Why are M4/3 lenses so slow?

[Pietro Impagliazzo]

Chart's wrong for the AF100. They're using the 17.3mm "stated" size in 4/3 literature, but the actual sensor is an oversized 19mm, so it's closer to the size of 35mm film than the chart shows.

It should be showing 19mm x 10.7mm, with an image diagonal of about 21.8, and an overall image size of 76% of the size of Super35, or 88% of the size of the 35mm cinema frame.

That's what I was going to ask you: "Why the hell people are saying the AF100 crop is different?"

Now I know!

:thumbsup:

I'll check if Mitch made a new one.

PS: Nah, the latest version on Abel blog is just a not oversharpened version of this one.

 

[samsara]

If you are willing to pay a higher price, lens designers can accomodate you.

I have top quality Nikon primes... If I jump to the AF100, I need fast zoom (2 or 2.8) with fast auto focus , Image stabilisation and build like tank ! and I dont mind to pay 2500€ for It.

 

[cgold]

This phenomenon is the only thing holding me back from the AF100 (for now). I have no problem with the sensor size, and the ability to mount almost lens you want is great, but that extra crop makes it hard to find fast glass that is wide on the AF100. Although you have a ton of affordable fast telephoto options (from other lens mounts) you need to stick for lenses made for the m 4/3 to go wide. And allthough it is theoretically cheaper to make and manafacture 4/3" lenses they seem to be a good bit more expensive then APS-C designed lenses. I love my 11-16 2.8 for APS-C, and it was only 600 dollars. The only equivalently wide lens avaiable (that I am aware) is the 7-14 but its a stop slower and more expensive, and 2.8 is usually right on the cusp of usable for me (or I'm in the sun/a studio where even 5.6 would work) so an extra stop of light loss is a big deal.

I assume its because there isn't enough of a market for 4/3" lenses so the price is higher. Hopefully that will change.

I got to play with the AF100 at the creative expo in New York and I was very impressed, it was very sharp with little skew! I am going to wait for Sony and Canon to release their competition first and go with the best, so perhaps by then there will be more 4/3" lenses.

 

[Barry_Green]

It should cost more to make wide/fast lenses for a larger-sensor camera. It should cost less to make wide/fast lenses for 4/3. The only equalizing factor must be the smaller quantities since 4/3 is such a newer format.

If you like the 11-16 2.8 for APS-C for $600, you may be interested in the Olympus 11-22 f/2.8-f/3.5. Same price, same speed, same range (except longer). It's made for Four Thirds so you'd need the MFA-1 adapter. Or, if you already have the Tokina, you can use it on the AF100 with an adapter.

 

[Ticheli]

Since most of us shooting Red for television use the 16x9HD setting instead of the slightly larger 16x9 setting, the crop factor is less than the 1.2 given by the AbelCine calculator. Barry, can you tell us what the crop factor on the AF100 is compared to the Red at 16x9HD?

Thanks!
Leo

 

[Barry_Green]

Barry, can you tell us what the crop factor on the AF100 is compared to the Red at 16x9HD?

Well, it depends on what exact mode you mean in the Red One. Do you know the pixel dimensions for that mode? If you mean the mode that's referenced on this chart, that's called "Red 1 @ 2K HD 2048 x 1152, 1.78:1 HDTV Format", then there'd be a reverse crop factor, as the AF100's sensor is much larger than that.

 

[agcohn]

Well, it depends on what exact mode you mean in the Red One. Do you know the pixel dimensions for that mode? If you mean the mode that's referenced on this chart, that's called "Red 1 @ 2K HD 2048 x 1152, 1.78:1 HDTV Format", then there'd be a reverse crop factor, as the AF100's sensor is much larger than that.

The mode he is talking about is 3840 x 2160.

 

[Barry_Green]

The mode he is talking about is 3840 x 2160.

Ah. Right, that makes sense... should have thought of that.

Well, in that case, I'd have to do a little math... I think the sensor size in that mode would be 20.6 x 11.3. Which is pretty close to the AF100's 18.9 x 10.7. I think the effective crop factor between them would be 1.09.

 

[Ticheli]

Thanks guys! I should have been more clear and specificized 4K 16x9HD.

This means there is no appreciable difference in the coverage and DOF characteristics of Red One and the AF100!

I haven't been so excited about the arrival of Santa in many, many years!

Good shooting and best regards,

Leo

 

[Joe Walker]

Ah. Right, that makes sense... should have thought of that.

Well, in that case, I'd have to do a little math... I think the sensor size in that mode would be 20.6 x 11.3. Which is pretty close to the AF100's 18.9 x 10.7. I think the effective crop factor between them would be 1.09.

Now that's cool!