Simlar 5cm F1.5 lens- Flood Cleaning

[Brian]

I "took a gamble" on a rare lens and camera on Ebay, one that had been in storage for many years. The Leotax arrived, with 5cm F1.5 Simlar lens and a Canon 85/2. Cosmetically, all were near mint. The Canon Aperture was inoperative- a quick disassembly and flood cleaning took care of the mechanism.

The SImlar was what I was really after. It turned out to be #74 of the series. Later, found photo's of an earlier one, #17,which stopped down only to F12.5. Found a photo pf a later one, which had the retaining screws for the focus mount on the outside, like a Leitz LTM lens. This one went to F16 and had four retaining screws inside the mount.

And is was completely frozen.

Ronsonol to the Rescue. I let it soak for three days. After the first day, I managed to get the four retaining screws out. After the second day, "it budged". Today, It is "100%". I put the rear cap on the lens and filled it with lighter fluid, and a little machine oil. Worked it back and forth, added a little more machine oil. Once it was freely rotating, I used vacuum pump grease on the helicals for a nice, smooth motion.

[Brian]

This is a fairly rare lens- probably about 1/3rd the number made as Canon 50/1.5's. The latest one that I've seen on Ebay is numbered in the low 4000's. Construction changed several times through the run, judging by the photo's that I've seen. This one takes 39mm filters, later ones are stated to use 40.5mm.

Some references state that the Simlar is a Sonnar copy. It's not. It's not a copy of the Xenon/Summarit, either. I'm not sure "what it is", so the test roll will be interesting. The element behind the aperture is concave, typical Sonnar lenses have a flat surface on the inside rear element. The diameter of the rear element is larger than the Sonnar, closer to the Summarit.

[Brian]

The front section unscrews fairly easily, then unscrews into two parts. The front element is held in by a retaining ring from the rear. The 2nd group is also held in by a retaining ring, but I am not taking it apart. Not worth messing with the alignment of such a rare lens. I'm not sure if it is a cemented triplet, or two groups. I left the Leitz 39mm filter on the lens, hence the "Germany" that you see. Note the "10" inscribed on the group. I suspect this is the 10th lens of that batch. I also suspect this is one of the first batches that was redesigned for F16.

[Brian]

It's fortunate that all of the glass could be removed to get to both sides of the aperture blades. Flood cleaning with Ronsonol (lighter fluid) was all that was required to regain a smooth and easy motion with them. I'd like to see the inside of the earlier lens that stopped down to F12.5. But I'm not buying it for $1000 to find out.

[Brian]

I'll post some test results from the lens in a week or two, will be trying it out today.

If you pick up any frozen lenses, that seem like they were glued tight, it's probably old and baked grease. Ronsonol to the Rescue.

Family Portrait- Pre-war Sonnar, Simlar, and Summarit. All 5cm F1.5 Leica Thread Mount lenses that start with an "S".

[Tom A]

Brian, interesting lens. The mount resembles a 50f2 Nikkor in LTM mount. Looking forward to see your test shots with it. I used to have the Simlar 50f3.5 - it came on an old Leotax. Nice. but flared a bit. Never tried the 50f1.5 though. Ronsonol is the "magic" elixir - it will dissolve decade old grease and evaporate easily without leaving a residue.
Tom

[digitalintrigue]

Yes, it's indeed a spitting image of an LTM Nikkor. Nice restoration. :)

[Brian]

I'll get some shots next to the Rigid Mount LTM Nikkor 5cm/2. I've taken apart some 5cm F1.4 Nikkors, the mount of the front group reminded me of it.

This mount is a single-helical design. The entire lens rotates with the focus. Explains the two aperture scales.

[raid]

Brian,

This is quite interesting. I will read up on the Leotax and its lenses. You never know what I could encounter on a lonely evening online ...

[Brian]

Yes, we are wild and crazy guys! Going online late in the evening, hoping to get hooked uo with 60 year old camera equipment...

Excitement Abounded in the Sweeney Household when the helical finally freed up! Well, i was excited anyway. Nikki posed for pictures with the new lens. With one hand in Red Nail polish, and the other in Blue! If I get her to where the green hair braid, I can get an RGB test.

[Trius]

Drumming fingers on desktop, waiting for pics. ;)

[Brian]

Two test rolls went in yesterday for processing. Trip to the Udvar Hazy Air and Space Museum, Simlar on one camera and a LTM-converted 1939 5cm F1.5 "T" Sonnar on the other.

[digitalintrigue]

I'm waiting for pics, as well!

My father is listed on the Wall of Honor at Udvar Hazy...

[Brian]

That is cool! We go there a lot. The second phase is underway, they are moving the restoration work from Silver Hill to the Udvar Hazy.

Thet also have a nice collection of cameras there.

[Brian]

I got the test roll of the Simlar, will scan some negatives this weekend. I also have a war-time LTM Sonnar to repair for a friend. So I will be time-slicing. The Sonnar is WAY off, and I think I know why...

The SIMLAR- I believe it is closer to a Xenon/Summarit than it is to Sonnar. Soft wide-open, low-contrast, nice out-of-focus areas, but not as many "Swirlies" as a Summarit- meaning better corrected for astigmatism. I have a second roll loaded up for it. The original Simlar's (SN 150017 photo that I found) went to F12.5, which is more of a Leica progression than what Zeiss used. Early 5cm F1.5 Sonnar's went to F11, and they changed to F22 with the "T" Sonnar's in ~1939. The pre-war TTH Xenon made by Leitz went to F9. F12.5 would have been the logical next step. My lens, 150074, goes to F16.

Will scan and post. I'll also be doing macro shots of the LTM Sonnar as it gets a rebuild.

[raid]

I am interested in how much this lens is worth and in seeing results with it. Is it more a collector's item or does it have any optical features that are better than what you get with an uncoated 5cm 1.5 pre-war Zeiss Sonnar?

[Brian]

Okay- being honest here...

Collector's item if sharpness is the sole measure. It's more like a pre-war Leitz Xenon or Summarit. The Sonnar "blows them away" on Sharpness. So "Signature" and mood of a lens comes into play.

And collector's item as it is low-volume and not readily available. Most seem to have been snapped up by collectors, or the ravages of time.

I'll scan some negatives this week. I'm taking the lens out again for more test shots as well.

Today was spent reviving the Wartime SOnnar.

Thread on it is coming.

[Brian]

I was happier with the test roll that came back today. The test shots had more to identify.

Overall, I believe this lens exhibits the characteristics of a Xenon formula lens. I think it is fashioned after the pre-war Leitz Xenon, manufactured under license to TTH.

These are at F1.5, on the Leica IIIa.

[Brian]

Also wide-open, full-frame and tight crop. I use an Epson 3170 flatbed scanner for negatives. I spend my money on Cameras, not Computer gear.

[Brian]

One more for the Bokeh.

At F1.5, full-frame and Tight Crop

[Brian]

And as I fixed the Aperture Mechanism...

Stopped down to F5.6. The Simlar was quite good stopped down a bit, really good at F4. This is like a Summarit.

[Brian]

This lens is back in working order again. It's got a Xenon/Summarit signature. In terms of sharpness, the Sonnar and Nikkor "blow-it-away" used wide-open.

I'll be doing some more comparisons with it. Shooting with the Summarit, Nikkor, and Sonnar.

Is this lens worth twice the price of a Wartime Sonnar in LTM or a Leitz Xenon that some sellers want for it.... No. In terms of rarity, it is more common than a Nikkor 5cm F1.5. I suspect there were about 4,000 of these made, about 1/3rd the number of Canon 50/1.5's. That is going by SN's of lenses on Ebay acutions. I could be off, and there could be holes in the SN blocks that occur with design changes. But 4,000 is as good of a guess as any. Mine is the 74th lens made, which did not occur to me until I took it apart.

I like this lens. Of course, I like Summarit's, and Nokton's, and Sonnar's, and Nikkor's, and Canon's, and most lenses that were designed without the aid of a Computer.

[Brian]

The Leotax is back with new shutter curtains, shutter working, VF/RF completely restored. Youxin Ye is really good. This body was in storage for 3 5years. The only "design flaw" that I see with it is the 1.5x RF does not have a diopter adjustment, something Leica featured. Usable, but I will be looking to hack a correction lens. It's just glass.

[digitalintrigue]

Thanks for the updates, Brian. I too like the look of these old lenses. I have some 'new' old glass but haven't had time to try them out yet. I came across this a few days ago, do you know anything about it? http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=270328905271

Would be a nice lens for a thread mount conversion...

[Brian]

I think that lens would do well on an M8 or RD-1. On a full-frame camera, the image circle will probably not cover the frame.

Looks like C-Mount, so a conversion should be possible.

[Brian]

I created an album for some shots with the Simlar. This is an uncommon lens, and I've not found too many example pictures with it. The scans came out better than the prints.

http://www.ziforums.com/album.php?albumid=92

[furcafe]

In response to our exchange on the ZICG, here are a couple of my Simlar examples:

http://www.flickr.com/photos/furcafe/35214834/

http://www.flickr.com/photos/furcafe/94382577/

If you want to see all of my uploaded Simlar shots, just click on my flickr tag for the lens. I think I've gotten similar results to you, though mine front-focuses quite a bit @ close distances (just like a 1950s rigid Summicon I have) & presumably needs to be adjusted.

I've never taken mine apart, but it does seem to be extremely well-constructed, like the Leotax cameras of the same era. My Simlar came w/a Leotax S, #29631, which needs a complete overhaul/restoration (I haven't bothered because I have another working S body) & has a 40mm filter ring.

I would be interested in seeing photo's from your Simlar, if you have some scanned. Mine is early (150074), but I've seen photo's of one
that is even earlier (150017) that stopped down only to F12.5. After taking this one apart, it's got a real "hand-made, hand-fitted down to the last screw" feel about it. I suspect the design continued to be improved throughout the run. This lens came on an early D-IV, sn 9188.
Youxin Ye did a wonderful job putting new curtains in the Leotax. The covering was falling apart, and I put a new skin designed for a Leica on it. Fit well, except the screw holes were different.

http://flickr.com/photos/oldcamerapictures/3204519580/

The 39mm filter size surprised me seems too small for an F1.5 lens.
But, it did not vignette with the Leitz filter in place. I have 40mm Canon filters, 40.5mm filters for the Sonnars, and 41mm filters for the Summarit.

Brian

--- In ZICG@yahoogroups.com, "furcafe" <furcafe@...> wrote:
>
> Interesting re: the 39mm filter thread on your Simlar. I have a later
> example (#152071) & it has a 40mm filter thread, like many Canon RF
> lenses.
>
> --- In ZICG@yahoogroups.com, "brianvsweeney" <brianvsweeney@> wrote:
> >
> > I posted some pictures with the Simlar on the ziforums.com with the
> > thread on rebuilding the lens. I'm waiting for a roll to get back shot
> > at the Marine Museum with the 1941 Sonnar. I brought two Canon P's
> > with me that day, Simlar on one and Sonnar on the other.
> >
> > The Sonnar beat it for sharpness. Almost like comparing a Summarit at
> > F1.5 with a Sonnar at F1.5. I believe the Simlar is closer to a
> > pre-war Xenon. Odd think- it uses a 39mm filter, smallish for a 5cm
> > F1.5 lens. The Leotax body is made from Brass. I think the Nicca
> > outsold it as the Nikkor lenses were much sharper.
> >
> > http://www.ziforums.com/showthread.php?t=108&page=2
> >
> > I'll be posting some more when I get the next roll back. Will be
> > interesting to compare the Sonnar and Simlar shots of the museum
> > side-by-side.
> >
> > Brian

[Brian]

Thanks!

The lens module simply unscrewed on mine, and a single shim controlled the stand-off. The focus on mine looks good. Not the sharpest lens wide, open. It is much better stopped down. If I ever see one that has really bad glass, I'll pop the optics from the fixtures. But not on this one, it is just too nice.

Youxin repaired the camera as a favor to me. He will not work on the "S", as the extra portions for the Sync make it difficult to work on. Trying to get documentation for these old lenses and cameras is next to impossible.

[Brian]

Got back another roll with the Simlar. I'm getting used to this lens.

On the Canon P, Kodacolor 400.

http://www.ziforums.com/album.php?albumid=94

This lens has the "look and feel" of a Summarit/Xenon. The outer edge of the image gets a bit wild at F1.5. Or maybe I'm just used to the curvature of field of a Sonnar?

I'll add some full-res detail shots.

http://www.ziforums.com/picture.php?albumid=94&pictureid=759

It's been a good month for finding uncommon lenses.

[Brian]

I was sent some great information on this mystery formula lens by a new forum member!

http://www003.upp.so-net.ne.jp/Topconclub/lenscut.htm

It has the front section that looks like a Sonnar (single-element followed by a triplet) and the rear section of a Gauss formula lens. It is a 7-element in four group design, a 1-3-2-1 forumula lens.

An interesting design. Now- it was known with the glass at the time that doing an F1.5 lens was too much for a 6 element forumula. The designers chose an element and split it into two elements of less power. (Read that in Neblette, Photographic Lenses, 1973). The Summarit split the rear element in two. The Nikkor 5.8cm F1.4 split the front element into two. The Sonnar F1.5 used a triplet for the rear section rather than the doublet of the F2 lens.

I am going to speculate that the SImlar designers started with a Planar/Xenon 1-2-2-1 formula and made the front doublet into a triplet. The advantage of splitting the doublet into a triplet: Does not introduce more air/glass interfaces. It retains the transmittance of the 1-2-2-1 that it was derived from. How's that for making up stuff as I type?

A double-gauss lens works as the two sections work "like a relay lens". They cancel out each other's aberrations. The asymmetric Gauss, the Xenon, allows faster speed. (Again Neblette). SO: taking a front section of a Sonnar and using the back end of a Gauss- that would be hard to correct the aberrations! The front section looks like a Sonnar because of the 1-3 configuration. But I suspect that the designers started with a 1-2-2-1 double gauss.

With that said, I've played with some parts lenses that I have. I took a Jupiter-8 and removed the rear optics. The front section forms an image, about 80mm or so FL (using an eyeball MK1). The rear module also forms an image, as does the rear module from a Retina Xenon. The focal length of the J-8 rear module is longer. I put the rear module of the Xenon into the J-8, with a much longer stand-off, and got a decent image projected onto paper. Next test: mount the lens, play with the focal length by controlling stand-off, and put it into my Parts Summitar mount.

Wowee... Life just can't get more exciting than this....(humor!, arr-arr)

[Brian]

Okay- I made a "Simlar look-alike" out of a J-8 front end and Retina Xenon rear module.

http://www.ziforums.com/showthread.php?t=138

Will post some test shots in a week or two. It's not going to be sharp or contrasty, but it forms an image.

http://www.ziforums.com/attachment.php?attachmentid=80&stc=1&d=1233505942

[furcafe]

Interesting, the diagrams accord to what I was once told about the Simlar (by Peter Evans on photo.net, IIRC). I think your speculation is probably accurate.

The Simlar's design reminds me a little bit of the original Voigtlander Nokton (7 elements in 5 groups, 2-1-1-2-1), see, e.g.:

http://www.taunusreiter.de/Cameras/Bessa_RF_histo.html

though the Nokton's wide-open performance is generally considered to be top-notch, @ least on par w/the Sonnar (& is, in my experience).

I was sent some great information on this mystery formula lens by a new forum member!

http://www003.upp.so-net.ne.jp/Topconclub/lenscut.htm

It has the front section that looks like a Sonnar (single-element followed by a triplet) and the rear section of a Gauss formula lens. It is a 7-element in four group design, a 1-3-2-1 forumula lens.

An interesting design. Now- it was known with the glass at the time that doing an F1.5 lens was too much for a 6 element forumula. The designers chose an element and split it into two elements of less power. (Read that in Neblette, Photographic Lenses, 1973). The Summarit split the rear element in two. The Nikkor 5.8cm F1.4 split the front element into two. The Sonnar F1.5 used a triplet for the rear section rather than the doublet of the F2 lens.

I am going to speculate that the SImlar designers started with a Planar/Xenon 1-2-2-1 formula and made the front doublet into a triplet. The advantage of splitting the doublet into a triplet: Does not introduce more air/glass interfaces. It retains the transmittance of the 1-2-2-1 that it was derived from. How's that for making up stuff as I type?

A double-gauss lens works as the two sections work "like a relay lens". They cancel out each other's aberrations. The asymmetric Gauss, the Xenon, allows faster speed. (Again Neblette). SO: taking a front section of a Sonnar and using the back end of a Gauss- that would be hard to correct the aberrations! The front section looks like a Sonnar because of the 1-3 configuration. But I suspect that the designers started with a 1-2-2-1 double gauss.

[Brian]

I certainly agree about the Prominent Nokon performance being top-notch. I have two, including one for use with the Nikon RF's with an adapter.

I need to take a comparison roll of my Fast-Fifties from the Fourties and Fifties. I do not have them all, but have a number of them.

[DrLeoB]

Re-opening this thread just to say thanks, Brian for the thorough discussion of this lens (50mm F/1.5). I just got one yesterday and had the aperture unstuck and working smoothly within 1 hour with a flood clean using MEK (methyl ethyl ketone) and a relube with a trace of Krytox (fluorocarbon lube used on hard disks of old).

Currently trying it out on my Lumix G1 .... sweet!

[Brian]

Okay, I am glad to hear that!

This is an uncommon lens, and an uncommon optical formula. I would be interested in seeing images of the lens and taken with the lens.

Brian

[M. Valdemar]

I have a 50mm f1.5 Simlar Serial #150895.

I will post photos with this lens taken with a Leica M9 if anyone is interested.

My first impression of the lens was that it was extremely soft. With some use, I am learning the characteristics of the lens and it is not so bad.

[cookiecutter]

Hi Brian, just got the #76 of the 5cm f/1.5 Simlar ! Perfectly suits my Leotax !