LA-E2 plus Alpha Lenses on FS

[paulcurtis]

I wonder what the deal is going to be with this combination and the next firmware.

I'm running a 2470z with LA-E2 on both a NEX5 (which gives full support) and on the FS as a dumb adapter. On the FS the aperture is wide open so f2.8 and can't be changed yet.

I've not reached a conclusion about this combination. The translucent mirror really does cut down the light by at least 1/3 of a stop and perhaps a 1/2 stop. Obviously there would be internal absorption but the light coming out of the 2470z is comparable to an old CZ 2870 f3.5, pretty much the same - which is half a stop difference for what is probably a similar zeiss designed zoom. Whist the FS is sensitive enough to get around this, there's a question of why bother with an expensive f2.8 zoom when a cheaper one will have the same end result.

It's unclear what the LA-E2 adapter will allow for in terms of focusing on the FS. There is talk of a f3.5 limit but i don't understand how that is going to work. On the Nex 5 i can focus at 2.8 no problem. So what's with the f3.5 restriction...?

The focus ring on the 2470z is nice, there are some light stops at each end, not hard but tell you when you hit minimum and infinity. The focus is fly by wire and funnily enough you can see that on the recordings - the focus movement is damped, electronic looking.

I'd imagined that a set of zeiss ZA zooms would make for a nice range but i'm not sold on this yet. The light loss is an issue i feel, why pay £$ for a f2.8 zoom when the f3.5 zoom is really not that different. Continuous autofocus is unlikely to work in real situations, so we're looking at one touch focus being useful - but the manual focus ring on a real MF lens works better, even though as far as MF goes the 2470z is pretty usable.

I don't find the image quality of that 2470z that spectacular either, quite soft in the corners even on APS-C, i was hoping for more at this price. I found the Canon 1755 f2.8 to be better in the same kind of situations. Perhaps i have a bad sample but i've seen reviews online that concur.

What do others think? Does the LA-E1 adapter work better perhaps? I understand that changing iris is not smooth but there's no mirror in there.

Perhaps simple old school manual lenses are best after all.

thoughts would be most appreciated!
Paul

 

[Dermot]

I'm waiting for the upgrade before considering the LA2, auto focus is not key for me, i never use it - but i have only had a few camera's that had it, and it was unreliable there (EX 1 & 3)

i had both Zeiss zoom's and sold the midi, and am keeping the short one.. the midi has been replaced by a Angenieux/Tokina 28-70 2.6/2.8.. i found little dif between them opticaly on the FS in testing, and the A/T has internal focus and zoom, making it a better choice for living behind a matte box.. overall built like a cine lens.

d

 

[paulcurtis]

I'm waiting for the upgrade before considering the LA2, auto focus is not key for me, i never use it - but i have only had a few camera's that had it, and it was unreliable there (EX 1 & 3)

i had both Zeiss zoom's and sold the midi, and am keeping the short one.. the midi has been replaced by a Angenieux/Tokina 28-70 2.6/2.8.. i found little dif between them opticaly on the FS in testing, and the A/T has internal focus and zoom, making it a better choice for living behind a matte box.. overall built like a cine lens.

d

Thanks Dermot,

Yes, i've been on the look out for one of those.

I've literally just got back from a cycle where i took the 2470z and the CZ2870 for a comparison (with a Nex5N). The diminutive CZ is a very nice size on the FS and by the time you add that light loss there's very little between them in terms of exposure. I will study the results and make up my mind.

One concern is colour differences between all these lenses, at least i figure if i stick in the realm of zeiss they should all share a similar look. There is such a difference between OM, FD and Zeiss for example. Just adds another headache for post.

The only time AF has been useful for me (EX1) was just the one touch and get it to position, the rest is manual.

cheers
Paul

 

[BrianMurphy]

Paul,
I am spending the day setting up my FS100 and will do some tests with the 2470. As I now have both the LA-EA1 & 2. I bought the 2 first thinking it would be best to have the latest, but got annoyed not being able to set an iris and bought the LA-EA1 for a hundred bucks from B&H last week. In my initial tests wide open I have not experienced any edge softness with the 2470. I did notice a small light difference when I was comparing the LA-EA 1& 2 when wide open but couldn't say how much. I read the post by Shawn and did not see any mention of an F/3.5 limit. Has this been confirmed anywhere by Sony? My plan was to stick with Zeiss and eventually go next with the 1635 and eventually replace the 18/200.

 

[Chris Johnston]

It's unclear what the LA-E2 adapter will allow for in terms of focusing on the FS. There is talk of a f3.5 limit but i don't understand how that is going to work. On the Nex 5 i can focus at 2.8 no problem. So what's with the f3.5 restriction...?

Paul, can you clear something up for me? On the NX5 you can run continuous af in video mode at 2.8?

 

[paulcurtis]

Paul,
I am spending the day setting up my FS100 and will do some tests with the 2470. As I now have both the LA-EA1 & 2. I bought the 2 first thinking it would be best to have the latest, but got annoyed not being able to set an iris and bought the LA-EA1 for a hundred bucks from B&H last week. In my initial tests wide open I have not experienced any edge softness with the 2470. I did notice a small light difference when I was comparing the LA-EA 1& 2 when wide open but couldn't say how much. I read the post by Shawn and did not see any mention of an F/3.5 limit. Has this been confirmed anywhere by Sony? My plan was to stick with Zeiss and eventually go next with the 1635 and eventually replace the 18/200.

Brian, that was pretty much my intention too. I'm looking forward to hearing how you feel about the combination. I would say that things to look for:

- Compare the light loss with the two adapters. I'm rating the 2470z at f2.8 being roughly the same as my f3.5 CZ2870, maybe even slightly slower. Now this could mean that the t-stop between the 2470 and 2870 is quite different as well, i can't really compare this. If you don't find that much difference (half a stop) between the two adapters then perhaps the t stop of the 2470 is quite a bit slower than 2.8

- wide open in high contrast situations i'm finding quite a bit of CA at the edges, more than the Canon 1755 for example.

- i'm finding the corners quite soft too

- it's quite flarey in lights, much more so than the CZ.

The 2470z is being touted practically as good as primes, and i don't think it is really. It's a very solid, good performing lens but I think i expected more from it. I have no idea why it is the size it is though. Just to be different though there are lots of reports of 'nervous bokeh' and actually i think that side is great! Each to their own...

In addition AF on the NEX5 seems to be a bit hit and miss, i am wondering whether i need to do some kind of micro adjustments to the LA-E2 because i feel that it might be front focusing a bit. This begs the question whether the FS firmware would even allow for those kind of adjustments too.

I'm struggling now seeing the benefit of the LA-E2 with regards to the FS operation really. Hence trying to find out a bit more about what might be possible with it. Shame you can't whack an optical viewfinder off that adapter and take advantage of that mirror...

cheers
Paul

 

[paulcurtis]

Paul, can you clear something up for me? On the NX5 you can run continuous af in video mode at 2.8?

Very good point (bit of a doh moment because i hadn't considered trying this). Well...

Yes you can run the NEX5 is continuous AF. In fact you can ONLY run it in continuous AF and that stops down to f3.5 no matter what settings you seem to have. You can switch the lens to MF and then run at f2.8 with full manual focus though.

Well, that may end that pipe dream then... It looks like there isn't an option to do a single AF, then take over manually like you can on EX1 or the e mount lenses. The AF is jumpy, so as you pan around the focus points lock on then refocus, it's not a smooth continuous focus as it would be for an EX1 for example.

Of course perhaps the firmware on the FS will be different but that does seem to explain the f3.5 limit (which taking all things into account is going to be more like f4 in terms of light).

I wonder why f3.5 - you'd think that the more light the better the AF detection...

cheers
Paul

 

[Chris Johnston]

I wonder why f3.5 - you'd think that the more light the better the AF detection...

cheers
Paul

I think 3.5 (or the fastest apeture of the glass if your lens is , say f4) is because thats probably an easy setting for the af to see the contrasting edges. 2.8 might be a little too little DOF to make it look good for most circumstances. 6.5 or up might be too much DOF to figure out what the main focus point should be???? Just guessing. 30 days and counting.

 

[paulcurtis]

I think 3.5 (or the fastest apeture of the glass if your lens is , say f4) is because thats probably an easy setting for the af to see the contrasting edges. 2.8 might be a little too little DOF to make it look good for most circumstances. 6.5 or up might be too much DOF to figure out what the main focus point should be???? Just guessing. 30 days and counting.

I think the LA-E2 is phase detect not contrast, so it must be the type of AF sensors in there. Perhaps the f3.5 is a margin of error thing to stop people complaining that it can't focus at 2.8. And usually shallower DOF is better for edges as most the image of out of focus.

I'm having to rethink my strategy, i have doubts about the LA-E2 route now. We have a minor shoot next month but a major one june/july so i need to be happy by then. My minor shoot will be mostly vintage manual lenses for a purpose so not worried about that.

I do wonder what's up Sonys sleeves for e mount lenses. I look at olympus and panasonic and covet a few of their m43 possibilities! There's supposed to be a normal range G zoom in e mount on the horizon but there's no real info on when.

cheers
Paul

 

[no logo]

The good think of use adapter LA-E2 is protect sensor from dust .When you have few alpha lens you can easily change them and do not worry so much that you outside.
So I am going to get fs100+LA-E2 + sony 16-35 and sony 24-70 .
What about the sony DT 16-80 mm f/3.5-4.5 witch seems to be very good for the price . Can I stick it to adapter LA-E2 ?????? .16-80 is for APS-C .

 

[paulcurtis]

I have an LA-EA1 adapter on its way as well so i will be able to compare both adapters, see if i can quantify the light loss i'm seeing and whether the EA1 iris change is acceptable on this lens.
I wish the LA-EA2 adapter could raise the mirror, that would be neat but mechanically not possible in its current form.

I will also compare the 2470z to some CY Zeiss primes in that range too, you see i want to believe in the lens and convince myself of it's worth!

For me, a zoom would really need to be a 2.8 as i have the kit 18200 lens, speed and quality are the reasons for changing. I don't see the point of the 16-80, nice range though it is.

cheers
paul

 

[aly324]

I have an LA-EA1 adapter on its way as well so i will be able to compare both adapters, see if i can quantify the light loss i'm seeing and whether the EA1 iris change is acceptable on this lens.
I wish the LA-EA2 adapter could raise the mirror, that would be neat but mechanically not possible in its current form.

I will also compare the 2470z to some CY Zeiss primes in that range too, you see i want to believe in the lens and convince myself of it's worth!

For me, a zoom would really need to be a 2.8 as i have the kit 18200 lens, speed and quality are the reasons for changing. I don't see the point of the 16-80, nice range though it is.

cheers
paul

i am using the 16-80 on the FS100 via LA-EA1. i much prefer this to the kit lens, not only because i really like the wider look (for some reason 24mm-equiv just does it for me), but because i dislike focusing by wire very intensely. the slight lag and variable focus distance changes of e-mount lenses destroy the whole experience for me. also, the 16-80 lens has nice hard focus stops.

an inexplicable downside is that when you open aperture the LA-EA1 somehow resets it to wide open briefly every single time. so opening aperture during shooting is basically impossible.

another frustration is that the camera increases the aperture as you zoom in regardless of your initial aperture value. for example, even if you dial it at f/8 at 16mm, it'll increase to f/10 or so as you zoom in to 80mm.

the lens is also not quite parfocal. at least my copy isn't. weirdly it seems roughly parfocal within the 35-80 range and the 16-35 range, but not between these ranges.

the 16-80 also breathes a little. not too bad but noticeable.

 

[paulcurtis]

A few more observations that i hope helps others in similar situations.

I have both the LA-EA1 and EA2. One of my concerns was that the mirror in the EA2 was reducing the light by more than half a stop, this was based on the lens being f2.8 and another zoom being f3.5 and the exposure roughly the same.

Now i see that actually the transmission of the 2470Z isn't *that* good. The difference between LA-EA1 and EA2 is a lot less. I'm not sure how to quantify this, perhaps someone could jump in. If i have two images and average the luminance then the LA-EA1 would have a value (0-100) of 55, whereas the LA-EA2 would be 45. I'm not sure how that would translate into stops difference. By my guesswork that would be around 10% difference but because stops are logarithmic i'm not sure you can just say 10% of a stop darker?

On another note as observed by aly234 the LA-EA1 jumps when you change aperture down, however at least on the 2470z the LA-EA2 does not do this, the changes seem smooth. (This is on a NEX5N camera, so could be firmware dependent). I really don't understand why the LA-EA1 cannot do the changes smoothly if the EA2 can...?

another frustration is that the camera increases the aperture as you zoom in regardless of your initial aperture value. for example, even if you dial it at f/8 at 16mm, it'll increase to f/10 or so as you zoom in to 80mm.

The 16-80 ramps aperture anyway? Sounds like it's still keeping the ramping as a proportion of the zoom. A bit annoying and perhaps it's a bug?

One final note and i'll follow this one up with samples. But the DOF on the 2470Z is noticeably more shallow than the same on a CY 28mm Prime. I was quite taken back by this and will do a few more tests. This is something i've seen both on the FS100 and the NEX5N with the lens.

I'm being very critical of the lens, it's actually a superb piece of optics. But commands a hefty premium and i'm personally just ensuring that it's worth it. My aim is to sell my f2.8 primes in that range and keep primes to ones that are unusual FL or faster. I don't mind the transmission loss so much because the FS is so sensitive but the DOF characteristic is important and that doesn't change despite the transmission being less. It does make me wonder whether the lens is actually faster than 2.8 but because there is such a huge number of elements Zeiss rated it at 2.8 so that people weren't upset. Hence the DOF characteristics being so much shallower at f2.8 than a prime at f2.8

cheers
Paul