July 22, 2014, 10:28:16 AM

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Messages - docsmith

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16
Try tracking kids with contrast detect  ;D

:)  Faster AF with phase detect is something I couldn't live without.  I only use contrast detect for landscapes.  They move slow enough, typically.   ;)

I was just wondering how severe the problem may be, and if AFMA adjustments were just putting a band-aid on a more severe wound. 

I picked up a 35A in March and have the 50A pre-ordered.  I initially had AF issues with the 35A in that I felt my keeper rate was much lower than my other lenses.  But I also noticed that the AF wasn't quiet.  There was a clicking sound.  I re-AFMA'd the lens, and the clicking sound went away (I think these are separate events).  The AF is now both quiet (no clicking) and accurate at short distances.  I have noticed that it is off at longer distances and have ordered the dock so I can AFMA multiple distances.

While the 35A is working well, that doesn't inspire confidence.  Especially when combined with everything I am reading.

Everyone talks about the price different with the Sigma lenses, but that is just upfront costs.  The savings will quickly disappear if the life cycle of the Sigma lens is half the Canon.  Plus, one of the benefits of Canon's L lenses is how well they hold their value.  If Sigma's aren't built as well and don't hold their value as well, then the true cost difference could quickly become negligible or even favor Canon.

All that said, I am past the point where I can return the 35A so I'll play with it some more.  If I don't cancel my 50A order, I am planning on scrutinizing that lens a lot more before the return period ends.

17
Are the issues both with phase and contrast detect AF? 

18
Shane...great shots.

But am I hearing this right, both Eldar and Viggo are sending their lenses to Sigma to fix the AF?  Anyone else having issues?  I know TDP and lenstip identified some issues. 

Anyone not having AF issues?

19
BTW here are some shots from yesterday, of my son and his mother running towards me… Shot at f1.4 using a 6D, center focus point.

The first shot is back focused, and only the last one is okay sharp to me at least. So it seems the tracking can't keep up.  I've got a few from indoors today that are really sharp, so I guess going back and forth with calibration is always a good thing.

The thing about the Sigma is that it is soo sharp that even slightly misfocused shots appear sharp enough.

How can you tell that it is back focused?  I can't see where his focus point was.  Is it in the exif data?  Sorry if this is obvious.

First of all, it is a great series of shots that any father should be very happy with......

But to expand on what Viggo said, look at the blur on the wife over the three shots.  First shot she is almost in focus.  Granted it looks like the separation between the two increased, but part of that is back focusing on the first shot.  And I agree, looking at the sand, it is sharpest behind the subject.

20
Again...thanks for the posts.  Very interesting and helpful.  I agree, the differences in this set range from very minor to imperceptible.  I can see a few instances were I like the bokeh better with the 50L, but others where I like the sharpness and detail of 50A.  But, for the most part, the images are extremely similar.  With Viggo coming around to trusting the AF..... :D

21
I would also point out that I have personally taken similar tests, and when I express that I believe I can tell a difference (knowing that sometimes there isn't one) I have got it right, normally to the chagrin or complete unacceptance of the poster.

I believe people spend too much time reading forum opinions, tests, reviews etc, and their buying decisions are influenced by that reading. I believe people are sold something on subtleties and nuances that they themselves can't actually see or appreciate and to "justify" that purchase, when no justification is needed, they will make silly claims about minutia.

I've taken a few of the online tests.  I am usually right ~70% of the time, so there is a little something to it, but, ultimately, sometimes I can't tell the difference.

On your second point, I absolutely have seen some people spend too much time reading and basing too much of their opinion in details only analytical tests are able to discern.  I am sure I've done it myself.  That said, I think we are in the phase where we are getting to know not only the 50A but the Sigma Art series.  Sigma did something very interesting.  But it will be over the next year or two where there is enough use out there to really know what that means.  Are there AF issues?  Does the dock fix the AF issues?  Do Sigma Art lenses develop issues with time?  Does Sigma Art have a "unique" color to them? Etc.

Just because there is the potential for over analysis doesn't mean you do not do any analysis.  Which is why I really appreciate a side by side comparison performed here at the start of this thread. 

22
EDIT-originally followed Mackguyver's post.

I think that is a very fair assessment.  Of course, I own the 50 f/1.4, so for me the list is a little different, but this thread is about the 50L vs 50A.  Of course, I would expect to learn a lot more as the 50A as more people get their hands on production models.

I also think there is a lot of benefit in things that may be subtle to others.  For example, the dock is likely necessary from the start.  I had told myself I didn't need the dock until Canon did something to prevent the Sigma lens from working.  Having read more, it looks like it would be good to have the dock from the start to better tune the AFMA at different distances.

I do "get" the concern that reaction in threads like this can give lenses a bad reputation, potentially undeserved.  With the 50A, potentially with AF issues or maybe color.  But, to me, it is more subtle.  As for the color, I see a difference.  I may prefer the 50L, but what it really means is that I'll develop a color profile for the 50A to see if that addresses the issue.  But it doesn't change the fact that everything I've seen to date says that this is a very good lens. 

The AF issue is the main one I am interested in seeing if it proves out.  But, hopefully I'll have my own lens soon to assess.


23
Yup, that was kind of my point--people will see what they want to see.

I know, I was agreeing.

Nice cartoon too  :)

So, do we have confirmatory bias about the lenses....or do you have confirmatory bias about people trying to assess a lens?   :o ;D

I can tell you for myself, I am interested in the 50A (have it on preorder) and am just trying to learn as much about it as I can.


24
Thanks for all the shots.  I've probably scrolled through them a dozen times. 

I think center sharpness is very similar, however, there are a couple of shots were I think the 50A clearly wins the off center sharpness.  I am actually very happy with my 50 f/1.4 except for off center sharpness.  I like to use 50 mm to frame my subjects off center, so this has been a problem at wider than f/2.8.  It is for this reason I have preordered the 50A (still waiting).

However, I give consistent natural colors to the 50L.  As drjlo noted, some reds and yellows in the 50A look unnatural/more saturated/cartoonish to me.  Are others seeing this?

25
Count me in the crowd that is simply happy that Sigma is providing a quality alternative.  I never thought I'd own a Sigma lens but recently bought the 35A.  I am one of the people that feels the AF is a bit off, but there is no doubting its optics and I am still getting to know it as a lens and do like it.  Primes are niche lenses for me, but I would likely buy the 24A in a heartbeat if it's optics check out, especially corner sharpness and coma.  As a consumer, it is very nice to have quality alternatives. 

While I would love to see additional lens released from Canon and, frankly, find it a bit puzzling what they have and haven't released in 2013 and so far in 2014, I can't bring myself to criticize a company, to the extent some here have, that has produced a wide array of lenses that have been used to produced some of the world's best photographs for decades.  And by wide array, I just counted the following off of Canon USA's website:

51 EF lenses
12 EF-S lenses
2 EF-M lenses (3 if you count the EF-M 11-22)
4 TS-E lenses
2 TC extenders
1 MPE lens

So, Sigma has now released 3-4 "Art" lenses that compete well against specific Canon lenses.  It's nice for us consumers to have alternatives, I am sure Canon is aware of what Sigma has done, but I seriously doubt it represents much of an impact to Canon's thinking even in regards to their lens lineup, much less their overall corporate strategy. 

26
Lenses / Re: Have to make a choice, finally!
« on: April 25, 2014, 04:50:28 PM »
I would also vote "A"

I am not sure what you mean by 17-40 for "long exposures."  Of course, all lenses could be used for long exposures.  I would get the 17-40 for ultra wide angle landscapes.  If you are thinking starscapes, you might want to consider the Rokinon/Samyang 14 mm f/2.8 UMC for an ultrawide angle option.  While I have never owned the 17-40, I have definitely seen some great images and the charts are good from f/5.6-f/11, which is perfect for normal landscapes.

But for long exposures, of say waterfalls, you'll be using the 24-70 II a lot of that.  Just remember to also buy some good filters.  Lots of people talk about the 10 stop filters (Lee Big Stopper, etc).  My favorite ND filter is the B+W 6 Stop ND filter.  But I also have the B+W 10 Stop ND filter.  TDP just did a comparison of 10 Stop ND filters.  Singh Ray came out on top.

I started with the 50 f/1.8.  I found it to be nicely sharp starting at ~f/2.8.  I upgraded to the 50 f/1.4 about 2 years ago.  I find it to be sufficiently sharp, at least in the center, starting at f/2.  I am now planning on evaluating the Sigma 50 f/1.4 Art.  It may be worth the money to me to be sharp at f/1.4.  That said, I have heard a number of people state, upon buying the 24-70 II, that they no longer used their 50 f/1.4.  So, I might buy the 24-70II first and wait to see if you need the 50 f/1.4. 

Good luck

27
Lenses / Re: Review: Sigma 50mm f/1.4 DG HSM Art Lens
« on: April 25, 2014, 04:05:01 PM »
Which still has worth

....and stop......that is all.  There is value to the observations, it is something for us to consider and evaluate.   Each person will value those observations differently.  No lens is perfect.  The Sigma has been getting rave reviews optically, but now we have two trusted testing sites that have observed AF issues, of single copies, of preproduction lenses.  That is all.  BOTH sites still recommended the lens. 

Bryan/TDP even concluded:

"While I will dock a few points from this lens for occasional AF inconsistency, the Sigma 50mm f/1.4 DG HSM Art Lens is now the overwhelming favorite in the 50mm field. This lens delivers excellent image quality, has a beautiful design and for what you get, a very attractive price. The Sigma 50mm f/1.4 DG HSM Art Lens is the easy 50mm choice for those with a moderate budget."

Lenstip:
"....-Those arguments are so strong that we didn’t have any qualms about giving the Sigma our “Editors Choice Award” badge, even though it had a slight coma slip-up during our test and its autofocus performance on the EOS 1 Ds MkIII was patchy."

Even the groups pointing out the potential flaws are still calling this the "overwhelming favorite in the 50 mm field" and have no qualms about giving it the "Editors Choice Award" badge. 


28
Canon General / Re: $10,000
« on: April 25, 2014, 06:18:37 AM »
And this gets back to "what are you going to shoot" but I haven't seen too many filters on the list.  Say a couple of CPLs, ND, grad ND filters?

I would go 5DIII (~$3000) if you need the AF points (action shots/personal preference), 6D (~$1,800) if you are primarily a causal or landscape shooter. 

I'd go 24-105 (~$600) if you shoot mostly landscape and well lit scenes, or 24-70 II (~$2,100) if you shoot in lower light more often/prefer natural light photograph/tend to obsess about having the "best."  If you are mostly well lit/outdoor scenes with the occasional natural indoor light photography, the 24-105 plus a prime or two (see below) should be a good combo.

I'd go 70-200 f/2.8 II ($2,100) if you shoot indoors or the 70-200 f/4 IS (~$1,200) if primarily outdoors.

Think about adding a 1.4xTC/2x TC ($500 each).

If you shoot birds/wildlife I would be adding the 100-400L ($1,600), 400 f/5.6 ($1,200), or the recent Tamron 150-600 (($1,069).

A nice set of reasonably fast primes are always good, Rokinon/Samyang 14 f/2.8 UMC is a good lens to give you an ultrawide/nightscape option for $300.  But ultrawide is a beast of its own.  To stay on a budget I'd likely go Sigma 50 f/1.4 Art ($950; to be released, but initial reviews are good with a potential AF consistency issue) or Canon 50 f/1.4 ($300) to start.  Then figure out which scenarios you need primes and add from there.  The EF 100 mm f/2.8 IS L Macro is great ($900).

Then at least one flash, the Canon 600 EX RT ($450).

Then I'd save at least $1,500 for gear you identify down the road, $500 for accessories such as a good pack/bag (Lowepro Flipside 400 AW is a good choice, ~$70 off ebay), $800 for filters (clear/UV to protect your front elements, CPL and then ND filters as needed), and $300-$600 for a mid-range carbon fiber tripod and ballhead.  You may want to consider a smaller camera for when you don't want to carry this around, but I am going to assume you already have that.

Overall, I think people would gravitate toward calling the 5DIII, 24-70 f/2.8 II, 70-200 f/2.8 II, 2xTC, 600 EX RT, with B+W 77 mm and 82 mm CPL/007 filters as the "ultimate" basic kit, supplemented with a few primes, as needed.  That is ~$8,500 without any primes, tripods, backpacks, macro lenses, "super tele" etc.  But, a heckuva place to start, and perhaps finish.

So, it depends on what you want to shoot, but you can spend $10,000 remarkably fast.  I am on a multi year plan.  Each year I spend ~$2k adding to my kit.  That will change as soon as I add a big white. 

Good luck.

Edit:
Oops, my bad...I just realized this was a hypothetical and not an actual question....but what I would do is what I have done and is pretty closely outlined above.

29
How quickly "new" Sigma's reputation went downhill.  The 35A was hailed a great lens and now a lot of forum members seem to be bashing the 50A before they get their hands on a copy.  And now some are already saying that this will have poor autofocus performance.


That's mob mentality for you.


Is there a problem with people discussing a potential flaw?  I think Roger has already summarized what we are seeing....just with the prerelease copies hitting reviewers it may be happening a bit ahead of schedule.

 http://www.lensrentals.com/blog/2013/12/a-bit-of-a7r-sanity

BTW...if the 24A is optically similar to the 50A and 35A from f/1.4 to f/2.8 with reasonable coma, I'll buy one in a heartbeat.

30
Yup. Too bad it won't auto focus good enough to hit the broad side of a galaxy ;D

Must wait for the 85...

When I read back over TDP's review of the S50A and I think to myself on how to obtain the best focus using a tripod, using the AF from the camera with phase detect focusing is not how I'd do it.

With Canon lenses mounted on a Canon camera, I've watched it focus on something and lock, then I press the focus button again, it de-focuses and refocuses again. Why can't it just "know" that it has acquired focus and not move the second time?

Likely, the camera needs more than one data point to optimize/determine focus.  With Phase detect, it could be that OoF is used to define what is in focus.

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