Correct proportions at various distances

[BillN_33]

I'll start by saying that I may not be able to explain this well

I have taken a lot of Damselfly images in the last two months, mainly with a 300mm lens on a small sensor Nikon V1, (x 2.7), and with a D7100 using the 300mm and the Nikon 105mm

I have noticed that on some of my images the proportions are not quite "right' - all are taken in the usual 36 x 24 size, (?)

Obviously with a wide angle lens the image gets "distorted" the nearer you get - (I'm talking about close ups, here).

My question is do the proportions change with distance when taking close ups ……… here I am talking about a difference of a foot or inches, say the closest focusing distances on a particular less and comparing the two.

I have read with telephoto lens you get "compression" which makes the image look "better"

Also the Lens correction function in the develop module of LR - I am a Nikon user and in LR there are only 6 lenses mentioned - can this function automatically adjust any lens distortion.

I know little about the technicalities of the above, but hopefully someone has the knowledge to understand what I am talking about

what I am suggesting is that close up and macro shots can distort the proportions depending on how near you are …….. and if so is there a way to at least part correct this ……..is this true or is it an optical elusion on my part

 

[Sharky]

Do you mean image compression? Wide angle lens push the background further away, long focal lengths bring the background closer.

 

[arad85]

You mean like the second image on the right here: http://en.wikipedia.org/wiki/Wide-angle_lens

 

[BillN_33]

You mean like the second image on the right here: http://en.wikipedia.org/wiki/Wide-angle_lens

yes but the reverse in a way, distortion with a wide can be corrected, but does the same thing, (but different and not as extreme), happen when using the same fixed lens as you move nearer the subject - i.e. if you are using a 105mm lens at say one foot, do the proportions change when you move in to 6 inches ……… and if so is this recognised by PS and can be adjusted

As I said earlier I could just be talking rubbish, in that it does not happen but appears because of the way different "crops" can look or because of the DOF problems with close ups

 

[arad85]

yes but the reverse in a way, distortion with a wide can be corrected, but does the same thing, (but different and not as extreme), happen when using the same fixed lens as you move nearer the subject - i.e. if you are using a 105mm lens at say one foot, do the proportions change when you move in to 6 inches ……… and if so is this recognised by PS and can be adjusted

As I said earlier I could just be talking rubbish, in that it does not happen but appears because of the way different "crops" can look or because of the DOF problems with close ups

You can't correct for distortions that are introduced by perspective without any depth information. What the distortion correction does is remove the effects of the lens, not the placement of the camera...

 

[StewartR]

My question is do the proportions change with distance when taking close ups ………

Yes.

I don't know anything about damselflies, so instead let's imagine you're photographing a person.

You could get a nice head shot with a lens of around 100mm focal length, from a range of about 2m. If you did, we'd all say the proportions look correct. But if you tried it again with a 10mm lens from a range of 0.2m, the framing would be the same but the face would look horribly distorted and badly proportioned.

But that's not caused by the optics of the 10mm lens: it's caused by the positioning of the lens relative to the subject.

With the 100mm lens, the subject's nose is 2m from the camera and her ears are say 2.1m away. That's not a very big difference in proportionate terms - only 5% - so the relative sizes of the ears and nose will look correct. But with the 10mm lens, the subject's nose is 0.2m away and her ears are now 0.3m away. The ears are 50% further away than the nose, so the nose will seem 50% bigger. That's your distortion and bad proportions, right there.

Here's the phenomenon illustrated:
http://stepheneastwood.com/tutorials/lensdistortion/index.htm

Does that make sense if you apply it to the world of damselflies?

 

[BillN_33]

Yes.

I don't know anything about damselflies, so instead let's imagine you're photographing a person.

You could get a nice head shot with a lens of around 100mm focal length, from a range of about 2m. If you did, we'd all say the proportions look correct. But if you tried it again with a 10mm lens from a range of 0.2m, the framing would be the same but the face would look horribly distorted and badly proportioned.

But that's not caused by the optics of the 10mm lens: it's caused by the positioning of the lens relative to the subject.

With the 100mm lens, the subject's nose is 2m from the camera and her ears are say 2.1m away. That's not a very big difference in proportionate terms - only 5% - so the relative sizes of the ears and nose will look correct. But with the 10mm lens, the subject's nose is 0.2m away and her ears are now 0.3m away. The ears are 50% further away than the nose, so the nose will seem 50% bigger. That's your distortion and bad proportions, right there.

Here's the phenomenon illustrated:
http://stepheneastwood.com/tutorials/lensdistortion/index.htm

Does that make sense if you apply it to the world of damselflies?

Thanks

Basically what I am sometimes finding is that the body of the Damsel or Dragonfly is a little longer or shorter than it should be - i.e. the proportions between the horizontal, (wing span) and vertical, (body), planes are, (look), "not correct" - I can sometimes correct this with a un-proportional crop, but most of the time I cannot accurately and I wondered if there was a mathematical formula that took into account the mm of the lens and the distance from the subject.

In reality (at the extremes), I find that using a 300mm lens is "better" than using a 105mm macro too close - but maybe it's my eyes!!!!