A7M: help with RF wide performance

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uhoh7

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Kolarivision will replace the thick A7 sensor stack, which plagues WA and UWA performance, with a thinner version.

My A7 is in the post for this mod as are several others.

http://kolarivision.com/thinfilterconversion.html

Lloyd has his A7r back already:

http://diglloyd.com/blog/2015/20150117_1818-SonyA7R.mod-lensBehavior.html

I shot a test series with Leica SEM 21 before posting the body, so I can compare.

Here is a comparison of filter stack thickness of various cameras:

http://www.lensrentals.com/blog/2014/06/sensor-stack-thickness-when-does-it-matter
 
noimmunity said:
Sweet.

Thanks for the link.

Now I really want an A7s, and regret that I didn't pick one up in Taipei last week.
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the OP was about improved performance with this 'K' modification, and your comment relates to the 'S'. now i have read many reviews stating that the 'S' performs without issue with WA rfs. in fact i have not read anything that counters that, though i believe OP might feel differently, and his mod site claims so en passant.

as for the 'K', i understood this simply meant 'kit' as in a7 with kit lens. so obviously this mod is going to be a little confusing if its referred to in the same parlance as an existing out-of-the-box un-modded combination.

so my question: what is the real story of the 'S' version with WA rfs, and by 'real story' i mean demontrable objective evidence?

thanks!
tony
 
rbelyell said:
the OP was about improved performance with this 'K' modification, and your comment relates to the 'S'. now i have read many reviews stating that the 'S' performs without issue with WA rfs. in fact i have not read anything that counters that, though i believe OP might feel differently, and his mod site claims so en passant.

as for the 'K', i understood this simply meant 'kit' as in a7 with kit lens. so obviously this mod is going to be a little confusing if its referred to in the same parlance as an existing out-of-the-box un-modded combination.

so my question: what is the real story of the 'S' version with WA rfs, and by 'real story' i mean demontrable objective evidence?

thanks!
tony
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Tony, the modification can be performed on the A7S. Due to the lower resolution, this body has the least problems with M mount lenses of any of the Sony A7* series.

As for the difference between the A7S and other models with regard to M mount lenses, it is not quite as radical as some early people caught in the enthusiasm of the moment led us to believe. There is much much less color shift, to the point of it being insignificant. Corners are generally better, but this depends as always on the lens. Some M mount wides work well on the A7S. With the modification to the sensor stack, performance looks like it will be enhanced.

Let's see what users with the modified body have to say.
 
thank you jon, much appreciated. i have an elmarit 21/2.8 first version that i would use on the 7S. i also have a longer term interest in picking up the konica 21/35 as well.
 
rbelyell said:
the OP was about improved performance with this 'K' modification, and your comment relates to the 'S'. now i have read many reviews stating that the 'S' performs without issue with WA rfs. in fact i have not read anything that counters that, though i believe OP might feel differently, and his mod site claims so en passant.

as for the 'K', i understood this simply meant 'kit' as in a7 with kit lens. so obviously this mod is going to be a little confusing if its referred to in the same parlance as an existing out-of-the-box un-modded combination.

so my question: what is the real story of the 'S' version with WA rfs, and by 'real story' i mean demontrable objective evidence?

thanks!
tony
Click to expand...
Tony,
Despite glowing but vague reports by people like Steve Huff, who I like, the A7S does not do justice to RF wides. This post by very experienced shooter with both S and II:
http://www.fredmiranda.com/forum/topic/1338591/0#12770750

Note he is selling his 28cron and SEM21, two lenses most friendly to digital by design, which means the CV21/4 CV35/2.5 are totally out of the picture.

BUT: and here is a major source of confusion; if you want to really see the issues you need a proper landscape, infinity focus with distant objects on the edges and corners.

here you can see what happens with SEM 21 and A7:

SEM21_5.6_corrected by unoh7, f/5.6

Add to A7s attributes: low mp, high price, short warranty, poor resale as against great ISO performance, the M9 is a far better deal if you like RF wides. Yes you will have to send it in someday for a sensor, as we know. No option today is ideal.

I was also fooled by initial reports of great A7S performance with RF wides.
 
For myself, I'm interested in the A7S as a platform for normal to short tele M lenses. I'm not looking at it as a landscape camera. (I like my Sigma Merrills for that), so much as a candid-portrait-in-any-darkness camera. On the wide side, my 24 Elmar M would probably work out just fine stopped down a little, and if I were really into it, I could always pick up the CV 21/1.8, which should work just fine, and the soon-to-be-released 15/4.5 v3.
 
thanks uhoh. very interesting. i still like the S due to its great high iso and silent shutter. i dont pay attention to resale value in this game, i only buy what i want. i wouldnt buy any leica digi M because i dont consider them reliable or a good value or much improved from my rd1. in fact, i'd put up my rd1 at 1600 against any m8/9. i shoot low light alot, and would be nothing but frustrated spending thousands on a tool that couldnt get me what my $800 rd1 gets me. i'm not proselytizing because digiMs work for you and lots of folks, and thats great, honestly. but theyre not for me. i'll keep waiting for the right digital back for my glass, but my eye is still on the S.

in truth i dont really care about edge sharpness at infinity at 100% crops. thats not how i think about or lokk at photos, though views of course can and do vary. i am concerned sbout edge color shift, high iso ability and silent shutter, and it seems the S takes care of all those more insurmountable issues.
 
I think your goals are fine guys, I just want to make the situation as clear as possible, so nobody spends a bunch expecting "no issues", but then is surprised. :)

For low light the A7S seems great, and subjects are closer then too.

As to the 24 SEM, It's not a lens I would count on loving with the A7S.

The CV 21/1.8 and v3 15 should be just fine.

Those are just my honest impressions reading in various forums pretty often. :)
 
uhoh7 said:
I think your goals are fine guys, I just want to make the situation as clear as possible, so nobody spends a bunch expecting "no issues", but then is surprised. :)

For low light the A7S seems great, and subjects are closer then too.

As to the 24 SEM, It's not a lens I would count on loving with the A7S.

The CV 21/1.8 and v3 15 should be just fine.

Those are just my honest impressions reading in various forums pretty often. :)
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Thanks. That's what I'd gathered from reading other people's comments, too. (Edit: initial reports from Lloyd Chambers' testing may cause a revision in what people think of the Elmar M wides on the Sony A7*s).

The thing that makes me hesitate about the conversion itself concerns the possibility for corrosion. KolariVision is up front about this, and promises free replacement and eventually conversion service if/when a new non-corroding glass is available. Sending the body back for service with a quick turnaround is okay, but there are cost issues here related not just to the shipping but especially to import duties upon return shipping from New Jersey to France.

Somewhat OT: people used to buy lenses that would follow them for life. With digital sensors the way they are today, that rule is being challenged.

I picked up the SEM, and sold my cron 28, specifically in order to use it with the M9. For an A7S, my lens plans would be different. Perhaps the SEM would move on, too, depending on how far I go with my recent return to film. (In fact, that's really the key decision I'm looking at before all else).

One of the reasons the Sigma DP Merrills do so well is because of the mated lens-sensor design. I'd bet that digital sensors will eventually be developed to a point where the current issues of angle-ray incidence, sensor filter thickness, and exit pupil of the lens will no longer play such a decisive role.
 
Would it not be easier and less expensive to use an SLR lens like the Zuiko 2/21 or Zeiss Distagon 2.8/21 ?
Yes size and all but really... is it worth it doing such modiffications to preserve a bit of compactness ?
Just trying to understand. I'll be seeking a 36mp camera this spring/summer.
My SLR lens selection is still fairly rich and the a7r looks like a good option but for this wide drama.

Thanks
 
I don't have access to Lloyd Chambers' site, but others who do report that his preliminary tests with the 24 Elmar and the 21 Super Elmar are both very impressive.

As for SLR ultra wides, how many of them are sharp all the way into the corners on any mount?
 
noimmunity said:
I don't have access to Lloyd Chambers' site, but others who do report that his preliminary tests with the 24 Elmar and the 21 Super Elmar are both very impressive.

As for SLR ultra wides, how many of them are sharp all the way into the corners on any mount?
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I have the two listed and both become sharp to the corners.
Isn't unsharp better than smeared ? Do SLR wide lenses smear as well ?
 
No worries Jon.
I'm just curious if I can make proper use of my reflex wides for my summer project.
I'll need wides for a good part of the job and would like to make use of the lenses I have.
The A7r seems to be the least expensive hi-density sensor out there.
I rarely need such resolution.

This modification seems very dramatic and invasive. If this is what it takes to get the corners sharp maybe I should look elsewhere.
I would likely sell the camera after my job is done so an additional costly and risky modification seems undesirable.
 
f16sunshine said:
This modification seems very dramatic and invasive. If this is what it takes to get the corners sharp maybe I should look elsewhere.
I would likely sell the camera after my job is done so an additional costly and risky modification seems undesirable.
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The only dramatic thing about it, IMHO, is the potential for filter corrosion/delamination (similar to what is happening to the M9/MM/M-E). Kolari has said it could happen as early as one year after the conversion, but they will replace for free and hope to find a permanent solution (same as Leica).
 
After pursuing the matter further with Kolari, they have responded saying that they are in the process of developing glass that will resist corrosion. So if that is a concern (as it could be in my case), it might be best to wait a little. Perhaps in six months time a more permanent solution will be available.

Next thing I really want to know is whether the AA filter on the A7S or the CFA (on both the A7R and the A7S) can be removed after the conversion of the filter stack thickness by Kolari? A monochrome A7S or A7R that works well with M lenses could be awesome!
 
Hi Guys, We are calling these "A7M" "A7rM" etc. M is for 'mod', M-mount, and Michael, the guy who got kolari on the case.

Mine just got back today. This is a pretty big deal for a bunch of us. Really, this is the first serious digital FF alternative to Leica bodies for RF glass.

A few other guys just got theirs also and report dramatic changes with 50Lux asph and ZM35/2

I have bad weather and don't have decent wide samples for you yet, but the crappy ones I have shot are way better with ZM18.

Here is the tiny 50/1.1 Sonnetar this evening:
A7M with Sonnetar 50/1.1


DSC00298 by unoh7, on Flickr


DSC00293 by unoh7, on Flickr

Both wide open

BTW:

Untitled by unoh7, Sonnetar :)

also AA filter is gone with this mod. When you consider used A7 easy to find for 900 and 400 for MOD, you have something close to M240 for 1300USD
 
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