Why are Telephoto lens not so good?

[Bill Glickman]

Sol... I was very skeptical about teles for a long time...however, when I wanted to go very long, 800 and 1200mm, I had no choice, so I bought the Nikors. The image circle is just large enough to cover 8x10...I was not setting my expectations very high considering I would be comparing these results with some of the sharpest LF lenses such as SS XL's and Fuji A's etc. After getting my first chromes back, I wasu truly blown away at the resolution and contrast these teles produced! Now I am a big tele fan...of course in shorter fl's I would find their shortcomings to much to deal with as I do like to use movements and appreciate the large image circle offered by non tele lenses.

[Sol Campbell]

Bill,

I presume you have the 800 and just the rear element for the 1200. How do they work out? Is wind a problem? Is the 1200 as sharp as the 800? What is it like focusing at f18?

Tell us more about these monsters!

Thanks!

[Paul Schilliger]

I know of a photographer who shoots sea lions with his 1200 Nikkor. Amazing isn' t it! Hey Bill?

Sol, having the image of a 400 at 5,6 on the GG must be a real pleasure! In low light, it's a pain to focus even at f9.0. Have you noticed any effects of the shake at some shutter's speeds with your Cop al#3 New Tele-Xenar or is this shake issue a none-sense? I think you use it on a folding camera?

I would suggest one more thing to consider when choosing a tele over a long lens : it's the camera stabillity at long extension. A long lens might be sharp, but due to stabillity factors, a tele mig ht give better results on some cameras, when the heavy weight would suggest otherwise. On other cameras, a light lens ev en at full extention will be hold still enough to produce sharp shots. Strong tripod is also very important. There is an alchemy in all the elements!

[Bill Glickman]

Sol, their is only one front element for the 600, 800 and 1200 mm. You buy any of the rear elements which is a small barrell say 1.5" in diameter and 2" long. They each contain a thin piece of magnifying glass in them. It's hard to fathem when looking at the rear elements just how expensive they are?

The worst part of these lenses is their size! Forget backpacking with this puppies unless you have lamas with you. The weight can be a problem also if your camera is not sturdy enough. However, my Toyo 810MII and my Toyo VX125 with 1000mm of rails is very stiff. With 4x5, I do use two tripods, it is very solid...with 8x10 I put a monopod under the front standard on windy days, otherwise the 8x10 is OK with one tripod, but a good strong one! I use the Gitzo Carbon fiber 1349.

As for which is sharper? Well I have had better luck with the 1200mm, but it's probably just because I used it more often. So I would imagine they are very close to the same in quality. As for focusing at f18...considering I only shoot them in daylight and have a very well made hooded dark cloth with elastic band for both cameras, it's not as bad as I thought. I am not sure if the tele design which allows for almost half the extension as their non tele cousins, actually seem to dump more light on the gg? Does anyone know if this shorter extension reduces light loss vs. the longer extension required on non teles? From looking in the gg, I would think I saved a stop?

The one thing which is really amazing is just how tiny the DOF really is! WOW...you better shoot everything at infinity, unless you can accept a very blurred background.... Yes, Paul was right, I have shot sea lions with the 1200 on 4x5 with fair results, you have to catch them really still since the shutter speeds are very long, like 1/4 second at the fastest, but quite often 1/2 to 1 second. But soon I plan to try Provia 400F and see if I can pick up 2 or 3 stops of speed. That would really help these lenses out!!

[Brian Ellis]

I think there's some confusion in your original question and in some of the responses based on incorrect usage of the term "telephoto" lens. There is no such thing, to my knowledge, as a telephoto lens in 35 mm format. Based on your reference to Nikon and Canon 35 mm lenses of 200 and 300 mm focal lengths, I think you are using the term "telephoto" to simply mean a long focal length lens. This is a very common mistake. Used in this incorrect way (i.e. to mean a lens with a long focal length) I don't think anyone would suggest that long focal length lenses for large format cameras are inherently inferior to shorter focal length lenses. In fact there are some outstanding lenses in the range of 300 mm and up for large format cameras.

The disparaging remarks about "telephoto" lenses to which you refer were using the term "telephoto" in its true meaning. A "telephoto" lens isn't simply a lens of a long focal length but instead refers to a particular lens design in which the image nodal plane is placed in front of the lens rather than within the body of the lens. Thus a telephoto lens has a shorter lens to film distance than a normal lens of the same focal length and allows large format cameras with relatively short bellows lengths to be used with relatively long focal length lenses.

The criticisms of telephoto lenses (using the term in its correct meaning) are largely based on older telephoto lenses, which tended to produce negatives with lower contrast and possibly somewhat less resolution than normal design lenses of the same focal length. This has changed a lot with modern telephoto lenses and I doubt that you would notice any difference between a negative made with a normal design lens and a negative made with a modern telephoto lens unless you made a very careful comparison and even then I think the difference would be pretty minimal. I used the Fuji 400T telephoto lens for many years and it was outstanding.

[Ellis Vener]

Brian,

Sorry to have to correct you Brian, but almost all lens marked with a long focal length for 35mm cameras are true telephoto designs, especially once you get get longer than the 105 to 135mm range of focal lengths.

[Glenn Kroeger]

Brian: Have to agree with Ellis here... as an example, a Canon 400mm f/5.6 lens is only 256mm long, so unless Canon bodies swell to 150mm thick (6 inches) it's got to be a true telephoto! Other longer lenses follow suite, for example, the 300mm f/4L is only 213mm long, and those lengths go from the front of the filter thread to the back of the lens mount. Even the 200mm f/2.8 is only 136mm long.

[Brian Ellis]

Well, you learn something new every day. I dind't realize that (obviously). Thanks for the correction and sorry for the misinformaion.

[Glenn Kroeger]

Brian: No problem... we all learn something new everyday on this forum... that's why we visit it.