NEX-5 and infinity focus. A question for you.

[douglasf13]

Well, I've just made a discovery that should have been more obvious to me earlier. After complaining like a lot of users that my Leica M to E-mount adapter focused past infinity, I made another discovery today. My Sony issued A-mount to E-mount adapter does the same thing :shocked: This leads me to believe one of three things:

A) the tolerances of the camera aren't great, and my sensor and lens mount are too close together

B) I just so happen to have two adapters that are off by approximately the same value

C) There is something more to the idea that the AA filter or microlenses are further than normal away from the sensor, and that is causing the variation. See this thread: http://www.photoclubalpha.com/forum/viewtopic.php?f=49&t=4419

So, I was hoping that a few of you could throw on the various adapters you have for your NEX camera and do a manual focus zoom at infinity to see if yours is slightly off as well. That could help me narrow down the cause. Thanks!

 

[Vivek]

First off, I sincerely hope that folks would leave the AA filter alone in their discussions. No one knows anything about the AA filter, even when you take them apart, nothing can be gleaned from them.

I only have the RJ c-mount adapter which after my adaptation also doubles as a pen F adapter.

I have no problems with infinity focus of c-mount lenses or pen F lenses.

Using the c-mount, I can also mount:

1. Minolta MD

2. Olympus OM

3. Nikon F

all via the corresponding c to XX mount adapters.

No worries there.

The supplied kit lens 16/2.8 can focus way past infinity if one needs it. Adding a diopter lens to it, I can still focus close to infinity while getting close-up capabilities down to ~5cm.

BTW, what makes you suspect the tolerances of the camera registry based on the adapters? Who sets the standards for these adapters?

Is your Leica M lens sample calibrated for infiniity?

Way too many variables, Douglas.

IMHO, this issue (a non issue) is the least of NEX' problems.

 

[ken_vs_ryu]

Both my leica m and canon eos reaches infinity focus before the infinity mark.

 

[douglasf13]

Vivek, I'm not talking about the qualities of the AA filter itself, but rather its distance from the sensor. Regardless, it is probably a red herring. Just so I am clear, you're saying that, when you line up the infinity mark on all of your adapted lenses, they are actually focused to infinity? On mine, lining up the infinity mark is actually past infinity. Granted, like I mentioned, we're only talking about two adapters here.

 

[MPK2010]

I am using the RJ adapter and all of the M Leica and Voigtlander lenses reach infinity focus before the point marked for infinity on the lens. The mismatch is more than what I found with the Voigtlander M adapter for m43, but does not bother me because I use focus assist and never zone focus with the NEX. Of course, I assume I am losing a little range at the close end, which is a mild annoyance.

 

[douglasf13]

Yeah, I use the focus assist, too. I agree that loosing a little close end range would be annoying.

 

[Vivek]

Vivek, I'm not talking about the qualities of the AA filter itself, but rather its distance from the sensor. Regardless, it is probably a red herring. Just so I am clear, you're saying that, when you line up the infinity mark on all of your adapted lenses, they are actually focused to infinity? On mine, lining up the infinity mark is actually past infinity. Granted, like I mentioned, we're only talking about two adapters here.

I am saying that is a non issue due to live view and magnified focus assist possibilities with a live view cam.

On the m4/3rds, where I have dedicated lenses (adapted), I set the infinity by adjusting the focus scale on the lenses. The pen F lenses (most of them) close focus better than the Leica M/LTM lenses, so no worries about close focusing.

If I use a Cosina 35/1.4, specifically for the NEX (and no RF use at all), I would adjust the lens or use thin shims to adjust the adapter thickness for a given lens or a set of lenses.

This is one of the strong points of the live view cams as opposed to the RF ones where you will have to dig up the addresses of DAG or Sherry to get the cam aligned and the lens aligned/collimated and the RF patches aligned.

I still have painful memories of getting the Canon 50/0.95 (leica M mount) collimated so that the focus would be accurate. That is what led me away from the RF cams and once live view came about there was no turning back.

Add to this the fact about focus shifts- there are shifts associated even with aperture changes (few lenses, thankfully) and in my case, focus shift due to wavelength change. UV focus is different than visible focus and that is quite different than IR focus.

 

[sebboh]

all of my NEX adapters are from RJ and all allow focus past infinity (as they are supposed to). most cheap adapters are designed to allow for focus past infinity in order to make up for slop in machining precision (better going past infinity than not reaching it). i am surprised to hear that the sony adapter doesn't hit infinity bang on. i'm assuming alpha lenses don't focus past infinity on your a900? if not my best guess would be that sony is simply being economical and not bothering to be to precise with flange to sensor distance since precision doesn't matter for cdaf the way it does for a viewfinder + phase detect autofocus. as Vivek say's there is plenty of extra throw in the kit lens(es) to compensate for wide tolerances in sensor positioning.

 

[tmessenger]

All manual focus lens have some sort of adjustment to set infinite focus so they can be set up at the factory. Ya just need to adjust your lens to the adapter / camera.

Tim

 

[douglasf13]

Sebboh, yeah, you're probably right about the Sony adapter. Just poor tolerances.

tmessenger, my Alpha lenses focus fine on my A900, so I'm pretty sure it isn't the lenses.

 

[tmessenger]

Sebboh, yeah, you're probably right about the Sony adapter. Just poor tolerances.

tmessenger, my Alpha lenses focus fine on my A900, so I'm pretty sure it isn't the lenses.

I was referring to MF lenses only AF lenses are a different beast.

Tim

 

[douglasf13]

My adapted m42 lenses are also fine on my A900. If I adjust them to focus properly at infinity on NEX, then they will be off on the A900.

 

[barjohn]

I shimmed my RJ adapter for my M lens and it focuses right to infinity as it should. It took a few tries though.

 

[volkerhopf]

Both my Leica M adapter and the Contax one go past infinity. I shimmed the Leica adapter so it is pretty close now but only close.

Well, I've just made a discovery that should have been more obvious to me earlier. After complaining like a lot of users that my Leica M to E-mount adapter focused past infinity, I made another discovery today. My Sony issued A-mount to E-mount adapter does the same thing :shocked: This leads me to believe one of three things:

A) the tolerances of the camera aren't great, and my sensor and lens mount are too close together

B) I just so happen to have two adapters that are off by approximately the same value

C) There is something more to the idea that the AA filter or microlenses are further than normal away from the sensor, and that is causing the variation. See this thread: http://www.photoclubalpha.com/forum/viewtopic.php?f=49&t=4419

So, I was hoping that a few of you could throw on the various adapters you have for your NEX camera and do a manual focus zoom at infinity to see if yours is slightly off as well. That could help me narrow down the cause. Thanks!

 

[Vivek]

I shimmed my RJ adapter for my M lens and it focuses right to infinity as it should. It took a few tries though.

:thumbs:

 

[HansenTsang]

All of my adapters (RJ, Kipon, etc.) for my Contax G, Nikon F, Canon EOS, Leica M do focus past infinity. That becomes a problem for me since I want to use the NEX as an aerial photography camera. The best I can do right now is to pre-focus the lens on the ground to infinity and tape the focus dial so it won't move when I mount the camera to my radio control helicopter. The lens I try to use is the Sam Yang 14 mm f2.8.

I also have the 16mm f2.8 which is a good enough lens. However there is no distance mark for manual focus and it also focus way past infinity.

I have a hard time doing manual focus from the LCD in bright sun. Zooming in and focusing is just too cumbersome. So I am trying to build a little view finder box with a magnifying glass to clip on the LCD screen.

 

[douglasf13]

Hmm, it just seems strange to me that none of my adapters for DSLRs have this problem, yet all of the NEX adapters seem to so far.

 

[sebboh]

Hmm, it just seems strange to me that none of my adapters for DSLRs have this problem, yet all of the NEX adapters seem to so far.

most of my adapters for dslr have this problem as well. i've heard of a few people with canon dslrs having the opposite problem with their adapters.

 

[sebboh]

All of my adapters (RJ, Kipon, etc.) for my Contax G, Nikon F, Canon EOS, Leica M do focus past infinity. That becomes a problem for me since I want to use the NEX as an aerial photography camera. The best I can do right now is to pre-focus the lens on the ground to infinity and tape the focus dial so it won't move when I mount the camera to my radio control helicopter. The lens I try to use is the Sam Yang 14 mm f2.8.

I also have the 16mm f2.8 which is a good enough lens. However there is no distance mark for manual focus and it also focus way past infinity.

I have a hard time doing manual focus from the LCD in bright sun. Zooming in and focusing is just too cumbersome. So I am trying to build a little view finder box with a magnifying glass to clip on the LCD screen.

may i recommend shimming your adapter till you have infinity? the best method i've found to do this is to fold up a sheet of tin foil a number of times and then cut out a ring from the folded tin foil that matches the interior of the adapter. place the stack of tin foil rings in between the part of the adapter that connects to the lens and the rest of the adapter. check infinity focus. hopefully it now no longer reaches infinity (if it still focuses past infinity you need more tin foil rings). take out the tin foil rings one at a time checking infinity focus each time till it is dead on.

 

[simonclivehughes]

On the subject of adjusting adapters, I just got an RJ M39-NEX adapter and the lens ends up offset rotationally. I.e., the normal top position of the lens is about 30 degrees to the left. Is there a way to adjust the adapter to allow the lens to return to the top position?

Cheers,