Creative use of lens choice

[Don Hoey]

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

[jseaman]

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.

[robski]

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

[Bob Hastie]

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?

[Tannin]

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.)

[Don Hoey]

DOF and focal length is a common misconception.

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

[wolfie]

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

[robski]

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