Macro lens fudging

[dh003i]

Hi all,

I'm thinking about taking a few macro shots with my 4x5. I have a monorail with 398mm effective extension (i.e., at furthest spread position, that's the distance from the front of the front standard to the front of the rear standard). I have a 90/4.5 Nikkor-SW, and am thinking of experimenting to try using this at first for a few macro shots (outdoors for now).

Depending on the subject, I'm going to give it a shot with the 90/4.5 lens, but I can tell that focusing is going to get difficult quick.

Extension : Subject Distance : Magnification Factor : Effective Aperture (max - min)
180mm : 9.5in : 1x : f/9 - f/128
270mm : 7.1in : 2x : f/13.5 - f/216
360mm : 6.3in : 3x : f/18 - f/256

It seems like that would limit the the maximum usable magnification to 2:1 (generously).

Another thought that occurs to me is to have a custom lens-board drilled (there's a local metal company that made a copal 0 for me before, maybe I can corral them to do a custom job) and mount my Minolta Rokkor 50/1.4 MD on it. This is a 35mm lens that I currently use with my Olympus E3 via a Minolta => 4/3rds adapter. I have a spare adapter, and could have that strongly affixed to a lens board with a hole.

I've figured out that this lens covers 4x5 at a 185mm effective extension (the actual extension will be less, ~141mm because of a ~44mm flange of the lens). The lens only stops down to f/16, which is a significant downside, although at these extensions, effective aperture is already much smaller.

Extension : Subject Distance : Magnification Factor : Effective Aperture (max - min)
185mm : 3.6in : 2.7x : f/5.2 - f/59
200mm : 3.5in : 3.0x : f/5.6 - f/64
250mm : 3.3in : 4.0x : f/7.0 - f/80
300mm : 3.2in : 5.0x : f/8.4 - f/96
350mm : 3.1in : 6.0x : f/9.8 - f/112
400mm : 3.0in : 7.0x : f/11.2 - f/128

A major issue of course would be not having a shutter! However, I suspect that all exposure times would be numerous seconds long -- good enough to simply uncap the lens and recap it (or drop a darkcloth over the front when the exposure is done?). Any thoughts?

I realize that of course macro lenses will do better because they're designed for their purposes; however, it seems to me that they all have f-stops similar to what my 90/4.5 has, which would make focusing at very close distances...very difficult. Likewise with macro-substitute lenses, like the Tominar 75/4.5. Also, one reason I'm thinking of this is it'd be really cheap to try out (the last time, it cost me $25 to have a copal 0 lens board made).

The exist pupil of my 50/1.4 Rokkor is 1.75in, and the front aperture is 2.25in...I wonder if any shutters could be adapted?

Thoughts?

[dh003i]

PS: Another possibility is to use a Minolta 100mm Macro auto bellows lens. It is designed like the LF lenses, in that it has no focusing helicoid, thus needs a bellows on 35mm to get to infinity. Severe case of seller's regret here, as I just sold my former 100/4. It stops down to f/32 too. The downside of that would be, if I mount it to a similarly bored lens board, I would need to extend the bellows to 370mm to get full coverage on 4x5. Another downside is it is only f/4 instead of f/1.4. But it is a macro lens, and would presumably perform better.

For a Minolta 100/4 auto bellows lens mounted on a lens board, it to cover 4x5:

Extension : Subject Distance : Magnification Factor : Effective Aperture (max - min)
370mm : 7.2in : 2.7x : f/14.8 - f/118
400mm : 7.0in : 3.0x : f/16 - f/128

It might be able to cover a little bit more at lesser magnifications, if it has any excess coverage over 44mm on 35mm cameras (although it sells with tilt/shift bellows racks sometimes, that doesn't necessarily mean it as any excess image circle).

Of course, I could always use it at less than full coverage and just use whatever of the 4x5 is covered.

I wonder how sharp this lens would be on 4x5 at these magnification ratios?

[ic-racer]

An enlarging lens will likely work a little better than the 35mm camera lens and will be easier to fit into a shutter.

In fact KEH has a 60mm Componon in a shutter already for $160.

[dh003i]

An enlarging lens will likely work a little better than the 35mm camera lens and will be easier to fit into a shutter.

In fact KEH has a 60mm Componon in a shutter already for $160.

Even starting at those magnification ratios? 35mm lenses are generally sharper than LF lenses, right? And there are a few macro 35mm lenses that could be used (100/4 Minolta auto bellows, Olympus OM 80/4, Olympus OM 90/2, or even 50/3.5.

The disadvantage of those -- and the componon you mention, which is f/5.6 -- is simply the difficulty of focusing at large magnification ratios. (this doesn't apply to he Oly OM 90/2 so much). This is why I'm thinking about trying to use the 50/1.4 (maybe even reverse mounted? I think it'd then effectively only be 50/2, because of the diameter of the rear aperture), because focusing would be easier.

I get that macro lenses will do better than non-macro lenses used in the macro-range (and to a lesser extent reverse-mounted non-macro lenses used in the macro range) among lenses designed for the same format. But we're comparing 35mm lenses and 4x5 lenses here, and 35mm lenses deliver significantly better resolution to begin with, right?

[Dan Fromm]

Using a 50/1.4 lens for a 35 mm camera as a macro lens is stupid unless the magnification is enormous and the lens is reversed. Even then its not a good idea. This because 50/1.4 lenses for 35 mm cameras aren't that good.

Macro lenses made for 35 mm cameras are another story. I occasionally use a reversed 55/2.8 MicroNikkor AIS on 2x3. Superb lens. Reversing it, getting timed exposures, and using it with flash are easy. I paid SKGrimes to make a ring threaded M52x0.75 (fits the Nikkor's filter thread) on one side and M40x0.75 (fits the front of a #1 shutter) on the other. No need to screw around with hats ... This lens is best at f/4, gets worse as it is stopped down beyond f/4.

I gather that you're concerned about focusing with a small effective aperture. Try it before you give up on it.

If you're going to shoot above 1:1 you should reverse the lens you use unless it is a very nearly (or, sometimes, exactly) symmetrical process lens. In general, reversing a lens designed for working at normal distances when using it above 1:1 preserves its corrections. Using it above 1:1 facing normally just throws them away.

Before you do anything really stupid or expensive, buy a book. Lester Lefkowitz' The Manual of Closeup Photography. And read it. Available from sellers who can be found through any number of services, including but not limited to abebooks.com, alibris.com, and amazon.com.

The idea that lenses made for LF are inherently worse than lenses made for smaller formats has to be stamped out. Don't tell me that it stands to reason, test. Focal length for focal length, there's not much difference. But, other things equal, a short lens can be better than a long one.

Good luck, have fun,

Dan

[dh003i]

Using a 50/1.4 lens for a 35 mm camera as a macro lens is stupid unless the magnification is enormous and the lens is reversed. Even then its not a good idea. This because 50/1.4 lenses for 35 mm cameras aren't that good.

Macro lenses made for 35 mm cameras are another story. I occasionally use a reversed 55/2.8 MicroNikkor AIS on 2x3. Superb lens. Reversing it, getting timed exposures, and using it with flash are easy. I paid SKGrimes to make a ring threaded M52x0.75 (fits the Nikkor's filter thread) on one side and M40x0.75 (fits the front of a #1 shutter) on the other. No need to screw around with hats ... This lens is best at f/4, gets worse as it is stopped down beyond f/4.

I gather that you're concerned about focusing with a small effective aperture. Try it before you give up on it.

If you're going to shoot above 1:1 you should reverse the lens you use unless it is a very nearly (or, sometimes, exactly) symmetrical process lens. In general, reversing a lens designed for working at normal distances when using it above 1:1 preserves its corrections. Using it above 1:1 facing normally just throws them away.

Before you do anything really stupid or expensive, buy a book. Lester Lefkowitz' The Manual of Closeup Photography. And read it. Available from sellers who can be found through any number of services, including but not limited to abebooks.com, alibris.com, and amazon.com.

The idea that lenses made for LF are inherently worse than lenses made for smaller formats has to be stamped out. Don't tell me that it stands to reason, test. Focal length for focal length, there's not much difference. But, other things equal, a short lens can be better than a long one.

Good luck, have fun,

Dan

I just ordered a copy of the book. A few questions for you. You're using a MicroNikkor reversed. That's not a bellows lens, so I presume that it effectively gives you "more extension" than would be indicated by the separation of the bellows, right? Also, when reversing the lens, does the effective f-stop decrease due to the smaller rear aperture? (and how do you compensate for this when doing exposure calculations?).

Thanks.

[Tom Monego]

When I did a long series of macro with my 4x5, I started experimenting with a 90 f8 SA, this lens was (still is) great at infinity but wasn't with bellows extension, just mushy. I bought a 120 f5.6 Apo-Nikor Macro in shutter for the work and never looked back, a great lens at macro and so-so at infinity. An enlarging lens or a 35 mm bellows lenses sound like a less expensive idea. I had a contract I had to do so when my first thought didn't work I decided to get the right tool, I needed 1:1 - 3:1 magnification. I could just barely get the latter on my Calumet/Cambo. If you don't mind spending the $ the 120 Nikor is terrific.
I did try to go with higher mag with some Canon bellows lenses a 20mm and a 35mm, ran into the problem that I didn't have a stand the could hold the camera steady enough for the very high mag 10:1 - 20:1.

Tom

[ic-racer]

Even starting at those magnification ratios?

Without getting into any complicated math, I just imagine the distances between the negative and lens and paper when enlarging. If a macro setup uses similar distances, the enlarging lense will be just as good or identical to a macro lens (assuming its a good enlarging lens to begin with). If you need to reverse the lens or not depends on your setup. Just put the front of the lens toward the long distance.

The main advangage of the enlarging lens is if you have them laying there is nothing additional to buy to try it out.. If you have to buy a new lens, then thats another story.

[Dan Fromm]

I just ordered a copy of the book. A few questions for you. You're using a MicroNikkor reversed. That's not a bellows lens, so I presume that it effectively gives you "more extension" than would be indicated by the separation of the bellows, right? Also, when reversing the lens, does the effective f-stop decrease due to the smaller rear aperture? (and how do you compensate for this when doing exposure calculations?).

Thanks.

Yep, front-mounting adds the shutter's thickness, the adapter adds a couple of mm, and then there's the lens' integral hood and the front cell.

MicroNikkors are sort of symmetrical (being sort of symmetrical is much easier than being sort of pregnant) and their nodes are close to the diaphragm. So to find extension, measure from the diaphragm to the film plane.

Effective aperture = aperture set * (1 + m) where m is magnification, ignoring the correction for pupillary magnification. M = (extension/focal length) - 1. All this is true regardless of the lens' orientation. But note that the pupillary magnification correction depends on orientation. Its all in Lefkowitz.

How do I compensate? Mental arithmetic aided by a tape measure. This also works for flash when I don't use my wonder-working miraculous close-up flash rig what gives the right exposure for a fixed aperture (set) from roughly 1:4 to 2:1 and when I don't use a less miraculous precalibrated flash rig.

Cheers,

Dan

[Dan Fromm]

IC, I don't completely agree with you about enlarging lenses as taking lenses for closeup (magnification up to 1:1) and macro (above 1:1).

Some are very very good. I just love my 4"/5.6 Enlarging Pro Raptar, and by test it is about as good in the range 1:8 - 4:1 as a known good 100/6.3 Luminar. It is very nearly symmetrical -- the two cells' focal lengths are very close -- and doesn't need to be reversed above 1:1.

Others are not so good, e.g., the 80/5.6 Minolta I used to have.

That said, if one has an enlarging lens ready to hand and doesn't own a macro lens, by all means the enlarging lens should be tried out. If it yields good enough results, wonderful. If not, time to go shopping.