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Archive 2013Our prayers have been answered: Nex-FF in 2 months
p.27 #1Our prayers have been answered: Nex-FF in 2 months
wfrank wrote:
I dont know too much about that but in general the CY lenses have longer (/worse) MFD while doing nice things slightly further back. My personal non-scientific hunch is that the short MFD required by modern lenses sacrifice some overall attractive optical properties further back.
We are a bit off-topic here, but I am not sure I agree, Wilhelm. For example, the newer Zeiss, Z* 35 f:1.4 and 25 f:2.0 are both very good indeed very close up and very good indeed at infinity. Similarly, Leica Elmar 24 and Summilux 50 perform really well whatever the distance, as does the Zeiss Touit 12mm f:2.8. That is not the case however, IMHO, with the Sony-Zeiss ZA 24 f:1.8, so I will be watching the new Sony-Zeiss releases (16-70 f:4.0, 85 f:1.8) in this respect.
artur5 wrote
that new Sonnar has aprox. the same diameter of the old C/Y Distagon 35/2.8 but it's significatively shorter ( 36 vs. 46 mm) and lighter ( 120 vs 245 gr). I wonder if that means that the optical design is more alike to a classic RF lens than to a SLR one ?.We are a bit off-topic here, but I am not sure I agree, Wilhelm. For example, the newer Zeiss, Z* 35 f:1.4 and 25 f:2.0 are both very good indeed very close up and very good indeed at infinity. Similarly, Leica Elmar 24 and Summilux 50 perform really well whatever the distance, as does the Zeiss Touit 12mm f:2.8. That is not the case however, IMHO, with the Sony-Zeiss ZA 24 f:1.8, so I will be watching the new Sony-Zeiss releases (16-70 f:4.0, 85 f:1.8) in this respect.
Sep 01, 2013 at 01:26 AM
p.27 #2Our prayers have been answered: Nex-FF in 2 months
philber wrote:
But the DOF remains the same. Hence, when you use a 35mm on FF, you get the same DOF as when you use it on APS-C or M 4/3. But, because you have a different equivalent focal length, the ratio of DOF to FL changes. Meaning, if you are using APS-C, you get a different DOF on your "equivalent 35mm" (meaning, a 24mm) than you would on a 35mm on FF.
Yes, it is very important to make a distinction between the two usage cases:
1: When you use two different focal lengths on two different sensors to get the same field of view.
2: When the same focal length is used on two different sensor sizes.
This is all for usage case 1:
The formula is based upon the sensor size ratio. Since different formats also may have different aspect ratios, the best general approximation is to use the diagonal, the size measured from corner to corner.
When going from a small to large sensor, we simply multiply by the sensor size ratio to get both the
focal length for equivalent Field of Viev, and the f-number for equivalent Depth of Field.
u43 sensor diagonal: 21.6 mm
Canon APS-C sensor diagonal: 26.8 mm
Sony APS-C sensor diagonal: 28.1 mm
FF sensor diagonal: 43.2 mm
I use the Sony variant of APS-C here:
FF/u43 ratio: 2
FF/APS-C ratio: 1.5
APS-C/u43 ratio: 1.3
Hope this answers your question, Joan
edwardkaraa wrote
Joan, on APS-C it's around 1.5 and on u4/3 it's around 2.2 in DOF equivalent. Basically 2 f/stops when you reduce the sensor size by half.Yes, it is very important to make a distinction between the two usage cases:
1: When you use two different focal lengths on two different sensors to get the same field of view.
2: When the same focal length is used on two different sensor sizes.
This is all for usage case 1:
The formula is based upon the sensor size ratio. Since different formats also may have different aspect ratios, the best general approximation is to use the diagonal, the size measured from corner to corner.
When going from a small to large sensor, we simply multiply by the sensor size ratio to get both the
focal length for equivalent Field of Viev, and the f-number for equivalent Depth of Field.
u43 sensor diagonal: 21.6 mm
Canon APS-C sensor diagonal: 26.8 mm
Sony APS-C sensor diagonal: 28.1 mm
FF sensor diagonal: 43.2 mm
I use the Sony variant of APS-C here:
FF/u43 ratio: 2
FF/APS-C ratio: 1.5
APS-C/u43 ratio: 1.3
Hope this answers your question, Joan
Sep 01, 2013 at 02:24 AM
p.27 #3Our prayers have been answered: Nex-FF in 2 months
philber wrote:
But the DOF remains the same. Hence, when you use a 35mm on FF, you get the same DOF as when you use it on APS-C or M 4/3. But, because you have a different equivalent focal length, the ratio of DOF to FL changes. Meaning, if you are using APS-C, you get a different DOF on your "equivalent 35mm" (meaning, a 24mm) than you would on a 35mm on FF.
Yes Philippe, DOF is a function of magnification too.
edwardkaraa wrote
Joan, on APS-C it's around 1.5 and on u4/3 it's around 2.2 in DOF equivalent. Basically 2 f/stops when you reduce the sensor size by half.Yes Philippe, DOF is a function of magnification too.
Sep 01, 2013 at 03:43 AM
p.27 #4Our prayers have been answered: Nex-FF in 2 months
According to the side, we should'nt be watching instead of photographing, we get sensor shift in one of the next E mount cameras.
Hope it is for a FF camera. Would be amazing, also for macro possibititys without ext. tubes.
Hope it is for a FF camera. Would be amazing, also for macro possibititys without ext. tubes.
Sep 01, 2013 at 04:03 AM
p.27 #5Our prayers have been answered: Nex-FF in 2 months
philber wrote:
But the DOF remains the same. Hence, when you use a 35mm on FF, you get the same DOF as when you use it on APS-C or M 4/3. But, because you have a different equivalent focal length, the ratio of DOF to FL changes. Meaning, if you are using APS-C, you get a different DOF on your "equivalent 35mm" (meaning, a 24mm) than you would on a 35mm on FF.
I don't think you can even start to define "DoF" without using that ratio. The one and only reason that people talking about DoF think that it "should" be possible is the unfortunate end result of an old oversimplification.
1/1500 of the diagonal of a 36x24mm film frame was estimated to give "not improvable sharpness" in a small/medium size printed photo viewed at half arms length (exact numbers are on the Zeiss site). That's why the 0.03mm CoC was chosen. Then those 0.03mm have been taken way out of their context, and people use that number as a base for "the one truth" regardless of film/sensor format and regardless of magnification.
The definition of DoF is a relationship between image diagonal, magnification and blur size. Remove or change one of those parameters, and the number becomes meaningless. The 0.03mm means nothing - if they're not applied to a shot taken on a 36x24mm capture area, and inspected at an image magnification about the same as holding an A5 size sheet of paper at 40cm (1'4") viewing distance.
But the DOF remains the same. Hence, when you use a 35mm on FF, you get the same DOF as when you use it on APS-C or M 4/3. But, because you have a different equivalent focal length, the ratio of DOF to FL changes. Meaning, if you are using APS-C, you get a different DOF on your "equivalent 35mm" (meaning, a 24mm) than you would on a 35mm on FF.
I don't think you can even start to define "DoF" without using that ratio. The one and only reason that people talking about DoF think that it "should" be possible is the unfortunate end result of an old oversimplification.
1/1500 of the diagonal of a 36x24mm film frame was estimated to give "not improvable sharpness" in a small/medium size printed photo viewed at half arms length (exact numbers are on the Zeiss site). That's why the 0.03mm CoC was chosen. Then those 0.03mm have been taken way out of their context, and people use that number as a base for "the one truth" regardless of film/sensor format and regardless of magnification.
The definition of DoF is a relationship between image diagonal, magnification and blur size. Remove or change one of those parameters, and the number becomes meaningless. The 0.03mm means nothing - if they're not applied to a shot taken on a 36x24mm capture area, and inspected at an image magnification about the same as holding an A5 size sheet of paper at 40cm (1'4") viewing distance.
Sep 01, 2013 at 05:12 AM
p.27 #6Our prayers have been answered: Nex-FF in 2 months
18mm z-shift?
http://www.sonyalpharumors.com/sr5-there-is-a-sony-camera-to-come-also-for-nikon-and-canon-lens-owners/#comments
We are talking about a larg'ish body now I fear. If this pans out I hope they offer a plain version without this.
http://www.sonyalpharumors.com/sr5-there-is-a-sony-camera-to-come-also-for-nikon-and-canon-lens-owners/#comments
We are talking about a larg'ish body now I fear. If this pans out I hope they offer a plain version without this.
Sep 01, 2013 at 05:53 AM
p.27 #7Our prayers have been answered: Nex-FF in 2 months
I don't think (or hope) the SAR guy has implied that the FF NEX and the CaNikon Trojan Horse is the same camera.
Sep 01, 2013 at 05:59 AM
p.27 #8Our prayers have been answered: Nex-FF in 2 months
No, I don't think he implied it. Intuitively, if the sensor can move front and back, it suggests that there needs to be some pare room for this movement, i.e. not the smallest, tightest camera body. That that is just a guess...
Sep 01, 2013 at 06:48 AM
p.27 #9Our prayers have been answered: Nex-FF in 2 months
Regarding DOF I agree with theSuede, too many variables. There's an interesting new DOF calculator beeing discussed at LuLa:
http://www.luminous-landscape.com/forum/index.php?topic=81485.0
As for the shifting sensor, interesting (if true of course) they chose 18 mm, since NEX means New Eighteen (mm) Experience, which is the flange focal distance of the NEX system.
http://www.luminous-landscape.com/forum/index.php?topic=81485.0
As for the shifting sensor, interesting (if true of course) they chose 18 mm, since NEX means New Eighteen (mm) Experience, which is the flange focal distance of the NEX system.
Sep 01, 2013 at 06:59 AM
p.27 #10Our prayers have been answered: Nex-FF in 2 months
I'm assuming that the Z-shift sensor camera will have an e-mount but be as thick as the SLT cameras, so that the sensor has space to shift back and forth.
The current Z-shift sensor camera being talked about on SAR is an aps-c camera, although the admin an that site believes there may also be a FF version in the works.
The current Z-shift sensor camera being talked about on SAR is an aps-c camera, although the admin an that site believes there may also be a FF version in the works.
Sep 01, 2013 at 07:27 AM
p.27 #11Our prayers have been answered: Nex-FF in 2 months
- 18mm. are a lot of shift, much more than in the Contax-AX. It reads as bulky, heavy, and rather expensive camera..
- Focus speed is the first question: I don't see it competing directly with AF DSLR systems in that aspect. That would be asking too much, but let's wait and see.
- Of course longish focal lenses will require a manual prefocus, -18mm. isn't enough to cover all range from infinity to MFD with focals above 135mm. or so.
- The issue of lenses with floating elements is another aspect to consider. Sensor shift isn't an optimal solution here. Again, manual prefocus and automatic fine tuning will be the answer.
- Iris control for Nikon/Canon/Pentax AF glass. Is that considered or they assume that the user will be contented with stop down focus/metering ? There's the Metabones smart adapter for Canon EF; nothing for Nikon/Pentax. Will Sony release adapters for using lenses from other manufacturers on their own cameras ? That would be unprecedented.
IMO that Trojan horse is an improved version of peaking/focus magnification, not a true universal AF body. There's no such thing as free lunch, etc...
- Focus speed is the first question: I don't see it competing directly with AF DSLR systems in that aspect. That would be asking too much, but let's wait and see.
- Of course longish focal lenses will require a manual prefocus, -18mm. isn't enough to cover all range from infinity to MFD with focals above 135mm. or so.
- The issue of lenses with floating elements is another aspect to consider. Sensor shift isn't an optimal solution here. Again, manual prefocus and automatic fine tuning will be the answer.
- Iris control for Nikon/Canon/Pentax AF glass. Is that considered or they assume that the user will be contented with stop down focus/metering ? There's the Metabones smart adapter for Canon EF; nothing for Nikon/Pentax. Will Sony release adapters for using lenses from other manufacturers on their own cameras ? That would be unprecedented.
IMO that Trojan horse is an improved version of peaking/focus magnification, not a true universal AF body. There's no such thing as free lunch, etc...
Sep 01, 2013 at 08:57 AM
p.27 #12Our prayers have been answered: Nex-FF in 2 months
I wonder if there are some rumor signals crossed at SAR? Rather than actually moving the sensor to AF, maybe this is just the new "hybrid" mount that was rumored several months ago, and the sensor simply moves into a static position to accommodate the lens that you attach to the camera? Sony could then release a line of very thin adapters for all of the various SLR brands, since the sensor could move back into the camera to set the correct registration distance. They could also throw in a focusing motor into the camera body, like with a-mount cameras, so lenses without an internal AF motor will still work without a big, bulky adapter.
Aren't both Canon and Nikon's mounts out of patent now? Sony could probably release their own, small adapter versions of the various mounts, and maybe even have all of the electronic protocol in order to deal with things like aperture, no?
Aren't both Canon and Nikon's mounts out of patent now? Sony could probably release their own, small adapter versions of the various mounts, and maybe even have all of the electronic protocol in order to deal with things like aperture, no?
Sep 01, 2013 at 10:16 AM
p.27 #13Our prayers have been answered: Nex-FF in 2 months
douglasf13 wrote:
Aren't both Canon and Nikon's mounts out of patent now?
Yes I think so. It has been mentioned that Sigma could have used the EF mount for their own cameras if they wanted to.
Aren't both Canon and Nikon's mounts out of patent now?
Yes I think so. It has been mentioned that Sigma could have used the EF mount for their own cameras if they wanted to.
Sep 01, 2013 at 11:01 AM
p.27 #14Our prayers have been answered: Nex-FF in 2 months
Forgive me if I'm wrong, but didn't that Contax thing used to have a rather limited AF range? But anyway, I'll judge when I see it but it does sound interesting. I'd just like to see and feel whatever it is though, as it'll be the first of its kind in digital so many questions will need to be answered... Eg battery life, noise levels (sensor movement), accuracy, speed, dust, etc. It'll have to do everything the 'normal cameras' do, with very insignificant compromises if it is going to win users over. Otherwise people will have too many ifs and buts.
Sep 01, 2013 at 11:21 AM
p.27 #15Our prayers have been answered: Nex-FF in 2 months
ricardovaste wrote:
Forgive me if I'm wrong, but didn't that Contax thing used to have a rather limited AF range? But anyway, I'll judge when I see it but it does sound interesting. I'd just like to see and feel whatever it is though, as it'll be the first of its kind in digital so many questions will need to be answered... Eg battery life, noise levels (sensor movement), accuracy, speed, dust, etc. It'll have to do everything the 'normal cameras' do, with very insignificant compromises if it is going to win users over. Otherwise people will have too many ifs and...Show more →
True. The AX still needs you to focus manually while the AF fine tunes the focus. It is a very complex mechanism, and it is almost impossible to find functioning AX cameras at this time, so I have doubts about the accuracy and long term usage reliability.
Forgive me if I'm wrong, but didn't that Contax thing used to have a rather limited AF range? But anyway, I'll judge when I see it but it does sound interesting. I'd just like to see and feel whatever it is though, as it'll be the first of its kind in digital so many questions will need to be answered... Eg battery life, noise levels (sensor movement), accuracy, speed, dust, etc. It'll have to do everything the 'normal cameras' do, with very insignificant compromises if it is going to win users over. Otherwise people will have too many ifs and...Show more →
True. The AX still needs you to focus manually while the AF fine tunes the focus. It is a very complex mechanism, and it is almost impossible to find functioning AX cameras at this time, so I have doubts about the accuracy and long term usage reliability.
Sep 01, 2013 at 11:27 AM
p.27 #16Our prayers have been answered: Nex-FF in 2 months
edwardkaraa wrote:
True. The AX still needs you to focus manually while the AF fine tunes the focus. It is a very complex mechanism, and it is almost impossible to find functioning AX cameras at this time, so I have doubts about the accuracy and long term usage reliability.
Oh yes. Given the numbers of still working Walkman, Betamax Video recorders etc. it sounds as if a Digital AX would be an ideal Sony product
ricardovaste wrote
Forgive me if I'm wrong, but didn't that Contax thing used to have a rather limited AF range? But anyway, I'll judge when I see it but it does sound interesting. I'd just like to see and feel whatever it is though, as it'll be the first of its kind in digital so many questions will need to be answered... Eg battery life, noise levels (sensor movement), accuracy, speed, dust, etc. It'll have to do everything the 'normal cameras' do, with very insignificant compromises if it is going to win users over. Otherwise people will have too many ifs and buts.Oh yes. Given the numbers of still working Walkman, Betamax Video recorders etc. it sounds as if a Digital AX would be an ideal Sony product
Sep 01, 2013 at 12:15 PM
p.27 #17Our prayers have been answered: Nex-FF in 2 months
'There's no such thing as free lunch, etc...' You may consider how far technology has advanced in the past 10 years, if not 200 years. Technical advances are all about 'free lunches'.
'would be an ideal Sony product' - these guys are never far away. What have you done for the world lately, Jon ;-)
'would be an ideal Sony product' - these guys are never far away. What have you done for the world lately, Jon ;-)
Sep 01, 2013 at 03:33 PM
p.27 #18Our prayers have been answered: Nex-FF in 2 months
edwardkaraa wrote:
True. The AX still needs you to focus manually while the AF fine tunes the focus. It is a very complex mechanism, and it is almost impossible to find functioning AX cameras at this time, so I have doubts about the accuracy and long term usage reliability.
The mechanism may be complex but the AX isn't complicated to use...just a bit slow by today's standards. You generally don't need to prefocus...set the lens to infinity and let the AX focus.
Mine works fine BTW and I've seen several functioning units for sale recently so the mechanism seems reasonably durable.
ricardovaste wrote
Forgive me if I'm wrong, but didn't that Contax thing used to have a rather limited AF range? But anyway, I'll judge when I see it but it does sound interesting. I'd just like to see and feel whatever it is though, as it'll be the first of its kind in digital so many questions will need to be answered... Eg battery life, noise levels (sensor movement), accuracy, speed, dust, etc. It'll have to do everything the 'normal cameras' do, with very insignificant compromises if it is going to win users over. Otherwise people will have too many ifs and buts.The mechanism may be complex but the AX isn't complicated to use...just a bit slow by today's standards. You generally don't need to prefocus...set the lens to infinity and let the AX focus.
Mine works fine BTW and I've seen several functioning units for sale recently so the mechanism seems reasonably durable.
Sep 01, 2013 at 04:15 PM
p.27 #19Our prayers have been answered: Nex-FF in 2 months
Actually DOF of the same lens on smaller format is narrower than on larger format. You can check DOF calculator for that.
Sep 01, 2013 at 04:22 PM
p.27 #20Our prayers have been answered: Nex-FF in 2 months
Well, technically it's shallower if the pixel pitch is finer, because they calculate it based on the size of the focus blur compared to the pixel size.
Sep 01, 2013 at 04:54 PM