10 right hand side of your illustration. When I had enlarged the 4X6 to an 8X10, I had to cloned extra part of the image to complete the 8X10. What method did you use in photoshop cs2 in the past to enlarge a 4X6 to an 8X10?
What I want to know is if there is a better method that I can use. I hope this is not too confusing to explain. Thanks

Gerald McClaren

[skydog]

Just curious if anyone knows how certain sizes: 4x6, 5x7, 8x10, 5x5, 11x14, became the standard? Have I missed one? The ratio differences really kill me when I retouch a photo and and a customer orders sizes of different ratios.

[Cameraken]

Hi Gerald

What Gary and Peano have said is correct. It is not possible to double the height without doubling the width. So you could enlarge a 6 x 4 to 10 x 6.67 and then ‘fill in the gaps’ or you could enlarge to 12 x 8 and the crop 2” to make 10 x 8.


There is one other way but it will distort the image
Open the 6 x 4
Click Image > Image size
Uncheck the ‘Constrain Proportions’ box
Change the Width and height to 10 and 8
OK

This will change your 6x4 to a 10x8 BUT it will alter the aspect ratio. So the image will be stretched.

Some images will stand this stretching but most won’t. My attached picture was a circle at 6x4 but is now an oval at 10x8

This method is sometimes great for making up the extra missing portion of the image.
Sometimes you can use a ‘stretched’ image as the background and then put an ‘unstretched’ image above in the correct aspect ratio. Then by merging the two images together it is easy to make up the missing portion.

Skydog
Here is a list of film formats
http://en.wikipedia.org/wiki/Film_formats

I do agree. It’s very confusing why some print sizes were chosen which don’t match the common negative sizes. I would also be interested in the answer.


Ken.

[Mike]

As for the "common" print sizes and "common" negative sizes, consider this.

Starting way back around the end of WW1, the professional photographers tended to standardize into 8x10 inch cameras for studio work and 4x5 inch cameras for the more candid work. Hence that ratio for the print sizes. So common photo paper came in mostly 8x10 inch sizes although one could also buy paper in smaller sizes it was not as popular or as cheap.

So one could cut down a sheet of 8x10 into 4 4x5 pieces or in half with 2 5x8's. Why that got down to a 5x7 I cannot say, but it fit really well when the 35mm cameras started coming into the mass market in the late 30's and during WW2 as the proportions where the same.

Its only been for the last (maybe?) 10 years or so that 4x6 prints have become so popular. When they first started they were considered very amateurish.

So if you are going to change the industries entire line say from 8x10 to 8x12, there are a lot of things to change including the entire framing industry and also the mindset of all the population that has a large collection framed and on the wall as 8x10's and now the new 8x12's do not match and on and on.... So we kind of have to live with all the old stuff and try to get the new in there when we can.

Just remember that there is no law and there are no print size police that mandate that you make your prints any specific size, but there is a customer to satisfy.

[Cameraken]

Hi Mike

Thanks for the info. Maybe print sizes make more sense in the USA but in the UK Full (Whole) Plate (8 1/2" x 6 ½”) and Half Plate (4.25” x 6.5”) were more of the standard. (5x7 came later)

I guess print sizes were perhaps derived from a mish-mash of them all. Or perhaps print sizes were just made on a ratio that looked good as a print and nothing to do with the negative sizes.

It’s always been a problem and will probably always be. Even digital camera formats do not fit standard frames.


Ken.

[skydog]

Interesting...thanks