Confused about focal lengths

[pajamas]

I search and read a few threads on this topic but Im still very confused on this subject. Hope someone can clear things up a bit without being too technical.

I'm looking to get my first manual focus prime (either CV or ZM) for a Nex body for street photography/travel. I want a 35mm lens equivalent. Do I get a 25mm lens then?


Thanks in advance.

 

[steelydam]

Pretty much; that should make for a 37.5 mm equivalent in 35mm film cameras. A 24mm would be closer to 35mm equivalent but harder to find in rangefinder lenses I think - easy to find in 35mm film SLR mount though.

 

[pajamas]

I read somewhere that a 25mm lens would still get a 25mm perspective but a 35mm's crop or magnification

 

[vladimir]

Do not beleve everything you read, work it out yoursef:
25 x 1.5 = 37.5 mm. If you really wanted 35 mm on your NEX you would have to get a 23.33 mm lens. Given that no lens is exactly the foca length that is mark on the lens 25 mm is your best bet. Enjoy.

 

[pajamas]

ok thank you, 25mm it is then
i might hold off a bit now seeing that there might be a possibilty of an AF 24mm f1.7 Zeiss rumored to be coming this year

 

[douglasf13]

Be aware that just about any rangefinder lens that is wider than 30mm will have some degree of purple color shift in the corners, so you'll probably need to look at Colorfix. I'm personally waiting for the upcoming Sony Zeiss 24mm for that focal length.

 

[greyelm]

Be aware that just about any rangefinder lens that is wider than 30mm will have some degree of purple color shift in the corners, so you'll probably need to look at Colorfix. I'm personally waiting for the upcoming Sony Zeiss 24mm for that focal length.

As the sensor of the Nex is less than full frame and crops from the middle would this still be true?

 

[douglasf13]

Yes. Oddly enough, m4/3 shows even more issues at the edges, including smearing. It comes down to the thickness and tuning of the sensor toppings. The Zeiss ZM 25 seems to perform the best in this range, but it does have a purple cast at the edges in some conditions. Personally, I only use rangefinder lenses 35mm and longer on this camera, but Cornerfix will help the issue.

 

[pajamas]

Ya I wanted the zm 25 but now I should switch to a 50mm sonnar or planar. Will the sonnar focus shift thingy affect if it's not a rangefinder like on a nex body?
Any inputs ? Thanks

 

[douglasf13]

Focus shift is not an issue on NEX. Both ZM 35 lenses are good on NEX, btw.