Longest lens on camera with 225mm bellows extension

[Former Member 8144]

Hi,

I currently use a nikkor 200mm as my 'longer' lens on my ebony SW45 with a 35mm top hat extension...but nine times out of ten its just not longer enough from my two main lenses (90 and 135) to make the difference for the shots I'd like the longer lens for.
I shoot very rarely with longer than the 135mm so the few times I do its usually for the occasions when a fair bit longer is wanted.
So given my total extension of 225mm, what is the longest lens I can use at infinity focus.

I realise a 200/210 etc will fit and focus to infinity fine but can I get longer with this set up?
Are there, for instance, any tele designs that will do the trick and not weight ridiculous amounts?

I know a back extension exists for the ebonies but that starts to become fairly bulky, heavy, etc so I'm looking at doing it with my current lightweight set up.

I'm looking for something to almost roughly emulate the 150mm focal length I used on my hasselblad so I guess something around 270mm-300mm, etc?

Cheers,

Marc

[Gene McCluney]

There are a number of "Telephoto" design LF lenses that would work, look for models such as Tele-Xenon, Tele-Arton, Komura Telephoto, Congo. Nikon and Fuji also had Telephoto design lenses. I have used a 500mm Komura Telephoto on my Super Graphic that has a similar bellows extension. The disadvantage with "telephoto" design lenses, is the small circle of illumination prevents a lot of shift or tilt.

[drew.saunders]

You'll need a telephoto, but the tough part is finding information on the flange focal distance of the lens. That's roughly the distance from the film plane to the lens board at infinity, and you need something with less than 220mm. The Schneider 250/5.6 telephoto has a flange focal distance of 195.1mm (see http://www.schneideroptics.com/pdfs/...ensCharts.pdf), so it'll work fine with 225mm of bellows. This handy chart: http://www.graflex.org/lenses/lens-spec.html shows that the Nikkor 270 T is 188mm, and the Fuji 300 T is 199mm, so any of those three will work.

[Former Member 8144]

I've just remembered and re-found this great page here:

http://www.ebonycamera.com/articles/lenses.html

very usefull for flange etc distances of various lenses.

The fuji looks a good bet as it is fairly light and compact and with good image circle to boot...and 300mm would be a reat focal length for my needs.
I'll try to find more info on sizes, weights etc of others and go from there.
Thanks for the help.

Marc

[Former Member 8144]

Is there a general difference in image quality between tele and non tele lenses?
Or are they both on an equal footing in terms of image quality?

Marc

[steve simmons]

A telephoto lens will generally require a bellows that will extend to 2/3 the focal length of the lens. There are 270mm telephoto lenses that will require about 180mm of extension that will work on your camera.

The optical quality of the older telephoto lenses is not very good compared to a new modern non-tele design. However, life is full of compromises and this may be the best you can do. Nikon made a tele series of 360-500-720. The front element stayed the same and the rear element changed to change the focal length. However, a 360mm tele lens will require about 240mm of bellows. You will have to find a used set to try as they are no longer made. The optical quality is very good.

View Camera did a very thorough article on telephoto lenses and the article is on our CD about lenses.


steve simmons
www.viewcamera.com

[Robert A. Zeichner]

I had a similar situation years ago when I used a Horseman 45FA. I ended up getting a Fujinon 300T which turned out to be a wonderful lens. Telephoto formulas typically require only about 60% of their focal length in bellows draw so the 300 should require about 180 mm. There are some things you should be aware of with a telephoto though and they are: 1. Telephoto lenses usually don't have as big an image circle as their normal counterparts. 2. Any time you are shooting close enough to the subject to render its size on the gg any greater than 1/10th of the objects actual size, you will need to compensate with additional exposure to accommodate the exit pupil factor. 3. The optical center of the lens is far forward of where you think it might be. This can sometimes be a source of confusion when setting up a tilt or swing at the front standard.

[Former Member 8144]

The fuji 300T is the one I am looking at for its combination of focal length, low size + weight, and good image circle. (The nikoor T 270mm for instance is much heavier and with a very small image circle)
This lens is for far off infinity focus shots so no problems there.

Now to find one!

Marc

[Former Member 8144]

Well I've found a good fuji 300T but before I pull that final trigger one more question.
With my maximum bellows extension of 225mm...what I wonder would be the longest non tele lens I could use if only focussing at infinity, which is all I will ever do with this long lens?
I.E. what for instance is the bellows extension needed for infinity focus of a 270mm or even 300mm non tele lens?

Marc

[Dan Fromm]

Marc, at infinity the distance from a lens' rear node to the film plane is the focal length.

Most lenses of normal construction -- but not all, 6/4 and 5/4 double Gauss types can be somewhat telephoto -- have the rear node within a few hundredths of the focal length behind the diaphragm. The rear of the shutter butts up against the flange and the diaphragm is a couple or three or four mm in front of the back of the shutter. So you might, great stress might, be able to focus a 230 mm lens in shutter to infinity with 225 mm extension. But don't count on it, that's around the limit.

The standard rule of thumb is pretty good; according to it, focusing a normal (non-tele, non-retrofocus) x mm lens to infinity needs x mm of bellows. Fill in the x yourself.