April 23, 2014, 10:24:25 AM

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Messages - dilbert

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1
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.

2
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?
That part of the focusing algorithm is necessary because your camera has no knowledge that it hasn't moved or whatever you are shooting hasn't moved. It may have GPS in some models, but I've yet to hear of one with gyroscopes, accelerometers, and radar.  ;D

Edit: I see Lightmaster was thinking the same thing I was. Great minds think alike!

You know I think I could come up with any bogus behaviour by a Canon product and one or more people would find a way to justify it.

But then if a 3rd party behaves strangely, well, it is all the fault of the 3rd party and should never happen!

The point I was making above is that if you've already focused the lens on X and press the button again, it is doubtful that the lens will end up in exactly the same position as before (and by exact, I mean exact, not some "within half a millimeter.")

3
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?

4
2014 is turning to be the Year of the Lens...



...for SIGMA.  ;D

+1

5
Lenses / Re: Review: Sigma 50mm f/1.4 DG HSM Art Lens
« on: April 22, 2014, 11:23:00 PM »
...
All that said, I'm surprised nobody has been discussing how odd it seems that AI Servo was apparently ok, but One Shot on a tripod wasn't...Any conjecture?
...

With a static subject and on a tripod, the reviewer should have been using "Live View" (contrast based focus) and focused through that and should not have used the normal TTL method of focusing. This would then allow the review to check that the camera was no longer vibrating (at 10x view) when they took the photo: depending on the residual motion, 2 seconds is not always enough to allow the camera to become still.

This makes me think that there are some questions to be asked about the procedures used by the reviewer as they have obviously been found wanting.

6
Lenses / Re: Review: Sigma 50mm f/1.4 DG HSM Art Lens
« on: April 22, 2014, 11:10:50 PM »
Is there a lens out there that never has occasional AF inconsistency?

Does a 40% miss rate really constitute occasional inconsistency?  I think not...

Compare this to Zeiss missing 100% of AF shots  ;)

Well you could turn the AF off and then the Sigma lens would have the same rate of AF misses as the Zeiss lens, for $3000 less.

7
Lenses / Re: Review: Sigma 50mm f/1.4 DG HSM Art Lens
« on: April 22, 2014, 11:07:51 PM »
I just tried my 4th... Yes, 4th copy of the Sigma 35... I have written Sigma off at this point. I tried, but I just could not deal with the AF.

The first two I tried right when the lens came out... MA changed heavily indoors vs. outdoors... 0 MA near to far outdoors, +10 required indoors. Was a PITA.

Fast forward to last week, I tried another. Copy 1 seemed to work fine indoors vs. outdoors but was decentered... OK, just get another... I have had plenty of Canon lenses that I needed to exchange.

Got the replacement, indoors to outdoors is perfectly fine (thankfully). However, the AF is just way too darn unreliable. Some shots are so far OOF you wonder how the camera ever thought it was right. Yet the next photo be perfectly sharp, the next somewhat soft, sharp again, way out of focus the next, etc... Mostly near infinity focus it had these issues.

I just slapped my 35L back on and sent the Sigma back home for the last time... Until Sigma can have even better AF, the Canon options are for me.

With that much trouble, one has to wonder whether the problems are with the lenses or somewhere else ... like the camera or the "driver".

8
Canon General / Re: Canon Hong Kong Announcement April 24, 2014
« on: April 22, 2014, 09:39:37 AM »
what about a new printer?

haven't had an announcement for them in a while...

10
Lenses / Re: New TS-E Lenses for Photokina [CR2]
« on: April 21, 2014, 09:25:42 PM »
Maybe they'll be tilt, shift and swing lenses?

Pardon my ignorance, but what is a swing lens?

I think dilbert is suggesting a lens that can tilt in two axes at the same time.  For view cameras, tilt referreded to up/down and swing left/right movements.

Dilbert is being silly. All Canon T/S lenses can be used to combine Tilt and Swing in any direction.

But there are alignment features in the latest two (17 & 24) that were not present in prior models however the current design (i believe) is limited to having both planes either aligned or at right angles. Maybe they've worked out how to allow an arbitrary alignment of axes?

btw, hasn't someone found a patent or two to read??

You need to look at stuff more before making silly misinformed posts. All Canon T/S lenses from the FD 35mm T/S can do unlimited swing/tilt movements, the rotation needed to do that has always been there.

What was new to the 24 MkII and 17 was the ability to set the tilt/swing combo anywhere in relation to the shift/rise/fall movement. It does not need to be aligned or at right angles with these lenses, though the earlier ones do.

I was sure that this is what they had brought into being but when I looked, I couldn't find anything on the web (easily) that demonstrated it so I wasn't sure enough to post about it.

11
Lenses / Re: Will Sigma 50/1.4 Art push Canon to release a 50/1.2L II?
« on: April 21, 2014, 07:47:34 PM »
Sigma's 50/1.4 A won't 'force' Canon to do anything.

Correct. I'm pretty sure that lens design and manufacture is something that is planned out many years in advance.

Quote
They'll likely come out with a 50/2 IS delivering very good IQ, priced around $800, and that lens will probably outsell the Sigma. The Canon 50/1.4 will likely continue to outsell the Sigma, and the 50/1.8 II will far outsell both.  Cheaper sells.

So long as Canon continue to make the cheaper models, yes...

Quote
If Canon updates the 50/1.2, which is probably a long way off, it'll remain f/1.2.

+1

12
Lenses / Re: New TS-E Lenses for Photokina [CR2]
« on: April 21, 2014, 06:25:39 PM »
I like the idea of registering the tilt and especially the shift amount for correction in post best, and it would make the most difference in time to me. But again I fear that would mean a compulsory trip to DPP to make it work.

I've had a discussion with folks at DxO about TS lens corection profiles - having the mechanisms encoded and the settings recorded in the EXIF would really facilitate development and implementation of those profiles.

I think you'd need four encoders - tilt, shift, and the rotation for each.

Unless existing camera firmware has been written in advance of that, it'll require new firmware for cameras to not only know how to talk to the lens in order to get that information but also write it into a CR2 file.

13
Lenses / Re: New TS-E Lenses for Photokina [CR2]
« on: April 21, 2014, 11:49:13 AM »
Maybe they'll be tilt, shift and swing lenses?

Pardon my ignorance, but what is a swing lens?

I think dilbert is suggesting a lens that can tilt in two axes at the same time.  For view cameras, tilt referreded to up/down and swing left/right movements.

Dilbert is being silly. All Canon T/S lenses can be used to combine Tilt and Swing in any direction.

But there are alignment features in the latest two (17 & 24) that were not present in prior models however the current design (i believe) is limited to having both planes either aligned or at right angles. Maybe they've worked out how to allow an arbitrary alignment of axes?

btw, hasn't someone found a patent or two to read??

14
Lenses / Re: New TS-E Lenses for Photokina [CR2]
« on: April 21, 2014, 11:39:02 AM »
Maybe they'll be tilt, shift and swing lenses?

Pardon my ignorance, but what is a swing lens?

I think dilbert is suggesting a lens that can tilt in two axes at the same time.  For view cameras, tilt referreded to up/down and swing left/right movements.

But Canon's 17 and 24 already do both tilt and shift and rotations of that. After more browsing, swing appears to be just another word for tilt used in the horizontal plane

15
Lenses / Re: New TS-E Lenses for Photokina [CR2]
« on: April 21, 2014, 11:09:44 AM »
Maybe they'll be tilt, shift and swing lenses?

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