Creative use of lens choice
 

I am going to need some help on this thread as I do not as yet have than many pictures on my computer and without a scanner I'm going to have to sort through and photograph prints.......... So please attatch any pictures with lens choice details..........

Dont just match the view through your lens to the scene. Apart from the field of view the depth of field and its effect has a major impact on the image.
There is also an impact on perspective.

Wide angle .... Huge depth of field. Tendancy to distort the view close to the lens.
Standard ...... Increased depth of field. No perspective impact.
Medium telephoto ..... Depth of field limited. No significant impact on perspective.
Telephoto through to super telephoto ....... Very limited depth of field. Has the tendancy to draw up the background. (eg. if used in a landscape can be used to make a distant mountain look more impressive.

There are some good gallery pictures that demonstrate these effects so I will link just a few samples to get things going.

Wide angle
http://www.worldphotographyforum.com...2&limit=recent bags of DOF
http://www.worldphotographyforum.com...3&limit=recent works well on sujects like this.

Medium telephoto - (100-135 in 35mm ) traditional portrait lens
http://www.worldphotographyforum.com...0&limit=recent
http://www.worldphotographyforum.com...1&limit=recent
Telephoto
http://www.worldphotographyforum.com...1&limit=recent an example of a telephoto use in close up to blurr background.
http://www.worldphotographyforum.com...3&limit=recent I don't know the focal length used but this is a good example of where a telephoto can be used to compress a scene. At a higher focal length the church would become even more dominant.

Super telephoto - huge choice in the gallery but this is a super example where the background is so out of focus and the subject so sharp that it totally holds the eye.
http://www.worldphotographyforum.com...1&limit=recent

I have not included Macro to allow those with their new toys to show examples. These lenses when used at 1:1 have very limited DOF. They can be used at their normal focal length it is just that true macro lenses are specially corrected for close up photography.

Got to go now ......... have fun.

Don

I don't mean to be nitpicky but ...

Try reading this article on DOF: http://www.luminous-landscape.com/tutorials/dof2.shtml

As strange as it seems, DOF is not affected by the focal length of a lens.

I agree Jim

DOF and focal length is a common misconception.

The point came home to me the other week when I was doing some calculations for a 300mm and 400mm lens. Basically I wanted to increase the DOF by using a 300mm. By the time you reduced the subject to lens distance to get the same image size as the 400mm you find you end up with the same DOF at the same apeture.

Part of the exercise was also to look at the effect a TC or an extention tube would have on DOF and again maintain the same image size.

Rob

Does this hold true with zoom lenes, ie if using a 100-400 would you get the characteristics of a 100 when zoomed right in and the characteristics of a 400 when zoomed out?

Yes Bob. For the purposes of the current discussion, a 100-400 at 100mm is the same thing as a 100mm prime. (Well, the same thing as a very heavy and expensive 100mm prime.)

I hold my hand up to this.

As members are on during the day and without many new posts, I was posting this thread was to suggest to members that were on, that using focal lengths other than the most obvious would have an impact on the final image. Almost I soon came on I was under pressure from the ' management ' as a trip to the shops had been scheduled and I was holding things up...... priorities, priorities.

So if I can, with a drink in hand, ammend the topic to lens effects on perspective which was the primary thought.

Its Robs ' Gable Roofs ' that brought this to mind.
I had a lot of explaining to do to the ' Boys in Blue ' at Windsor when I was setting up to take the castle with 400mm + 2x. As the castle is set up on high ground and across the main road is also high ground level with the castle, this is where I was. I wanted to use the perspective compression of 800mm to make the road to the castle appear considerably steeper than it is. I had to prove to the boys in blue that the camera was a camera and the lens a lens etc, etc. This was years ago - would not try it today.

Saphire's ' Frozen Lake ' or Steve Randles ' Buttermere View ' both use the huge depth of field that a wide angle gives. This is really where the DOF bit came in. Take Steves, picture selective focusing and use of dof gets everything sharp.
Snappy's ' Bright Eyes ' using a 500mm lens at f5.6 has just blown the background away ( selective use of aperture ).

I have to admit to being a bit confused by some of the conversion factors shown in the exifs. Steves reads Camera - Canon EOS DIGITAL REBEL - Lens 25.0mm (35mm equivalent: 174mm). I have difficulty seeing this as an aperture of f10 at 174mm.

I have never considered dof from the image size on film before. If I wanted more dof I would use a slower film wider lens and enlarge that part of the frame. I have used bellows on a 300mm just to blast the background before now. That is what I was referring to.

Forgiven? ............

Don

PS greypoints ' Riverside flowers ' is another example of using a long lens small aperture to blow a background. Although this could have been taken with a shorter lens the effect on out of focus area would not be the same. If you return to the tutorial and look at the tower in the background it has a far softer blurr at 400 than the 200 and through to 50mm. It is a good example if you ignore the blurr, of telephoto perspective compression effect. Compare the tower to subject through all focal lengths imagining they were both in focus.

PPS I must be nuts being here at this time of night. Trying to catch up on the Gallery.

I often use the long telephoto for landscapes, you don't always need a wide angle and the shallow DOF from a telephoto sometimes helps.

http://www.worldphotographyforum.com...5&limit=recent

Agree with Kevin, even for flowers and large insects, such as butter/dradonflies I use the Sigma 50-500mm, as this allows you to get in close and put the background rubbish OOF.

Harry

Hi Harry

I just realised when I saw your location it was you.

The only draw back with the Bigma for closeup is the closest focus distance which I think is around 9ft but for butterfly's that means you don't disturb them.

Kevin

In the case of my Blue Tit shot you will notice the tail is out of focus due to the limited DOF. The shot was taken with a 300 @f8 with the lens just about on it's MFD of 8ft (DOF is about 1 inch). Because of the need to maintain a high shutter speed without pushing the ISO into the very noisey region I was investigating different lens setups to try and squeeze abit more DOF into the shot at this distance. That is when I realised that even if I used my 24-70 and got even closer to the subject I would be no better off.

I think the point Don is trying to make is the flattening effect on the vanishing point perspective which is more to do with focal length and lens to subject distance.

Rob

Don you love it you know you do ;)

Rob

On the button. When I was out with a group some time ago choice of lens was being made on the basis of what focal length fits what I see from where I am standing. People did not realise that by either moving closer to ( where possible ) or further back would allow them to select a different focal length that may give their pictures more impact. As digital slrs are becoming more affordable, people are moving up to these systems that accept a huge range of lenses. If your last camera was a short zoom range compact, the first lens choice tends to favour the salesmans recommendation yet he may never have taken a picture in his life.

Landscapes are not only the domain of wide angles for panoramic views but it is an area where their huge dof can be very effectivly used. Telephoto's can be used to draw up the background that a wide angle will not.
Many pictures posted here show that many nature subjects positivly benefit from the step back and use a telephoto approach rather than a shorter lens.

Its all about understanding the effects of using a particular lens on a subject and not what one that just fits the view. Before the common use of zooms a conscious choice had to be made, with a zoom it is too easy to zoom without thinking about the effect.

As I mentioned before, some pictures have details of lens and aperture, that allow you to see the effect of using a particular lens and others don't.
So pics or links that show the image benefits of lens choice are the most effective way of broadening members awareness.

Don

Management happy after a trip to the shops. Just had to do a bit of catching up. Caught in the act, so I'm now also in the ' You're MAD ' catagory.

Forgot to mention in the previous thead that some time ago I changed my 200 from an f4 to a f2.8 to take advantage of shallower dof when used wide open. I wonder what aperture Andy shoots at with his BIGgun.

Don

Just to throw another spanner in, focal length does not affect perspective either. Only subject distance affects perspective.

John,

I was trying my best to describe an effect that the use of lenses of different focal lengths has on objects in the near and far distance.

I may well have used the wrong term and for that I appologise. As the bulk of my education was done under a Flat Top Thorn tree in Kenya and I have only one book on photographic technique, ( and this is not described there ). I was trying my best to find one word that would do.

So I am quite happy to bow to your knowlege of terms.

Allways willing to learn - what word is used to describe this effect ?

Don

Don,

And a very good job you made of it too! My comment was made with a bit of tongue in cheek. The effects you described were spot on. Many people observing wide angle and telephoto effects think that focal length effects perspective. I did for nearly fifty years until I read an article explaining how use of non standard lenses causes one to adopt a different view point and it is this which changes the perspective. I think your explanations were far more valuable than my pedantic comment. I am sure you were aware of all this. My sense of humour often gets me into trouble. I should learn but somehow I don't.
Kind regards,
John