When I spoke with maxmax, I think they said the A7s were 1.7mm, while an M9 is .8mm
dug up the conversation:
"Dan: (from maxmax)
Hi Charlie,
I have gotten some questions about this from others as well.
The Sony A7 ICF/AA stack is 1.75mm thick which is relatively thick. The lens flange to sensor distance is also short. If you think about the path of light exiting the lens as it goes to the sensor, it has to pass through the ICF/AA. If the light is going through the center, then the path is the shortest. As you move toward the sensor edges, the light has to travel at greater distance because the light is going through the ICF/AA at an angle. The effect is the same as if the ICF/AA stack changes thickness getting thicker towards the edges. The lens design and aperture also will affect this. A wide aperture longer lens will have less of a problem than a small aperture wide angle lens.
When we do an HR conversion, we remove the stock ICF/AA and replace it with a new ICF-Only having the exact same thickness. If you don't use the correct thickness, then you change the focal plane of the camera. So, our HR conversion AF will work correctly. Biggest downside on HR, and this changes depending on the camera ICF/AA design, is that the AA part of the stack is clear while the ICF has a teal tint. The new ICF-Only has a thicker ICF which shifts WB toward the cyan. Most just set a custom WB if it is an issue, but some don't like it. The thinner the ICF/AA stack, the less of a color shift.
To fix the A7, you would need to go with a thinner ICF. A thinner ICF is going to move the focal plane towards the lens. To get correct focus, you would need to move the sensor closer to the lens which is hard to do on the A7. You would have to either mill the sensor mounting points and modify the camera body sensor mounting points. Neither is an attractive option. Possible, but it would be a lot of work and easy to spend a lot of time trying to get it just right.
The Sony conversions are $550 because their bodies are all really hard to take apart."
He also said he could go ultra-thin, and install a .6mm cover.
"Dan:
Hi Charlie,
If I could put and a thin ICF and move the sensor closer to the lens, then the camera would focus. If put in a thinner ICF, then the camera will become near-sited. You would need to focus past infinity for focus or use one of those adapters that moves the lens back and forth. The thickness of the ICF/AA stack is the problem - you would still have the issue with a thinner ICF, but not as bad.
A quick check shows I have a 0.58mm ICF that I can cut to fit.
Most camera ICF/AA stack have a teal tint to the ICF layer. On a DLSR, typically, there is something like BG38 IR absorbing glass which has a teal tint and then vapor deposition coatings to help block IR as well. Since I put in a new ICF only that has the same thickness as the stock ICF/AA, the WB gets more teal. If I used 0.59mm, I don't think you would see much WB shift. There would be some shift somewhere because the stack is changing. Also, not sure if the Sony auto WB is off the sensor anyhow rather than a separate sensor like a typical DLSR."
I bet that one is not going to be cheap! $2K maybe?
It's going to be very interesitng to see how this Distagon performs on the A7/A7r, particularly since Zeiss designed this more recently, perhaps with an eye towards eventually porting it to the Loxia line.
artur5 wrote:
I hope you're right.
Really, I've been thinking for years that instead of concentrating their resources and time to develop new lens designs to accommodate the current ( and finicky ) sensor technology, manufacturers should focus (pun intended.) on developing a sensor which behaves like film concerning angles of incidence. No need to get a new specific line of glass for each series of cameras with different sensor stacks. That's a waste of time and money. Go direct to the point Mr.Sony and give us a film-like sensor without any crappy glass on top.
Of course, the devil's advocate inside me thinks also that they (Sony, Fuji, Zeiss, Olympus..) are happy with the current situation. People can't use properly their legacy lenses with the A7x or the Fuji-X cameras. They need to buy native glass or new 'dedicated' Zeiss manual offerings for the more demanding customers. More lenses to sell More profit. Don't be surprised if the new 'revolutionary' mirrorless from any of the big names sports a 5 mmtr.thick sensor stack....Show more →
Sony can do Leica and put an insufficient filter stack with no IR filtering, and give the shots a nice caste. Stacks are there for a reason...there are trade offs.
AhamB wrote:
Sony may already have the technology (at least they have patents for organic sensors), but still no cost effective way to produce it.
Seems unlikely to me that they're holding back technology because of this. The majority of photographers still want AF lenses.
They need AF. It's a need. Very few togs are quick enough with manual focus on any camera to catch the action let alone a camera with a sensor like the A7r which demands precise focus.
Sep 04, 2014 at 07:32 AM
Steve Spencer Offline • • • • • • • Upload & Sell: On
Bluffer wrote:
They need AF. It's a need. Very few togs are quick enough with manual focus on any camera to catch the action let alone a camera with a sensor like the A7r which demands precise focus.
We have been through this before, but I will point out that manual focus is a different way of shooting and you can get some great action shots by using it. With manual focus you don't try to follow the action and focus quickly--at least I don't--instead you try to understand the action and focus where the action will be and get the timing right. Definitely a different way of shooting, but it can produce excellent results. As an example, at SI they recently did a compilation of Neil Leifer's greatest boxing photos. His work has some of the greatest boxing shots of all time including this stunning shot of Ali standing over Liston after he knocked him out.
That was a manual focus shot of course. He described his method which was about trying to get in the right position to get the shot and sometimes it worked and sometimes it didn't, but it was about being in position and being ready. What he described as the hard work of being a tog. Or how about this shot:
My favourite football shot ever. It is about being in the right place, being ready, and have excellent timing much more than about fast AF. Sure fast AF may be quite useful for action shots, but the real skills are about knowing where the action will take place (i.e., being in the right place), being vigilant including having focus ready even if using AF (i.e., being ready) and capturing the image at exactly the right moment (i.e., excellent timing).
So, IMO, what an action photographer needs to be is, in the right place and ready, and he or she needs excellent timing. That is what made Leifer's work so special and what makes "the catch" such a memorable shot. Fast AF is nice to have, but I don't think it is a need in the way these others skills are. my two cents.
I firmly believe that people make their best work when working under tight, well understood constraints, and (the lack of) AF is definitely such a constraint. I have seen very, very, very few amazing shots which relied on perfect AF for their success.
This is not to say that no one should use AF, but so much is possible without that not having AF should rarely be seen as a disadvantage, but a challenge.
carstenw wrote:
I firmly believe that people make their best work when working under tight, well understood constraints, and (the lack of) AF is definitely such a constraint. I have seen very, very, very few amazing shots which relied on perfect AF for their success.
This is not to say that no one should use AF, but so much is possible without that not having AF should rarely be seen as a disadvantage, but a challenge.
No. My point is merely that the vast majority of the greatest shots ever made were made without AF, and very many of them would still be considered amazing shots if made today. The world was awfully quick to "require" AF in my opinion, too quick. It helps in some situations, sure, but it isn't required at all. Especially now that we have awesome EVFs.
Steve Spencer wrote:
So, IMO, what an action photographer needs to be is, in the right place and ready, and he or she needs excellent timing. That is what made Leifer's work so special and what makes "the catch" such a memorable shot. Fast AF is nice to have, but I don't think it is a need in the way these others skills are. my two cents.
Now, ask Neil Leifer if he prefers to use AF or manual focus...
molson wrote:
Now, ask Neil Leifer if he prefers to use AF or manual focus...
I wasn't talking about preferences, I was talking about needs. I do wish I could ask him if he thinks he needs AF, and whether he thinks AF is essential to getting good shots. I never said AF wasn't useful and explicitly said it can be nice, but I do not believe it is necessary.
carstenw wrote:
No. My point is merely that the vast majority of the greatest shots ever made were made without AF, and very many of them would still be considered amazing shots if made today. The world was awfully quick to "require" AF in my opinion, too quick. It helps in some situations, sure, but it isn't required at all. Especially now that we have awesome EVFs.
I know Telyt (Doug Herr) has some quality MF wildlife images. But see the AF tests 2 & 3 here http://www.andyrouse.co.uk/blog/223.php I'd be incredulous to see this done with MF.
At this point in time the words 'awesome and EVF' are an oxymoron IMHO.
Back in the early 90s I covered a motor sports event also covered by SI and the photographer said AF extended his career because of his weakening eyesight. I would have pegged him as being in his early 50s at that time.
I shoot a fair amount of football and all of the SI photographers at those games use AF systems. I remember shooting a Packers game alongside Walter Iooss Jr., about a year or so prior to Favre's departure from the team, when everyone was speculating it was his last season. Iooss was covering Favre specifically and had an interesting style that was different from any other SI photographer I'd seen previously. He worked with a couple cameras and 24-70 and 300/4, whereas at that time those guys typically shot multiple cameras with 24-70, 70-200, 300/500 or 400/600 and an assistant to manage it all... Anyway, his was AF gear too, of course.
At least from my sports/action experience, AF isn't essential to getting good shots, but it does make the process easier and the number of keepers much greater, in many situations. It's also the situation where manual focus now is not the best option due to how the cameras are designed. The OVFs and focusing screens are not as good for this as 20+ years ago, nor is the MF feel of the lenses. 99% of sports/action photographers also haven't ever relied on, or 'trained' their reflexes for manual focusing. That said, I'm also shooting 'action', such as at weddings, with a Leica M...
Back in the days there were a few guys who had amazing hand-eye coordination and were excellent sports photographers. Apparently Rich Clarkson was one of those.
Not sure if this is relevant at all, but thought I'd share my in-the-field experiences.
If using MF and a ovf, you are crippled if you don't own a camera that has easily changed focus screens. EVFs are far superior if you can't change the screens. I switch my screens all the time on my A900.
Sep 04, 2014 at 09:58 AM
Steve Spencer Offline • • • • • • • Upload & Sell: On
Jon Tainton wrote:
I know Telyt (Doug Herr) has some quality MF wildlife images. But see the AF tests 2 & 3 here http://www.andyrouse.co.uk/blog/223.php I'd be incredulous to see this done with MF.
At this point in time the words 'awesome and EVF' are an oxymoron IMHO.
I can't imagine that anyone using MF would try to do what Rouse was doing in the AF tests 2 & 3. Instead, you would pick a spot where you would expect the owl to fly to in test 2 or the otter run to in test 3, focus on that spot and try to capture the image as the animal came to that spot. I do think that somebody like Doug (but not me) could get excellent images of these animals using such a technique, but I can also see why most togs would prefer to have AF for this type of shooting. What I think this analysis is missing, however, especially for this sort of wildlife shooting that knowing these animals, how to get close to them, and their habits is a necessary part of the process. Being in the right place and being ready to shoot these animals is really the required skills and that is what Rouse and Doug share and why they can both produce amazing shots.
Steve Spencer wrote:
[We have been through this before, but I will point out that manual focus is a different way of shooting and you can get some great action shots by using it. .
Agreed, but am I the only one that hasn't figured out how to disable automatic focus magnification when you turn the focus ring on an E mount lens?
Often times, especially for action shots, I want to MF, but don't want focus magnification. I haven't figured out how to turn off that "feature." I just read that the new Loxia lenses automatically engage focus magnification when you turn the focus ring.
carstenw wrote:
I firmly believe that people make their best work when working under tight, well understood constraints
spoken like a true gear head. of course you "firmly believe" - as are all your beliefs, I'm sure.
ask Michael Stipe or Mozart about how many tight constraints they forced upon themselves. but then again, you probably would not see the equivalence given you hardly approach photography as an art form.
there are so many types of photography that it would be impossible to make any such categorical statement. certainly no artist ever would about whatever their format - the great ones would simply say 'the rules are there to be broken'.
carstenw wrote:
I have seen very, very, very few amazing shots which relied on perfect AF for their success.
is that so?
I took a workshop with Joe McNally a few years back - I would consider him personally amazing (and humble) and his work extraordinary: http://portfolio.joemcnally.com
Jeff Kott wrote:
Agreed, but am I the only one that hasn't figured out how to disable automatic focus magnification when you turn the focus ring on an E mount lens?
yes.
it might be oddly labeled but its one of the first changes i made when i got the camera. i'll check how i did it in minute.
