Lighting and DOF ?s

[Chris S.]

Jim, if not too late, I would cancel the order for the phase version of this objective.

--Chris

[jmarkus]

It's ok Chris. He already printed the label right after accepting my offer. My CME has a slot through the condenser, for introducing contrast masks and filters, and I have noticed that transparent subjects are difficult to adjust the condenser to get them to show well. Looks like I'll be exploring phase contrast; at least it is another tool in the tool box for modifying light.

[Chris S.]

. . . but I quickly realized I could use the Nikon TC-16A to get a series of images for focus stacking. I've done it before with reversed lens photos. The TC has a group of lens elements that certain Nikon DSLRs AF screw drive can move like when using an AF lens.

What an interesting beast! I know Nikon cameras and lenses reasonably well, but had never heard of this particular teleconverter. Apparently, Nikon introduced it in 1986 to give manual focus lenses autofocus capability with a 1.6x magnification boost. While I've used a number of Nikon teleconverters, none has ever had motor-driven optics.

Which also confuses me about working distances. Some objectives are infinity corrected, some have specific working distances inscribed (170, 200, etc) some merely claim LWD. Those Nikon MM objectives look like you need their specific microscope to use, and I really like the Leica compound scopes I already own.

I think you may be confusing some of the specifications associated with microscope objectives. The 10x objective you just purchased says "160/0.17" on it. The "160" is not a working distance, but the "tube length"--that is, the nominal length of the "tube" of empty air on a finite microscope. This tube went from the shoulder of the microscope objective (where the threads join the barrel) to the top of the microscope where the eyepiece is inserted. In most cases, this specification was given in millimeters, and allowed 10 millimeters for the eyepiece. When using a finite objective on a macro rig, this number is useful because it tells us how far to place the objective from the camera's sensor. In the case of a 160 finite, mount the objective's shoulder 150mm (160mm minus 10mm for the missing eyepiece) from the sensor. Another common tube length is 210--in which case, mount the objective 200mm from the sensor.

For low NA objectives such as 4x/0.20 and 10x/0.30, tube length is not critical. For higher NA objectives, it becomes more so. But knowing the tube length gives you a starting point for using the objective close to the way the original designers intended.

If we define "working distance" as the amount of space between the front of the objective and an in-focus subject, working distances such as 160mm and 200mm would be almost unheard of, and would require serious optical compromises to be made (or very high cost, or both). The working distance of the Nikon 10x 160/0.30 is 9.2mm. WD is often not specified on the lens.

Those Nikon MM objectives have some of the longest working distances found on decent, relatively inexpensive microscope objectives. They do not need to be used on a special microscope, but are very easy to mount on a macro rig. (They would of course not work on your Leica scope, as you know.)

The phrase "Infinity corrected," in microscope objectives, also has nothing to do with working distance. It means that the objective is designed for a lens tube of infinite length. Microscope designers switched to this approach to allow more accessories to be placed between the objective and eyepiece on a traditional microscope. With an infinity corrected objective, one needs a second lens--originally placed inside the microscope's tube--to converge the light from parallel to a point, a step needed to form an image with an eyepiece or camera sensor. This lens is often referred to as a "tube lens" because of where it was mounted, though I often call it a "converging lens" because of what it does.

Neither finite nor infinite objectives have any inherent advantage in working distance. I might opine that neither design has any intrinsic advantage at all, except for that option to place more accessories in the optical path. This said, many classic finite lenses are of older design and manufacture than infinite lenses, and so some infinite lenses have benefited from modern glass types, more sophisticated computer design, and advanced coatings.

Approaches for building macro rigs around either finite or infinite objectives are well understood, but it's vital to know which type of objective you have when designing the macro rig. Finite objectives need a certain distance of empty air between objective and sensor; infinite objectives need a converging lens placed a certain distance from sensor.

(Or, apparently, one can place at least some objectives on a Nikon TC-16a, as you've done. That's new to me.)

--Chris S.

[jmarkus]

Chris,
Thanks for the terminology education - I'm likely to mess up more in the future.

Nikon only made about 1 million of the TC-16A, and they were only intended to work with a about 2-3 film cameras. Someone brighter than I noticed the pins were different on the TC mount, and found that by moving one pin - and a few other mods were later added - made it work on a larger number of camera bodies - including Digital cameras. The hardest part is keeping the springs under control. They seem possessed during disassembly, and like to go on walk-about, or react to metal tweezers that may have the slightest magnetic charge.
Jim

What an interesting beast! I know Nikon cameras and lenses reasonably well, but had never heard of this particular teleconverter. Apparently, Nikon introduced it in 1986 to give manual focus lenses autofocus capability with a 1.6x magnification boost. While I've used a number of Nikon teleconverters, none has ever had motor-driven optics.

[Chris S.]

Jim,

I used to have a pair of Nikon N90s bodies, and telephoto lenses for which this adapter would have worked. Still, not sure I'd have played with it even if I'd known it existed, as I'm moderately allergic to autofocus. I thought autofocus a silly fad when it came along in the 1980's. . . and still do.

But I also suspect my cameras may have light meters in them, and perhaps even automatic modes. How could anyone find use for such frivolities???

--Chris S.

[jmarkus]

Chris,
I started with manual everything, and lived through the advent of auto everything in photography. I still like to shoot in manual mode, picking my apeture, shutter speed, white balance etc. However, when my eyes went wonky in Oct 2023, because I controlled my blood sugar dramatically better (ironic) - I began leaning on AF more. I still use the green dot, or and audible beep when on my ai to eos adapters while using my manual focus Nikkors.

BTW, I shot over 500,000 frames on 3.5 Nikon n90 & n90s camera bodies - before I ever shot one frame of film on them. The N90 was the basis for the first professional portable digital camera ever produced. It was a collaborative effort by Kodak (the sensor), Nikon (the body), and the Associate Press (software). I tested a raft of digital cameras for this effort between 1992-1994 and ended up with one of the very first NC2000AP cameras in 1994. The film bodies shutter would quit at about 150,000 actuations. You could switch out for a new body in about one minute. One giant 4-5 inch screw held the whole rig together, and only required a coin to remove. The new film body you needed to remove one jewelers screw and the back pooped off with a spring loaded pin. Recently when I began shooting film again I got a bunch of used bodies for incredibly low prices ($15-45 each - use to be $1100-1400), and they perform amazingly well with film. A caveat to any n90 or n90s buyer - if the back or battery compartment is missing - it is a spent body used on a digital back and likely inoperable.

Jim

[jmarkus]

I now have the Nikon N Plan 10x/0.30 0.17, and the Nikon N Plan ph1 10x/0.30 0.17. Plus 27mm contrast masks and the CME condenser filter tray are on the way. Examining the ph1 version of the 10x I can see the semi transparent black ring is literally a part of the glass. It is impossible to remove. So the mask and the filter tray are meant to be used with the objective which is why I purchased them. I was able to determine some things of interest to me

1-Side by side the Leica E2 10x working distance is 1-2 mm & and the Nikon is 11-12mm on a prepared slide.
2-There are color differences. The Nikon rendered the same diatom with an aqua background color-Leica a greenish/blue
3-The Nikon 10x objective is definitely sharper than the Leica 10x
4- There is a clarity or accutance (old film term) when combining the Nikon objective with two old Nikon CF PL Photo relay eyepiece lenses. Interestingly, it does not have the same effect with the Leica objectives. There is a slight shimmer to edges that even I, with my poor eyes, can see. It looks stronger with the 2.5x than the 5x, but both have it.

I was so impressed with the recent diatom feature that I thought I would try an old prepared slide I have of "various diatoms". The 10x paired with the 2.5x photo relay lens I believe makes for 25x - plus I cropped it. These diatoms are almost completely transparent. I just used the rheostat on the light and the condenser aperture slider. Hopefully the contrast masks and the ph1 objective can improve on this.

Color or Colour and B&W

[Chris S.]

BTW, I shot over 500,000 frames on 3.5 Nikon n90 & n90s camera bodies - before I ever shot one frame of film on them. The N90 was the basis for the first professional portable digital camera ever produced. It was a collaborative effort by Kodak (the sensor), Nikon (the body), and the Associate Press (software). I tested a raft of digital cameras for this effort between 1992-1994 and ended up with one of the very first NC2000AP cameras in 1994. The film bodies shutter would quit at about 150,000 actuations. You could switch out for a new body in about one minute. One giant 4-5 inch screw held the whole rig together, and only required a coin to remove. The new film body you needed to remove one jewelers screw and the back pooped off with a spring loaded pin. Recently when I began shooting film again I got a bunch of used bodies for incredibly low prices ($15-45 each - use to be $1100-1400), and they perform amazingly well with film. A caveat to any n90 or n90s buyer - if the back or battery compartment is missing - it is a spent body used on a digital back and likely inoperable.

What an interesting story! I certainly read about those early hybrids, but never anything written by someone who used them extensively. I can imagine they were a boon for a news photographer on deadline.

In my early newspaper days, I was the paper's main photographer (also a reporter--small paper) and did the darkroom work for everybody on staff. Running out to get the shot, then running back to soup and print the negs, in time to get the journal laid out and to the printer, was often a tough stretch. Digital would have saved time, I suspect.

This said, I shot a lot of Tri-X (ISO 400) film, and sometimes needed to push it (shoot as if the film were more sensitive to light, and process it a bit differently to make up for the underexposure). (I know you know this stuff--including it for younger folks.) My first DSLR was very light thirsty--basically crap above ISO 200.

So I'm wondering--was ISO a significant problem for those early digital hybrids in press work?

--Chris

[jmarkus]

What an interesting story! I certainly read about those early hybrids, but never anything written by someone who used them extensively. I can imagine they were a boon for a news photographer on deadline.

In my early newspaper days, I was the paper's main photographer (also a reporter--small paper) and did the darkroom work for everybody on staff. Running out to get the shot, then running back to soup and print the negs, in time to get the journal laid out and to the printer, was often a tough stretch. Digital would have saved time, I suspect.

This said, I shot a lot of Tri-X (ISO 400) film, and sometimes needed to push it (shoot as if the film were more sensitive to light, and process it a bit differently to make up for the underexposure). (I know you know this stuff--including it for younger folks.) My first DSLR was very light thirsty--basically crap above ISO 200.

So I'm wondering--was ISO a significant problem for those early digital hybrids in press work?

Chris,
The editorial (news) photographers resisted switching to digital for many years. They already had a way to accomplish the task, and, at the time, it was superior to digital. I worked in the marketing dept, but we did our own sections with editorial content. Our sub department name was "Creative Services", and we had our own editors, writers, photographers, stringers, etc. I ran both film and digital for many years.

It really happened by serendipity when I went to a local photography store to pick up supplies for the editorial photo department (we shared a studio and darkroom), and I took a look see at the new photo gear while waiting for them to collect the press order. There was this Canon video camera (this is 1989) that shot 320x240 pixel digital stills to check lighting and exposure. At that time I would devote an entire day to souping film and printing (Thursday), and I really didn't care for the taste of fixer in my mouth, and not being free to roam and shoot more images. So out of self interest, and to save time and money, I decided to start writing reports about why we needed to go digital asap - and submitting them to management. Even Canon, at that time, wasn't promoting the idea of using digital stills for any practical purpose - other than as a lighting aid. However, it didn't take a Sherlock to figure out that scaling the resolution would happen, and what that would mean to analog photography.

The paper was the flagship of the owners vast media holdings, and all the latest tech was used there first. The first digital created ad that was ever publish was done at The Grand Rapids Press, February 1978 - so there was a history at the paper. Laser cameras, Atex monochrome computers, Unix based Camex ad & page workstations, photographically derived flexible print plates, etc. I was just pointing out something anyone could see could replace or help film photography, and save time & money.

Lucky for me - someone was actually reading these "reports", and boy was I surprised when they showed up with prototype cameras wanting to know what I thought of them. I am profoundly humbled at how lucky I was to be in the right place at the right time. ugh, I'm getting off track.

ISO was a problem. The first sensors were very exposure sensitive - even more so than transparencies like Kodachrome. The N90 had a great feature - auto bracketing (and a great matrix metering system). It did about 4 frames per second. So I set it to one third of a stop increments, and would squeeze off a sequence ranging from under exposure to over exposure - and generate 3-7 frames for every shot. It is part of the reason I wore out so many camera bodies + plus the volumes of photos were very high.

Jim

[Chris S.]

Jim,

Your story gets increasingly interesting the more we hear!

ISO was a problem. The first sensors were very exposure sensitive - even more so than transparencies like Kodachrome. The N90 had a great feature - auto bracketing (and a great matrix metering system). It did about 4 frames per second. So I set it to one third of a stop increments, and would squeeze off a sequence ranging from under exposure to over exposure - and generate 3-7 frames for every shot. It is part of the reason I wore out so many camera bodies + plus the volumes of photos were very high.

Eek—I can see why editorial photographers didn’t want to deal with this. Your workaround, however, seems elegant, and likely practical for the work you were doing. I shot a lot of Kodachrome, some under assignment, but usually not under breaking-news conditions. “Even more exposure sensitive than Kodachrome” sounds, um, challenging. (For any digital-only folks reading who want a challenge, try shooting a film with an ISO of 25 and a dynamic range 4-5 EVs. Extra credit: Do this with a hand-held light meter.)

At that time I would devote an entire day to souping film and printing (Thursday), and I really didn't care for the taste of fixer in my mouth, and not being free to roam and shoot more images.

I spent so many days and weeks in the darkroom that I came to regard it as a dungeon, and desire never to return. I think that a lot of photographers love light (“The camera is not our tool; light is our tool”). If so, it seems ironically cruel that once upon a time, to realize our photographic vision, we had to toil away in darkness.

The paper was the flagship of the owners vast media holdings, and all the latest tech was used there first.

That first small paper I worked for was less a flagship than a rowboat—the only boat owned by a family of modest means, who felt called to perform solid journalism for several small towns. And we did it--really, truly, did a great job--as long as we could. I’m proud of the first class journalism that little paper put out, that I got to be a part of. Alas, the newspaper went bankrupt. To their credit, the family owners, facing ruin, still funded the staff's (meager) final paychecks out of their own pockets.

I later worked for bigger, well-financed publications, and continually observed that journalists (photographic or word) care dearly about informing the public, with studious care for accuracy and fairness. "Find the truth, and tell it to everybody" is what drives them. We all worked long hours and tolerated low pay. The advertising sales people, by contrast, worked much shorter hours, and their cars in the parking lot were a lot nicer than those of the journalists. But no journalist I met ever wanted to change sides.

It breaks my heart to see journalism collapsing around us (in truth, it's mostly collapsed—past tense). I don’t believe a democracy, republic, or any form of self-government can survive without a large, powerful, independent, well-trained, and free-to-act press corps. Dystopian novelists predicted that totalitarians would kill the press; in reality, targeted Internet advertising killed it for them. (Subscription dollars traditionally covered production and distribution costs of newspapers and magazines; advertising created profits, if any.)

Sorry for the digression. Thanks for your posts.

--Chris S.

[jmarkus]

I put to use the Nikon N Plan 10x/0.30 0.17 and the Nikon 2.5x cf-pl (photo relay eyepiece) on a prepared Hydra slide. Also paired it with the Leica E2 4x Plan. I still am not keeping the vibration dampened enough. I literally am considering epoxying a 5/16ths of an inch nut to the head, and putting a threaded rod parallel to the camera adapter tubes, and then attaching to the adapter at 2-3 points along it's length.

Leica 4x

Nikon 10x

[jmarkus]

Chris,

It breaks my heart to see journalism collapsing around us (in truth, it's mostly collapsed—past tense). I don’t believe a democracy, republic, or any form of self-government can survive without a large, powerful, independent, well-trained, and free-to-act press corps. Dystopian novelists predicted that totalitarians would kill the press; in reality, targeted Internet advertising killed it for them. (Subscription dollars traditionally covered production and distribution costs of newspapers and magazines; advertising created profits, if any.)

I agree and the evidence of that is all around us. Nobody is holding politicians accountable - from the local level to the national level. Where I worked advertising funded the whole shebang, and a tradition of getting a newspaper for almost nothing made pushing subscription rates up impossible. Now, you can't get people to read for more than a few seconds anyway.
Jim

[jmarkus]

I have made changes to the microscope, microscope objectives, eyepiece lens, camera adapter, how I mount the camera, camera settings, how I collect the images, and now, how I light some of the 3D subjects. Chris S. has been invaluable with advice, knowledge, and equipment. My latest top down lighting (darkfield-ish) + a slight brightfield-ish combo has got very close to what I was hoping to achieve initially a few months ago. I added cake decorating tips to my translucent balls on the end of the guide lights. Chris had warned me about a loss of resolution that may result in my attempt to bring traditional photography snooted lights down to this level. A "mirror effect" was an accurate description. I decided to embrace the diffusion of light, and choose ragged tips instead of clean holes. It seems to have worked for this subject (there is some reflected light flare) - the Blue Jay feather that had so disappointed me at the very beginning (due to a lack of color) - now shows it's color. Thanks for the help understanding, and the direction guidance.

Cake tipped guide lights

Nikon N Plan CF 10x 0.30

Nikon M Plan CF 20x 0.40 ELWD

Nikon M Plan CF 40x 0.50 ELWD

[jmarkus]

Just straight brightfield (transmitted light) images of a stained pine leaf cross section. Was practicing condenser aperture and height adjustments.

Leica E2 Plan 4x 0.10

Nikon N Plan CF 10x 0.30

Nikon M Plan CF 20x 0.40 ELWD

Nikon M Plan CF 40x 0.50 ELWD

[jmarkus]

Just top down (reflected lighting) of the eagle (and then it's eye) on the back of the one dollar US note. Cake decorator - translucent ball tipped guide lights used on the last four.

55mm f3.5 ai + modified TC-16A - Area of interest

L:eica E2 Plan 4x 0.10

Nikon N Plan CF 10x 0.30

Nikon M Plan CF 20x 0.40 ELWD

Nikon M Plan CF 40x 0.50 ELWD