leica R lens focusing with Panasonic L1

[ricardo_villagran]

Hello,

 

 

Yesterday I got my 35mm Summicron R lens which I am trying to use with my L1.

Exposure is right-on but I have problems with focusing, even when I got the

focus confirmation green dot on the finder, some of the shots come out of focus

and some don't.

 

Any help would be very aappreciate here, I have great expectations in that lens!

 

 

 

Regards,

Ricardo

[erikhaugsby]

Don't trust the camera to tell you what's in focus and what's not in focus--they make SLR cameras so that the user can see how the lens is focused. Trust yourself, and make sure the diopter is set correctly.

[ricardo_villagran]

Hello Eric, I been doing some further tests and the sharpness gets much better when closing down the lens, giving their best performance @ f5.6. I don't know if it is a matter of shallow depth @ f2, or simply the lens gets better when stepping it down...

 

Regards,

Ricardo

[godfrey]

Focusing relatively short focal length lenses takes some effort. I find that 35mm is about

as short as I can focus easily and reliably without using the Live View and MF assist, unless

I'm using a dedicated 4/3 System lens. Go to 105 and 180 mm, and I have no trouble at all

focusing very accurately.

 

So I tend to use the 4/3 System lenses for the ultra-wide to normal, and the adapted

lenses in the telephoto range. Or I calibrate my short lenses' focusing, use DoF and scale

focus to get the job done.

 

Godfrey

[xavier_dalfort]

On mee Digilux 3, I have noticed as Ricardo that results are better when using a f4 or f5.6 the lens.

 

 

In fact, when using a summilux 50mm, it is difficult to trust the green dot in the screen.

 

it helps but not that much.

 

It is improved further when the central sensor is used (one of the option in some menu) ut not that much in fact.

 

FWIW.

[ricardo_villagran]

After several tests I realized is not a matter of focusing, but an issue of depth of field, since I been using tripoid and only stepping down the aperture... at f5.6 the images look very sharp, at f2 there is no a single point of focus area... So I guess this lens is simply useless at f2-2.8... it is a shame since I was trying to use it for portraits!

 

 

Ricardo

[Rob F.]

Depth of field may not be the only factor here. I think that less than perfect accuracy of the focus confirmation system may be a contributing factor. I'm not convinced that focus confirmation is all that it's cracked up to be, whether on your L1 or my D200--perhaps others as well.

[dougmiles]

I have little experience with AF systems, but I find it astonishing that the manual focus confirmation would be inaccurate while AF with AF lenses is working well. How could that be?

 

Totally different system of course, but I have used manual focus lenses (some are P67 lenses on adapter) with my Pentax 645NII and its focus confirmation gives me focus where I expect it every time.

 

Naturally, wide apertures give narrow DoF but at least your chosen focus point should be in focus.

[luan_doan_minh]

This is from memory so there maybe some inaccuracies and also applies to phase-detection AF systems so may not be directly applicable to the L1 (I just don't know the specifics of the L1 AF system). In the aforementioned AF system, the camera uses lens parameter(s) to compute acceptable focus (the depth of focus). The camera then tells the lens, or moves the lens to place the image within the depth of focus zone.

 

Assuming the AF indicator stays on for the full extent of the depth of focus zone, humans using only the AF indicator to manually focus still do not know how far to move the lens (focus ring) to place the image in the optimum depth of focus zone. Depending upon the lens and the human, moving the lens into the optimum focus position maybe challenging and certainly not consistently achievable.

 

Unless there's a way to enter the lens parameters in the camera (at least the max. aperture); there's no knowing how the camera is determining the depth of focus, hence no guarantee that the AF indicator is turning on and off at the appropriate points for the lens. Thus, it is not altogether unreasonable to expect that an AF camera with AF lens can focus better than a human trying to focus manually using just the AF indicator. Closing down the lens will compensate for some focus errors due to increased depth of field. This maybe why lenses appear to be only usable when stopped down.

 

I recommend using the AF indicator to quickly get to the "zone", and as has been suggested, then use your eyes to determine final focus.

[dougmiles]

An interesting point! Indeed, how wide IS the zone of acceptable focus in which the in-focus symbol is lit? My sense is that it's narrower than the wide-open DoF but perhaps not...

[luan_doan_minh]

Note that depth of field (DoF) and depth of focus are similar and related concepts, but depth of focus refers to the image side of the lens and is 2 times the distance between the focal plane and an image dot the size of a permissible circle of confusion in front of, or behind the focal plane. Permissible circle of confusion is the size of an image dot deemed to be of acceptable sharpness.

 

Canon state in their "EF Lens Work Book" that the depth of focus is equal to the minimum circle of confusion multiplied by the F number. They also indicate that EF lenses are designed to produce a minimum circle of confusion of 0.035mm. Since the depth of focus is probably mostly in the sub-mm range (tens to hundreds of microns); this is what makes it difficult to accurately focus a lens manually without suitable focusing aids.

[peter]

I wonder if someone can help me by answering a question. I have had a Panasonic L1 for a few weeks and am loving it. I have just bought two lens adapters - one for my Nikon glass and another for my M42 glass. But I cannot figure how to get it to work with manual focus lenses and the adapter. I have successfully mounted the lens on the adapter and the adapter on the camera. I have set the camera's focus mode to manual focus and metering mode to center weighted (not sure if the latter is a requirement) but I still get no focus confirmation through the viewfinder and the shutter button will depress but will not fire the shutter. What am I doing wrong?