20 mm lens for the G1

[Martin S]

Cosina has just released a 20 mm f 3.5 pancake style lens in either a Nikon F mount, or Pentax K mount. With the delay in releasing the Panasonic 20 mm pancake , this could be a great walk around lens.

It sounds like a good lens for the G1 with stacked adapters (Pentax K to 4/3. 4/3 to m 4/3).

However, this brings up some questions
1) Is an SLR lens better to use on the G1 than a RF lens due to the edge smearing?? (Other 20 mm lenses do exist in RF format).
2) Does stacking adapters alter the flange to sensor distance, and so prevent accurate, and full range focussing??
3) I'v seen great results with using SLR lenses on the G1 on this site, and I was wondering if there are other problems caused by stacking adapters, and thus adding distance from the back of the lens to the sensor??

Thanks for your help.

Martin

 

[Per Ofverbeck]

Cosina has just released a 20 mm f 3.5 pancake style lens in either a Nikon F mount, or Pentax K mount. With the delay in releasing the Panasonic 20 mm pancake , this could be a great walk around lens.

It sounds like a good lens for the G1 with stacked adapters (Pentax K to 4/3. 4/3 to m 4/3).

However, this brings up some questions
1) Is an SLR lens better to use on the G1 than a RF lens due to the edge smearing?? (Other 20 mm lenses do exist in RF format).
2) Does stacking adapters alter the flange to sensor distance, and so prevent accurate, and full range focussing??
3) I'v seen great results with using SLR lenses on the G1 on this site, and I was wondering if there are other problems caused by stacking adapters, and thus adding distance from the back of the lens to the sensor??

Thanks for your help.

Martin

Well, I´m another one waiting eagerly for that 20/1.7....

Only, I don´t quite see the point in the Cosina combination. With two adapters, it can´t be very much shorter and lighter than the kit lens, and then it´s only f/3.5 and lacks both AF and IS. The kit lens is f/4.5 at 20 mm, it does have AF and IS, and can be zoomed in either direction if needed for fine adjustment. Also, it is very good optically, even wide open.

And, unless you own or need both adapters for other lenses, the total cost will be rather high for a "stopgap" solution. I´ve seriously considered the PanaLeica 25/1.4 with adapter, but it´s just TOO big, heavy, and expensive...

Panasonic, get going with that 20/1.7! P-L-E-E-E-Z-E!!!

 

[Martin S]

Thanks Per for ur comments.

I was more interested in the Cosina lens a few days ago.
But as reality struck, I could see the complications, and lack of features (IS,AF) that the combination of adapters, and manual focus lens could cause.

I guess, that I will also wait for Panasonic to get its act together.

Martin

 

[Ranger 9]

Depending on how much you're willing to spend on a stopgap solution, and your tolerance for inconvenience, you might want to consider a C-mount 25mm lens plus C-mount adapter.

Many of these lenses have maximum apertures of f/1.4 or so, and at least you'll only need one adapter rather than a stack. Some of the C-mount lenses give severely compromised performance on µ4/3, but others seem quite usable.

There are a couple of threads here with examples of shots from various C-mount lenses that should give you an idea of what types of results you might expect.

 

[monza]

For possible c-mount lenses, check out the database. There are several lenses in the 25mm range that are fast and cover the sensor.

http://spreadsheets.google.com/pub?key=p9kkgjwEQQQ-HJwvNDobeEw