Leica 007 - A Warning To Potential Buyers

[D&A]

Erik wrote--->>>"Just to say, the 33x44 mm Sony sensor has issues with non retrofocus ultrawides on technical cameras."<<<<

Just a quick question Erik based on your statement above (without deviating too much from the topic of this thread). In testing numerous samples of the Pentax 25mm 645 lens on the 645Z (effective angle of view is approx. 19mm in 35mm terms), I found corner softness at virtually all f-stops as compared to very high resolving power in the centralized portion of the frame. The lenses all appeared to have little if any signs of decentering. I wonder if this had to do with the sensor/microlens design of this particular Sony sensor dealing with the obtuse angle of light generated by the design of this lens towards the corner microlenses? If so, it may be one of the reasons Pentax limited the wide end of their 28-45mm 645 zoom to 28mm (effective 22.5mm), which has consistently better corner performance. I am also taking into the account the field curvature exhibited in the Pentax 25mm lens. Thanks.

Dave (D&A)

 

[MGrayson]

The incident angle on an SLR is never very steep. On a rangefinder, tech cam, or other mirrorless, the rear element can be MUCH closer to the sensor. The rear lenscap on a Mamiya 43/4.5 is about 2" deep!

But corners on retro focus lenses seem to be Difficult. Even the Leica S 24 is soft in the extreme corners wide open, but cleans up by f/8. (I've never noticed it in a real photo. )

Best,

Matt

 

[glenerrolrd]

I assume if I add all threads in various forums about AF failure of S lenses I might have 10 people posting about AF failures.
On the other side I havent had any S lens fail in many years, and the other 2 persons I know in person who own a S also didnt have any AF failure with their lenses.
I have had 1 Nikon 70-200VR fail and a Pentax lens where AF failed.

I am not denying there are some people who do have such problems, and I understand this is disappointing, and long repair times are even more disappointing,
But we really do not know how high is the percentage, and IMO its speculation to generalize that S lenses show more problems than lenses from other brands.

Most know I am a big supporter of the Leica S system...having 2 bodies and 9 lenses ...I am committed . It has the best IQ I ve seen except for the P1 100MP system (which is in a different weight class). It also has the form (size ,weight,OVF ) that I am most pleased with .

Two problems are real and should be considered . (1) sending gear thru NJ for any Leica product is a bad idea ...they are in the mist of a messy technology conversion and have had several key employees leave . (2) the AF failure problem is real .

The AF failures greatly increased with the new firmware for both the bodies and lenses ...last year . The added speed (its now plenty fast enough) caused too much load on the AF gear and it breaks . While a permanent fix seems to be close ...this does not help those that own existing S lenses .

Failure most often occurs just after mounting a lens on a S 007 or updated S 006 . Lenses that require a lot of movement to go from close focus to infinity and /or utilize floating elements (24) ...may strip even if brand new .

This isn t going away ....most all the S lenses will need their AF motor replaced (unless you plan on using an S2 body ).

My recommendations (1) take your S lenses someplace you can find a S 007 with the latest software ...set the lens to close focus and mount it ...you can feel the torque . If you buy a new lens ..do this immediately and send it back if it fails . (2) lenses that fail need to go directly to Germany and preferably thru your dealer .

Not what any of us want to hear but I believe that in a few months I will have my set of lenses updated .

Otherwise my S system has been without any major issues . If you have an S2 or S 006 have it checked for sensor corrosion ..same issue as M9 and Mono CCD.

 

[algrove]

Roger

Spoken like an "realistically honest" Leica fanboy and not like a fanboy with blinders. Thanks.

 

[D&A]

The incident angle on an SLR is never very steep. On a rangefinder, tech cam, or other mirrorless, the rear element can be MUCH closer to the sensor. The rear lenscap on a Mamiya 43/4.5 is about 2" deep!

But corners on retro focus lenses seem to be Difficult. Even the Leica S 24 is soft in the extreme corners wide open, but cleans up by f/8. (I've never noticed it in a real photo. )

Best,

Matt

Matt, thats one of the reasons I brought up the Pentax 25mm 645 lens and its relatively soft corners compared to very high resolving ability in the greater central area of the frame. I'm trying to determine of this lens is of a retrofocus design, which would explain things as compared to the Pentax 28-45mm 645 zoom which has better corner performance and most assuredly is not a retrofocus designed lens.

Dave (D&A)

 

[atanabe]

The AF failures greatly increased with the new firmware for both the bodies and lenses ...last year . The added speed (its now plenty fast enough) caused too much load on the AF gear and it breaks . While a permanent fix seems to be close ...this does not help those that own existing S lenses .

Failure most often occurs just after mounting a lens on a S 007 or updated S 006 . Lenses that require a lot of movement to go from close focus to infinity and /or utilize floating elements (24) ...may strip even if brand new .

This isn t going away ....most all the S lenses will need their AF motor replaced (unless you plan on using an S2 body ).

Roger, the AF problem affects owners of the S2 as well, sadly.

 

[MGrayson]

Dave,

I'd think anything that wide on a DSLR the size of the Pentax would have to be retrofocus. All the glass has to be far from the sensor to avoid the mirror. Granted, I don't know the optical formula for the zoom in its wide configuration. Is it really not retro?

--Matt

 

[D&A]

Dave,

I'd think anything that wide on a DSLR the size of the Pentax would have to be retrofocus. All the glass has to be far from the sensor to avoid the mirror. Granted, I don't know the optical formula for the zoom in its wide configuration. Is it really not retro?

--Matt

Thanks Matt. I thought but am not certain if the zoom is of retrofocus design. Clearly though my suspicion is that Pentax might have limited thr zoom to 28mm on the wide end to enhance corner performance. This is especially so in light that Pentax knew they would be discontinuing production of the 25mm with no imminent replacement for it around the time of the zoom's release.

Dave (D&A)

 

[ErikKaffehr]

Off topic: cover glass effects

Hi Dave,

Deviating from the topic of the thread, that is mea culpa!

There are two issues with large beam angle designs, one is the sensor and the other is the cover glass. At large beam angles the cover glass induces significant astigmatism. I posted a question on the issue at DPReview and a guy actually popped a piece of glass into his Zemax model of a lens and reported back that it caused both astigmatism and field curvature.

Sony sensors have 2-2.5 mm of cover glass, while MFD sensors have around 2 mm, this would be taken into account when calculating the lens. DSLR lenses have smaller beam angles, because the lens is sitting in front of the mirror box.

But, with lenses having short distance between outlet pupil and sensor plane, it is a problem. That is the reason Leica experimented with extremely thin glass on the M8, but that glass failed to achieve proper IR filtration.

As an example, the cover glass can be replaced on the A7r with glass corresponding to Leica specifications and the Leica lenses improve a lot with the thinner glass. But, Sony lenses may suffer from the thinner glass. Lloyd Chambers demonstrated this quite clearly on the Sony 55/1.8ZA lens.

I am routinely using Canon glass on my A7rII. Ken Rockwell has published some report saying that the 16-35/4 L performed horribly on the A7rII (?) but that is not my experience. My sample of the 16-35/4L outperforms my Distagon 40/4 on the P45+ and int also outperforms the Distagon 60/3.5. That is with the exception of the extreme corners, where the 16-35/4 drops even more than the Distagon 40/4.

So, I don't think problems with DSLR lenses are sensor related. But with more symmetric lenses cover glass could be a problem, especially with lenses designed for film. I would guess that most modern lenses are calculated for 2mm of cover glass.

The pixel design and microlenses are more relevant with regard to vignetting and cross talk. Light beams coming in at shallow angles wil be cut off by the well. Also shallow angle beams may contaminate adjacent pixels, so a beam passing trough the red filter may affect say a green pixel. That is called cross talk.

The CCD sensors made by Kodak had least issues with cross talk, these are used in Leica M8, Leica M9, Leica S2 and Leica S (typ 006), Dalsa sensors were more problematic. This issues increase with decreasing pixel size.

Best regards
Erik

Erik wrote--->>>"Just to say, the 33x44 mm Sony sensor has issues with non retrofocus ultrawides on technical cameras."<<<<

Just a quick question Erik based on your statement above (without deviating too much from the topic of this thread). In testing numerous samples of the Pentax 25mm 645 lens on the 645Z (effective angle of view is approx. 19mm in 35mm terms), I found corner softness at virtually all f-stops as compared to very high resolving power in the centralized portion of the frame. The lenses all appeared to have little if any signs of decentering. I wonder if this had to do with the sensor/microlens design of this particular Sony sensor dealing with the obtuse angle of light generated by the design of this lens towards the corner microlenses? If so, it may be one of the reasons Pentax limited the wide end of their 28-45mm 645 zoom to 28mm (effective 22.5mm), which has consistently better corner performance. I am also taking into the account the field curvature exhibited in the Pentax 25mm lens. Thanks.

Dave (D&A)

 

[D&A]

Hi Dave,

Deviating from the topic of the thread, that is mea culpa!

There are two issues with large beam angle designs, one is the sensor and the other is the cover glass. At large beam angles the cover glass induces significant astigmatism. I posted a question on the issue at DPReview and a guy actually popped a piece of glass into his Zemax model of a lens and reported back that it caused both astigmatism and field curvature.

Sony sensors have 2-2.5 mm of cover glass, while MFD sensors have around 2 mm, this would be taken into account when calculating the lens. DSLR lenses have smaller beam angles, because the lens is sitting in front of the mirror box.

But, with lenses having short distance between outlet pupil and sensor plane, it is a problem. That is the reason Leica experimented with extremely thin glass on the M8, but that glass failed to achieve proper IR filtration.

As an example, the cover glass can be replaced on the A7r with glass corresponding to Leica specifications and the Leica lenses improve a lot with the thinner glass. But, Sony lenses may suffer from the thinner glass. Lloyd Chambers demonstrated this quite clearly on the Sony 55/1.8ZA lens.

I am routinely using Canon glass on my A7rII. Ken Rockwell has published some report saying that the 16-35/4 L performed horribly on the A7rII (?) but that is not my experience. My sample of the 16-35/4L outperforms my Distagon 40/4 on the P45+ and int also outperforms the Distagon 60/3.5. That is with the exception of the extreme corners, where the 16-35/4 drops even more than the Distagon 40/4.

So, I don't think problems with DSLR lenses are sensor related. But with more symmetric lenses cover glass could be a problem, especially with lenses designed for film. I would guess that most modern lenses are calculated for 2mm of cover glass.

The pixel design and microlenses are more relevant with regard to vignetting and cross talk. Light beams coming in at shallow angles wil be cut off by the well. Also shallow angle beams may contaminate adjacent pixels, so a beam passing trough the red filter may affect say a green pixel. That is called cross talk.

The CCD sensors made by Kodak had least issues with cross talk, these are used in Leica M8, Leica M9, Leica S2 and Leica S (typ 006), Dalsa sensors were more problematic. This issues increase with decreasing pixel size.

Best regards
Erik

Thanks for the interesting discussion and information Erik. With regards to astigmatism and field curvature, that may be hsppening with the example of the Pentax 25mm 645 lens, although it was an all new optical design specifically for a digital sensor. I also believe its a retrofocus design, so both the field curvature as well as being a retrofocus design may contribute to exhibiting soft corners as good and attractive a lens it might be.

Cross talk is still prevelant with the M9 although containing the Kodak designed CCD sensor.

I have read about replcement of thr cover glass on the Sony a7rII with one with Leica specs contributing to better corner performance with M lenses but at same time worsening performance with native Sony glass. It stands to reasons why this is so.

Still trying to get a handle on the Pentax 25mm 645 lens samples I tried and to get a better understanding of what I am observing as described in my few posts above.

Dave (D&A)

 

[Bernard]

Still trying to get a handle on the Pentax 25mm 645 lens samples I tried and to get a better understanding of what I am observing as described in my few posts above.

One can infer that the 25 was discontinued because it does not work well with the Sony sensor in the 645Z, as opposed to the Kodak sensor in the 645D. The small jump in resolution between the two sensors should not make a huge difference, but the difference in sensor architecture could.

 

[Paratom]

Most know I am a big supporter of the Leica S system...having 2 bodies and 9 lenses ...I am committed . It has the best IQ I ve seen except for the P1 100MP system (which is in a different weight class). It also has the form (size ,weight,OVF ) that I am most pleased with .

Two problems are real and should be considered . (1) sending gear thru NJ for any Leica product is a bad idea ...they are in the mist of a messy technology conversion and have had several key employees leave . (2) the AF failure problem is real .

The AF failures greatly increased with the new firmware for both the bodies and lenses ...last year . The added speed (its now plenty fast enough) caused too much load on the AF gear and it breaks . While a permanent fix seems to be close ...this does not help those that own existing S lenses .

Failure most often occurs just after mounting a lens on a S 007 or updated S 006 . Lenses that require a lot of movement to go from close focus to infinity and /or utilize floating elements (24) ...may strip even if brand new .

This isn t going away ....most all the S lenses will need their AF motor replaced (unless you plan on using an S2 body ).

My recommendations (1) take your S lenses someplace you can find a S 007 with the latest software ...set the lens to close focus and mount it ...you can feel the torque . If you buy a new lens ..do this immediately and send it back if it fails . (2) lenses that fail need to go directly to Germany and preferably thru your dealer .

Not what any of us want to hear but I believe that in a few months I will have my set of lenses updated .

Otherwise my S system has been without any major issues . If you have an S2 or S 006 have it checked for sensor corrosion ..same issue as M9 and Mono CCD.

Hi Roger,
Maybe I am just lucky (so far?) in regards of my lenses.
Tom

 

[ErikKaffehr]

Hi,

I have seen an excellent article describing many of the Pentax lenses when I finally found it I discovered that

• The 25 mm was missing
• You are the author

I know that Lloyd Chambers has tested the lens on both the Pentax 645D and the Pentax 645Z, although it may have been different lenses. Lloyds tests used to be adequate and as good as it gets. But his site is a subscription site.

I used to subscribe to his site, but he has very restrictive terms on sharing information and I also found that he was not very open to constructive discussions about his findings, so I no longer subscribe.

But it was very clear that he had focusing issues with all Leica S2 and Leica S systems he had access to and there were several of those. But Lloyd Chambers is extremely critical in his testing. On the other hand he makes a lot of noise about his findings but that is a part of reviews for money approach. He also shot together with a Leica representative demonstrated the issue. My take is really that if I invested say 20k€ in a system, I would buy a Diglloyd prenumeration to find out what he thinks.

Best regards
Erik

Thanks for the interesting discussion and information Erik. With regards to astigmatism and field curvature, that may be hsppening with the example of the Pentax 25mm 645 lens, although it was an all new optical design specifically for a digital sensor. I also believe its a retrofocus design, so both the field curvature as well as being a retrofocus design may contribute to exhibiting soft corners as good and attractive a lens it might be.

Cross talk is still prevelant with the M9 although containing the Kodak designed CCD sensor.

I have read about replcement of thr cover glass on the Sony a7rII with one with Leica specs contributing to better corner performance with M lenses but at same time worsening performance with native Sony glass. It stands to reasons why this is so.

Still trying to get a handle on the Pentax 25mm 645 lens samples I tried and to get a better understanding of what I am observing as described in my few posts above.

Dave (D&A)

 

[Yevgeny NP]

If there are not problems with S lenses, then why have they announced via dealers that there is now a permanent fix available for S lenses if lenses are sent in to Germany. This means other fixes did not fix the problem.

I left my faulty S100mm with the Moscow dealer to be sent to Germany and the technician there said that this time I shall expect a permanent fix.

 

[D&A]

Hi,

I have seen an excellent article describing many of the Pentax lenses when I finally found it I discovered that

• The 25 mm was missing
• You are the author

I know that Lloyd Chambers has tested the lens on both the Pentax 645D and the Pentax 645Z, although it may have been different lenses. Lloyds tests used to be adequate and as good as it gets. But his site is a subscription site.

I used to subscribe to his site, but he has very restrictive terms on sharing information and I also found that he was not very open to constructive discussions about his findings, so I no longer subscribe.

But it was very clear that he had focusing issues with all Leica S2 and Leica S systems he had access to and there were several of those. But Lloyd Chambers is extremely critical in his testing. On the other hand he makes a lot of noise about his findings but that is a part of reviews for money approach. He also shot together with a Leica representative demonstrated the issue. My take is really that if I invested say 20k€ in a system, I would buy a Diglloyd prenumeration to find out what he thinks.

Best regards
Erik

Thanks Erik. Since I wrote that article on testing Pentax 645 legacy lenses, I proceeded to test all of thrir most recent lenses including the Pentax DA and DFA 25mm, 28-45 zoom and 90mm. The one lens of this new grouping thats still a bit of a mystery in terms of getting a handle on regarding consistantcy in performance, is the 25mm. Even Ming in his excellent multi part review of the 645Z and lenses found great inconsistancy with the 25mm.

In the past I read many of Lloyds artcles on the Pentax 645 and its lenses and I must say there were numerous findings and observations of his I would disagree with (in the case of this

You have characterized his website and methodology quite accurately.

As for the issue of S lenses and their defective AF gearing, it would be welcome news if they found a perminant solution.

Dave (D&A)

 

[ErikKaffehr]

Hi Dave,

You may find this article quite informative:
http://lenspire.zeiss.com/en/wp-con...2015/09/en_CLB41_Nasse_LensNames_Distagon.pdf



Best regards
Erik

Thanks for the interesting discussion and information Erik. With regards to astigmatism and field curvature, that may be hsppening with the example of the Pentax 25mm 645 lens, although it was an all new optical design specifically for a digital sensor. I also believe its a retrofocus design, so both the field curvature as well as being a retrofocus design may contribute to exhibiting soft corners as good and attractive a lens it might be.

Cross talk is still prevelant with the M9 although containing the Kodak designed CCD sensor.

I have read about replcement of thr cover glass on the Sony a7rII with one with Leica specs contributing to better corner performance with M lenses but at same time worsening performance with native Sony glass. It stands to reasons why this is so.

Still trying to get a handle on the Pentax 25mm 645 lens samples I tried and to get a better understanding of what I am observing as described in my few posts above.

Dave (D&A)

 

[ErikKaffehr]

Hi Dave,

You may find this article by the late Hubert Nasse of Zeiss quite informative:
http://lenspire.zeiss.com/en/wp-con...2015/09/en_CLB41_Nasse_LensNames_Distagon.pdf

View attachment 123484

Check this page too, please: https://www.lensrentals.com/blog/2014/06/the-glass-in-the-path-sensor-stacks-and-adapted-lenses/

Best regards
Erik

Ps. I feel Dr. Nasse was a great guy, I miss him.

Thanks for the interesting discussion and information Erik. With regards to astigmatism and field curvature, that may be hsppening with the example of the Pentax 25mm 645 lens, although it was an all new optical design specifically for a digital sensor. I also believe its a retrofocus design, so both the field curvature as well as being a retrofocus design may contribute to exhibiting soft corners as good and attractive a lens it might be.

Cross talk is still prevelant with the M9 although containing the Kodak designed CCD sensor.

I have read about replcement of thr cover glass on the Sony a7rII with one with Leica specs contributing to better corner performance with M lenses but at same time worsening performance with native Sony glass. It stands to reasons why this is so.

Still trying to get a handle on the Pentax 25mm 645 lens samples I tried and to get a better understanding of what I am observing as described in my few posts above.

Dave (D&A)

 

[D&A]

Thanks ever so much Erik, truly appreciated! When I have a lengthy break later tonight, I'll have a good read of both of them.

Dave (D&A)

 

[2WK]

:OT:

 

[Miller]

Has taken its natural course, I would say...