Home
SearchSearch MemberlistMemberlist RegisterRegister ProfileProfile Log in to check your private messagesLog in to check your private messages Log inLog in

Sony mirrorless, Focus confirmation in live view?
View previous topic :: View next topic  


PostPosted: Thu Mar 29, 2018 11:20 pm    Post subject: Sony mirrorless, Focus confirmation in live view? Reply with quote

I've always used Pentax, and I still use one (K-1).
I also have plenty of PK and M42 vintage optics. If I consider the number of native, M42, T-mount, Adaptall-2, adapted objectives, I guess I have about 350 of them, which is a good reason to stick to the mount.
Though I also own many old glasses that are either impossible to convert, or too complex.
On top of that, some valuable vintage objectives should better be left alone, I don't want to butcher them.
So I'm pondering about the possibility of getting a second system that easily allows to mount almost any MF lens.
After trying an old Olympus Pen, I realized that I want a full frame.
That leaves Sony as the only choice.
It has to be second hand, not too expensive, and not necessarily super high resolution.
IBIS would be a nice feature, so I'm considering the A7 II.
I don't know much about Sony mirrorless cameras, so I'm asking about a feature that could be quite useful. Focus confirmation.
I know about Focus Peaking in LiveView. And I know that focus confirmation is not working in LiveView on my Pentax K-1.
I guess it could come useful if the subject has to be focused quickly. At least with the Pentax it would...
How about the Sony A7 II?
Anything I'm not considering?

Another question?
Is there any other Sony FF camera that could be an alternative to the A7 II, considering my specific needs?

Thanks in advance
Ciao

Paolo


PostPosted: Fri Mar 30, 2018 12:27 am    Post subject: Reply with quote

I have an APS-C crop-body Sony NEX 7. It has the same resolution as the A7 and A7II -- 24.3mp. I find this to be ample resolution in almost all situations I've come across.

As for focus peaking, with the Sony mirrorless cameras, it works in Live View. And if the camera has a viewfinder, as my NEX 7 does, it works in the VF display also. I find it to be very helpful. But it is not something that you should rely exclusively upon. The Focus Peaking Routine in the NEX 7 (dunno about the A-series, it might be improved in them) requires a fair amount of contrast in order to even be visible.

Even when I'm getting a solid FP hit, though, I like to always double check by zooming in on the object. The NEX 7 has about 6x and 11x (as I dimly recall) magnification. I will often use this to confirm accurate focusing on the object in question. Often I find that a slight adjustment can be made to improve focus beyond what FP recognizes. But it at least gets me in the ball park and for that, I find it useful.


PostPosted: Fri Mar 30, 2018 2:44 am    Post subject: Reply with quote

Try Techart Autofocus Adapter if you need to focus quickly, works quiet well with small primes.


PostPosted: Fri Mar 30, 2018 6:10 am    Post subject: Reply with quote

Paolo, it looks as if you have similar needs since I'm also considering the purchase of a new FF mirrorless camera from time to time. Wink

My problem with the Sony A7 series is the thick filter stack issue which results in strange performance with many of my existing RF lenses which are performing excellent both on film and on my Ricoh GXR-M APS-C camera. As I have invested quite heavily in these lenses it would be a pity to use them on a new camera with so-so results. Therefore I'm also considering the purchase of the only alternative which is for the time being a digital Leica M. Obviously the A7 is designed to work best with Sony E-mount lenses and although it's technically possible to adapt almost every lens the results wich some of these old lenses may vary.

IMHO the by far best camera for adapting old lenses and particularly RF ones is still my Ricoh GXR-M as it has been exclusively designed for the usage of MF lenses designed for film. It's also offering a state of the art focus aid system; at least I haven't seen any better one so far. Unfortunately it's only APS-C and there is not even a focal reducer available for the Leica-M mount yet. However, as I'm also owning some ultra wide angle RF lenses (which are known to perform lousy on the A7) the smaller sensor and the limited angle of view isn't really that big problem for me. Even my 12 and 15mm ultra wides from Voigtlaender perform excellently and without color shift or smearing corners on the Ricoh.

Therefore I'm more in the "wait and see"-mode for the time being and possibly safe some more money for a Leica which would be the better solution for me. Maybe I'll go for a cheap used A7 (the A7 is already available for EUR 750 NEW) to make use of my old Minolta MC/MD and Pentax-K MF lenses also on FF and a Leica for my RF lenses as well. Wink


PostPosted: Fri Mar 30, 2018 4:43 pm    Post subject: Reply with quote

Somebody correct me if I'm wrong, but isn't the A7R II devoid of a filter stack? In particular the Anti-Aliasing filter, which reduces sharpness, but helps to eliminate Moire effects. Also, I've read of an outfit (don't recall their name tho) that can remove the stack from your sensor for a fee, of course.


PostPosted: Fri Mar 30, 2018 5:09 pm    Post subject: Reply with quote

cooltouch wrote:
Somebody correct me if I'm wrong, but isn't the A7R II devoid of a filter stack? In particular the Anti-Aliasing filter, which reduces sharpness, but helps to eliminate Moire effects. Also, I've read of an outfit (don't recall their name tho) that can remove the stack from your sensor for a fee, of course.


That's the so called Kolari-Mod: https://kolarivision.com/product/sony-a7-series-thin-filter-legacy-lens-upgrade/

That's not really cheap and for non-US residents far too cumbersome. Additionally I've read that although it works better it doesn't solve the problems with every lens.

BTW the R versions still have a filter stack. They only lack of the AA-filter.


PostPosted: Fri Mar 30, 2018 7:11 pm    Post subject: Reply with quote

calvin83 wrote:
Try Techart Autofocus Adapter if you need to focus quickly, works quiet well with small primes.


It works well with a bit havyer lenses (under 700g), too. I can use it nicely with my 85mm f/1.4 Samyang, for instance.
With bigger lenses you can focus by letting the adapter move the camera and keep the lens steady in hand.


PostPosted: Mon Apr 02, 2018 1:14 pm    Post subject: Reply with quote

This is a very interesting discussion.
I also have a few LTM and M mount lenses, but the main scope of my hypothetical mirrorless FF body would be complete freedom from lens mount. I still have just a few short register objctives, and of the Leitz ones only a 40mm and a 28mm are "orphaned". The two I like the most (Summicron 2/80 and Elmarit 2.8/135, both Mandler's Canadian designs) have been already converted to PK mount with good results. My only gripe is the minimum focusing distance, cause I'm using the Viso helicoid for both, which is insufficient especially for the 135mm. Thanks to that original Leitz focusing accessory, I can use a modified Viso-to-R Leitz adapter (swapped bayonet with a cheap Chinese knock-off of the Leitax)... and the trick is done Smile
The Ricoh/Pentax implementation of the Sony sensor works more than fine with most vintage optics. On average I see a huge improvement vs older cameras. Some optics do better than others, and even those that don't perform at their best are not as bad as I remember them to be, on previous CMOS sensors and older CCD ones. Like some long teles (still some lateral CA) and of course most extra wides.
My need for a full frame mirrorless, I don't know if its' just perceived or is real, has more to do with SLR's lenses, like the Hexanons, a few Exakta bayonet ones, and in perspective Minolta MD, Canon FD and Zuikos. Knowing about my hobby, sometimes it happens that friends tell me they have film gear, including objectives, sitting unused since years. Unfortunately never Pentax! So I never took anything. What a pity Sad
Another field that I find very intriguing are super fast projector lenses. I have many that could be used only with a shorter register. A very nice Kowa f/1.2 50mm comes to my mind...
I'm sure that others have similar needs/tastes, and I guess many have direct experience with the different models of Sony mirrorless FF cameras. APS-C isn't so attractive, as I see its usefulness limited to 50mm and long teles.

Regarding the thickness of the glass in front of the sensor, and the presence of an anti aliasing layer, which are the differences between 7, 7R and 7 II ?
These are the ones I'm considering. The 7S seems to be dedicated to other use, and the more expensive models are beyond my reach.
If I decide to buy one, I'd like to make an informed purchase, but I really know very little about the peculiarities of Sony cameras.
AF is not a priority, I don't think I would ever buy something like the Techart, but I admit I'm very ignorant about performance/features...

cheers

Paolo


Last edited by cyberjunkie on Mon Apr 02, 2018 7:26 pm; edited 1 time in total


PostPosted: Mon Apr 02, 2018 2:18 pm    Post subject: Reply with quote

cyberjunkie wrote:
This is a very interesting discussion.
I also have a few LTM and M mount lenses, but the main scope of my hypothetical mirrorless FF body would be the complete freedom from lens mount. Only a few have a short register, and of the Leitz ones only a 40mm and a 28mm are "orphaned". The two I like the most (Summicron 2/80 and Elmarit 2.8/135, both Canadian) have been already converted to PK mount with good results. My only gripe is the minimum focusing distance, cause I'm using the Viso helicoid for both, which is insufficient especially for the 135mm. Thanks to that original Leitz accessory, I can use a Leitaxed (cheap Chinese knock-off) Viso-to-R adapter... and the trick is done Smile
The Ricoh/Pentax implementation of the Sony sensor works more than fine with most vintage optics, excluding some long teles (still some lateral CA) and of course most extra wides.
My need for a full frame mirrorless, I don't know if its' just perceived or is real, has more to do with reflex lenses, like the Hexanons, a few Exakta bayonet ones, and in perspective Minolta MD, Canon FD and Zuikos. Knowing about my hobby, sometimes it happens that friends tell me they have film gar, including objectives, sitting unused since years. Unfortunately never Pentax! So I never took anything Sad
Another field that I find very intriguing are super fast projector lenses. I have many that could be used only with a shorter register. A very nice Kowa f/1.2 50mm comes to my mind...
I'm sure that others have similar needs/tastes, and I guess many have direct experience with the different models of Sony mirrorless FF cameras. APS-C isn't so attractive, as I see its usefulness limited to 50mm and long teles.

Regarding the thickness of the glass in front of the sensor, and the presence or not of anti aliasing, which are the differences between 7, 7R and 7 II ?
The 7S seems to be dedicated to other use, and the more expensive models are beyond my reach.
If I decide to buy one, I'd like to make an informed purchase, but I really know very little about the peculiarities of Sony cameras.
AF is not a priority, I don't think I would ever buy something like the Techart, but I admit I'm very gnorant about performance/features...

cheers

Paolo


Well, the 7S series is optimized for movie offering a 12MP sensor. The 7 series comes with 24MP and the 7R with high resolution 36 or 42MP and without AA-filter. Most probably the 7 would be best and it's the cheapest as well. For the differences between model I, II and III I would recommend to look at DPR and compare the features:
https://www.dpreview.com/products/compare/side-by-side?products=sony_a7&products=sony_a7ii&products=sony_a7iii&products=sony_a7r&products=sony_a7rii&products=sony_a7riii
To read their test reports may also help.
I think the main difference betw. A7 and A7 II is the introduced anti shake picture stabilization in the model II.


PostPosted: Mon Apr 02, 2018 10:55 pm    Post subject: Reply with quote

Thanks Thomas.
More or less I already knew the informations you kindly provided.
Though I thought that the 7 II had no AA (with a moving sensor it's possible to fight moire another way).
What I'm looking for are information about practical usability with MF lenses, and first-hand impressions (what works fine and what not).
My concerns are mainly about focusing, especially with super fast lenses used wide open. With the K-1 I get focus peaking in LiveView, but there is no focus confirmation led. With the optical viewfinder I get focusing confirmation, but it's unreliable under f/2.8. The solution is either focus bracketing in OVF, or enlarged LiveView. Unfortunately the former is a counterintuitive process (at least for me), and also quite slow.
It seems that all the Sony cameras have focus confirmation in the EVF. Is it true? Is it accurate enough at large apertures?
The accuracy of metering and focusing aid are the two most important points I can think of. Performance with short register wide angles is not really a concern.

Anti shaking is a very nice feature, but my K-1 does great in that regard, also using the floating sensor (5 axis, combined) for other nice things like PixelShift and Astro Tracing.
If the 7 II still has the AA glass, and doesn't have any really useful advantage regarding the usage of vintage MF lenses apart SR, it could make sense to just go for the first version, if I find one for really cheap.

Anything I'm missing?
Personal insights are welcomed

cheers

Paolo


PostPosted: Tue Apr 03, 2018 1:54 am    Post subject: Reply with quote

Quote:
It seems that all the Sony cameras have focus confirmation in the EVF. Is it true? Is it accurate enough at large apertures?

Only peaking. focus confirmation/focus beep will appear only if you use af lens in af mode.

Quote:
If the 7 II still has the AA glass, and doesn't have any really useful advantage regarding the usage of vintage MF lenses apart SR, it could make sense to just go for the first version, if I find one for really cheap.

It is your choice.


PostPosted: Tue Apr 03, 2018 7:21 am    Post subject: Reply with quote

cyberjunkie wrote:

If the 7 II still has the AA glass, and doesn't have any really useful advantage regarding the usage of vintage MF lenses apart SR, it could make sense to just go for the first version, if I find one for really cheap.


Well, I'm in a similar dilemma. Wink

Having already a Sony FF 24MP DSLR camera with AS and the same sensor, the A7 doesn't add much value other that I can use some more adapted SLR lenses on FF as well. Therefore I wouldn't be prepared to spend much for that as well.

On the other hand the A7R would be the far better choice (no AA filter and higher resolution) but is still too expensive for that rather limited usage as it's incompatible with many of my RF lenses.

I think the focus peaking functionality is good enough for the usage of MF lenses. I don't really need a focus confirmation additionally. My Sony DSLR offers such a confirmation LED if a chipped adapter is used but I don't use even that when I use it with old M42 lenses.

Finally the most important question for me is whether I really need an additional FF body just for the adaption of old MF lenses which I can already adapt to an APS-C camera without AA filter anyway. In direct comparison (e.g. the same M42 lens used on both my APS-C and FF camera) the FF camera adds only more FOV but not more quality. I tend to say that quality wise it's rather the other way round as on the smaller sensor only the "sweet spot" of the lens is used even without AA filter. Last but not least the smaller sensor may be a real advantage hence I use also my Leitz Elmar 135/4 even on my Panasonic MFT camera which gives me an excellent "270 mm" tele for birding.

A really cheap alternative may also be a used NEX with a focal reducer. I've made some comparisons here:
http://forum.mflenses.com/lens-turbo-aka-speed-booster-t78931.html

Hard decisions. Wink


PostPosted: Sun Apr 08, 2018 1:39 pm    Post subject: Reply with quote

tb_a wrote:
cyberjunkie wrote:

If the 7 II still has the AA glass, and doesn't have any really useful advantage regarding the usage of vintage MF lenses apart SR, it could make sense to just go for the first version, if I find one for really cheap.


A really cheap alternative may also be a used NEX with a focal reducer. I've made some comparisons here:
http://forum.mflenses.com/lens-turbo-aka-speed-booster-t78931.html

Hard decisions. Wink


That's another option!
I didn't think about that.
My friend/repairman/stereocameras collector, who loves old lenses almost as much as I do, has recently made the move to a K7, but for long time he's been happy with his Nex.
I have a taste for old fast wide angles, used wide open at close distance. I don't think out of focus rendition is of concern only for longer focals , but if you want to use vintage 28mm or 35mm optics you got to make full use of them. Which means let them cover the same format and give the same field of view.
Focal reducer could be an unconventional answer. Though I'm hesitant... introducing extraneous optical elements affects the performance and the "character" of a lens.
In all sincerity I know nothing about that, and I also have no idea on how a Techart AF adapter affects optical performance.
It would be very interesting to read about your opinions.

I'm still tempted by the A7 models. Unfortunately the prices aren't as low as I expected.
Maybe I will find a beat-up A7 for an affordable price, but prices of A7R and A7 II models aren't exactly cheap...
Before checking the prices, I found a nice A7R on auction on Ebay. I bid 570 dollars. The camera sold for almost $780! Smile Smile
This is not the kind of money I can spend without knowing in advance that the sensor mates well with vintage SLR lenses, and that the focusing can be precise enough.
The ease of focusing is my main point. The Pentax implementation of the Sony sensor in my K-1 is definitely better than I expected, and using almost all my vintage lenses to their full potential is a dream come true, BUT there is a huge weak spot.
Focus confirm led based on PDAF (using the optical viewfinder) is completely unreliable at f/2 and below.
Using enlarged LiveView with focus peaking allows for much better precision, but using a screen instead of a viewfinder is not intuitive nor ergonomic, and the implementation of LiveView (and Focus Peaking) is not as refined and effective as in other recent cameras.
Sony seems to do much better, from what I've been told, cause both the screen and the electronic viewfinder should be easier to use and allow precise control of focusing with manual lenses.
I've spent good money on a few vintage optics that were at the top of my "most desired" list.
My budget is at its lowest Sad So I'm trying to find out if my expectations are excessive or not.
The chance to use other mounts is really great, but at this time what I really want is a camera that allows easy, intuitive, precise focusing using fast lenses, as a 50/55mm f/1.2, an 85mm f/1.8 or faster, or a 135mm f/2 or faster.

Thanks for the feedback

ciao

Paolo


PostPosted: Sun Apr 08, 2018 2:51 pm    Post subject: Reply with quote

A camera with IBIS may be necessary for handle focusing with teles. I can focus preciously with a 200/2.8 and 200/4 macro on my A7RII using enlarged LiveView with the IBIS turn.


PostPosted: Sun Apr 08, 2018 11:57 pm    Post subject: Reply with quote

cyberjunkie wrote:

That's another option!
I didn't think about that.
My friend/repairman/stereocameras collector, who loves old lenses almost as much as I do, has recently made the move to a K7, but for long time he's been happy with his Nex.
I have a taste for old fast wide angles, used wide open at close distance. I don't think out of focus rendition is of concern only for longer focals , but if you want to use vintage 28mm or 35mm optics you got to make full use of them. Which means let them cover the same format and give the same field of view.
Focal reducer could be an unconventional answer. Though I'm hesitant... introducing extraneous optical elements affects the performance and the "character" of a lens.
In all sincerity I know nothing about that, and I also have no idea on how a Techart AF adapter affects optical performance.
It would be very interesting to read about your opinions.


IMHO neither the Techart AF adapter (which is BTW glassless) nor any focal reducer does change the "character" of any lens.

A focal reducer just downsizes the picture from the lens to fit on a smaller image circle; i.e. sensor. It's more or less acting like a tele converter just the other way round. Obviously the Zhongyi Lens Turbo II is at least for the time being best in terms of optical quality.

I think I will skip the idea to buy any A7 for the time being. Maybe I'll go for the Lens Turbo II instead. For my FF camera I have more than enough excellent lenses anyway and for my most used camera (which is my Ricoh GXR-M APS-C) there is no alternative in sight with comparable compactness and picture quality with my RF lenses. FF isn't important at all. It's more a physiological phenomenon to be better familiar with the focal length vs. field of view relationship like in the old 135 film times. As I'm shooting with several formats from smartphone up to medium format 6x9 I'm not so fixed on that. Finally I have more than enough ultra wide angle lenses wide enough even on APS-C. Maybe it's better for me to invest my money in the Voigtländer Hyper Wide Heliar aspherical 10mm/F5.6 lens than in any A7 camera. That would fill the gap between my 8mm and 12mm lenses. Wink

At least the discussion with you helped me to make up my mind for that decision.


PostPosted: Wed Apr 11, 2018 6:57 am    Post subject: Reply with quote

tb_a wrote:

IMHO neither the Techart AF adapter (which is BTW glassless) nor any focal reducer does change the "character" of any lens.

A focal reducer just downsizes the picture from the lens to fit on a smaller image circle; i.e. sensor. It's more or less acting like a tele converter just the other way round. Obviously the Zhongyi Lens Turbo II is at least for the time being best in terms of optical quality.


Well, it's glass in between the lens and the film/sensor...
If an optically complex afocal accessory screwed on top of (any) objective affects the basic optical characteristics, I can't believe that a similar optical system placed behind the main lens has NO influence...
No personal experience, but it's really too good to be true.
I tend to believe that a focal reducer has less influence that an AF converter.
The reasons are rather obvious. Though ANY glass added to an optical project does make a difference, even a perfectly plainparallel "filter" placed in the middle, or behind, a given lens. A couple of fisheyes I own have such interchangeable filters for B/W use; if you don't need the other filters you have to fit a clear filter in their place, other way the lens works much worse.

Any air to glass surface introduces reflection and refraction.
Whatever... if your personal experience is positive, I believe that the influence could be considered minimal. Good news Smile