Difference between tele and long lens

[Steve Bell]

What would be the difference be between a 360mm telephoto lens used on 4x5, and a 360mm normal lens? Am I right in saying the only difference is the telepho lens can use a shorter bellows?

Steve Bell

[steve simmons]

A telephoto lens is designed such that the optical center is actually out in front of the lens. Wih a non telephotodesign the optical center is approx where the diaphragm is. This means that a telephoto lens needs a bellows about 66% of its lentgh for a focus at infiity.

There are advantges and drawbacks o hese lenss. They have limited coverage and the older ones are not very good lenses. The Fuji T series, the Nikon series are the best as are the newer Schneider versions. The older Tele Xenon, Tele Artar are, IMHO not a good lens.

steve simmons

[David A. Goldfarb]

"Tele Xenon, Tele Artar "?

I'm guessing you mean "Tele-Xenar" and "Tele-Arton"

[Frank Petronio]

Isn't the recent Tele-Arton the same formula as the 1960s version? I have one from the 1970s, it is as sharp as my modern glass.

[Gem Singer]

Hi Steve,

There is another difference, that I have noticed, between the 300mm. tele lens that I formerly owned and the two 300mm. non-tele design lenses that I now own (all of these lenses are Fujinons of recent manufacture). I cannot be certain that it is actually due to the tele lens design, but the non-tele lenses seemed to be sharper. I never actually did a scientific comparison of prints under high magnification, but it appears that the non-tele lenses are sharper lens. It also seems like the slightest amount of camera shake is magnified with a tele lens. Perhaps that is due to the nodal point being out in front of the lens.

The only 360 Tele lens I am aware of is the Nikkor 360T-ED, mounted in a Copal 1 shutter. It has the reputation of being an extremely sharp lens for 4x5. Most non-tele 360mm. lenses are usually mounted in larger, heavier Copal 3 shutters and used on 8x10 cameras.

[Steve Bell]

The lens I was enquiring of is in fact a Schneider Tele-Xenar 360mm F5.5. It was part of a Linhoff Technika 70 kit I was given. It has 230mm coverage, enough for 4x5. As it was a Linfoff selected lens I was hoping it would be reasonable and worth buying a lens board for, probably not now. It looks immaculate, and the compound shutter appears accurate. It can go back in the junk draw. To be worth keeping I'd be looking at producing sharp 20x16 prints from it.

[Emmanuel BIGLER]

May be we could add that the advantage of a telephoto lens to require a shorter bellows is obvious when focusing at infinity or for far distant objects. But the additional bellows extension, measured from the focal plane, and required to reach a certain magnification ratio is exactly the same for a telephoto and for a quasi-symmetric lens ; of course for any magnification ratio the total bellows drag will be shorter for the telephoto, but for example if you want to reach the life-size 1:1 ratio with a 360 mm lens, you'll have to add 360mm to the infinity->focus position for all 360mm lens designs. In practical terms ; a quasi-symmetric 360 apo-ronar will require a 360 mm(14") flange focal distance at infinity, whereas the 360 tele-Arton will require only 209 mm (8") according to Schneider vintage lens data specs. At 1:1 the apo-ronar will require 720 mm (28") of total belows drag and the tele-Arton 209+360=569mm (22") which is not really compact in both cases.

[Steve Hamley]

Steve,

The picture on the right here


http://www.jerrygreerphotography.com/gallery_posters.htm

was made with a 360mm Linhof select Tele-Xenar in Compound. Jerry likes it very much except for the size. He reports low flare.

Steve

[Leonard Evens]

I think that, other things being equal, a telephoto lens of the same focal length will deliver lower quality. That is because the additional constraint on the short rear flange distance makes it harder to design a lens. But, of course, other things are seldom equal.

[David A. Goldfarb]

I have a 360.5.5 Tele-Xenar and a 360/5.5 Tele-Arton (which is for sale, by the way), and the Tele-Arton is definitely a sharper lens than the Tele-Xenar, but it's way too big for a Tech 70, and with medium format you're only using the center of the image circle, so with a proper lens shade, it should be fine for good 16x20's from 6x7 or 6x9cm negs. I wouldn't put it in the junk drawer at all.

Another advantage of Tele lenses for outdoor use is that with less bellows extension, you get less wind-induced vibration, which sometimes can be more important than the absolute optical quality of the lens.