Jump to content

focus shift on fast voigtländer lenses


Guest zoz

Recommended Posts

Advertisement (gone after registration)

For me the image of the lightbulb is oof on the first image, and the front edge of the carton is oof in the 2.8 images. The focus moves several cm.

Both images are ok for a 13x18 Print, but blown up to 50x70 You will see that the focus is not on the eye but at the tip of the nose.

If You do not need that accuracy, and You just bought the fast lens for available light, fine!

 

btw the 1.1/50 has got a quite mild shift compared to other lenses. especially the 2/28

Link to post
Share on other sites

  • Replies 69
  • Created
  • Last Reply
Hello,

 

I've read several threads about focus shift all centered around rangefinder lenses. Is this a potential problem for all lenses or are other lens designs/systems less prone for some reason?

 

Just curious as I've gone Dig 1,2 and three so far then Canon 5DMk 2 while waiting to see what may come out at Photokina. I'm seriously considering moving to an M but issues like this are not something I look forward to dealing with.

 

Kind of hoping for an optical/electrical viewfinder system but would focus shift still be an issue?

 

Thanks

Johnny

Simple answer - it is a problem with all systems and basically with all lenses,as the aberration-free lens does not exist. Some lenses like the newest Leica floating-elements lenses are more successful at combating the issue. The main advantage of a manual rangefinder system is that the user can compensate for the effect by using that marvellous portable computer: his brain. Works better than any gizmo thought up by camera designers, provided it is used.;)

Link to post
Share on other sites

Which array captures the light in one plane focussed by the micolenses. The AA filter, IR filter and micfrolenses are not light-capturing devices, thus their thickness is irrelevant in this context. The emulsion as a whole is a light-capturing device, so that thickness is relevant.

 

I don´t agree!

Light is refracted and scattered by this 3D structures before it is sensed. So of course it will have an effect.

Link to post
Share on other sites

The main advantage of a manual rangefinder system is that the user can compensate for the effect by using that marvellous portable computer: his brain.

 

What is hindering You from using the same marvellous portable computer with different types of cameras?

;):D

Link to post
Share on other sites

For one thing you have to stop down on an SLR to see the effect of focus shift - which reduces focussing accuracy, both for manual and AF. And doing it manually, as AF is too inaccurate to do it properly (and shortcicuits your private computer :p) Then stopping down the image darkens so much you won't see it anyway.

Link to post
Share on other sites

I don´t agree!

Light is refracted and scattered by this 3D structures before it is sensed. So of course it will have an effect.

Well, microlenses don't scatter, they concentrate, and the M9 has no AA filter and a minimal IR filter.
Link to post
Share on other sites

Advertisement (gone after registration)

For me the image of the lightbulb is oof on the first image, and the front edge of the carton is oof in the 2.8 images. The focus moves several cm.

Both images are ok for a 13x18 Print, but blown up to 50x70 You will see that the focus is not on the eye but at the tip of the nose.

If You do not need that accuracy, and You just bought the fast lens for available light, fine!

 

btw the 1.1/50 has got a quite mild shift compared to other lenses. especially the 2/28

There is no difference in print sizes - if each is viewed at its appropriate distance. Looking at photographs bears no relationship to pixel-peeping.
Link to post
Share on other sites

For one thing you have to stop down on an SLR to see the effect of focus shift - which reduces focussing accuracy, both for manual and AF. And doing it manually, as AF is too inaccurate to do it properly (and shortcicuits your private computer :p) Then stopping down the image darkens so much you won't see it anyway.

 

 

You do not see it on a rangefinder at all, why do you wan´t to see it on an SLR?:confused:

Link to post
Share on other sites

There is no difference in print sizes - if each is viewed at its appropriate distance. Looking at photographs bears no relationship to pixel-peeping.

 

I´m looking closer (relatively) at larger prints than on small ones. I don´t think I´m the only one.

 

If a few cm misfocused images on 1m distance suites Your needs, fine for You.

Link to post
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...