Teach me about Lens Design

[giganova]

Hi all --

After having exclusively shot b&w film on 135 and 120 film since the 1980s, I recently got into LF photography and love it! Got me a nice Linhof Technika 4x5 and a couple of lenses. My frustration -- which is ironic! -- is that I find those more modern lenses way too sharp and clinical. What I am after is a more vintage look, moderately sharp in the middle, with a drop-off in image quality as you go further from the optical axis, a tiny DOF (being aware that focal length beats aperture), and use the movements of the camera to place the focal point where I want it. Sally Mann's images come to mind, even though I am aware that she uses collodion plates and ULF, a look that is hard to achieve with 4x5.

In other words, I am looking for a lens that is far from perfect.

Over the past weeks I have studied various lens design (e.g., Artar, Dagor, Plasmats, Petzval, Tessar ...) and did some search which images were taken with those lenses. Short of actually owning vintage lenses, I'm still not entire sure how these lenses actually perform. The closest I have gotten to the look I desire is by removing the rear group of two Dagor-design lenses that I have (two Schneider Symmars, one modern, one un-coated from the 60s, which I like best).

What options do you think I should pursue? Get a vintage brass lens, mount a Packard Shutter behind it, use it wide open and use ND filters to regulate exposure? Maybe a triplet or an old Tessar?

[Mark Woods]

I'd look into the Imagons. I have two of them, a 200mm & a 300mm. The amount of diffusion depends on the disk that is used. Love them!

[Bob Salomon]

I'd look into the Imagons. I have two of them, a 200mm & a 300mm. The amount of diffusion depends on the disk that is used. Love them!

+1. But the effect also depends on the type of lighting, a greater lighting ratio and practice.
However, depth of field is greater with an Imagon then other lenses of the same focal length and aperture.

[MAubrey]

Picking up a copy of Rudolf Kingslake's (1989) A History of the Photographic Lens would be worthwhile!

[giganova]

Great suggestion!

[Dan Fromm]

OP, what you're asking for is is exactly lens manufacturers have not tried to make. Your best bet in conventional (= not deliberately soft focus) lenses is an old relatively fast (f/4.5 or perhaps even f/3.5, certainly not f/6.3) Tessar type shot near wide open. Old means no later than the mid-1920s. Or a fast Heliar type, again shot wide open. And somewhat shorter than normal for 4x5. In other words, not a 150, probably not a 135. Think 120 - 130 mm.

[Bernice Loui]

Camera is not relevant until your image goals and what lens and all related has been decided. Then the choice of camera is decide based on the lens's suitability to any camera choice.

Back up more than a few steps, consider what your image goals are or what specific kind of print images would you like to produce?

As exampled by Sally Mann, personalty I don't care for her images made using collodion plates and ULF and all that, the Sally Mann images that interest me were LF images of her kids growing up from decades ago. Know this is an opinion and not a lot more than an opinion.

LF lenses are essentially divided into two basic groups, sharp or idealized optical performance and sort of focus or lenses specifically designed to have what are considered optical flaws specifically designed into the lens.

As for sharp -vs- maybe less sharp, this could be a expression of contrast more than "sharpness" of any given lens as higher contrast can often deliver the illusion of sharpness. All of those "vintage" lenses mention "Artar, Dagor, Plasmats, Petzval, Tessar" can be plenty sharp in every way. The Symmar from the 1960's IS coated, single coated. If you're drawn to the image this lens produces, it is likely due to lower contrast not "sharpness".

The other factor that is often not considered enough, lighting, composition, film processing then print making. It all functions as a print making system with the camera being relegated to being nothing more than a light tight box that is flexi in the middle.

If you go into the direction of soft focus LF, know 4x5 is too small a film format. There are plenty that will completely disagree with my assertion of this. Fact is, soft focus lenses used on 8x10 film then contact printed with proper lighting of the subject to achieve an image in mind is special.. and not a print image that can be equaled by enlargement of a smaller film format.. been there, done this.

For now, it might be best to spend plenty of time in museums, art exhibits, Foto galleries and such to take in as many images as possible to aid in figuring out what your print image goals are.. then it is time to consider and figure out how to achieve that. Once you're at a place where some of these print image goals are met, ponder how you can impose your own style and personality upon these print image goals.


Bernice




Hi all --

After having exclusively shot b&w film on 135 and 120 film since the 1980s, I recently got into LF photography and love it! Got me a nice Linhof Technika 4x5 and a couple of lenses. My frustration -- which is ironic! -- is that I find those more modern lenses way too sharp and clinical. What I am after is a more vintage look, moderately sharp in the middle, with a drop-off in image quality as you go further from the optical axis, a tiny DOF (being aware that focal length beats aperture), and use the movements of the camera to place the focal point where I want it. Sally Mann's images come to mind, even though I am aware that she uses collodion plates and ULF, a look that is hard to achieve with 4x5.

In other words, I am looking for a lens that is far from perfect.

Over the past weeks I have studied various lens design (e.g., Artar, Dagor, Plasmats, Petzval, Tessar ...) and did some search which images were taken with those lenses. Short of actually owning vintage lenses, I'm still not entire sure how these lenses actually perform. The closest I have gotten to the look I desire is by removing the rear group of two Dagor-design lenses that I have (two Schneider Symmars, one modern, one un-coated from the 60s, which I like best).

What options do you think I should pursue? Get a vintage brass lens, mount a Packard Shutter behind it, use it wide open and use ND filters to regulate exposure? Maybe a triplet or an old Tessar?

[Havoc]

Alan Greene describes 2- lenses to make yourself in his book "primitive photography". They are based on old designs. Might be a starting point. They don't have a shutter, can't recall if they have apertures (probably waterhouse stops).

[J. Patric Dahlen]

OP, what you're asking for is is exactly lens manufacturers have not tried to make. Your best bet in conventional (= not deliberately soft focus) lenses is an old relatively fast (f/4.5 or perhaps even f/3.5, certainly not f/6.3) Tessar type shot near wide open. Old means no later than the mid-1920s. Or a fast Heliar type, again shot wide open. And somewhat shorter than normal for 4x5. In other words, not a 150, probably not a 135. Think 120 - 130 mm.

I agree with most of this. And older lens made to be sharp, so not a soft focus lens. I would personally not use shorter focal lengths than meant for the format. Yes, that would introduce softer/blurrier corners, but since the focal length wouldn't match the format this effect would feel artificial. At least for me. I wouldn't exclude three element lenses, as they were made to be sharp at a lower price point. They will have less critical sharpness in the corners even when you stop down a bit for DOF. From the German manufacturers you have triplets like Radionar, Trinar, Trioplan, Corygon, Actinar, preferably in a Compur shutter. And there are of course American made triplets.

[Oslolens]

Go to Flickr.com and search for Calceman. I had his contact copies in hand, and seen the toned cyanotypes, wonderful!

Sent fra min SM-G975F via Tapatalk

[Bernice Loui]

Seen some prints made from glass plates dating back to about 1900 or just before 1900. These prints have quite remarkable definition, detail, contrast rendition.

Point being optics or lenses and photographic materials dating back to 1900 can produce rather remarkable image results.


Bernice

[Dan Fromm]

Seen some prints made from glass plates dating back to about 1900 or just before 1900. These prints have quite remarkable definition, detail, contrast rendition.

Point being optics or lenses and photographic materials dating back to 1900 can produce rather remarkable image results.


Bernice

Bernice, I've been looking at lens articles in the Bulletin of the French Photographic Society. It is clear that from 1855, when the Society started publishing, lens makers and photographers prized coverage, by which they meant the circle covered with good definition, contrast, even illumination and depth of field. The OP has picked up on a modern fad that involves lens abuse in one form or another.

There's nothing wrong with the fad or joining it. Tastes differ. People should do what pleases them and not worry about what pleases others. But it is completely wrong to assert that old lenses -- the typical faddist is very vague about when old ended and modern began -- were intended to produce what non-faddists see as poor image quality.

[giganova]

Hi Bernice --


For now, it might be best to spend plenty of time in museums, art exhibits, Foto galleries and such to take in as many images as possible to aid in figuring out what your print image goals are.. then it is time to consider and figure out how to achieve that. Once you're at a place where some of these print image goals are met, ponder how you can impose your own style and personality upon these print image goals.

I have visited exhibits, museum shows, galleries, studied photography books and artists monographs, light & composition, developed and printed myself for my entire life and I know exactly what I am striving for in my art. My question was more of a practical one, i.e. how vintage lenses render since I don't have one. I do agree with the concept of contrast vs sharpness.

[Dan Fromm]

Hi Bernice --



I have visited exhibits, museum shows, galleries, studied photography books and artists monographs, light & composition, developed and printed myself for my entire life and I know exactly what I am striving for in my art. My question was more of a practical one, i.e. how vintage lenses render since I don't have one. I do agree with the concept of contrast vs sharpness.

I've already told you that you want to practice lens abuse and made practical suggestions that might get you what you want. Old, old fast (f/4.5) Tessar a bit shorter than normal and shot wide open. Try it, you might like it.

I didn't remark on your goals because they're yours. They're not mine, but that doesn't bother me. You're allowed to have your own objectives, pun intended.

[Bernice Loui]

Dan,

This is the first time I've heard of the current fad of abusing lenses by using them in parts or etc.
Guess this is an extension of GAS? or trying to be creative by imposing experimentation upon image making devices to achieve some unexpected result?

There is a clip from the Sally Mann documentary where one of her images were of happenstance that became appealing. This reminds me of digital camera folks who zip off a Ga-Zillion digital images with none worthy.

This creativity, in ways yes, but it appears to be a very iffy way to achieve an expressive image.


Bernice







Bernice, I've been looking at lens articles in the Bulletin of the French Photographic Society. It is clear that from 1855, when the Society started publishing, lens makers and photographers prized coverage, by which they meant the circle covered with good definition, contrast, even illumination and depth of field. The OP has picked up on a modern fad that involves lens abuse in one form or another.

There's nothing wrong with the fad or joining it. Tastes differ. People should do what pleases them and not worry about what pleases others. But it is completely wrong to assert that old lenses -- the typical faddist is very vague about when old ended and modern began -- were intended to produce what non-faddists see as poor image quality.

[Tin Can]

All is fair in Love and War

aka laissez faire

[drew.saunders]

Hi all --


What options do you think I should pursue? Get a vintage brass lens, mount a Packard Shutter behind it, use it wide open and use ND filters to regulate exposure? Maybe a triplet or an old Tessar?

I have four single-coated "fast" Tessar design lenses:
A real Zeiss 165/3.5 Tessar T
Schneider Xenar 180/4.5
Fujinar 210/4.5
Fujinar 250/4.7

They may still be too "modern and sharp" for your needs, but they're reasonably priced, and all of mine are in shutters. The Fujinars are in reasonably modern Copal 3S shutters. You might want to try one of them, worst case, you find another buyer. I would describe them as "gentle focus" not soft focus when wide open, and quite sharp (except the Xenar) when stopped down just a bit.

I also have a 250 Imagon, and it's quite different, but also worth investigating, and also not obscenely expensive. Mine was a reasonably recent one in a modern Copal 3 shutter.

[giganova]

I tested "abusing" lenses by removing the rear groups from symmetrical lenses and liked the outcome quite a bit. This was a quick test and can still be improved substantially by using the camera's movements to put the focal point on the eyes. All tests with lenses fully opened. I particularly like the image at the bottom right, which is a single-coated Schneider 150/265 convertible with the rear element removed. Look at the the softer skin and interesting bokeh:

https://live.staticflickr.com/65535/50139778587_b2713e255e_h.jpg (https://flic.kr/p/2joFtka)Convertible_Lens_Test (https://flic.kr/p/2joFtka)

[giganova]

I like your <1920s f/4.5 Tessar recommendation and will buy one to test it. They are rather cheap ($100-ish) and if I slap a ND filter in front of it, I can easily get 1-sec exposure time at f/4.5 for a "lens cap shutter" and don't have to worry about missing or kaputt shutters.

[Bernice Loui]

There is only one way to really know if any given lens-optic works for your image making, obtain it, run some very basic test, if these basic test are ok enough, use it LOTs to decided if that specific lens-optic is for you. Once any given lens is a known tool, make it a keeper.

Difficulty with making film images with older lenses, most are in barrel with no shutter and can be BIG depending on focal length, full aperture and barrel.
These older or vintage lens realities does not go well with a Linhof Technika as that camera is limited to size of shutter, size of lens, length of bellows (regardless of what some say about the Technika having plenty of bellows). It is really a field folder and might not work at all with some of these older vintage lenses.

It's much about that saying, "one picture is worth a thousand words." To learn and discover what lenses-optics work for you, trial is a requirement.

There are some basic generalizations that do apply. Modern multi-coated LF lenses tend to be higher contrast and optimized optical performance around f22. They are more similar than different. Most are in shutter, most work as designed and intended for commercial image work back in the era when LF was the point of reference for high quality photographic images. Or, they can be mostly and generally put into this group-set.

One generation back brings up lenses like Kodak Ektar, Schneider Xenar, and such. These lenses in shutter often need their shutter serviced in some way due to neglect and age. Many can be had in barrel with lots of iris blades which aid in out of focus rendition. This generation of normal focal length lenses remain favored over modern multi-coated lenses by many LF folks.

Older yet comes Dagor, Dialyte, Triplets, a long list of Tessar (Kodak commercial Ektar, Schneider Xenar) , Gauss and numerous others that evolved and improved to the generation of lenses above.

What remains is the reality of obtaining lenses-optics, testing, using and Deciding yes-no. There is no way to effectively escape this fact.


Bernice









Hi Bernice --

I have visited exhibits, museum shows, galleries, studied photography books and artists monographs, light & composition, developed and printed myself for my entire life and I know exactly what I am striving for in my art. My question was more of a practical one, i.e. how vintage lenses render since I don't have one. I do agree with the concept of contrast vs sharpness.

[giganova]

Good points, Bernice, much appreciated.

[Bernice Loui]

Image contrast is all over tonal scale in these four different images and images transmitted via web are no where near idea to "judge", but ok..

Based on your mention of preferring the bottom right image and this head shot outdoors, going to make a totally biased recommendation and suggestion. Get a 10" f6.3 Kodak Commercial Ektar or 250mm f4.5 Xenar or similar tessar design lens. Suspect these will render closer to what
you're after. Both the C. Ektar and Xenar are GOOD at f8, Xenar is softish at f4.5, C. Ektar is not softish at f6.3 full aperture.

The single element convertible focal length about 265mm is a reasonable 4x5 focal length for a head shot like this.

Problem might be, both the Kodak C. Ektar and Schneider Xenar might be a bit big on a 4x5 Technika to handle. The 10" Kodak Ektar is modernly common in shutter, the 240mm Xenar in shutter is not. There are a number of other 250mm_ish tessar View camera lenses in shutter similar in many ways to these two suggested. What ever lens is decided upon, testing is a MUST do. There is no way out of the testing, evaluating and deciding process before any individual lens is considered to be a keeper.

Keep in mind there is reason why modern multi-coated view camera lenses have a high contrast, hard hitting image result often optimized for f22. It has much to do what who used a view camera during that time, the images expected and what the bulk of the market demanded from sheet film images. Majority of 4x5 view camera images from that era were for marketing-advertising. The fashion and expectation at the time was often hard hitting, eye poking images of color. Since this was what the majority of the market expected, this is what companies that made view camera lenses designed, produced sold. View camera back then was never a "hobby" film format, some tinkered in it, most were trying to put food on their table, roof over their head and studio and make ends meet producing advertising images and related. Essentially, all involved had to meet a specific level of quality and performance if they were to survive at all. This is why modern lensed produced by the big four are mostly similar and built to last the demands of daily image making day in, day out.

This was not quite the image fashion and expectation one generation back, thus the lenses, film and images produced reflect this. Today that world has been flipped around where once monorail cameras used in a controlled studio setting has been mostly replace by field folders that were a niche market and were considered out of the main stream of view camera photography. Since then the field folder camera crowd has become the majority and a reflection of how the LF market and image makers have changed.


Bernice





I particularly like the image at the bottom right, which is a single-coated Schneider 150/265 convertible with the rear element removed. Look at the the softer skin and interesting bokeh:

[LabRat]

If on a budget, you can try Tessar types in a shutter by finding old Wollensak lenses that would go on SG'S or other cameras... Plenty of 127/135/150/210mm lenses to try for not much $$$... Sharpish, with a smoother rendering than modern lenses...

You might like them!!!

Steve K

[giganova]

Based on your recommendations, I bought a 1937 uncoated Carl Zeiss Jena Tessar 150mm f/3.5 lens in a Compur shutter that was recently CLA-ed. Shutter speeds sound good.

Also bought a blank lens board and need to find a local machine shop to drill a 57mm hole in it. I actually bought two: one 3D-printed to test the lens and if I'm happy I'll permanently mount it in an original blank Linhof metal lens board that needs a hole.

Now, in oder to use the lens wide open, I intend to use ND filters. Problem is that the lens seems to have a rather rare 50mm filter thread and filters in that thread are nowhere to be found. So I ordered a set of 52mm ND filters that I can put over the lens in reverse and use tape to secure the filter to lens. Not ideal but should work.

Will post pictures soon, so stay tuned.

[Bob Salomon]

Based on your recommendations, I bought a 1937 uncoated Carl Zeiss Jena Tessar 150mm f/3.5 lens in a Compur shutter that was recently CLA-ed. Shutter speeds sound good.

Also bought a blank lens board and need to find a local machine shop to drill a 57mm hole in it. I actually bought two: one 3D-printed to test the lens and if I'm happy I'll permanently mount it in an original blank Linhof metal lens board that needs a hole.

Now, in oder to use the lens wide open, I intend to use ND filters. Problem is that the lens seems to have a rather rare 50mm filter thread and filters in that thread are nowhere to be found. So I ordered a set of 52mm ND filters that I can put over the lens in reverse and use tape to secure the filter to lens. Not ideal but should work.

Will post pictures soon, so stay tuned.
LInhof boards, real ones, either have a 0, 1 or 3 hole or a pilot hole. No blank boards.
You don’t drill a board, it’s milled. Your machinist would no or you could just have PromCamera in DC do it for you.

[Bernice Loui]

GOOD!

Might be easier to make a test lens board out of heavy card board- mat board. If flat, this could be easier than 3D printing a lens board.

Testing is the only way to really know if this individual lens is for you.


Bernice




Based on your recommendations, I bought a 1937 uncoated Carl Zeiss Jena Tessar 150mm f/3.5 lens in a Compur shutter that was recently CLA-ed. Shutter speeds sound good.

Also bought a blank lens board and need to find a local machine shop to drill a 57mm hole in it. I actually bought two: one 3D-printed to test the lens and if I'm happy I'll permanently mount it in an original blank Linhof metal lens board that needs a hole.

Now, in oder to use the lens wide open, I intend to use ND filters. Problem is that the lens seems to have a rather rare 50mm filter thread and filters in that thread are nowhere to be found. So I ordered a set of 52mm ND filters that I can put over the lens in reverse and use tape to secure the filter to lens. Not ideal but should work.

Will post pictures soon, so stay tuned.

[grat]

GOOD!

Might be easier to make a test lens board out of heavy card board- mat board. If flat, this could be easier than 3D printing a lens board.

Having carved a lens board out of corrugated cardboard, and 3D printed one, I can honestly say, the 3D printed board was easier-- Granted, I have a 3D printer, which puts me a step up, and linhof-style board designs can be downloaded. It didn't help when I discovered the cardboard was slightly translucent.

Also, while I'd be willing to take the 3D printed board out in the field, the cardboard mock-up would never leave my house.

[giganova]

I found someone who sold me a 3D-printed lens board for $10, so I use that for testing. Is drilling a hole with a step-drill bit OK?

[Bernice Loui]

Do step drill bits go that large, think it was 57mm? Ideal way is to set up the board in a lathe and bore the hole to the size needed. Making a hole in plastic can be as difficult as aluminum.


Bernice


I found someone who sold me a 3D-printed lens board for $10, so I use that for testing. Is drilling a hole with a step-drill bit OK?

[Havoc]

Easiest way is to fly-cut in a mill. Setting up a thin board like that in a lathe isn't that easy. Certainly as it isn't circular.

[MartinP]

Making the board from 3mm birch ply, with a fretsawed-and-sanded hole would be quick and easy, and both stronger and more reliable than mattboard. If there aren't enough threads to get through 3mm of wood you can always put a 1mm aluminium mounting plate on the lens/shutter, then bolt that to the ply board. These sorts of materials are available in any model-making outlet or hobby-shop.

[giganova]

Do step drill bits go that large, think it was 57mm?
Yes, I bought one on Amazon (https://www.amazon.com/gp/product/B07CMPH9VY/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1) that goes to 2 3/8" = 60mm. The 2 1/16 size (= 56mm) should work with a bit of sanding.

[LabRat]

I usually make lensboards out of hobby basswood... To build thickness, I layer pieces with grain layers crossing for best stiffness while staying very flat... Easy to cut with utility knife, sand, and cut holes into...

Adjustable auger bits work good for smaller holes (in a drill press, or soft enough by hand power), or even cheap hole saw sets for over 2 1/4" holes... Even poking enough small slits into the basswood with an Xacto knife will allow hole to emerge...

My fave hole maker for wood boards is a circle template attachment for a router... Makes a very nice hole in 1/16" increments... Mine goes from about 1/2" to over 6" diameter... And can make stepped holes if carefully planned...

Steve K

[giganova]

I drilled a 57mm hole with a step drill bit. Wasn't easy and I wouldn't recommend using a step drill bit, but I made it work. Its a bit off-center but I can use the camera movements to correct that.

Next: test photos! :D

https://live.staticflickr.com/65535/50251996223_6c97e97cf9_c.jpg (https://flic.kr/p/2jyABHZ)Tessar_150 (https://flic.kr/p/2jyABHZ)

[giganova]

Also, I bought a cheap 52mm filter, removed the glass, put it "inverted" over lens (perfect fit!) and secured the filter ring with electrical tape to the lens barrel. Now the lens has a filter thread and I can screw in 52mm ND filters (inverted) to use the lens wide open. Clever, huh? ;)

https://live.staticflickr.com/65535/50252029433_63f2a9fe11_c.jpg (https://flic.kr/p/2jyAMAz)Tessar_150_2 (https://flic.kr/p/2jyAMAz)

[goamules]

... more modern lenses way too sharp and clinical. What I am after is a more vintage look, moderately sharp in the middle, with a drop-off in image quality as you go further from the optical axis, a tiny DOF ... Get a vintage brass lens, mount a Packard Shutter behind it, use it wide open and use ND filters to regulate exposure? Maybe a triplet or an old Tessar?

I didn't see this the past few days, but to me, if you want a fairly assertive "old" look, you have to use a fairly old or uncorrected type. Your example shots are looking nice, but very sharp and just some secular highlights in the background out of focus area. Any lens can do that.

If you are looking for fall off within the focal plane, vs behind, I'd consider a Petzval to get more of that look. It's a little hard to get one that will cover a 4x5 well and still fit a lensboard, but it can be done. This is a shot I did on 4x5 with a Cox petzval. Click for larger to see DOF.

https://live.staticflickr.com/65535/49855702832_b0129cea9f_c.jpg (https://live.staticflickr.com/65535/49855702832_92519c75f0_h.jpg)

Many today are getting quasi-petzval looks with very fast or very poor lenses. This cine lens I like on m4/3 is probably a petzval type, and again shows the look. If you don't like swirl, just get a slightly longer lens, if you can fit it on the board.

https://live.staticflickr.com/3727/12770225243_613195de1d_c.jpg

[giganova]

Thanks, Garrett! Your image of the chair is pretty extreme. :o Below are two pictures I took with a single-coated Schneider 150/265 convertible and rear group removed at full aperture. Maybe not the best example because almost everything is at infinity, but you can see tons of aberration/coma (?) except in the middle. I want to go further than that, somewhere between your and my picture.

https://live.staticflickr.com/65535/50253021542_ce7fe7aa06_b.jpg (https://flic.kr/p/2jyFSvU)Coveys_Landing_1_2_2000pix (https://flic.kr/p/2jyFSvU)

https://live.staticflickr.com/65535/50253047232_0bfc330bb3_b.jpg (https://flic.kr/p/2jyG19Q)Hillsboro_Landing_1_3_2000pix (https://flic.kr/p/2jyG19Q)

[giganova]

First photo taken with the 1930s Zeiss Tessar 150mm f/3.5 at full aperture with a 4-stop ND filter. Lovely low-contrast, soft, but sharp lens.

Thank you all for the recommendations!

https://live.staticflickr.com/65535/50256970777_ee3fed5a7a_b.jpg (https://flic.kr/p/2jz37ua)Zeiss_Tessar_150_2_2000pix (https://flic.kr/p/2jz37ua)

[Bernice Loui]

Excellent result :)


Bernice




First photo taken with the 1930s Zeiss Tessar 150mm f/3.5 at full aperture with a 4-stop ND filter. Lovely low-contrast, soft, but sharp lens.

Thank you all for the recommendations!