pen f focal length comparison

[ben-on-net]

Hi, first post to this site, I've been dipping in and out for some time (google a rf type issue and rf forum normally comes up)

My question if anybody can help is, how do I compare pen f lens focal lengths with 35mm full frame focal lengths. Is there a simple formula?
ie 20mm pen f lens is what focal length in full frame 35mm thinking?

I know that pen half frame is not exactly half of 35mm, this complicates matters, and I know its a bit dumb to be stuck on 35mm focal lengths but when a system is so entrenched its hard to not think by that standard.

Many thanks Ben😀

 

[ferider]

Welcome !

The image diagonal of half frame is 30mm, that of full frame is 43mm.

then the 35mm equivalent to 20mm (PF) is 20mm*43/30 = 28,... mm.

So 20mm corresponds roughly to 28 in full frame.
25mm in half frame corresponds roughly to 35 in full frame.

Best,

Roland.

 

[delible]

My question if anybody can help is, how do I compare pen f lens focal lengths with 35mm full frame focal lengths. Is there a simple formula?

Multiplying the hf lens focal length by 1.4 will work.

 

[Hibbs]

Yeah...just multiply by 1.43 to be totally exact.

HIBBS

 

[ben-on-net]

Many Thanks for the posts, thats that then, sorted, I wonder why olympus only went as wide as 28mm (in 35mm terms). Maybe technical constraints.

Anyway thanks guys. Regards Ben

 

[Al Kaplan]

When Olympus was making the Pen F and FT they had the market all to themselves. If another maker had jumped in and started to make wider and/or faster wide angle lenses we would have seen the same "race" as the one in full frame optics. Also keep in mind that Angenieux had come out with their "Retrofocus" (yes, but they never trademarked the name so everybody started using it) design for wide angle SLR lenses about circa 1950 or there abouts, and the Pen F was introduced in 1964, a few years before SLR lenses like even a 35mm f/2 or a 24mm f/2.8 was even imagined.

The format was never popular. Few photofinishers were set up to print half frame or mount the slides. Amateurs were put off by having to shoot so many pictures to finish a roll. By the time Kodak came out with a 12 exposure roll, giving 24 half frame shots, the format had been orphaned by the camera makers. Just about all the the non slr cameras were scale focus, not rangefinder. The exceptions supposedly were some very rare short production runs of M Leicas and the Robot Royal, a Swiss made camera with built in wind-up motor. They were the same size as the full frame variety.

Of course film technology has greatly improved over the last forty plus years, so getting decent 8 X 10 prints today from the negatives would be a breeze. For me the biggest downside was trying to look at the contact sheets, even with a loupe.