Bellows Macro Lenses

<p>I want to know what are the major image quality differences between in using a standard 20mm Nikor lens on a bellows, possible revere mounted and a dedicated belows type macro lens like the old 19 mm f2.8 Nikor lens?</p>

<p>The standard lens is usually not corrected for a flat field, whereas most lenses designed for use on a bellows (for macro work) have a design correction to produce a flatter field.</p>

Thanks. What about a short focal lens enlarging lens vs the 19 mm bellows macro lens?

<p>Most enlarging lenses are designed to capture a flat image and project it onto a flat surface. Macro lenses, again, are designed to smooth out a curved field and project it onto a flat surface.</p>

<p>I`m not sure of it at all... If the enlarging lens is working into its own optimal range, it should work as good as a dedicated macro lens (I may be wrong, there are many lenses out there :)<br /> Think that a Macro lens could be optimized for e.g., near 1:1 reproduction (my Nikkor 120 is for 2:1 to 1:5), whereas the enlarging lens could be for 1:5 or higher (a plain Rodagon 105 is for 1:2 to 10, shorter ones are for 1:2 to 15 or even 20). I wonder if Rörslett have more detailed info about the topic.</p>

Thanks for the info about the range of magnification of the various enlarger lenses. My thinking was along the similar

lines. Enlrger lenses are easily available whereas the old 19mm Nikon macro lens I have seen on eBay (a used beat up

lens) for about $1600. I think that is too much for the slight difference. I could be wrong.

<p>I use both my 55mm f/2.8 Micro Nikkor and 50nn f/1,4 AI Nikkor, either in the forward or reverseed configuration depending on that I want to do, on a PB-6 bellows with outstanding results. I often prefer the 50mm f.1,4 because it is two stops faster than the f/2.8 and with long bellows extension that makes a big difference in how well you can see.</p>

<p>The problem with using an enlarging lens is they are usually slower and have a manual diaphragm only and require an adapter to be able to be mounted on the front standard of the bellows.</p>

<p>Enlarging lenses are generally optimized for 8x magnification.</p>

<p>I have an older (1970's) Novoflex bellows with Nikon front and rear adapter rings.<br>

Unscrewing the front Nikon ring leaves a threaded hole for Leica M39 threads that my <br>

EL-nikkor 50mm f/4 enlarging lens mounts fine. Only downside is that the front and <br>

rear bellows standards are too thick to let lens focus to infinity for normal shooting.<br>

But it works fine as a macro. Looking for a Nikon reverse adapter for the EL lenses.<br>

Have a reversing ring for normal Nikkor lenses as well.<br>

Best regards,<br>

/Clay</p>

The best thing you can put on a bellows for magnification in that range is a "finite" 10x microscope objective.

 

The Nikon CF 10x M Plan 210/0 0.25 is among the most popular. It's a 21mm f2.0 optimized for 10x macro. It frequently

pops up on the bay of e for around $100. The Nikon CF series is corrected for chromatic aberration in the objective, and

doesn't require a matching occular to bring it up to its highest performance. It will shred a reversed 20mm f2.8 Nikkor or

an exotic and expensive 19mm f2.8 Macro-Nikkor as far as resolution or contrast. The field is small, it's good at 10x, but

you can expect terrible corner performance if you shorten the bellows enough to get it down to 5x. Then again, the 20mm

Nikkor and the 19mm macro-Nikkor aren't much good at 5x magnification, either. I have a 5 element RMS turret mounted

on one of my bellows, loaded with the CF M Plan 2.5x, 5x, 10x, 20x ELWD, and 40x ELWD. Death from above.

 

The 20mm Nikkor shines in "working distance", the rear element is a whopping 41mm from the subject at 10x, while the

CF 10x M Plan is 9mm.

 

The 19mm macro-Nikkor shines in collectibility, like a Leitz Photar or a Zeiss Luminar. If you luck into one of these

obsolete lenses cheap, say as part of a lot of salvage, you can sell it for $500 and get maybe three really decent CF

objectives. Aside from that, it has an aperture adjustment. However, since you're already at an effective f28 at 10x, you

will probably never stop the silly thing down.

 

The 40mm enlarging lens is slow and has a limited working distance. It's a footnote in the history of macro photography,

nothing more.

<p>Joseph, Are inverted microscope objectives good for macro work? They are designed for longer working distances than standard brightfield microscope objectives.</p>

Any finite (160, 170, or 210mm) chromatic aberration free objective is good.

 

Nikon and Oly had huge lines of suitable objectives. Zeiss and Leica, to the best of my knowledge, designed their finite

objectives to leave a certain amount of chromatic aberration to be corrected by the occular and aren't well suited to

bellows use.

 

Is there a particular objective or line of objectives you are interested in?

<p>Are microscopy lenses with infinity optics bad as photo objectives?</p>

<p>They're great as photo objectives, in fact, they're the current darlings of the macrophotography world. It's just that they're essentially useless on a bellows. If the bellows isn't a requirement for your shooting, read on.<br>

The finite objective is designed to bring an image into focus at some distance from 160- 210mm from the objective's mount. You can stick a sensor or piece of film at that point, and capture an image, and that's exactly what a bellows and camera lets you do.<br>

The infinity objective brings an image into focus at infinity. Since it's very had to position a camera infinitely far from the objective, you need a second set of optics, called a "tube lens" by microscope makers (because it lives in the microscope "tube") to bring the image into focus. The camera and bellows lack a tube lens. Fortunately, almost any telephoto lens can perform as an excellent tube lens when you just lock the focus to infinity. 180mm prime telephotos, 180mm or 200mm macros, 70-210mm and 70-300mm zooms are all very popular. Pick a lens that works well at infinity, though, because some macro lenses are pretty weak at infinity. Yeah, logic failure, macro lenses can't shoot macro, at least not this way. Whatever aberrations the "tube lens" has combine with the aberrations of the objective, but the sum of the aberrations of a good infinity objective and tube lens is typically lower than the aberrations of a finite objective all by itself.<br>

Your "tube lens" should also have a tripod foot, and you really want to invest in a quality focus rail like an RRS, Velbon, StackShot, or Hejnar. (Believe it or not, Kirk and Novoflex are "name brands" that you should avoid, along with the "mystery meat" products).<br>

The FOB (finite objective + bellows) and the IOL (infinity objective + lens) both have their advantages and disadvantages.<br>

FOB</p>

<ul>

<li>Can vary magnification over about a 2:1 range, depending on the objective.</li>

<li>Can focus by either moving the camera and lens together (focus rail) or by moving just the rear standard (bellows draw) which is a real boon to focus stacking.</li>

<li>Some bellows, like the Nikon PB-4, have limited tilt abilities.</li>

<li>Lots of excellent objectives available at low cost.</li>

<li>Very vulnerable to damage from weather, impact, condensation.</li>

</ul>

<p>IOL</p>

<ul>

<li>Generally higher image quality.</li>

<li>Much more rugged than a bellows.</li>

<li>Much easier to use polarizers or other filters. Filters have to be placed behind microscope objectives, not in front of them.</li>

<li>Very quick to set up.</li>

<li>Can't vary magnification easily unless you have a constant length zoom lens.</li>

</ul>

<p>Juri, what magnification are you seeking? The key to getting quality images for all these lenses is to use them at the magnification for which they were intended.</p>