Various 90mm's focus trouble

[BerndReini]

Advertisement (gone after registration)

Tim,

 

the other night, I took a 2mm allen wrench to my rangefinder to find the sweet spot for all my lenses, and here is what I realized. All my short lenses up including my 35mm seem to focus

closer than all my long lenses (50 and 75). Especially taking into consideration the focus shift toward backfocussing when you stop down the 50lux, it is incredibly difficult to adjust for all lense equally. But let me know if you see the same results between your long and short lenses.

[billh]

A bit of an update:

 

Today my dealer, Artaphoto of Nice, who has been exceptionally helpful throughout, exchanged my M8.

 

The replacement camera focuses spot on will all my lenses!

 

Close up, mid range and infinity snaps in perfectly as well. One small problem , one of the segments of the LED viewfinder display is missing! I can live with that for the moment, after 4 months its so nice to have a camera that I can take pictures with at last.

 

This amazes me, but it is the second story I have heard like this. With your previous M8, did any of your lenses focus correctly, or did some focus to the rear, while the plane of focus for others was forward? What I am trying to learn is, if as so many of us have experienced, we have some lenses that are back focusing, some OK, and perhaps even some focusing to the front, will a correctly adjusted/functioning M8 have them all focusing correctly?

 

Thanks,

 

Bill

[Guest Lotw]

I agree with Alan, it has always been there, but the M8 gives the possibility to immediately recognize it. It is not the M8, it's the lenses. However, there can also be another aspect working: focus-shift occurring while stopping down. A phenomenon already known with the better enlarger-lenses (Schneider e.g.) which seems to occur in Leica camera-lenses too as suggested by Puts lately for the 35lux asph en zeiss 50/1.5: if you have focus at 2.8 it does not mean you have focus at F8.0. So how do they adjust at Solms: at 2.0 or at F8.0?

http://www.imx.nl/photosite/comments/c035.html

[London Lad]

With the old M8 all my lenses back focused and my 90/4 macro elmar did not line up at infinity. (the range finder image aligned very slightly before the lens reached the infinity stop)

 

With the new camera all my lenses focus properly.

I test at 1 meter with a 45degree focus chart, at 10 meters by bracketing and at infinity on a sea / sky horizon.

 

My 50 / 1.4 lux asph does focus shift when stopping down at close range but the target of focus stays within the DOF area.

[pklein]

I have three 90s, none of them focus correctly on the M8. All of them focus correctly with film. What is interesting is that one lens front focuses on the M8, the other two back focus. Yet they are fine with film, using the "shoot a ruler from a 45-degree angle" test, and also using the "I shot with them for years and never had a focus problem" test.

 

For example, my 90mm Summicron back focuses about 8-12 inches on the M8, when shooting at about 20 feet. I could repeat this over and over when testing.

 

I have no such problems on the M6TTL with film.

 

Since some of my lenses focus fine on the M8 (disregarding the backward creep as you stop down), something must be different on the M8. I think tolerances are less, because with film, if the point of sharpest focus was anywhere within the emulsion, you were OK. But with the sensor, you don't have that fudge factor. I also agree with whoever said that the longer the lens, the more likely it is not to focus correctly.

 

Add questionable QC, and lenses that have been used for years, and the situation can be confusing.

 

The first two attached files (in color) are from a set of 90 'Cron test shots on the M8. These are at from about 6 feet away. You can already see the back focusing. I focused on the second box from the left, on the vertical line next to the words "Vitamin D." From 20 feet away, the actual focus was way back to the cutting board and plate behind all the boxes (I already discarded those files, sorry).

 

And just to show you that I have no such problems focusing the same lens on the M6TTL, the third B&W image is on TRI-X FILM, with the M6TTL. No back focus there! Both images shot with the same 90mm Summicron

 

--Peter

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

[pklein]

Again, the two color shots above are with the M8. The black and white shot of the cellist is with Tri-X in an M6TTL. The same 90mm Summicron was used for both.

--Peter

[colorflow]

Advertisement (gone after registration)

Again, the two color shots above are with the M8. The black and white shot of the cellist is with Tri-X in an M6TTL. The same 90mm Summicron was used for both.

--Peter

 

I'm not sure if the M6 cellist shot is as critical as the M8 shots. I tested with both M8 and M6 shooting a tape measure at 45 degrees using a tripod. The results are similar for film and M8.

 

Also I noticed all my lenses shift their focus back when stopped down. So I would think the best way to adjust a lens is to have it at the front of the DOF wide open, then the back focus shift when stopping down along with the increasing DOF will produce good focus.

 

Just my TCW,

 

Alan

[woodyspedden]

Hi Bill,

 

I certainly will report back - there's been a bit of a tendency for people not to believe that there are problems with currently shipping lenses on the M8 but I am now quite sure there is. My 50 Lux has however always behaved impeccably and is my favourite lens. Having two bodies helps in the sanity stakes but if my black one returns on good terms with the 35 cron but with a cold shoulder for any of the lenses it used to like, I really will spit nails.. I don't want one camera per lens!

 

That shot is mine - it's on my zenfolio site under Sussex Land & Seascapes and I have a 40" lambda print from a crop of it that is really rather nice. It was taken with a 24mm 2.8.

 

Best

 

Tim

 

tim

 

I totally agree with you on these issues. However I would like to at least congratulate you on outstanding images on the Sussex landscapes thread. Whatever focussing issues you may have you have certainly been able, with your outstanding talents, to bring beautiful images to the world. What in the world can you achieve if he equipment doesn't fail you?

 

WoodySpedden

[Guest Lotw]

Again, the two color shots above are with the M8. The black and white shot of the cellist is with Tri-X in an M6TTL. The same 90mm Summicron was used for both.

--Peter

 

Seems to me that the M6TTL shot is at least F4.0 and I would expect that you focused on her face. In that case the cello is remarkably sharp and seems sharper than the face. I guess the distance between the two is about 12 inches.

[pklein]

I may be comparing apples and oranges here. But I checked the lens with film about a year ago, focusing on a ruler at 1 meter and 2 meters, and it was dead-on back then.

[chris_tribble]

Funny - I have a 135 APO, an ancient (Canadian) 90 cron, and an old 75 lux + old 50 lux. They all focus spot on with both my M8 bodies and I've not had problems with my M6 or M7. I had to have infinity focus adjusted on the 90 when I bought it used about 8 years ago. Guess I'm lucky - the point of the post being that some of us aren't having problems, which may be some comfort.

[billh]

Peter,

 

Your cereal box illustration is exactly what I have seen in repeated tests. This mainly proves a point to others, that the camera/lens is indeed back focusing. However, as you know, this immediately becomes obvious when you use the camera/lens combination, which is why you are forced to do these “tests”. If the lenses were back focusing on film, you would have been aware of it long ago, and perhaps compelled to run similar tests.

 

Chris, it is encouraging, but also puzzling to those of us who have been struggling with this problem. My APO134 f3.4 focuses accurately on my M7, but is way off on the M8s. The thing that worries me is I have one lens, the APO75, which focuses accurately on the M8 and the M7. All of my other lenses back focus on the M8, and none are right at infinity on the M8 (i have to set the infinity mark on the lens barrel to get the photo in focus - otherwise it is way off). If I understood why - what the problem is - then it could be addressed. Maybe the replacement M8 will work correctly. I sure hope so.

 

Bill

 

APO135@f3.4 (my other lenses give very similar results)

 

 

APO75@f2.0

 

 

APO75, lens set on infinity mark,

 

 

APO75, focused at infinity with rangefinder

 

[billh]

For some reason these two did not show in that post,

 

APO75@f2.0

 

APO75, focused at infinity with rangefinder

[tashley]

Tim,

 

the other night, I took a 2mm allen wrench to my rangefinder to find the sweet spot for all my lenses, and here is what I realized. All my short lenses up including my 35mm seem to focus

closer than all my long lenses (50 and 75). Especially taking into consideration the focus shift toward backfocussing when you stop down the 50lux, it is incredibly difficult to adjust for all lense equally. But let me know if you see the same results between your long and short lenses.

 

I've so far failed to see anything consistent other than that Leica 28 and 35s don't focus well, though two CV35s were spot on. This is on 2 bodies where other lenses seem good. I am increasingly certain that there is something to be bottomed out here.

 

t

[tashley]

tim

 

I totally agree with you on these issues. However I would like to at least congratulate you on outstanding images on the Sussex landscapes thread. Whatever focussing issues you may have you have certainly been able, with your outstanding talents, to bring beautiful images to the world. What in the world can you achieve if he equipment doesn't fail you?

 

WoodySpedden

 

Woody, shucks, you made me blush... and the best thing about landscapes is that if you set the lens to infinity, stop down to f5.6 then pull focus a tad forward, it will nearly always be sharp even if both the lens and the RF are off.

 

So does that makes the M8 the best landscape camera, or the landscape the best scene for an M8?

 

You, the jury, will decide!

 

t

[tashley]

Funny - I have a 135 APO, an ancient (Canadian) 90 cron, and an old 75 lux + old 50 lux. They all focus spot on with both my M8 bodies and I've not had problems with my M6 or M7. I had to have infinity focus adjusted on the 90 when I bought it used about 8 years ago. Guess I'm lucky - the point of the post being that some of us aren't having problems, which may be some comfort.

 

It so isn't comfort. It's like having a gorgeous sister who keeps telling you your zits will clear up!

 

 

t

[colorflow]

Tim:

This is off topic. I went to your web-site after Woody's comments. The Sussex landscapes are absolutely mesmerizing and left me speechless. Have you given any workshop or written articles on landscape photography? I'd be really interested.

 

Alan