Thambar-Crazy

[wattsy]

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As vignette changes with aperture and Ms are oblivious to aperture, I would guess there is no in camera correction.

 

 

The digital M cameras are not oblivious to aperture. Gaining a rough estimation of aperture is the purpose of the little sensor on the front of the top plate. I believe that there is vignetting correction for wider lenses like the 28 Summicron.

[Exodies]

The digital M cameras are not oblivious to aperture. Gaining a rough estimation of aperture is the purpose of the little sensor on the front of the top plate. I believe that there is vignetting correction for wider lenses like the 28 Summicron.

I was going to restrict my comment to M10s (does this camera estimate it but not put it in EXIF?) but decided not to as the aperture estimate is so variable it seemed unlikely Leica would use it for anything but information.

My Summicron 50 APO shows varying amounts of vignette at different apertures - lots wide open, non closed (with hood out).

Should be easy to test - various apertures with the sensor covered/uncovered. I’ll get on it right away.

[Exodies]

Not so easy to test. At full aperture where the 50 APO shows most vignetting, covering the sensor gives full aperture, shining a light into the sensor gives f2.8. no visible difference in the vignette. Need a brighter light.

[wattsy]

Not so easy to test. At full aperture where the 50 APO shows most vignetting, covering the sensor gives full aperture, shining a light into the sensor gives f2.8. no visible difference in the vignette. Need a brighter light.

 

 

I'm loath to get into some kind of discussion with you on this because I only asked about the possibility of lens corrections for the Thambar and I'm not entirely sure what you are now trying to prove. However, I would suggest that, rather than fiddle around with the light sensor, you might try simply shooting your lens "unrecognised" and "recognised" and see what difference that makes in terms of vignetting. I don't know whether Leica have made the vignetting corrections sensitive to the aperture being used or whether they have just applied a rough correction that aims to correct some of the vignetting on a lens only basis. I'm rather more interested in the Thambar than going off on this tangent.

Edited February 9, 2018 by wattsy

[farnz]

Not wishing to contribute to the tangent but I had understood that vignetting correction through lens recognition was to correct for vignetting in wide angle lenses caused by oblique light falling on the offset sencels at the sensor's edge owing to the restricted (rangefinder) register rather than for vignetting resulting 'lost' light at the edges of the front element when the diaphragm is opened up.  Since there is no data link between lens and body the camera has no way of knowing the aperture or for compensating for it.  The vignetting correction normally only has effect on wide angle lenses and has little or no effect on lenses longer than about 50 mm so any Thambar recognition would only add to the EXIF.

 

Pete.

[LichtUndDunkelheit]

... great.

 

Forum tells me "You have posted more than the allowed number of quoted blocks of text" but

 

1. it doesnt tell me how many are actually allowed and

 

2. it didnt stop me to multiquote so many in the first place.

 

Sigh. I'll just skip the quotes altogether, then.

 

 

 

First of all, thanks to the many great examples for images here.

 

 

 

As many others I dont get this pricing. I would say maybe a quarter of the price (ca $1500 / 1200€) would be OK. Its a lens with three elements, it has no raised tolerances or anything, so why would it be so expensive ?

 

Leica was NOT always THIS expensive. If you look at historical prices and correct them for inflation, you'll end up with the conclusion that Leica was actually quite a bit cheaper back in the day. Thats the effect of stuff thats handmade, really.

 

Being able to change aperture without changing focus is VERY important with such a lens. Thus I dont get whats the point of trying to make it exactly the same as the 1930s lens. Its not like collectors will bother to get this new iteration. They will want the original. So why torture todays buyers with the old, awful interface ?

 

A soft filter will never compare to a soft focus lens, because a soft focus lens will give an impression of the room, i.e. the effect will get stronger in the out of focus areas, making the effect look quite a bit better.

 

It is not uncommon for soft focus lenses that the center might actually be sharp. Thats what that filter is for. This still makes the Thambar a soft focus lens.

 

As always in every discussion of soft focus lenses, somebody comes a long and claims they could just misfocus their lens for the same effect. Wrong. Out of focus is unpleasant to look at, while soft focus can be highly aesthetical. A soft focus lens is still clearly in focus (or not in focus, if you misfocused).

 

The difficulty with any soft focus lens is to get the soft focus effect just right.

 

 

 

There was also some comments on Fisheyes here.

 

Fisheyes are NOT one trick ponies.They're a whole new perspective with unlimited possibilities, just like a regular lens really.

 

If you think Fisheyes are cheap, then maybe you need to look up what a really high quality original Nikkor 220 degree circular fisheye will cost you. Makes that Leica Thambar look cheap again.

 

 

[wattsy]

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Not wishing to contribute to the tangent but I had understood that vignetting correction through lens recognition was to correct for vignetting in wide angle lenses caused by oblique light falling on the offset sencels at the sensor's edge owing to the restricted (rangefinder) register rather than for vignetting resulting 'lost' light at the edges of the front element when the diaphragm is opened up.  Since there is no data link between lens and body the camera has no way of knowing the aperture or for compensating for it.  The vignetting correction normally only has effect on wide angle lenses and has little or no effect on lenses longer than about 50 mm so any Thambar recognition would only add to the EXIF.

 

 

Yes, I believe that this is correct Pete though I question the point about the lack of a "data link". Of course there isn't a mechanical/electrical connection (other than the rather crude lens identifying code system) but I thought the light sensor which provides the rough estimate of aperture (and, until the M10 placed this information in the EXIF) was developed for such a purpose. Is it the case that this guessed aperture has never been used as part of the in camera corrections?

 

I also take your point that the vignetting corrections have been likely aimed at the sensor vignetting rather than correcting for optical vignetting of the lens. Yes, the Thambar being a 90mm is unlikely to cause any sensor vignetting (from oblique rays) but I was curious if the coding of the lens offers anything more than simply identifying it in EXIF. I guess it will be easy enough to check by simply turning off the lens recognition and seeing if there is any differences.

[farnz]

I believe the 'third eye' at the apex of the step in the top deck is for colour balance although it's also used for a differential calculation with the reflection off the shutter blades for a best guess at what the lens aperture might be set to which can be fed into the EXIF file.

 

When I used the term 'data link' I should have written "communication" instead.  Still had my work head on.

 

Pete.

[jmahto]

At least on M240, the vignetting is not corrected in tele. I have checked my 180APO3.4 which vignettes wide open. No camera correction (with manual lens selection in camera).

[algrove]

Confusion by me. What do I have wrong here?

 

Looking at the manual EN p12 "2.2 -2.6 -or 9-25 (values in white: for use with the associated center spot filter) / 2.3-6.3 (values in red: for use without the associated center spot filter)

 

Then on p15 while discussing use with/without the center spot filter and discussing controlling the degree of soft focus can be controlled to a certain extent. Then it continues--"Without the center spot filter (2) supplied, this is done only with the aperture; the scale with the white values applies in this case...

 

This paragraph continues for many lines.

 

Wow, I say.

[LocalHero1953]

Confusion by me. What do I have wrong here?

 

Looking at the manual EN p12 "2.2 -2.6 -or 9-25 (values in white: for use with the associated center spot filter) / 2.3-6.3 (values in red: for use without the associated center spot filter)

 

Then on p15 while discussing use with/without the center spot filter and discussing controlling the degree of soft focus can be controlled to a certain extent. Then it continues--"Without the center spot filter (2) supplied, this is done only with the aperture; the scale with the white values applies in this case...

 

This paragraph continues for many lines.

 

Wow, I say.

As mentioned earlier in the thread, this is an error in the manual.

A Leica manual wouldn't be complete without one (often many).

White is for without, red is for with.

Edited February 9, 2018 by LocalHero1953

[algrove]

Thanks. Makes sense. Since this thread is longer than my life I must have missed it.

Edited February 10, 2018 by algrove

[ldhrads]

First couple of shots with the Thambar-M on the SL-601 (color) and MMV1 (B&W)

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[ldhrads]

A couple more.  I found myself much more sure with focusing on the rangefinder vs. the EVF on the SL-601

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[ldhrads]

Last two!

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[wattsy]

Can you remember what aperture you used and whether it had the centre filter in place? Thanks for posting your examples.

 

Last two!

 

[ldhrads]

Can you remember what aperture you used and whether it had the centre filter in place? Thanks for posting your examples.

Yes, I shot wide open on all of these posted with the center spot filter on all as well.

[LocalHero1953]

Dinner table portraits

 

M240+Thambar @f/2.2 ISO 1250 & ISO 2000 respectively. No spot filter. Processed in SilverEfex.

 

I should have shot these at around f/2.8-4.

 

Now I have started using the Thambar with the M240, I find its focus calibration is out - about 10cm at 2m - checked with tripod, EVF and tape measure. The body is fine with other lenses, so it must be the Thambar: going back for recalibration. Even compensating (leaning back just before shooting) I missed focus slightly with the first one, but the second is OK.

 

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[Tante Ilse]

These pictures look very familiar to me. They show exactly what I see when I forgot my glasses.

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Hallo,

Look here: Leica M

[M9reno]

These pictures look very familiar to me. They show exactly what I see when I forgot my glasses.

Surely there are places or moments when you don't want to use your glasses? It's the same with a lens and camera - nice to open one's mind and see the world in different ways sometimes.