28 Summicron asph - Shallower DOF?

[notturtle]

I have read in a few places that some (or a couple of owners on lots of forums) claims that his 28 asph cron gives less depth of field at equivalent apertures that his V4 elmarit did.

From reading on Leica forum it sounds like this is possible, due to differences in the exit pupils of lenses of the same FL. It is apaprently not the case that all lenses of the same FL produce the same DOF at a given aperture, though most are very close.

Can anyone who has used this lens and other 28s comment on whether it does produce less DOF at equivalent apertures to other lenses. One owner on photographyreview.com said he was shocked to find himself needing to stop down about two more stops! This sounds excessive, but can anyone comment with authority?

 

[sleepyhead]

I don't know about the 28mm Summicron ASPH, but I did compare once my 35mm Summilux ASPH at f/2 to my Canon 35mm f/2 LTM lens.

At f/2 the Summilux photos appeared to have "more bokeh" - that is, the transition from in-focus to out-of-focus was much more abrupt than with the Canon lens. Background elements in with the Canon lens still we recognizable, while the Summilux background elements were fuzzy-er.

So, I suppose it's possible with the 28mm Summicron ASPH as well. Could this be a design feature of ASPH lenses?

 

[notturtle]

I belive it is more common with asph lenses to have less apparent DOF. I have seen tests showing a noticeable difference between the 35 V4 and asph, but few mention a real issue with that lens, simply commenting that the transition is more abrupt. I am wondering if the same is true of the 28 cron asph or whether the difference is more dramatic and sometimes an issue. You would expect a 28 to offer up loads of DOF pretty well regardless....

 

[sleepyhead]

I personally don't see the apparently more abrupt transition from in-focus to OOF with my 35mm Summilux ASPH as an issue, but rather as a feature 🙂

As you say about 28mm lenses, there is already more inherent DOF, so I would be surprised if it was a big issue, unless you were often shooting at f/2 or f/2.8 and wanted the maximum DOF possible to have near and far elements as sharp as possible.