Symmar convertible focusing with rangefinder

[Deleted member 88956]

Looking at Schneider Symmar convertible, which is cammed to rangefinder on a Linhof Technika (not on hand, looking at buying it).

I would suspect focus is no longer maintained after removal of front element making it a ground glass focusing only at converted FL. Is this correct?

 

[neilt3]

Correct .
The focal length of the 150mm is something like 265mm with the front element removed .

When I used one on my Crown Graphic I had to make a top hat lens board to even maintain infinity focus at the long end .

 

[Deleted member 88956]

Correct .
The focal length of the 150mm is something like 265mm with the front element removed .

When I used one on my Crown Graphic I had to make a top hat lens board to even maintain infinity focus at the long end .

Thanks. I was not hoping it would maintain focus, but neither did I believe the man has landed on the Moon .

How is its performance at long FL? Is it vastly worse than at 150?

 

[neilt3]

As a combined unit , image quality is certainly better , but I certainly wouldn't say it's was "vastly worse " .
Stopped down a bit it's certainly satisfactory .
Mounting a yellow filter to the front section improves IQ .
Double check focus after you stop the lens down when using only the rear group , as IIRC there's a bit of focus shift which depends on lens model and aperture used .
That can explain some negative reviews .

I bought an adapter that screws into the shutter and allows a standard screw in filter to fit on it from an eBay seller in Russia .

 

[Deleted member 88956]

As a combined unit , image quality is certainly better , but I certainly wouldn't say it's was "vastly worse " .
Stopped down a bit it's certainly satisfactory .
Mounting a yellow filter to the front section improves IQ .
Double check focus after you stop the lens down when using only the rear group , as IIRC there's a bit of focus shift which depends on lens model and aperture used .
That can explain some negative reviews .

I bought an adapter that screws into the shutter and allows a standard screw in filter to fit on it from an eBay seller in Russia .

Thanks, good tips.

 

[removed account4]

Hi Witold
Be advised that the FL symmar convertibles is a. bit longer than expected .. you would think the 150/265 would focus at infinity at 265 when the front element is removed (and it is converted) but it takes quite a bit more bellows; to give you an example my 210/370 takes close to 450mm to focus at infinity converted. no clue where the focus node is on the 150/265. im guessing about 340mm. great lenses, sleepers...

YMMV
John

 

[Deleted member 88956]

@jnantz Aha, that's a good one too, thanks. I was asking mainly to evaluate pros and cons of a convertible and whether it is as flexible as it appears on the label. Knowing this pitfall at converted FL will take surprises out of the picture. I actually have long lengths covered enough for my needs, yet convertible seemed appealing for some take outs. With this in mind, planning will get a bit easier though.

 

[removed account4]

Hi Witold
I have other convertible lenses and the symmar seems to be the only one I have experienced with this particular focus node issue... I have always heard folks mention this particular lens suffers focus shift ( I have never experienced this ) and that it isn't sharp and lacks contrast (I've never experienced that either) I have shot portraits with it wide open and stopped down a bit and did a bit of site work stopped down (4x5 chromes and c41 ) too. .. mine is "Linhof badged" so maybe that had something to do with my good luck. Legend has it that Linhof picked the best from each litter, so if you have the opportunity to pick up a linhof badged version of this lens ( or any other Schneider lens ) chances are you might not get a lemon.

have fun !
John

 

[Deleted member 88956]

Hi John,

Yes I'm basically only after Linhof lenses now, especially since I have the Kardan Bi and now Technika 70, neither looks good without Linhof on a lens

Thanks for extra input.

 

[neilt3]

Hi Witold
Be advised that the FL symmar convertibles is a. bit longer than expected .. you would think the 150/265 would focus at infinity at 265 when the front element is removed (and it is converted) but it takes quite a bit more bellows; to give you an example my 210/370 takes close to 450mm to focus at infinity converted. no clue where the focus node is on the 150/265. im guessing about 340mm. great lenses, sleepers...

YMMV
John

I'd have to check in daylight when I'm off work what bellows is needed of infinity focus at 265mm , but I think it might have been a bit under 340mm .
On the Crown graphic , it couldn't focus to infinity on a flat lens board .
I did get caught out when I bought it as I didn't know it needed the extra bellows draw . If the 265mm at infinity was measured from the lensboard it would have worked on the camera fine and I wouldn't have been scratching my head wondering why I couldn't focus on anything the first time I tried it as a converted lens before I made the top hat !
With the top hat I made that added about 35mm or 40mm so I think I could focus from infinity down to about 25 feet away .
I can't check by measuring the camera bed as it's not at my house at the moment . ( we're still in another lockdown here in the U.K )

Hi Witold
I have other convertible lenses and the symmar seems to be the only one I have experienced with this particular focus node issue... I have always heard folks mention this particular lens suffers focus shift ( I have never experienced this ) and that it isn't sharp and lacks contrast (I've never experienced that either) I have shot portraits with it wide open and stopped down a bit and did a bit of site work stopped down (4x5 chromes and c41 ) too. .. mine is "Linhof badged" so maybe that had something to do with my good luck. Legend has it that Linhof picked the best from each litter, so if you have the opportunity to pick up a linhof badged version of this lens ( or any other Schneider lens ) chances are you might not get a lemon.

have fun !
John

Regarding focus shift .
With the 150/265 , I have one with Sinar on the lens . I focus wide open , stop down and if I check again everything generally seems O.K to me .
Stopped down a couple of stops is f/22 , so it's getting dark especially on a cloudy day , plus DOF helps out .
So it's hard to say if there is any focus shift .
As i said , I'm satisfied with mine .
The current 5x4 camera I'm using has much more bellows so I should try it doing some much closer shots wide open to see how it performs at 265mm .

I've also got the Symmar 210/370mm that I got for use on 7x5 . I'm still restoring/repairing my 7x5 camera so haven't used on that .
210mm on 5x4 worked well .

I'm confident enough that they'll do a good job on the larger formats I've got two others for when I build my DIY 10x8 camera .
Ones also in a Compur shutter , a Symmar 240/420mm , and the other is on a Sinar DB board that I'll use a modified front mounted Thornton Pickard shutter on which is a Symmar 300/500mm lens .
I'd be interested to hear thoughts on if anyone's any experience with those .

@ Witold .
The adapter I got to mount filters on the 150/265 with the front removed was this one ; https://www.ebay.co.uk/itm/M39x1-female-to-M40x0-75-male-thread-adapter-for-1-shutters/142396284712?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

EDIT ;

It then lets you mounts a step up ring to 49mm ( which is the same filter thread as the front half of the lens ) where I have a good selection , or Cokin A size if I want to use ND Grads .

It's a much coarser thread on the adapter than the step up ring , so you could either have one made of the correct pitch , as I intended to get or do as I did and cross thread the damn thing into it so it doesn't fall out !

 

[Deleted member 88956]

It's a much coarser thread on the adapter than the step up ring ,

Do you mean the claimed 40x0.75 thread ... isn't? Quite a price for being off specs if that's the case.

At any rate however, something to look up around as I'm sure I can find a local shop to make this and go straight to larger filter size.

 

[reddesert]

@ Witold .
The adapter I got to mount filters on the 150/265 with the front removed was this one ; https://www.ebay.co.uk/itm/M39x1-female-to-M40x0-75-male-thread-adapter-for-1-shutters/142396284712?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

EDIT ;

It then lets you mounts a step up ring to 49mm ( which is the same filter thread as the front half of the lens ) where I have a good selection , or Cokin A size if I want to use ND Grads .

It's a much coarser thread on the adapter than the step up ring , so you could either have one made of the correct pitch , as I intended to get or do as I did and cross thread the damn thing into it so it doesn't fall out !

This adapter is presumably intended to mount an enlarging lens or other Leica thread mount lens with an approx 39x1mm pitch in front of a shutter. (Technically Leica thread mount is 39mm x 26tpi, but this is very close in practice).

Filter threads at these sizes usually have an 0.75mm pitch, that's why the step-up ring doesn't fit right. Filters and step up rings from 40mm are pretty rare (as opposed to 40.5mm), but if you could find a 40->49 step up ring it would work properly.

 

[Deleted member 88956]

This adapter is presumably intended to mount an enlarging lens or other Leica thread mount lens with an approx 39x1mm pitch in front of a shutter. (Technically Leica thread mount is 39mm x 26tpi, but this is very close in practice).

Filter threads at these sizes usually have an 0.75mm pitch, that's why the step-up ring doesn't fit right. Filters and step up rings from 40mm are pretty rare (as opposed to 40.5mm), but if you could find a 40->49 step up ring it would work properly.

If the step ring was 40.5 than it would feel like "coarser" thread going into a 40, but 0.5 mm is no small difference, so I'm not sure if this is the case here. We'll find out soon enough. But I am going to get this right and make one made for purpose going straight to whichever filter diameter I will need.

This is a good tip though as I might not have thought about it right away, especially since it looks like I'm going to end up with at least two convertibles. Turned out already have Linhof Symmar 210/370 that came with Kardan Bi.

 

[reddesert]

If the step ring was 40.5 than it would feel like "coarser" thread going into a 40, but 0.5 mm is no small difference, so I'm not sure if this is the case here. We'll find out soon enough. But I am going to get this right and make one made for purpose going straight to whichever filter diameter I will need.

This is a good tip though as I might not have thought about it right away, especially since it looks like I'm going to end up with at least two convertibles. Turned out already have Linhof Symmar 210/370 that came with Kardan Bi.

Maybe I wasn't clear. The shutter thread is 40 x 0.75mm. The easy way to fit a filter would be to find a filter step ring from 40->46 or 40-49, etc, but 40mm filters and step rings are rare. A 40.5mm->XX step ring is easy to find, but would either not go in or would damage the shutter threads.

The adapter ring that neilt3 linked has the correct 40x0.75mm thread on one end, but he has trouble screwing a step ring into it on the other end because the adapter is 39x1mm, not 39x0.75mm, because it isn't for adapting filters, it's for adapting lenses.

 

[Deleted member 88956]

Maybe I wasn't clear. The shutter thread is 40 x 0.75mm. The easy way to fit a filter would be to find a filter step ring from 40->46 or 40-49, etc, but 40mm filters and step rings are rare. A 40.5mm->XX step ring is easy to find, but would either not go in or would damage the shutter threads.

The adapter ring that neilt3 linked has the correct 40x0.75mm thread on one end, but he has trouble screwing a step ring into it on the other end because the adapter is 39x1mm, not 39x0.75mm, because it isn't for adapting filters, it's for adapting lenses.

I see where I went wrong, flipping, end for ending thread sizes, well it's wee hours over here

But it changes little to the issue, need to make a right sizes ring and that's there is to it.

 

[neilt3]

.

The adapter ring that neilt3 linked has the correct 40x0.75mm thread on one end, but he has trouble screwing a step ring into it on the other end because the adapter is 39x1mm, not 39x0.75mm, because it isn't for adapting filters, it's for adapting lenses.

That's exactly what it's for , adapting lenses , not filters .
I think it's listed as such as well .
I bought it as it was the first step in adapting filters to the shutter , as it's essential you don't damage the thread on the shutter .

Although I planned on having a thread adapter made by SRB Griturn in the UK , the thread if the step up ring cut into the other thread and holds well , so I've saved £15 or £20 .
Epoxying a filter step up ring into the adapter would work as well , or external slip on or clamp on filters .

If your in the states , I think SK Grimes are tho go to guys .
No doubt they could just make an adapter to go straight from the shutter to a filter thread .
Make sure the unit is long enough to still allow easy alteration of the shutter settings when filters are attached .

 

[Bob S]

Maybe I wasn't clear. The shutter thread is 40 x 0.75mm. The easy way to fit a filter would be to find a filter step ring from 40->46 or 40-49, etc, but 40mm filters and step rings are rare. A 40.5mm->XX step ring is easy to find, but would either not go in or would damage the shutter threads.

The adapter ring that neilt3 linked has the correct 40x0.75mm thread on one end, but he has trouble screwing a step ring into it on the other end because the adapter is 39x1mm, not 39x0.75mm, because it isn't for adapting filters, it's for adapting lenses.

Ask heliopan if they have a. Ri

 

[Bob S]

Ask Heliopan if they have a ring.

 

[138S]

How is its performance at long FL? Is it vastly worse than at 150?

The 265mn converted (rear cell only) is softer in the corners if wide open at f/12 or f/16, but those corners do improve as you stop to f/22 of f/32. Still, wide open, no problem for portraiture. No problem for landscape if you have sky in the top and in the bottom corners you have terrain that is out of focus. No problem anyway if you are not to enlarge to much. And no problem in any situation if stopping f/32 anyway.


C. Pérez measured this for a sample unit

lp/mm 150mm (center / mid / corner) (https://web.hevanet.com/cperez/testing.html)

f/11 42 48 38
f/16 42 48 42
f/22 48 64 42

converted to 265mm
f/16 48 48 23
f/22 48 48 33
f/32 42 42 38


If using the symmar conversion of longer focal length mates ( 210mm lens and up) then the issue in the corners disapears, the 370mm conversion of the 210mm has no problems in the 4x5 corners (if no large shift) because as the image circle is well larger you don't reach the outer boundary of the image circle.

For the conversion of 240, 300 and 360 lenses (620mm focal for the 360), you only take he center of the image circle with a very good yield. Those conversions are always interesting, but as the focal is longer (for the format) then yield is better as you not need to stop to have sharp corners, if wnating that.

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The converted version has potential for very low flare (being single coated glass) as only two groups are there, but think that the illumination circle of the converted lens is very, very large and it may provocate relexions in the bellows ending on the sheet, so a compendium shade may be quite suitable if wanting a well contrasty result.

I've a 150, two 210 (for a 3D project) and the 360. Ive tested them with CMS 20 4x5 sheets and I found all quite sharp, with corners a softer for the 265mm conversion (150 lens) when wide open. The 360 converted to 620 (Technika selected) is ultra sharp side to side.

Ken Rockwell says this and he looks not being a joke: https://www.kenrockwell.com/schneider/150.htm

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Those convertibles had been discredited many sometimes, but IMO they perform amazing in the right hands, even when converted, if photograpers knows how to use them.

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The conversion requires longer than usual bellows, as the lens rests behing the lens board, but the front cell alone can also be used as a converted lens requiring lens than nominal bellows extension, single problem is that green aperture scale is only for the rear cell conversion, the front cell conversion requires a correction. Firs symmay version (Dagor type) had three aperture scales, fo rthe full lens, for the rear cell alone, and for the front cell alone.