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04-01-2011, 10:33 AM   #16
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QuoteOriginally posted by kenyee Quote
p.s., on your focus tests, be aware that Pentax's focus points are a *lot* larger than the little red indicators in the display, unlike Canikon systems. They also might be a little off center from the red dots on the display too. Won't matter as much w/ wide DOF, but w/ the 85/1.4's narrow DOF wide open, it may make a difference...
I totally agree with you Kenyee. Right on my K7, see it locks on to the most contrasty thing that is in the vicinity of the "point" being used. But I'm careful when I'm doing the test, making sure the sensor is not able to "see" the other prints on the test chart.

QuoteOriginally posted by Class A Quote
B&H claim they don't send "open box" items to customers. According to their public statements they should have sold your copy as an "open box" item with a discount. If you decide to keep your copy, at least ask them for a discount. You paid full price for a brand new copy and don't need to accept a product someone else already marked or even dropped.
I have never received a camera body/lens/accessory that is in a "sealed" box. They always come unsealed. Any store, online or direct from the store. Though, only once I heard a B&H manager flaunt about not being able to give me a lens to test at their store because they will have to open the box, it made me wonder what difference it makes because the box is not sealed anyway. Let me study my copy more.

QuoteOriginally posted by Class A Quote
Note that the K-7 is not perfect in compensating AF errors due to non-daylight lighting.

Before you draw final conclusions, make sure that you did some tests in non-dim daylight.
You know what, I too have a feeling that I must test it in daylight to rule out all possibilities. But, given the winter daylight time, it's all but gone by the time I'm home. And I'm really looking forward to testing it tonight(flurascent light) and tomorrow (daylight). This being the weekend again!!

Sorry to keep you guys waiting.

Cheers..

04-01-2011, 10:03 PM   #17
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QuoteOriginally posted by icypepsi Quote
I have never received a camera body/lens/accessory that is in a "sealed" box.
"Open box" is a technical term that refers to a product that has been used by someone else already. Often you can already tell by crumpled plastic bags, etc. that the product has been put back into its original box.

B&H claims they sell returned items in a special "open box" category. Whenever I looked at it there was hardly anything there while one hears about people returning items to B&H quite a lot in comparison. I'm sure it makes sense somehow...

QuoteOriginally posted by icypepsi Quote
Though, only once I heard a B&H manager flaunt about not being able to give me a lens to test at their store because they will have to open the box, it made me wonder what difference it makes because the box is not sealed anyway.
Well, strictly speaking he would not have been able to sell the item as brand new anymore, in particular if the same item is handed out to customers more than once, or the packaging is such that a customer will always notice that the item had been used already.
04-01-2011, 10:17 PM   #18
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QuoteOriginally posted by Class A Quote
"Open box" is a technical term that refers to a product that has been used by someone else already. Often you can already tell by crumpled plastic bags, etc. that the product has been put back into its original box.

B&H claims they sell returned items in a special "open box" category. Whenever I looked at it there was hardly anything there while one hears about people returning items to B&H quite a lot in comparison. I'm sure it makes sense somehow...


Well, strictly speaking he would not have been able to sell the item as brand new anymore, in particular if the same item is handed out to customers more than once, or the packaging is such that a customer will always notice that the item had been used already.
I'm not sure if B&H purposely opened the item for QC purposes as this would save them and the buyer money and time, not to mention losing sales as well. it's no different from someone who tries out a product at a store, atleast they are giving you a favor for that. but with regards to actual open box category, that should had been discounted. anyways, the OP could ask for an inquiry regarding the actual condition of the lens if it's an open box or a new sale protocol.
04-01-2011, 11:03 PM   #19
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QuoteOriginally posted by Pentaxor Quote
I'm not sure if B&H purposely opened the item for QC purposes as this would save them and the buyer money and time, not to mention losing sales as well.
B&H don't open boxes for QC purposes. I remember someone asking whether they could check a K-5 for stains first and they said "no".

04-02-2011, 03:10 PM   #20
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I have no experience with the Sigma 85/1.4, but I did try the Sigma 50/1.4 on my K-7, and I noted very inconsistent focusing. It was almost as though the lens was focusing randomly around the true focus point and only occasionally hitting it. This matters when you are using an ultrafast lens with a paper thin DOF. If you cannot trust such a lens, why own it?

I agree that you might exchange it for another copy, but do not be surprised if it exhibits the same behavior. FWIW, the Pentax 77/1.8 Limited costs less and is regarded as one of the most beautiful rendering lenses from any manufacturer. It never misbehaves, at least on my K-7. It does not have SDM, but I should think you could live without it.

Rob
04-03-2011, 04:18 AM   #21
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QuoteOriginally posted by robgo2 Quote
I have no experience with the Sigma 85/1.4, but I did try the Sigma 50/1.4 on my K-7, and I noted very inconsistent focusing. It was almost as though the lens was focusing randomly around the true focus point and only occasionally hitting it. This matters when you are using an ultrafast lens with a paper thin DOF. If you cannot trust such a lens, why own it?
Maybe it is worth adding that you tried five DA* 55/1.4 which showed the same behaviour. This suggests that maybe your camera plays a role in this too. The fact that it focuses fine with slower lenses may not need to mean that it is free of problems for very fast lenses.
04-03-2011, 11:11 AM   #22
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QuoteOriginally posted by Class A Quote
Maybe it is worth adding that you tried five DA* 55/1.4 which showed the same behaviour. This suggests that maybe your camera plays a role in this too. The fact that it focuses fine with slower lenses may not need to mean that it is free of problems for very fast lenses.
Perhaps, but I had issues with a K-5 as well. My f1.8 lenses focus consistently, and those are pretty fast. I use the LensAlign system to test AF accuracy, and I could see the focal plane moving back and forth with each successive exposure with the DA* 55 and the Sigma 50/1.4 on my K-7, even when stopped down to f2.8. That means that even greater DOF could not always make up for focusing inaccuracy. Fortunately, my new FA 43/1.9 seems to be very steady and is a spectacular lens to boot. (I am so glad that the other lenses failed and led me to the truly splendid FA 43. That is one reason that I have suggested that the OP consider the equally splendid FA 77/1.8 Limited.) It is possible that the problem lies with the SDM/HSM motors interacting with my camera, but my other SDM lenses seem to be fine (although they are f2.8.)

My advice to the OP was to try another Sigma 85/1.4 but not to be surprised to find the same problem. He has a K-7 also.

Rob

Last edited by robgo2; 04-03-2011 at 11:53 AM.
04-03-2011, 06:07 PM   #23
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Success!!!

I have great news.. my 2nd copy is a keeper Albeit with a -2 microfocus adj. on my K7

But here's the ghost I am unable to decipher. When I first did a formal test with charts/tripod in bright daylight (diffused and indirect), it clearly and consistently (well, almost) showed a need for a -8 microfocus adj. at all subject distances I used (1/2/3 m). I took multiple shots per test scenario just to cover up false results (yes, it is inconsistent sometimes. It's a machine). BUT, BUT BUT...

BUT.. the moment I shot some test shots in the real-world freehanded, it consistently showed BF (will post the pics). By trial and error (hand held) I found a -2 microfocus adj. to be correct. With this, shot after shot (with some acceptable inconsistency) showed spot on focus at -2 microfocus adj. Then what the hell was that formal test result of -8???

I felt it was in flurascent lighting, while the testing was done in daylight. But, to my surprise, when I took the lens out the next day(light), the -2 microfocus adj. seemed fine for everything (except a near infinity AF it did on a flying airplane.

There is definitely something to this. Maybe the test chart itself. But for now, I'm happy that it is quite consistent with this copy 2. Almost spot on focus except in the most difficult conditions. As opposed to my copy 1 that was behaving very inconsistently. Perhaps like what Rob noticed with his Sigma 50 1.4. And my copy 2 was more contrasty (signature Sigma contrast) than my copy 1. Also my copy 2 shows almost no difference when stopped down or for different subject distances, while the copy 1 was slightly crazy with subject distance. So I declare the copy 1 as faulty.

Some things I observed about the Sigma 85mm F1.4, compared to the Sigma 50mm F1.4
1. The 85mm is slightly less sharp than the Sigma 50mm F1.4, @ 1.4. Maybe given the extra FL
2. 85 is as contrasty as 50mm
4. The 85's AF (maybe in combination with my K7 copy) is almost immune to stopping down and to different subject distances. The 50mm's AF varied a lot with stopping down and different subject distances. Very un-handlable (for lack of a better term). However, this is a known behavior among superfast lenses. But it's surprising that the 85 is this immune.
5. The 85mm seems to require a lot of contrast in the subject to be able to AF lock. In some other strange situations, where there is plenty of light (even daylight) and plenty contrast in the subject, the sigma finds it very tough to AF.

Thanks to all you folks for sharing your knowledge. Images will follow in my subsequent post.

Cheers,
Anil

04-03-2011, 06:35 PM   #24
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Good to hear you've got a keeper!

I'd be interested in seeing your focus chart tests. I don't think we'll be able to tell anything from (back-focused) real-world shots but maybe there is a hint in the focus chart test shots about what could have gone wrong.

Have you ever tried to re-validate your current AF adjustment setting with the focus chart?

BTW, a little variation in AF precision is perfectly normal.
04-03-2011, 06:38 PM   #25
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QuoteOriginally posted by icypepsi Quote
I have great news.. my 2nd copy is a keeper Albeit with a -2 microfocus adj. on my K7

But here's the ghost I am unable to decipher. When I first did a formal test with charts/tripod in bright daylight (diffused and indirect), it clearly and consistently (well, almost) showed a need for a -8 microfocus adj. at all subject distances I used (1/2/3 m). I took multiple shots per test scenario just to cover up false results (yes, it is inconsistent sometimes. It's a machine). BUT, BUT BUT...

BUT.. the moment I shot some test shots in the real-world freehanded, it consistently showed BF (will post the pics). By trial and error (hand held) I found a -2 microfocus adj. to be correct. With this, shot after shot (with some acceptable inconsistency) showed spot on focus at -2 microfocus adj. Then what the hell was that formal test result of -8???

I felt it was in flurascent lighting, while the testing was done in daylight. But, to my surprise, when I took the lens out the next day(light), the -2 microfocus adj. seemed fine for everything (except a near infinity AF it did on a flying airplane.

There is definitely something to this. Maybe the test chart itself. But for now, I'm happy that it is quite consistent with this copy 2. Almost spot on focus except in the most difficult conditions. As opposed to my copy 1 that was behaving very inconsistently. Perhaps like what Rob noticed with his Sigma 50 1.4. And my copy 2 was more contrasty (signature Sigma contrast) than my copy 1. Also my copy 2 shows almost no difference when stopped down or for different subject distances, while the copy 1 was slightly crazy with subject distance. So I declare the copy 1 as faulty.

Some things I observed about the Sigma 85mm F1.4, compared to the Sigma 50mm F1.4
1. The 85mm is slightly less sharp than the Sigma 50mm F1.4, @ 1.4. Maybe given the extra FL
2. 85 is as contrasty as 50mm
4. The 85's AF (maybe in combination with my K7 copy) is almost immune to stopping down and to different subject distances. The 50mm's AF varied a lot with stopping down and different subject distances. Very un-handlable (for lack of a better term). However, this is a known behavior among superfast lenses. But it's surprising that the 85 is this immune.
5. The 85mm seems to require a lot of contrast in the subject to be able to AF lock. In some other strange situations, where there is plenty of light (even daylight) and plenty contrast in the subject, the sigma finds it very tough to AF.

Thanks to all you folks for sharing your knowledge. Images will follow in my subsequent post.

Cheers,
Anil

that is some great news indeed and we are happy as well that you enjoyed the lens.

I'm not sure about why it is tough to AF under the daylight conditions that you are saying other than it's one of the limits of fast lenses, especially at f1.4. under such opening, it is somehow elementary that one should MF, although if it locks on for most of the time at wide open, the better. I would assume that you won't have much problem locking AF at f1.8 or f2.

as far as the 50/1.4 being just slightly sharper at wide open, I believe it has much to do with the 85 being made consistently sharp (balanced sharpness) all over the frame from wide open. from the multiple comparative 85mm lens test results, the Sigma 85 is sharper in the borders and corners in comparison with other 85mm lenses.
04-03-2011, 06:42 PM   #26
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QuoteOriginally posted by robgo2 Quote
...I could see the focal plane moving back and forth with each successive exposure with the DA* 55 and the Sigma 50/1.4 on my K-7, even when stopped down to f2.8.
Focusing always takes place wide open so you seem to be saying that the focusing was so inaccurate that the focus target wasn't within the DOF even at f/2.8?

It is normal for the exact focus point to slightly shift between different attempts and one will see such a shift at any shooting aperture, but at f/2.8 the target should always easily be within the DOF.

QuoteOriginally posted by robgo2 Quote
It is possible that the problem lies with the SDM/HSM motors interacting with my camera, but my other SDM lenses seem to be fine (although they are f2.8.)
I think it is safe to eliminate the motors as a potential cause of the problems.

Glad you like the FA 43/1.9. I think I'd love it too.

I'm not sure at this point whether the FA 77/1.8 has some pixie dust that the Sigma 85/1.4 does not have. I'd love the speed and focal length of the Sigma but would probably prefer the pixie dust of the FA 77/1.8, should the latter have an advantage in this area.
04-03-2011, 07:30 PM   #27
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QuoteOriginally posted by Pentaxor Quote
I'm not sure if B&H purposely opened the item for QC purposes as this would save them and the buyer money and time, not to mention losing sales as well. it's no different from someone who tries out a product at a store, atleast they are giving you a favor for that. but with regards to actual open box category, that should had been discounted. anyways, the OP could ask for an inquiry regarding the actual condition of the lens if it's an open box or a new sale protocol.
Yes, I'll check with them. But looking at the mount the second time, I don't think it's any problem. (image underexposed to show the scratch). Ofcourse, it has been an etch from multiple mount-ons and mount-offs. Maybe it was returned. But I don't think it will cause a problem. It is tight and secure. In that case, it'd be stupid of me to return a perfectly working copy that required only just -2 microfocus adj. on my K7 body.
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04-03-2011, 09:12 PM   #28
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QuoteOriginally posted by Class A Quote
I'm not sure at this point whether the FA 77/1.8 has some pixie dust that the Sigma 85/1.4 does not have. I'd love the speed and focal length of the Sigma but would probably prefer the pixie dust of the FA 77/1.8, should the latter have an advantage in this area.
I have no idea how the two lenses compare in terms of rendering, but I thought that it should be considered as a possible alternative to the Sigma 85/1.4. I do own the FA 77 Limited, and I can tell you that it is a beautiful lens that has many of the same qualities as the FA 31 and FA 43 Limiteds. I am very fortunate to have all three. I don't know about pixie dust, but they really are special.

Rob
04-03-2011, 09:14 PM   #29
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My testing

Here, it had a -8 microfocus adj. and it seemed just perfect
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04-03-2011, 09:16 PM   #30
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Real world with -8 microfocus adj.

But, with the -8 adj., the real world pics were clearly BF-ed. (Imgs with center focus point)
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Last edited by icypepsi; 04-03-2011 at 10:23 PM.
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