Converting Nikkor 35mm lenses for Bronica S2...

[sarah_noce]

I have read several articles on the internet about converting older

Nikkor 35mm manual focus lenses to fit my Bronica S2, yet I am still

confused on what will actually work and what won't. Does the lens

focal length need to be longer or shorter than the 101.7mm film plane

distance on the camera body or does that matter? I'm just looking for

some clarification on whether I would need an custom threaded

extension tube and if so, how long would it need to be and for what

focal length. I understand infinity focusing is limited but would

this apply to all 35mm Nikkor lenses that I tried to convert? Is

there any way to remedy that? Any input would be much appreciated!

Thanks!

Sarah Noce

[steve_rasmussen]

Since the 35mm lenses are designed to have the film plane closer than

you would be using them, you would be forced to use these lenses at

macro and near macro focusing. I don't think the focal length of the

lens you choose will make much difference because all the nikkors

were designed for a given distance between the lens mount and the film

plane. Infinity focusing would be a problem for any Nikkor lens you

could choose unless you could mount them at the same distance from the

film plane that they were designed to be used. That might be

impossible and would probably cause vignetting. SR

[s_p]

If you have not already done so, visit <a href="http://

www.smu.edu/~rmonagha/bronica.html/"><u>http://www.smu.edu/

~rmonagha/bronica.html/</u></a>. Its a huge site with all kinds

of info, including DIY lens hacking for the Bronica.<p>

Bronica lenses for the S2 are not that expensive used (at least

not expensive compared to other MF systems). Perhaps it would

be much easier to find what you want in original S2 equipment.

[bobatkins]

Since 35mm lenses are designed for a 43mm circle of coverage, they

wouldn't be much use on any MF camera, even if you could mechanically

adapt them and get them close enough to the film to focus outside

the macro range. I suppose there might be some special applications,

but not any I can think of at the moment!

[s_p]

By coincidence (funny how it works) I came across a page with

some info on the very subject of mounting 35mm Nikon lenses to

the Bronica S2. Go to <a href="http://www.cameraquest.com/

nrfbron.htm"><u>http://www.cameraquest.com/nrfbron.htm</a></u>.<

p>

When I originally read your posting, I assumed you were talking

about Nikon SLR lenses. The author of this page has info about

an adapter for old Nikon RF lenses. The adapter shown is

designed to do this and so will probably work, but it doesn't

seem to be cheap --- it and the lenses it will work with are

rare collectibles according to this page. I would also point

out that these RF lenses do not have automatic diaphragms ---

you would have to open up to full aperture to focus, stop down

and take your picture.<p>

[dieter_lefeling]

As Bob pointed out, you cannot use 35mm lenses for 2 1/4 cameras - the

image circle is much too small. You also wouldn't be able to focus to

infinity since the different distances between film plane and lens

flange would act as an extension tube, in this case one with 101.7

minus 46.5 (Nikon) = 55.2mm.

 

<p>

 

But: You *can* use 35mm lenses on 2 1/4 bodies for macro photography,

as long as you don't use them below a certain magnification. This

"critical value" can be determined by dividing the image circles of

the two film formats and decreasing the result by 1. For a 6x6 camera

with 35mm lenses, this would be 80mm : 43mm = 1.86, and 1.86-1 would

result in a minimum magnification of 0.86x. For quality reasons I'd

recomend even higher magnifications (2x and up) and mount the lens

with a reversing ring. Since the lens is now mounted with its filter

thread facing the camera resp. your extension tubes or bellows, you

wouldn't even need a complicated Nikon-Bronica adapter. Another great

idea (for best quality at low prices) is using a usual enlarging lens

for macro photography. That's how I do it.

 

<p>

 

Dieter

[twmeyer]

circular images can be quite beautiful.

 

<p>

 

if you use a lens that yeilds a complete circle within the square of

the s2 can mat beautifully square or round.

 

<p>

 

if you apply this idea with a camera that has tilts, your circle

becomes an oval.

 

<p>

 

see early work by Emmett Gowin on 8x10 film with an angulon (not

super). landscapes, "environmental" portraits and interiors that are

incredibly beautiful.

[twmeyer]

sorry about that syntax, it's needing corrected.

[robert_monaghan]

Actually, there are a surprising number of 35mm long-focus telephoto

lenses, bellows mount lenses (and lens heads), and adapters which can

be used on medium format cameras. Some dual format lenses exist too.

 

<p>

 

From Bronica S2/EC alone, we have these dual format 6x6 and 35mm

lenses:

 

<p>

 

Astro-Tachar (Ercona)

Meyer Optik (Tele-megor)

Novoflex

Omnitar (Birns and Sawyer)

Zoomar (macro-kilar, Kilfit)

 

<p>

 

The Novovflex are most familiar, esp. in their follow-focus mounts.

 

<p>

 

My homebrew lenses http://www.smu.edu/~rmonagha/bronhb.html

for medium format page describes the 500mm f/8 Samyang/Phoenix or

Cambron medium format (Phoenix/Cambron) lens for various 645 and 6x6

cameras. This lens is only $395, largely because it is a 35mm lens

which happens to have enough coverage to provide "surprisingly sharp"

coverage on 6x6 and 6x4.5cm per Keppler (Pop Photo Nov 1997 review).

 

<p>

 

The trick with this 35mm lens is that the rear mount unscrews easily,

making it easy to adapt to medium format cameras with longer lens

mounting distances than on most 35mm cameras. There are other long

focus (not compact or collapsed telephoto designs, but full length)

telephotos from 35mm which also have lots of coverage, and will work

on 6x6cm too. Any 35mm tele lenses with a long enough air space at the

rear of the lens gets my interest if the price is right ;-)

 

<p>

 

Of course, most of the T-mount eyepiece based microscope and

telescope adapters will also work, a reverse T-mount adapter makes it

easier to build a reverse T-mount body cap adapter on med fmt; the

trick here is adjusting eyepiece focusing point for longer med fmt use

 

<p>

 

Similarly, most of the bellows mount and macro bellows mount lenses

from 35mm that are longer than your medium format camera's lens

registration distance will also mount. Enlarging lenses also work if

in the 100mm and 135mm range or above (on S2a, less on other mounts).

 

<p>

 

Again, most of these tele and macro lenses have lots of coverage,

especially stopped down, although the edge quality is less than the

center, it often is acceptable for the low price of a simple adapter

to use that lens (e.g., bodycap mount). Also, since med fmt needs less

enlargement, so-so lenses and adapters on 35mm seem to produce better

results on medium format than on the smaller 35mm image etc.

 

<p>

 

Personally, I think the most useful and interesting and handy 35mm

optics are the front-of-the-lens adapters, especially if you have a

medium format camera with a fixed normal lens! While the quality is

less than a prime medium format optic, the effects are often unique

and obtainable no other way, and the price is right and they're fun!

 

<p>

 

fisheye 0.18x converts 80mm to a 15mm equiv. circular 180 degree

fisheye, cost is only $50-100 US used

 

<p>

 

superwide 0.42x adapter converts 80mm to a 34mm superwide ($25-50 US)

 

<p>

 

very wide 0.6x adapter converts 80mm to a 48mm wide angle ($20-35 US)

 

<p>

 

wide 0.75x adapter converts 80mm to 60mm wide angle ($10-25 US)

 

<p>

 

short tele 1.25x adapter converts 80mm to a 100mm short tele ($10-25

US) - softening of low cost adapter is actually a plus in some photos

 

<p>

 

plus some wierd 220 degree coverage "bird's eye" adapters ($20 US)

using a reflective mirror and clear tube camera mount and shift mounts

 

<p>

 

monocular telephoto adapters (e.g. 350mm f/11) are afocal telephotos

that screw into your front-of-normal-lens filter ring, using filter

thread adapter, and provide (circular) telephoto 350mm effect for

$35-100+). There are other sizes and powers available; basically this

is one side of a pair of binoculars mounted on the front of your lens.

 

<p>

 

Anamorphic adapters (1:1.5x or 1:2x) compress panoramic scenes on

short teles so you get 6x9 (1:1.5x) or 6x12 (1:2x) compressed images

on film; use similar adapter on enlarger or slide project to recover

the 1:1.5 or 1:2 panoramic images; most of these adapters are from

Cinemascope cameras or Panavision models used in movie theatres.

($25-100+)

 

<p>

 

In other words, a fixed or single lens owning medium format user can

experiment with super-fisheye (15mm), ultrawide (35mm), very wide

(50mm) and wide (60mm) plus short tele (100mm) and longer tele (350mm

but some variable 150-750mm versions exist) for low $$. Surprise! ;-)

 

<p>

 

URLs-

http://www.smu.edu/~rmonagha/bronhb.html homebrew lenses

http://www.smu.edu/~rmonagha/bronadap.html (lens head 135mm f/4)

http://www.smu.edu/~rmonagha/bronaux.html tele and wide adapters

http://www.smu.edu/~rmonagha/bronfe.html fisheye and ultrawides

http://www.smu.edu/~rmonagha/third/wierd.html Bird's eye 220 degrees

http://www.smu.edu/~rmonagha/mf/anamorphic.html anamorphic lenses

 

<p>

 

Since none of the above require any lens hacking other than finding

the right filter thread mounting adapter, they seem easier and more

fun for most users, and easier to experiment with. Again, these

adapters won't replace prime lenses, but if you are saving for that

Hassy fisheye, it may be awhile, and the 0.18x fisheye may be lots of

fun in the meantime. If you have a fixed lens or one lens med fmt

setup, these adapters can add some fun and tricks for low dollars...

 

<p>

 

regards to all - bobm