No AFMA (Auto Focus Micro Adjustment), available on SD Quattro.

Hello:

So, as I have still been thinking about the SD Quattro, I was reading more things about mirrorless cameras, and they "stated in most reviews / spec sheet data" - they DO NOT offer (nor need / require) the AFMA setup?

So, if that is the case as I understand it - then we can't therefore make any adjustments to the lenses we use on the SD Quattro, so maybe the only "last" resort / or other alternative we have is to (if an ART or Contemporary / Sports) lens, is to try getting a lens into better focusing with calibration using the Sigma Dock, is this a logical thought?

Also of course, there is Manual Focusing to work with too.

Just a thought, where on the SD1M (Merrill) we have that advantage to using AFMA.

Thanks for reading, and any comments...

Have a nice day / evening -

Ed

~ ~ ~

You only need AFMA with PDAF (Phase Detect Auto Focus), as that one can get off track.

The SD Quattro uses CDAF (Contrast Detect Auto Focus), which has its pluses and minuses, one of the pluses being that it simply doesn't need AFMA.

The SD1 is an SLR (Single Lens Reflex), these use PDAF. Hence, it has AFMA.

The SD Quattro is a mirrorless camera. Some mirrorless cameras have hybrid PDAF&CDAF of some sorts (and AFMA), but not the SD Quattro.

So you're good. No AFMA needed (nor possible).

goblin said:

You only need AFMA with PDAF (Phase Detect Auto Focus), as that one can get off track.

The SD Quattro uses CDAF (Contrast Detect Auto Focus), which has its pluses and minuses, one of the pluses being that it simply doesn't need AFMA.

The SD1 is an SLR (Single Lens Reflex), these use PDAF. Hence, it has AFMA.

The SD Quattro is a mirrorless camera. Some mirrorless cameras have hybrid PDAF&CDAF of some sorts (and AFMA), but not the SD Quattro.

So you're good. No AFMA needed (nor possible).

Click to expand...

Hello:

But, in that sense the negative is - IF any lens you use on the SD Quattro camera, don't remain "solid in focusing" - then there isn't any real recourse to "try to fix" the non-focusing errors, like you could, with the AFMA capable cameras.

I have the SD1M (Merrill), and at least I can make adjustments.

I am wondering - IF even one decided to STICK with the ART / Contemporary and Sports intended (suggested) by Sigma for use on the SD Quattro - if any lens does not perform AF - seems then there is not much "help to fixing it", correct?

I guess unless, you sent the lens(es) and camera to Sigma for adjustment, BUT - WHAT adjustments, if there really isn't any?

Thanks,

Ed

~ ~ ~

ELSOK4ME said:

goblin said:

You only need AFMA with PDAF (Phase Detect Auto Focus), as that one can get off track.

The SD Quattro uses CDAF (Contrast Detect Auto Focus), which has its pluses and minuses, one of the pluses being that it simply doesn't need AFMA.

The SD1 is an SLR (Single Lens Reflex), these use PDAF. Hence, it has AFMA.

The SD Quattro is a mirrorless camera. Some mirrorless cameras have hybrid PDAF&CDAF of some sorts (and AFMA), but not the SD Quattro.

So you're good. No AFMA needed (nor possible).

Click to expand...

Hello:

But, in that sense the negative is - IF any lens you use on the SD Quattro camera, don't remain "solid in focusing" - then there isn't any real recourse to "try to fix" the non-focusing errors, like you could, with the AFMA capable cameras.

I have the SD1M (Merrill), and at least I can make adjustments.

I am wondering - IF even one decided to STICK with the ART / Contemporary and Sports intended (suggested) by Sigma for use on the SD Quattro - if any lens does not perform AF - seems then there is not much "help to fixing it", correct?

I guess unless, you sent the lens(es) and camera to Sigma for adjustment, BUT - WHAT adjustments, if there really isn't any?

Thanks,

Ed

~ ~ ~

Click to expand...

Please reread what he wrote above. Your question is similar to trying to figure out how to get more petrol into your Tesla.

I'm curious: Do you have any experience with SDQuattro, or are you just thinking of potential future problems if you get one?

I don't have an SDQ, but I do have a lot of experience with cameras that use CDAF. As long as the CDAF algorithm is implemented well enough, there is nothing to "adjust" on the lens. Any lens will focus the same way. Any lens variability is inherently adjusted for by the CDAF.

CDAF comes down to having a fast enough readout on the sensor, high enough image quality (at that fast readout) and a good enough CDAF algorithm.

Laurence Matson said:

Your question is similar to trying to figure out how to get more petrol into your Tesla.

Click to expand...

That's easy. You can fit bunches of 5 gallon petrol cans in a Tesla. More in the Model X.

New business idea: Use Tesla cars to bring petrol to stranded motorists!

Imagine the two AF systems - PDAF and CDAF, as two basketball players.

- PDAF:

This is a heavy, powerful, very strong player with powerful arms, who will be very good at throwing the ball from even the opposite side of the basketball court, and will usually get the ball in the rim.

He will not be good at running around and changing directions, and will not have much control over the ball once it gets flying in the air.

Now imagine that with a specific ball (your lens), you notice that this player always hits the rim, rather than getting the ball inside. He's always a few inches short (front focusing), or a few inches too long (back focusing).

This is where AFMA will help. You will correct his throw (a bit stronger, or a bit weaker) so the ball lands inside the rim. AFMA will correct the players THROW, in the beginning, it will not be like a second player waiting by the rim to give the ball a final push to get in.

- CDAF:

A light, very fast, very nimble player who will never throw from across the court. He's so fast that he'll prefer to run with the ball, dribbling with it at every other step.

IF he makes it to the rim, he WILL get the ball in. He will not miss. Ever.

The problem is - he's very easilly distracted. AND, he has not much luck dribling the PDAF player's balls, because they are too heavy for him. So when he tries to run with them, he is not as nimble, not as fast, and very often simply drops them.

So having AFMA with the second player is useless, because he's simply never throwing the ball from far away, and thus not making the mistakes (throwing too strongly or too weakly) which AFMA can correct. If the lens is not CDAF optimized (= the ball is too heavy) - he will drop it somewhere mid-way, and no AFMA can correct that. If he manages to make it to the rim (slowly and paifully) - he'll mark anyway, and AFMA is again not needed.

This is oversimplifying, as AF algorithms are smartly made things and both systems have tricks up their sleeves, but to keep it simple - the older lenses will simply have motors which are too slow to do all the micro-corrections and movements in small steps that the CDAF will ask them to do, sometimes to the point of not being able to achieve focus properly.

GenGSP said:

I'm curious: Do you have any experience with SDQuattro, or are you just thinking of potential future problems if you get one?

I don't have an SDQ, but I do have a lot of experience with cameras that use CDAF. As long as the CDAF algorithm is implemented well enough, there is nothing to "adjust" on the lens. Any lens will focus the same way. Any lens variability is inherently adjusted for by the CDAF.

CDAF comes down to having a fast enough readout on the sensor, high enough image quality (at that fast readout) and a good enough CDAF algorithm.

Click to expand...

The issue Laurence was referring to is there is no need for AFMA in a mirrorless cameras just as there is no need for gas in an electric car. AFMA is necessary only for SLR's that use a separate autofocus sensor with a different light path that that that goes to the sensor. Hence the AFMA to compensate for the difference in light paths.

The auto focus on a mirrorless is a closed loop - the AF is taken off the sensor using the same light path that exposes the image onto the sensor. There is not need for adjustment. Fuji and Sony (and maybe others) have PDAF pixels that will perform PDAF. Sigma it seems still only uses CDAF. PDAF is faster and a bit better - especially in low contrast scenes - but both on sensor PDAF and CDAF are a closed loop and no AFMA's are requited.

That is one of the pluses for mirrorless cameras.

goblin said:

Imagine the two AF systems - PDAF and CDAF, as two basketball players.

- PDAF:

This is a heavy, powerful, very strong player with powerful arms, who will be very good at throwing the ball from even the opposite side of the basketball court, and will usually get the ball in the rim.

He will not be good at running around and changing directions, and will not have much control over the ball once it gets flying in the air.

Now imagine that with a specific ball (your lens), you notice that this player always hits the rim, rather than getting the ball inside. He's always a few inches short (front focusing), or a few inches too long (back focusing).

This is where AFMA will help. You will correct his throw (a bit stronger, or a bit weaker) so the ball lands inside the rim. AFMA will correct the players THROW, in the beginning, it will not be like a second player waiting by the rim to give the ball a final push to get in.

- CDAF:

A light, very fast, very nimble player who will never throw from across the court. He's so fast that he'll prefer to run with the ball, dribbling with it at every other step.

IF he makes it to the rim, he WILL get the ball in. He will not miss. Ever.

The problem is - he's very easilly distracted. AND, he has not much luck dribling the PDAF player's balls, because they are too heavy for him. So when he tries to run with them, he is not as nimble, not as fast, and very often simply drops them.

So having AFMA with the second player is useless, because he's simply never throwing the ball from far away, and thus not making the mistakes (throwing too strongly or too weakly) which AFMA can correct. If the lens is not CDAF optimized (= the ball is too heavy) - he will drop it somewhere mid-way, and no AFMA can correct that. If he manages to make it to the rim (slowly and paifully) - he'll mark anyway, and AFMA is again not needed.

This is oversimplifying, as AF algorithms are smartly made things and both systems have tricks up their sleeves, but to keep it simple - the older lenses will simply have motors which are too slow to do all the micro-corrections and movements in small steps that the CDAF will ask them to do, sometimes to the point of not being able to achieve focus properly.

Click to expand...

That explanation helps, in the understanding.

So, to take away from that correlation, sounds like IF there are Sigma SA mount lenses, that DON'T / WON'T / CAN'T focus correctly or consistently when used on the SD Quattro, there is really nothing to be done to remedy it?

(Sounds like to me).

Thanks for the help -

Ed

~ ~ ~

GenGSP said:

I'm curious: Do you have any experience with SDQuattro, or are you just thinking of potential future problems if you get one?

I don't have an SDQ, but I do have a lot of experience with cameras that use CDAF. As long as the CDAF algorithm is implemented well enough, there is nothing to "adjust" on the lens. Any lens will focus the same way. Any lens variability is inherently adjusted for by the CDAF.

CDAF comes down to having a fast enough readout on the sensor, high enough image quality (at that fast readout) and a good enough CDAF algorithm.

Click to expand...

Hello:

I do not have the SD Quattro, and was (have been) "contemplating" - wanting to consider getting one.

However, with the seemingly various "restrictions" and inabilities to using any of the older (possibly non-compatible) Sigma SA mount lenses, one has in their system used with the SD1M (Merrill), almost seems as not as wise an investment to get the Sigma SD Quattro vs. a Sony E-mount mirrorless with the Sigma MC-11 (SA-E) mount adapter, and have a possible maybe - MORE usable system, WITH the ability to using the older SA mount lenses.

Thanks -

Ed

~ ~ ~

ELSOK4ME said:

goblin said:

Imagine the two AF systems - PDAF and CDAF, as two basketball players.

- PDAF:

This is a heavy, powerful, very strong player with powerful arms, who will be very good at throwing the ball from even the opposite side of the basketball court, and will usually get the ball in the rim.

He will not be good at running around and changing directions, and will not have much control over the ball once it gets flying in the air.

Now imagine that with a specific ball (your lens), you notice that this player always hits the rim, rather than getting the ball inside. He's always a few inches short (front focusing), or a few inches too long (back focusing).

This is where AFMA will help. You will correct his throw (a bit stronger, or a bit weaker) so the ball lands inside the rim. AFMA will correct the players THROW, in the beginning, it will not be like a second player waiting by the rim to give the ball a final push to get in.

- CDAF:

A light, very fast, very nimble player who will never throw from across the court. He's so fast that he'll prefer to run with the ball, dribbling with it at every other step.

IF he makes it to the rim, he WILL get the ball in. He will not miss. Ever.

The problem is - he's very easilly distracted. AND, he has not much luck dribling the PDAF player's balls, because they are too heavy for him. So when he tries to run with them, he is not as nimble, not as fast, and very often simply drops them.

So having AFMA with the second player is useless, because he's simply never throwing the ball from far away, and thus not making the mistakes (throwing too strongly or too weakly) which AFMA can correct. If the lens is not CDAF optimized (= the ball is too heavy) - he will drop it somewhere mid-way, and no AFMA can correct that. If he manages to make it to the rim (slowly and paifully) - he'll mark anyway, and AFMA is again not needed.

This is oversimplifying, as AF algorithms are smartly made things and both systems have tricks up their sleeves, but to keep it simple - the older lenses will simply have motors which are too slow to do all the micro-corrections and movements in small steps that the CDAF will ask them to do, sometimes to the point of not being able to achieve focus properly.

Click to expand...

That explanation helps, in the understanding.

So, to take away from that correlation, sounds like IF there are Sigma SA mount lenses, that DON'T / WON'T / CAN'T focus correctly or consistently when used on the SD Quattro, there is really nothing to be done to remedy it?

(Sounds like to me).

Thanks for the help -

Ed

~ ~ ~

Click to expand...

The USB dock on global vision lenses can correct focus adjustment on those lenses in cases where the preprogrammed focus distances for PDAF are wrong for your specific copy of the lens, which can affect on chip PDAF. Usually this is because the focus throw isn't perfect due to mass production, not due to the seperate PDAF mirror like on SLRs, and I personally have never needed to do this (but helped someone program their lens for a front focus defect around 2 meters since I have a dock).

For OLDER lenses, you can use focus peaking, which is based on CDAF and highlights all the lines the CDAF logic can see.

ELSOK4ME said:

So, as I have still been thinking about the SD Quattro, I was reading more things about mirrorless cameras, and they "stated in most reviews / spec sheet data" - they DO NOT offer (nor need / require) the AFMA setup?

Click to expand...

The SD Quattro uses PDAF + CDAF. So from what I gather it would use PDAF to quick focus, then switch to CDAF for fine focus adjustment so the lens shuffles back/forwards to lock on focus, meaning you don't need the AF Micro Adjustment system. This also is probably why some people complain the SD Quattro is "slow" to focus, compared to a pure PDAF system with better tracking support. If you had an older lens that was struggling using CDAF with Focus Peaking is the way to go.

ELSOK4ME said:

sounds like IF there are Sigma SA mount lenses, that DON'T / WON'T / CAN'T focus correctly or consistently when used on the SD Quattro, there is really nothing to be done to remedy it?

Click to expand...

Pretty much, BUT, keep in mind that Sigma has made A LOT of lenses throughout the years, and some of them were AF snails to begin with.

Sigma has to warn you as a user, should you suddenly decide that the best lens to use on an SDQ would be a 18-50mm f:3.5-5.6 or something like that.

It sounds very unlikely to me that any HSM lens would cause you (huge) problems on an SD Quattro.

In general, I would simply try to avoid anything with an AF motor that doesn't allow you to MF on the fly by simply touching the focus ring, rather requiring you to switch the AF/MF switch to MF first. There are not that many actually good lenses that do that. The older 105mm f:2.8 Macro maybe.

In any event, the day I get an SDQ I won't put anything else but ART lenses on it. That's also the reason I never got an SD1 (and boy have I dreamed about that camera for ages).

Thank-You to you all, who have contributed (thus far) - - to this thread.

Appreciate your thoughts, comments, etc.

Have a nice day / evening -

Ed

~ ~ ~

[B]goblin wrote:[/B] [QUOTE="goblin said:

ELSOK4ME, post: 58747146, member: 687445"]
sounds like IF there are Sigma SA mount lenses, that DON'T / WON'T / CAN'T focus correctly or consistently when used on the SD Quattro, there is really nothing to be done to remedy it?

Click to expand...

Pretty much, BUT, keep in mind that Sigma has made A LOT of lenses throughout the years, and some of them were AF snails to begin with.

Sigma has to warn you as a user, should you suddenly decide that the best lens to use on an SDQ would be a 18-50mm f:3.5-5.6 or something like that.

It sounds very unlikely to me that any HSM lens would cause you (huge) problems on an SD Quattro.

In general, I would simply try to avoid anything with an AF motor that doesn't allow you to MF on the fly by simply touching the focus ring, rather requiring you to switch the AF/MF switch to MF first. There are not that many actually good lenses that do that. The older 105mm f:2.8 Macro maybe.

In any event, the day I get an SDQ I won't put anything else but ART lenses on it. That's also the reason I never got an SD1 (and boy have I dreamed about that camera for ages).
[/QUOTE]
Hello goblin:

So, If then, one uses HSM lenses, "chances" might be good to achieve reasonably (and eventually) "solid locked in focus"?

Thanks -

Ed

~ ~ ~

GenGSP said:

Laurence Matson said:

Your question is similar to trying to figure out how to get more petrol into your Tesla.

Click to expand...

That's easy. You can fit bunches of 5 gallon petrol cans in a Tesla. More in the Model X.

New business idea: Use Tesla cars to bring petrol to stranded motorists!

Click to expand...

I had not thought of that. With the price of those babies, it might be a way of getting some of the investment back. $50 per full can x 20 cans makes about 1% of the S purchase price x 100 trips and there you have it.

Laurence Matson said:

GenGSP said:

Laurence Matson said:

Your question is similar to trying to figure out how to get more petrol into your Tesla.

Click to expand...

That's easy. You can fit bunches of 5 gallon petrol cans in a Tesla. More in the Model X.

New business idea: Use Tesla cars to bring petrol to stranded motorists!

Click to expand...

I had not thought of that. With the price of those babies, it might be a way of getting some of the investment back. $50 per full can x 20 cans makes about 1% of the S purchase price x 100 trips and there you have it.

Click to expand...

You two twits should go into business together.

PCummins said:

ELSOK4ME said:

So, as I have still been thinking about the SD Quattro, I was reading more things about mirrorless cameras, and they "stated in most reviews / spec sheet data" - they DO NOT offer (nor need / require) the AFMA setup?

Click to expand...

The SD Quattro uses PDAF + CDAF. So from what I gather it would use PDAF to quick focus, then switch to CDAF for fine focus adjustment so the lens shuffles back/forwards to lock on focus, meaning you don't need the AF Micro Adjustment system. This also is probably why some people complain the SD Quattro is "slow" to focus, compared to a pure PDAF system with better tracking support. If you had an older lens that was struggling using CDAF with Focus Peaking is the way to go.

Click to expand...

You seem to be the first one to mention that Sigma states their focus is PDAF+CDAF, unless I missed something. This is a true statement. Thanks for stating it.

We don't have any choice whether the camera uses just CDAF, or just PDAF. We have no control of the autofocus process at all. Wouldn't it be nice to have this choice? I think it would.

I have found focus peaking in my sd Quattro to be somewhat misleading. Others can and will disagree. I've turned it off in my sd Quattro and now if I want clarity I manually focus using the 4x or 8x magnifier in the EVF. That is, IF I am using a global vision lens. If I am not using a global vision lens, I have to take what I see with a grain of salt and hope for the best. Yes this seems to make no sense. If I am using a fully manual lens, and I focus at the shooting aperture, what I see is really what I get. I like this very much. Maybe one day Sigma will make a fully manual modern lens in SA mount.

I think optics gets in the way of theory here, so when people say that AFMA is not necessary they are forgetting about optics. The sd Quattro focuses with the lens wide open and I have had my best luck with older lenses if I put the camera in aperture priority mode and autofocus and shoot at or near the maximum aperture. This is because I can't set the lens to the shooting aperture and then focus.

In my opinion AFMA is a feature that should be in the sd Quattro. It would give users a stopgap small adjustment capability that could make the difference between almost OK autofocus and perfect autofocus (in the same specific circumstances that we get the benefit from AFMA in the SD1 of course). And, this benefit would apply to any lens we might be using. At the moment, the only way to get this is to use a global vision lens and tweak the focus performance offline using the USB dock.

I think it would be a mistake to buy any sort of lens that is not "global vision" if you have any thoughts about buying a sd Quattro.

We haven't seen the sd H, and maybe it will have nice stuff such as "focus at the shooting aperture", CDAF/PDAF control optioning, and even AFMA. We can always hope.

--
Tom Schum
Every day a new image.

SigmaChrome said:

Laurence Matson said:

GenGSP said:

Laurence Matson said:

Your question is similar to trying to figure out how to get more petrol into your Tesla.

Click to expand...

That's easy. You can fit bunches of 5 gallon petrol cans in a Tesla. More in the Model X.

New business idea: Use Tesla cars to bring petrol to stranded motorists!

Click to expand...

I had not thought of that. With the price of those babies, it might be a way of getting some of the investment back. $50 per full can x 20 cans makes about 1% of the S purchase price x 100 trips and there you have it.

Click to expand...

You two twits should go into business together.

Click to expand...

I am just trying to figure out how. I guess I can check with the 6 font of knowledge, our very own The Donald.

Laurence Matson said:

SigmaChrome said:

Laurence Matson said:

GenGSP said:

Laurence Matson said:

Your question is similar to trying to figure out how to get more petrol into your Tesla.

Click to expand...

That's easy. You can fit bunches of 5 gallon petrol cans in a Tesla. More in the Model X.

New business idea: Use Tesla cars to bring petrol to stranded motorists!

Click to expand...

I had not thought of that. With the price of those babies, it might be a way of getting some of the investment back. $50 per full can x 20 cans makes about 1% of the S purchase price x 100 trips and there you have it.

Click to expand...

You two twits should go into business together.

Click to expand...

I am just trying to figure out how. I guess I can check with the 6 font of knowledge, our very own The Donald.

Click to expand...

Yep. Take a holiday and call him up from Taiwan. He'll Love It!