Lens Selection, Perspective and Scale

In this Tutorial we will look at how to choose the right lens for the right situation in order to achieve the look and composition you want in your image with a foreground subject and a background. We will also explore the scale of the subject and the perspective of it to the background

In this first set of images using some of my fine Object d’ Art from the Artist Tar’get’, I have keep the scale  of the Vase the same through out all the images. In other words the size of the Vase stays the same in each image even though I am moving back from the vase but I am also changing Focal Lengths of the lens to keep the vase in the same scale

Notice how though the scale of the Vase stays the same, the scale of the Background changes and becomes smaller in perspective as I zoom to a longer focal length.

One thing you should also notice but isn’t apparent in the images (because I used f11) is The DOF around my subject remains the same through all the images... Since I have used the same Aperture, that is out of the equation, But as I change Distance to subject, I am also changing Focal length in the same proportion, therefore keeping the DOF essentially the same.

The foot designation is camera distance to subject. The camera is a Canon 20D 1.6X crop factor

In this second set, I attempted to keep the Background scale the same (a little harder to do since I ran out of space even in a huge park) But in this one, I would have the scale of the Subject change in each move backwards and zoom in focal length.

In this example we can see how the perspective of the Subject to the background changes. In the close up wide angle shots the Vase looks much larger then the statue behind it. But as I move back and zoom in the Statue begins to look larger then the vase and in the final image at 200mm we can probably see what is closer to the true perspective of scale of the two objects.

In these you will also see how the distance between the Subject and the Background becomes more compressed as we move back and zoom in.

And yes, that is a Horse’s Butt you are looking at… I figured...if a Horse’s ass is gonna do this Tutorial…I may as well have a self portrait included.

You can use this information and examples to choose the right lens for the composition you would like. Is the background important and big?…well then you may want a wider angle lens and getting closer to your subject. If the background is un-important or maybe even distracting, you will probably want to use a longer focal length and move away from your subject.

Moose Out 

Thanks Moose!  I think this is one of the most valuable tuts so far!  How did you get so accurate on keeping the vase the same size in the first series.

 Thanks Eric

The first set, I had in a tripod and just eyed it and I used my Left Focus Point indcator to level the top of the Vase.

The second set, I had to do twice cuz I screwed up the first time, so they were handheld and I was feeling flushed in the sun so long so I rushed though it 

Moose:

The second set, I had to do twice cuz I screwed up the first time, so they were handheld and I was feeling flushed in the sun so long so I rushed though it 

it's the tin pot hat. it acts as an oven to cook your brain.

Straw is much cooler and you can snack on it after the season.

 a very nice Exposition.

Thanks for taking the time!  Really helps to see all these images together like this!

Thank you, thank you This is one of the things I really needed.

OK, here is a Extra Point Riddle for you and you get super extra credit if you give two Photos showing it.(Exif must be intact)

In my examples, Both Cases. The Vase remained in the same place  and the distance from the Vase to the Background was constant. The only thing that moved was the Camera/Myself and The zoom of the lens.

The scale or perspective changed in every shot 

So here is the question. How would I Take  two different  Focal Lengths, say 18 mm and 50mm and get exactly the same shot. The same perspective, same scale. Two different Zooms.

Can it be done?..can you do it?
 

I would think that the vase to statue distance would have to be shorter at 18mm, than 50mm.  I'm not sure though.

Eric L:

I would think that the vase to statue distance would have to be shorter at 18mm, than 50mm.  I'm not sure though.

That is half the answer but since it seems no one is even looking.. I will give it to you  Good Going!

Would it have to be 3.05 times closer?  is that part two?

Holey Moley!  i just saw this - wow!  this is one of the few things i have always wanted to do but never taken the time to do it!  :)  THANK YOU SOOO MUCH!

this really helps me out!  now i can "see" the relation.  wow.  you just made my whole weekend. I am gonna try to switch up lenses in my shoot this weekend and see how i can make this really work for me! 

thanks mooosey!

Moose:

Eric L:

I would think that the vase to statue distance would have to be shorter at 18mm, than 50mm.  I'm not sure though.

 

That is half the answer but since it seems no one is even looking.. I will give it to you  Good Going!

This is an illustration of the concept called, "forced perspective"  It is how the Lord of the Rings films were shot to make hobbits look smaller than humans without having to composite every scene.  It is more complicated in motion picture though, because to move one element (camera, subject1, or subject2) you have to precisely move all three. 

Whether or not you like the movies, you should watch the making of feature on the Fellowship of the Ring just to help you think of photography differently.

Combining Moose's excellent two illustrations and the extra credit question, you can then think how to balance the multiple variables of subject position relative to background and other subjects as well as focal length.  Throw in the complexity of also wanting to blur or keep focused these different pieces, and then suddenly, Moose has forced us to think about being photographers rather than just go on a feel.

When Ansel Adams was field testing extra large large format cameras (they would barely fit onto flat bed trucks), he had worked out where he wanted to shoot from in Yosemite to keep the subjects in the right relative scale before they ever loaded the camera on the truck.  You don't have to put that much forethought in every shot, but few could quibble about his results.  That is why they stand out from any other people's images of the same scenes.

Jim 

Moose:

Eric L:

I would think that the vase to statue distance would have to be shorter at 18mm, than 50mm.  I'm not sure though.

 

That is half the answer but since it seems no one is even looking.. I will give it to you  Good Going!

Trying to figure this out.  I think the other half of the answer is that the camera needs to move closer to get the same shot with an 18mm.  I think I came close to getting the same shot - I know they are not exact, but close.  I also didn't have 18mm lens so I used 28mm and 80mm.

Here is my try:

#1 - camera is 5 feet from ball and 1.5 ft from box.  28mm

#2 camera is 12 feet from ball and 4 feet from box.  80mm

plane:

 

Moose:

Eric L:

I would think that the vase to statue distance would have to be shorter at 18mm, than 50mm.  I'm not sure though.

 

That is half the answer but since it seems no one is even looking.. I will give it to you  Good Going!

Trying to figure this out.  I think the other half of the answer is that the camera needs to move closer to get the same shot with an 18mm.  I think I came close to getting the same shot - I know they are not exact, but close.  I also didn't have 18mm lens so I used 18mm and 80mm.

Here is my try:

#1 - camera is 5 feet from ball and 1.5 ft from box.  28mm

That's probably it.  I was thinking 50mm/18mm.  And it looks like you got the pics to prove it.

 Excellent,

Yes Thanks Jim (Grenache) for the Technical explanation of it and Plane for the Great example. Thank you too Eric for taking the time.

Yes, In either of MY examples. The only thing I moved was Myself/Camera and my Focal length. The distnace of the subject to background remained the same.

In the Extra Credit question, In order to get the same Image using two different focal lengths (no matter what they Happened to be) You have to Change, Both your Camera's Distance to subject AND your Subjects Distance to the Background.

In Plane's example (Which assumes the Box is the subject and the background is the Ball ( we are taking the Garage door out of this)  Not only with the change in focal length did they change the Distance of the camera to the Box, but they changed the Distance between the Box and the Ball.

Now you will notice that there still is a difference in the two images (forgetting about the garage door) There is a difference in the Field of focus between the subject and the Background... And sometimes this is beyond Physics to over come. but there will be a few times that you could change your Aperture and therefore your depth of field  between each Image to make the images look the same...but it is not always possible... In this example..actually it could not have been achieved even f the 28mm was wide open and then 80 was shot at Max aperture. This shows us that...we do need more then one fixed lens because not everything is possible

Thanks everyone. Great job!
 

this is totally awesome!!!