I've had some pretty good results with my Olympus 75-300mm at full tele using my E-M10. But to be fair, 400mm could be a different experience all together.

I'm hoping it will perform well on the E-M1 as well with thoughts (maybe wishful thinking) of perhaps getting it. Zooms are certainly useful when wildlife moves in close as well as being at a distance.

What? Let's run with your logic then.

If larger sensors generally have larger pixels and therefore produce less noise then a FF sensor generally produces less noise than a 4/3"-type sensor. Right? I mean that's essentially what _you_ just said.

You are of course free to disagree with yourself ;)

And for the record the number of circumstances in which (and degree to which) your statement about pixel size is true is quite a bit different than what your general statement about such matters would suggest, as evidenced by the fact that for a given print/display size the 36MP D800/E/810 produces images with less noise and more dynamic range than the 16MP D4s up to ~ISO1000 (assuming you are shooting RAW and aren't at the mercy of any significant JPEG engine differences).

But again that's largely irrelevant to your argument anyway since a 16MP 4/3"-type sensor still has smaller pixels than a 36MP FF sensor. Smaller even than a 50MP FF sensor.

And your point is?

BTW. My first comment was not in reply to you but this one is. I thought it was clear that the point I was making was that the larger the sensor (generally) the less noise it produced compared to smaller sensors. The reviewer uses language that appears to be biased against MFT, which in my view was unnecessary.

That what Rishi said is accurate.

OK, Maybe I was being a little touchy & hasty in comment, but the constant doubling of the aperture for all aspects just wears a little thin at times. For exposure purposes it is f4-f6.3 & don't pixel peep so much & all is just fine.

Rishi isn't telling you that you need to change your exposure settings on different formats. Just as the 35mm equivalent focal length is a way to compare reach across different formats the 35mm equivalent fnumber is a way to compare "noise" across different formats. And for many people that's a very important part of the IQ equation.

This need not be anchored to FF either. Not in principle anyway. You can instead talk in terms of MFT equivalence which can be quite useful when trying to determine how much more noise you might see in your images when shooting with Nikon's CX format or any other 1"-type format camera when using lenses with the same nominal specifications as your existing MFT lenses. It can also tell you how fast your small-format lens needs to be in order to close the sensor size gap in challenging lighting conditions.

I think it's best described like this: equivalence isn't a shooting tool, it's a cross format performance comparison tool. A buying tool.

OK. Thanks for taking the time & patience to reply with that helpful comment. In using my Stylus 1 with a 1/1.7" sensor I know there is no headroom for recovering blown highlights like I can on my OM-D models & of course the ISO Auto level is cut back too. I appreciate there are limits within any format & should be used accordingly.

Hope we will see some Kenyan wildlife and scenery in your RS100400 test images!

Neat! I hope you're enjoying Kenya. I'm looking forward to seeing what you bring back. Do you have the Oly 300 f/4 with you too?

here's to hoping.

What are you smoking? I was quoting the author here. The statement is based on the relationship between focal length, aperture and the size of that part of the image circle used for capture. Pixel number/size is irrelevant. Yes, at any actual focal length, a smaller sensor gives a smaller apparent depth of field, simply because you enlarge imperfections more. However, that effect doesn't compensate for the difference between focal lengths needed to give the same angle of view, hence the statement holds.

Sorry, I hadn't realized you were quoting, and I made too many logical jumps. The point was that this factor 2 focal advantage of m43 over FF in terms of reach doesn't hold up so well with todays sensors, after all, what counts is how many pixels you get over your subject. m43 has not increased its pixel density as much as FF. But given diffraction limits, photosites will have a limited small size. There is a minimal size for photosites irrespective of sensor size. larger sensors just can have higher MPs. Think of it like the Nikon FF bodies that take DX crop lenses, and just crop the image on the sensor. Of course, not everybody has a 50 or 40 MP FF body (yet), but a 500mm lens on a 51MP body does the same job as a 400mm lens on a 20 Mp m43 (and olympus is still stuck at 16mp). So, comparing to a 800mm starts to be misleading.

The second you crop, you are effectively shooting a smaller format. That's why the point is irrelevant to this discussion, even if there is some truth to it, in theory.

I tend to agree. (Although 500mm f/6.3 does need significantly more effort than 400mm f/6.3... and a couple of years ago I had the opportunity to test-drive a Bigma on the E-30 and I was quite surprised back then how good it was at 500mm. Unfortunately not all specximens of that lens seemed to be that good, though, and while I never completely stopped looking for a good used one, I never bought one myself, because I never became really sure that its advantage over the 50-200 + EC-20 would justify the purchase, or the bulk to be carried.)

If we look at other camera manufacturers' current 400mm zooms, they're all in the price range from $2000 to $2300 now. Even if they are f/5.6 at 400mm, that makes $1799 for the Panasonic-Leica lens seem quite ok.

I also tried this lens on my E30 too & if I hadn't gone M4/3's with the OM-D's (E-M5 & E-M1) then I would have liked what I could get with this lens on the E-30. However, the lens is going back to the owner.

@Jorginho,
Are you saying they don't do bif well when focus is fastly changing?

I'm pretty sure you can't. Have you ever tried to manually focus an 800mm equivalent lens? It's one of the least pleasant things you can subject yourself to, photographically.

Androole.
I use a Takumar 135mm F2.5 in manual focus(XE-2). With peaking and magnification it's doable on anything not willing to move a single muscle.

As with longer lenses? no the shake handholding these at long ranges makes it unbeareable. And then we have the shallow depth of field issue.

If possible it's a ordeal i'd rather avoid.
That being said i don't see people picking up m43 to use these long lenses. They power of the system is still using small primes with excellent quality while remaining a small footprint.

And with Panasonic obviously video. This product is for people already invested in m43

Holy CRAP did you see what Nikon announced?!
the 7d mk2 is dead
meet the D500!

D500 + 200-500. Time to sell stuff.

Androole: ever heard of smart adapters?

BostonC: you're gathering F/6.3 worth of light on small sensor. And since in less than ideal light iso 800 on m43 looks like iso 12800 on full frame that F/6.3 is actually pretty bad.

On full frame you could crop (to get more zoom) and still have 16MP with pixels of similar size.

I think the best comparison would be with a similar quality lens on FF and then crop it enough to get the same "zoom" (800 equivalent in other words).

An example with APS-C: 400mm multiplied by the 1.6 crop factor = 640mm FF equivalent.
Then crop/multiply by 1.4 (896mm) since the APS-C is 40% larger than m43, right? Makes sense since a 24MP APS-C sensor has similar pixel size or "pitch" as a 16MP m43.

Rishi - I can agree with slightly less than 2 EV for best-of-breed examples (though I'd hardly call the D810 an underperformer, and the others are all current models).

But regardless, that is certainly not the same as halfwaythere's the absolutely preposterous suggestion that FF is 4 stops ahead in "less than ideal light" (M4/3 800 = FF 12800). Maybe if I were comparing a 12-year old Olympus E-1 to a Nikon D4S?

Saw that comparing image 8 and image 10

This looks very well thought out indeed.

I wonder how the on sensor AF works with long lenses like this. The 100-300 was always slow and it seems this one is priced and built a LOT more serious.