How do you crop?!

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Right, without sounding like a complete noob, but I am struggling to understand the concept of cropping images. Is it the technique in post that enables you to make your image larger? Is there a tutorial on this forum that will help me understand this.

I have recently purchased a macro lens and feel I need to know more about this to get the best out of my images.

Thanks in advance guys and girls
 
Chaz Photos said:
It will not make the photo bigger
Click to expand...

You can scale at the same time as cropping though...

ie: in Photoshop setting a fixed crop ratio/size such as 800px x 600px

The above would obviously shrink the image as well as crop, but you could set it to 80,000px x 60,000px
 
It is good to have basic questions like this. Those of us that have been doing this sort of thing for ages don't always realise how some simple things can confuse people new to the concepts.

There is no tutorial on this but there could be.

Crop means to select a part of your picture - like a bugs head instead of the whole bug - and save that bit as a new picture... throwing away all the stuff outside the 'crop' frame.

edit. if you zoom in to your 'new' picture to view it full screen you might think it is magnified or enlarged. It still has the same number of pixels and detail level as the picture it came from but you are seeing it larger on screen.
 
68lbs said:
You can scale at the same time as cropping though...

ie: in Photoshop setting a fixed crop ratio/size such as 800px x 600px

The above would obviously shrink the image as well as crop, but you could set it to 80,000px x 60,000px
Click to expand...

Yes you can make it bigger BUT at a cost it will Degrade the image as you will have to make up the pixels this is called Interpolation (spelling?)
 
As mentioned cropping gets rid of unwanted areas of an image, it can also be used to change the composition of a picture.

Say you had a nice landscape but there was a telegraph pole at the right hand side, you would use the crop tool to "cut off" the side of the image that contained the telegraph pole. This would change the proportions of the image as it would not be so wide so quite often you would crop some of the top and/or bottom to retain the original proportions.

The file data, the number of pixels in the image, will be smaller as there is less information but if you were to print both the original and the cropped versions on the same size paper then the things in the cropped image would be larger than in the original. The same goes for viewing on the screen assuming that you view both images at the same physical size.

Wait until you get a few more answers, have a think, then ask for clarification if you need it.
 
if you're completely new to cropping etc, I recommend IRFANVIEW

once installed, for free...you can just select with the mouse the bit of the photo you want to keep, then crop the rest, removing it with scissors almost (ctrl Y)
then you can resize it (ctrl R) to make it 800px across perhaps for a forum post.
then save it
just don't save over your nice original photo! otherwise you will lose the 'negative'
 
Where possible, you should aim NEVER to crop, (unless you are after a particular aspect ratio - say a square image - in which case cropping is unavoidable). This means that you should use the right lens, get to the right distance from your subject and compose the image in the viewfinder as you want it to appear in the final print. If you have a 10MP camera, why not use all 10MP? This is often heard in a much simpler way: "Fill the frame".

In a practical sense though, it is not always achievable. For example, when photographing sports, it is generally impossible to make the composiiton, get the right distance etc - so cropping is a "must do" in many cases.

Alan
 
Cheers guys. It does make sense. I understood what cropping meant as I have been doing it in post myself, but I just noticed with some peoples pictures on here that they have cropped AND enlarged them and I wasn't entirely sure about this. Thanks for clearing this up.

So, in regards to macro, would people agree it is more beneficial to use the 'fill the frame' aspect when possible to get the best out of macro shots?
 
What you need to remember is that even at something like 6 mega pixels (like my camera) the produced images are far larger than you would view on screen at 100% and if you were putting them on a site for example you would generally resize the image, so if you crop (or cut) out a section of you're photo then resize it, you won't actually notice a difference in quality... So for example you have an image that is at say 25% size to fill your screen, you could then crop that image so you only had 25% of the image and zoom it to fill your screen and the quality would be the same... this is one of the major benefits of having massive mega pixels on your camera....

If you are only viewing on screen or printing small prints you can crop an image without a problem as the image would have been shrunk to fit the desired screen / print anyway.
 
Here's a question on cropping within CS2.
To retain the standard format ratio, CS2 seems to expect dimensions in cm/dpi, or pixels (I use pixels). Is there a way of simply retaining the format ratio and purely give you a crop of the area you want (e.g. 1200*900 pixels) without scaling of the image?
 
Mr_Sukebe said:
Here's a question on cropping within CS2.
To retain the standard format ratio, CS2 seems to expect dimensions in cm/dpi, or pixels (I use pixels). Is there a way of simply retaining the format ratio and purely give you a crop of the area you want (e.g. 1200*900 pixels) without scaling of the image?
Click to expand...

Don't know about CS2 - but in CS4 if you go into the crop tool, there is a button on the toolbar that says Front Image - this ties your crop to the proportions of the original image
 
Mr_Sukebe said:
Here's a question on cropping within CS2.
To retain the standard format ratio, CS2 seems to expect dimensions in cm/dpi, or pixels (I use pixels). Is there a way of simply retaining the format ratio and purely give you a crop of the area you want (e.g. 1200*900 pixels) without scaling of the image?
Click to expand...

I'd just manually enter 12in and 9in into the crop size box things and leave the dpi bit blank.
It doesn't really matter that you don't necessarily want a 12"x9" result, it'll give you the aspect ratio you want. Leaving the dpi box empty keeps all of the pixels in the crop area, instead of throwing some away or upscaling them.
 
No worries, I learn plenty on forums, it's good to give something back on the odd occasion I can :D
 
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