p.15 #2 · Sony 85mm f/1.4 GM II Announced—Pre-Orders Now Open!
I was thinking the lens design determined the motor count. They always come in pairs. My understanding is the 4 motor lenses moved 2 groups for focus. The size of the motors can vary depending on the size of the elements. I seemed clear the design goals involved good 120Hz focus ability and they will do what is needed to get this.
Focus speed and accuracy is just another design objective, I don’t care much how many motors are used.
p.15 #5 · Sony 85mm f/1.4 GM II Announced—Pre-Orders Now Open!
Dj R wrote:
did you purchase one?
Not yet.
For me the decision comes down to AF alone (as I don't think I will be able to tell the difference in rendering vs DN):
if it behaves like a (until now) 4-motor, then I will be tempted to sell my Sigma...
Sep 20, 2024 at 03:59 PM
Steve Spencer Offline • • • • • • • Upload & Sell: On
p.15 #6 · Sony 85mm f/1.4 GM II Announced—Pre-Orders Now Open!
KarmaKramer wrote:
Maybe join a debate forum instead.
When people make simple basic statistical mistakes, I will point it out. Drawing inferences claiming they are from data when the data does not support those inferences is one of my pet peeves so you will see me comment on that from time to time. Some may find that useful. Some may not. If you don't like it, then feel free to use the hide me button.
p.15 #7 · Sony 85mm f/1.4 GM II Announced—Pre-Orders Now Open!
Steve Spencer wrote:
When people make simple basic statistical mistakes, I will point it out. Drawing inferences claiming they are from data when the data does not support those inferences is one of my pet peeves so you will see me comment on that from time to time. Some may find that useful. Some may not. If you don't like it, then feel free to use the hide me button.
For the sake of this thread, can you stop please?
Let's just agree to disagree .
I only said "simple basic statistics" does not apply so easily here, because the samples are not independent.
Do you want me to get my stats book off the shelf ?
Maybe for you "simple basic statistics" means something other than for me. The same way you're happy with your hit rate with MF lenses (and 85DN) and I'm not happy with AF hit rate of what 50/1.4GM (and 85DN) present in demanding action.
It's not a "simple basic statistical mistake" on my part but what I infer from the past 5 years of Sony lens releases. Can I be wrong? Sure, but that's how the trend looks to me for now and I hope I'm allowed to say what I think here.
From my perspective, you see the trees, I see the forest.
p.15 #8 · Sony 85mm f/1.4 GM II Announced—Pre-Orders Now Open!
It seems pretty clear what you gain with the II, but it is less clear what you lose. Is this I one of those lenses with such a magical rendering its shortcomings, including weight can be overlooked? That is the question (from someone who sold a Noct Nikkor for next to nothing before they became fashionable).
p.15 #9 · Sony 85mm f/1.4 GM II Announced—Pre-Orders Now Open!
My only issue with the DN is focus speed and that is pretty minor. I find the 85DN too slow for sports. Other than that it is fine. I have the 135GM and 50/1.2 GM that I use for sports. So I think I’m OK with skipping the 85GM. The price difference would be better applied to a 70-200 GM II for me.
j4nu wrote:
Not yet.
For me the decision comes down to AF alone (as I don't think I will be able to tell the difference in rendering vs DN):
if it behaves like a (until now) 4-motor, then I will be tempted to sell my Sigma...
p.15 #10 · Sony 85mm f/1.4 GM II Announced—Pre-Orders Now Open!
Patrick Murphy-Racey’s thoughts on the 85MM GM II. No sports, but he shoots a few dancers, and has a bunch of portraits with some good examples of subject/background separation and bokeh.
Sep 20, 2024 at 11:22 PM
Steve Spencer Offline • • • • • • • Upload & Sell: On
p.15 #11 · Sony 85mm f/1.4 GM II Announced—Pre-Orders Now Open!
j4nu wrote:
For the sake of this thread, can you stop please?
Let's just agree to disagree .
I only said "simple basic statistics" does not apply so easily here, because the samples are not independent.
Do you want me to get my stats book off the shelf ?
Maybe for you "simple basic statistics" means something other than for me. The same way you're happy with your hit rate with MF lenses (and 85DN) and I'm not happy with AF hit rate of what 50/1.4GM (and 85DN) present in demanding action.
It's not a "simple basic statistical mistake" on my part but what I infer from the past 5 years of Sony lens releases. Can I be wrong? Sure, but that's how the trend looks to me for now and I hope I'm allowed to say what I think here.
From my perspective, you see the trees, I see the forest....Show more →
I am happy to agree to disagree about the Sigma 85 DG DN. I am happy to agree to disagree about whether shooting kids playing on a playground is really demanding action shooting or not, and you can certainly say whatever you think about any Sony equipment. When you say that you think that this new 85 GM II is going to have suspect AF because it only has 2 XD AF motors, however, I am going to point out I don't think that is a reasonable inference because it is based on thinking about too few GM lenses and it is part of your general pattern in this thread of making inferences about this new lens with very little information. I think you are coming to strong conclusions when it is simply way too early. You are making claims that are based on the flimsiest of evidence.
You have the right to make those claims and I have the right to say I think they are highly suspect. I also have the right to point out the basic mathematical mistakes you make like thinking 5 or 6 lenses is enough to make any inference about characteristics those lenses posses or do not possess and AF performance--that simply is not enough lenses to make a reasonable inference, and I have the right to point out when you dig the hole deeper with that mistake by claiming that non-independence of the samples means you can't apply basic statistics which is simply categorically wrong. You should get out that statistics book and actually learn the concepts because independence of samples although needed for some basic statistical tests is not needed for all of them and definitely is not needed for the relevant tests here. By responding as you did, doubling down by claiming that statistics don't apply, you demonstrated how you clearly didn't understand the basic statistic involved and when you make egregious mistakes like that I am going to point them out.
Oh, and from my perspective you are not seeing the forest for the trees. The forest is that it is very early in what we know about this lens and that we need to be patient and see how the lens performs over time before we can draw good inferences about its performance.
Sep 21, 2024 at 07:41 AM
Steve Spencer Offline • • • • • • • Upload & Sell: On
p.15 #12 · Sony 85mm f/1.4 GM II Announced—Pre-Orders Now Open!
j4nu wrote:
Yes, let's wait for the outlier to prove itself in the hands of actual users ...
Let's wait to get the lens in a lot more hands and with a lot more test before we jump to conclusions about its performance and let's wait to call something an outlier until there are enough lenses to actually have a distribution of lenses.
p.15 #13 · Sony 85mm f/1.4 GM II Announced—Pre-Orders Now Open!
Honestly I think you are all over thinking this. Its going to be faster AF be more modern in weight and size and bottom line like all GM Version II be sharper on center that to me is obvious but you may loose a touch of character as it is more modern on the sharpness side on center. Bokeh balls will change slightly as well. I think the bigger question is the Sigma but a lot of folks are not even thinking about the 70-200 Version II as an option. I know it's slower and even more expensive but you gain more focal length and still come up with as sharp a lens. You loose that 1.4 option but I bet if you counted those 1.4 shots that number maybe not as high as you think. As a Working Pro im scared to death of shooting a gig at 1.4 as it is a focusing missing risk to take. For me maybe not such a big issue given my experience at shooting but for a hobbyist that may not have the shooting experience maybe even the zoom maybe a better option. These are things to consider a 85 1.4 is a great lens but you better have some mileage shooting it. Frankly if you're on the fence rent the dang thing for a week and see how you get along with it.
Another lens tester observation and you're not going to like this one. You're not going to find the best performing mechanical operating lens than Sony on a Sony body. I never found a Sigma/Tamron or anyone else perform better than a Sony. Im not talking optical performance but th function of the lens itself. I always found a glitch on 3rd party operations on our bodies. Not saying don't buy them but understand they are reverse engineering them.
And bottom line get your nose away from the costs as that says nothing about the performance of the lens. Thats a secondary issue that once you make that decision is something to deal with. I constantly hear this is cheaper and that's the decision. Find the lens first than deal with the costs. I also agree with the wait for it, I trust almost no one when it comes to lens testing and you really need to pay attention on who the hell is talking on these reviews. Be careful be smart and try them yourself
p.15 #14 · Sony 85mm f/1.4 GM II Announced—Pre-Orders Now Open!
Steve Spencer wrote:
I am happy to agree to disagree about the Sigma 85 DG DN. I am happy to agree to disagree about whether shooting kids playing on a playground is really demanding action shooting or not, and you can certainly say whatever you think about any Sony equipment. When you say that you think that this new 85 GM II is going to have suspect AF because it only has 2 XD AF motors, however, I am going to point out I don't think that is a reasonable inference because it is based on thinking about too few GM lenses and it is part of your general pattern in this thread of making inferences about this new lens with very little information. I think you are coming to strong conclusions when it is simply way too early. You are making claims that are based on the flimsiest of evidence.
You have the right to make those claims and I have the right to say I think they are highly suspect. I also have the right to point out the basic mathematical mistakes you make like thinking 5 or 6 lenses is enough to make any inference about characteristics those lenses posses or do not possess and AF performance--that simply is not enough lenses to make a reasonable inference, and I have the right to point out when you dig the hole deeper with that mistake by claiming that non-independence of the samples means you can't apply basic statistics which is simply categorically wrong. You should get out that statistics book and actually learn the concepts because independence of samples although needed for some basic statistical tests is not needed for all of them and definitely is not needed for the relevant tests here. By responding as you did, doubling down by claiming that statistics don't apply, you demonstrated how you clearly didn't understand the basic statistic involved and when you make egregious mistakes like that I am going to point them out.
Oh, and from my perspective you are not seeing the forest for the trees. The forest is that it is very early in what we know about this lens and that we need to be patient and see how the lens performs over time before we can draw good inferences about its performance....Show more →
I don't know how I could have had made any math mistakes as I did not to any math...
I also said that, as you called it, "simple basic statistics" is not so simple in this case because they are relations between those lenses.
If it's so simple, please tell me, how do you test your stats model against different design priorities (e.g. size/weight, which constrains AF that can be applied in the design) ? And that over a sample of 5 lenses, which as you repeatedly said yourself, is a small number? How long do you want to wait to collect samples to be able to state anything meaningful, until Sony starts releasing GM IIIs ?
So, maybe instead of taking pleasure in mocking me and saying that I'm wrong, you could show others why you're right?
As of now, the only thing you've shown is your inability to accept different opinions, which you didn't really have to do now, as that was already obvious from your post history.
So, to get back to the point, yes - if 85/1.4 GM II turns out to have the best focus out of the 5 second gen GMs you yourself listed, it will be an outlier, based on your list.
p.15 #15 · Sony 85mm f/1.4 GM II Announced—Pre-Orders Now Open!
Ok guys. Sure, it’s a discussion based forum, but this is no longer fun.
The lenses will arrive this week. Let’s shoot and circle back for happy hour.
Cheers
Sep 21, 2024 at 01:16 PM
Steve Spencer Offline • • • • • • • Upload & Sell: On
p.15 #16 · Sony 85mm f/1.4 GM II Announced—Pre-Orders Now Open!
j4nu wrote:
I don't know how I could have had made any math mistakes as I did not to any math...
I also said that, as you called it, "simple basic statistics" is not so simple in this case because they are relations between those lenses.
If it's so simple, please tell me, how do you test your stats model against different design priorities (e.g. size/weight, which constrains AF that can be applied in the design) ? And that over a sample of 5 lenses, which as you repeatedly said yourself, is a small number? How long do you want to wait to collect samples to be able to state anything meaningful, until Sony starts releasing GM IIIs ?
So, maybe instead of taking pleasure in mocking me and saying that I'm wrong, you could show others why you're right?
As of now, the only thing you've shown is your inability to accept different opinions, which you didn't really have to do now, as that was already obvious from your post history.
So, to get back to the point, yes - if 85/1.4 GM II turns out to have the best focus out of the 5 second gen GMs you yourself listed, it will be an outlier, based on your list. ...Show more →
The whole point I am making is that I don't know and I don't think any of us can know whether 2 XD AF motors lead to substandard AF whereas 4 XD motors are sufficient for great AF. Maybe someone who is a lens designer can make that sort of statement, but not us photographers.
I think you can draw inferences when you can look at lots of lenses too. For example, I think lenses with floating element design perform better for close up performance than lenses without floating element designs as a general pattern (there are notable exceptions) but across 100s of lenses you can see that pattern.
I think you can also say that lenses with Sony's XD motors focus faster than lenses with older SSD motors (like the 85 GM I) and again we can make that comparison by examining dozens if not hundreds of lenses.
You see both those inferences are based are comparing a large number of lenses and that is sensible. Trying to make inferences from just a half a dozen GM lenses isn't sensible and yes, statistics can demonstrate that but it is something that many people can appreciate without statistics.
So, I do like lenses with floating element designs as I think that improves close focus performance and I do like lenses with APD or ED elements as I think there is evidence across a large number of lenses that they reduce chromatic aberrations. I also shoot a lens and across a large number of shots with the lens see whether I like the shots with the lens. So, I look to some basic indicators of good performance that show up across a dozens of lenses and I use the lens and see if I like its performance across a large number of shots and shooting situations. It is that simple. I don't make inference (or at least I try not to do so) from a small number of lenses or from a small number of shots. This isn't a statistic model. This is simply recognizing that making good decisions requires evaluations of a fairly large number of instances and not a small number. That is all I am saying. Do I really need to prove that is right?
And please refrain from talking about what I take pleasure in. You obviously do not know that and it is rude. I also did not mock you. I just pointed out how your reasoning about this lens was not reasonable.
And I do accept other opinions and did in our interaction. I agreed to disagree about the Sigma 85 DG DN and I agreed to disagree about whether shooting kids in a playground is challenging AF. Those are matters of opinion. What I won't agreed to disagree on is whether it is reasonable to make inferences from a small number of instances. It simply is not and I won't agree to disagree on that matter any more than I will agree to disagree about what 2 + 2 =
p.15 #17 · Sony 85mm f/1.4 GM II Announced—Pre-Orders Now Open!
Steve Spencer wrote:
What I won't agreed to disagree on is whether it is reasonable to make inferences from a small number of instances. It simply is not and I won't agree to disagree on that matter any more than I will agree to disagree about what 2 + 2 =
I admit I haven't read your full response, but this quote is enough.
Your "2+2=" is saying that fast rapid close movement with thin DoF towards the camera is not a strenous AF test.
We can't discuss anything because you have a different understanding of words and facts.
So, yes it's like 2+2=whatever you want.
I'll take Keanu's approach to this, but at the same time I'll be waiting impatiently for your stats model.
Until then, maybe I'll get a chance to test the "outlier"...
Edit: Just read read the paragraph about "rude", that's rich coming from you .
Edit#2: Ok, read some more. I think the first paragraph hits the nail on the head: Steve Spencer wrote:
The whole point I am making is that I don't know and I don't think any of us can know whether 2 XD AF motors lead to substandard AF whereas 4 XD motors are sufficient for great AF.
You seem to be arguing with yourself, not with me, as I never said that 2 XD AF motors lead to substandard AF (vide 300GM).
I only said that given Sony's history of GM 2nd gen lenses, i.e. the list you provided, 4 AF motors tend to deliver better AF performance.
Where we don't agree is whether I can (obviously I can, as in I can be wrong) make this inference from such limited (5 years of Sony GM prime lens releases...) data.
Let's keep it that way.
Edit#3: Since you're a fan of direct communication, I have to wonder, how come you didn't notice how ridiculous posting MF pictures, none of which was 85/1.4, when discussing AF performance of 85/1.4 lenses, was?
Is it because it's as ridiculous as your (still missing) answer to the question on how long you are going to wait to collect enough samples from Sony to make any inference as to whether 2 vs 4 AF motors difference is significant to AF performance?
Sep 21, 2024 at 01:40 PM
Steve Spencer Offline • • • • • • • Upload & Sell: On
p.15 #18 · Sony 85mm f/1.4 GM II Announced—Pre-Orders Now Open!
j4nu wrote:
I admit I haven't read your full response, but this quote is enough.
Your "2+2=" is saying that fast rapid close movement with thin DoF towards the camera is not a strenous AF test.
We can't discuss anything because you have a different understanding of words and facts.
So, yes it's like 2+2=whatever you want.
I'll take Keanu's approach to this, but at the same time I'll be waiting impatiently for your stats model.
Until then, maybe I'll get a chance to test the "outlier"...
Edit: Just read read the paragraph about "rude", that's rich coming from you .
Edit#2: Ok, read some more. I think the first paragraph hits the nail on the head:
You seem to be arguing with yourself, not with me, as I never said that 2 XD AF motors lead to substandard AF (vide 300GM).
I only said that given Sony's history of GM 2nd gen lenses, i.e. the list you provided, 4 AF motors tend to deliver better AF performance.
Where we don't agree is whether I can (obviously I can, as in I can be wrong) make this inference from such limited (5 years of Sony GM prime lens releases...) data.
Let's keep it that way.
Edit#3: Since you're a fan of direct communication, I have to wonder, how come you didn't notice how ridiculous posting MF pictures, none of which was 85/1.4, when discussing AF performance of 85/1.4 lenses, was?
Is it because it's as ridiculous as your (still missing) answer to the question on how long you are going to wait to collect enough samples from Sony to make any inference as to whether 2 vs 4 AF motors difference is significant to AF performance? ...Show more →
I will try to keep my responses brief, but you keep coming back and adding more and then complain I am not addressing everything. So here goes:
What I am saying with 2 + 2 = is not anything about AF. I have no clue where you got that impression. What I am saying as you quoted is that making inferences from a small number of instances is not reasonable. That's it.
Edit #1: Don't make claims about other people's intentions on this forum. It isn't cool and it is against the forum rules.
Edit #2: I am glad we agree that you can't say anything about AF of Sony GM lenses based on the # of AF motors at this point.
Edit #3: Don't ask questions with disputed premises. The classic is, "have you stopped beating your wife?" which includes the premise that the person being asked the question is an abuser. Your questions have the same sort of disputed premises. I don't think my posting of MF picture is this thread was ridiculous, so asking if I noticed they were ridiculous is a poor question with a disputed question. I won't answer it. I posted those pictures to demonstrate that donblox's shooting of kids at a playground might not be a challenging AF situation. I stand by that point. As to when I will make an inference about whether 2 vs 4 AF motors matter for AF, I will do that when there are dozens of lens that have 2 and 4 AF motors. It simply takes that many instances of any characteristic before you have enough evidence to evaluate it.
And finally yes you can claim whatever you want based on whatever limited data you want. People do that all the time. People claim the world is flat. People claim vaccines cause autism. People claim Haitian immigrants in Springfield, OH are eating people's pets. All of those claims are based on very limited instances of events. So you can claim whatever you want about Sony lenses, but my point is not that you can't make such claims, but rather if you make such claims based on a very limited number of instances it isn't reasonable to do so and I stand by that claim.
...
? 
