October 23, 2014, 09:24:34 AM

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Messages - drmikeinpdx

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1
I've been really curious about the Sigma 50mm F1.4 DG HSM, aka: the 50 Art lens.  I've read a lot of reports about autofocus problems, but wanted to check it out for myself.

I rented a copy of the Sigma 50 Art from LensRentals.com.  Before I ordered, I emailed their customer service to ask if they used the USB dock to do any kind of calibration with the lens.  They replied that they take every 50 Art that comes back into the shop, put in on the USB dock and reset it to the default values.  That sounded good to me, as I planned to use the microfocus adjust feature on my 5D3 to make any needed changes.  I was planning to do an outdoor photoshoot where my models would always be roughly ten feet from the camera, so I did not feel like I'd need the USB dock to adjust the focus for different distances.

Upon receiving the lens, I did my usual autofocus calibration.  This time only at ten feet.  Using the center focus point, the Art lens was pretty consistent on my 5D3.   I settled on +3 MFA value and was pretty pleased with the stable focus from shot to shot.

Then I tried using other focus points.  I found that as you move away from the center point, the lens will front focus more and more.  Using the outermost horizontal points, the front focus was about two feet or a 20% error.  The next pair in toward the center front focused about one foot or 10%. Using the top and bottom points, the front focus error was about 1 foot or 10%.

When the lens was in focus, it was very sharp, so I went ahead and did the planned outdoor photoshoot.  I used mostly the center point, but occasionally moved the focus two spots left or right.   Used within this restriction, I was very happy with the sharpness, bokeh and autofocus accuracy.

I did a few shots with my old Sigma 50 Classic, which was autofocusing pretty well that day, since I fed it a shot of cheap gin before leaving the house and said some magic words over it.   The Art lens was definitely sharper, but not stunningly better.    They both created very nice bokeh of the distant trees when used wide open.

Here is a shot with the Art lens at F/2.0:



Here's a shot with the Sigma 50 Classic at F/1.4:



These are just fun shots to give you an idea of what kind of photoshoot I was doing, they don't really prove anything.

One thing I learned on this shoot was that the DOF at 1.4 is even more shallow than I thought.  Shooting two models standing side by side you have to make sure they are both exactly the same distance from the camera.  Unfortunately couples naturally want to move around.  I had a lot of shots where one model was in perfect focus and the other was slightly out of focus.  I was kind of expecting that and shifted focus back and forth between the two models, so I got plenty of usable photos.

In the future, if I'm not going for the absolute maximum bokeh, I plan to use my Sigma 50 Classic primarily at F/2 on these kinds of photoshoots.

One more item...  Before sending back the Art lens, I attached it to my old 7D backup body and ran it through my usual autofocus test.  It was difficult to come up with a precise AFMA number because the focus was not very consistent.  I settled on +12.  I tried the outer focus points to see if the 7D showed the same error pattern as the 5D3.  It did not, but the general accuracy and repeatability was poor enough that I would not venture a guess as to what the real pattern is.  Basically, I would not want to use the Art lens on my 7D unless I stopped it down to about F/4 or so.  As a control, I put my 40 pancake lens on the 7D.  It focused better than the Art lens, but still not as well as I wished.   I don't know about your 7D, but mine has never had a very accurate AF system, which is one reason I rarely use it now that I have a 5D3.

As a result of my experience, I have decided not to buy a new 50mm lens.  I will keep using my Sigma 50 Classic and wait and see if Canon comes out with a new 50mm lens in the 1.8 to 2.0 range.   If it is sharp wide open, it would be the perfect lens for me.

2
EOS Bodies / Re: Patent: Variable Diffusion Focusing Screen
« on: October 15, 2014, 11:52:09 AM »
That would be a very nice feature if it worked.  I'd have to see some positive reviews before I was convinced.

3
EOS Bodies / Canon profit report
« on: October 14, 2014, 04:55:12 PM »
http://asia.nikkei.com/Markets/Tokyo-Market/Canon-likely-saw-7-profit-boost-in-January-September

October 15, 2014 1:57 am JST

Canon likely saw 7% profit boost in January-SeptemberTOKYO -- Canon's operating profit apparently climbed 7% on the year to just over 260 billion yen ($2.41 billion) for the nine months through September thanks to strong office equipment sales and a weak yen.

     But sluggish camera sales blunted the Japanese company's profits, which had shot up 26% in the January-June half.

     Total sales for the January-September period likely stayed flat from the 2.69 trillion yen booked a year earlier.

     Both sales and profit appear to have grown at its mainstay office equipment unit. The recovery in the business environment has pushed up demand for photocopiers, laser printers and other office equipment around the world. The soft yen has further boosted profits. Yet sales of high-margin consumable items, such as toner, stalled.

     Meanwhile, profits in its imaging systems segment likely dipped from falling digital camera sales. The company sold about 30% fewer compact cameras due to competition from smartphones with better-quality cameras. Weak personal spending in Europe and repercussions from Japan's sales tax hike also contributed to a double-digit drop for interchangeable-lens products, such as SLRs.

     The company is focusing more on higher-end items, which have a wider profit margin, and has slashed production costs, but was unable to completely make up for the slow sales.

     Canon plans to release January-September results on Oct. 27. It is expected to retain its guidance for the year ending in December of an 8% operating profit gain to 365 billion yen.


4
Landscape / Moon over Portland this morning
« on: October 08, 2014, 08:24:05 PM »

This was taken with my old 7D Classic and a 200mm F/2.8 L wide open at 1/4 sec and ISO 400. Camera set for daylight color balance, did not change it in Lightroom.

 Feel free to make jokes about putting my logo on a moon shot.  LOL   Lightroom does it automatically.

5
If there is ever a contest to determine the best kit lens ever made, I would suggest the 24-105 as a contestant.  It really does a lot of things amazingly well for the price.  I bought one a year ago from Big Value for about $600 because I had to satisfy my Gear Acquisition Syndrome.  Didn't think I'd use it much at the time!  I'm still surprised how often I reach for it when I need a good reliable zoom lens for an important photoshoot.

6
Canon EF Prime Lenses / Re: Canon 35mm F2 IS
« on: September 30, 2014, 09:57:50 AM »
Shot at F/2.5


7
Pricewatch Deals / Re: Deal: Canon EOS-1D X Body $4799
« on: September 28, 2014, 11:07:06 PM »
Wow.  That price is amazing.  I bought a the 24-105 f4 L from them via this site and love it.

The 1Dx seems like a dream to me.  But I think I will go with 5D Mark III.   Has anyone seen a deal on those?  Is it just random on from this place?

I would so love to know as I really am ready to pull the trigger on this.

http://www.ebay.com/itm/Canon-EOS-5D-Mark-III-Digital-SLR-Camera-Body-Only-NEW-/151109057831?pt=Digital_Cameras&hash=item232ecd3d27

8
Lenses / Re: 50mm f/1.4 Canon vs. Sigma
« on: September 28, 2014, 09:00:04 PM »
I'm in the same boat, but I currently have the Sigma 50 classic (non art) that is rather soft wide open, has great bokeh, but seems to have a random number generator built into the autofocus processor.  Or maybe a Gremlin that has good days and bad days.  Well, maybe not quite that bad, but you can bet I shoot twice as many images as normal to make sure I get enough that are properly focused.

I'm waiting to see if user reports indicated an improvement in autofocus accuracy and consistency for the Sigma in the next few months.  But I'm also waiting, without much hope, for Canon to expand their lineup of primes with IS to include a 50mm lens.

9
EOS Bodies / My theory for the tepid response
« on: September 28, 2014, 01:13:46 PM »
My theory for the tepid response:  Most people who might be interested in the 7D also have experience with, or access to, full frame DSLRs.  They are spoiled by the full frame image quality.

Someone once said that Canon's goal for the 7D2 was to make it so desirable that full frame owners would want to own an APS-C camera as their second body.  While the 7D2 will appeal to limited groups, like sports photographers, I think it needs to demonstrate extremely good IQ to interest many pro and enthusiast photographers. 

I'm waiting for the test images from DP Review.  I always compare the crop sensor images with my current main camera, the 5D3, using the DP Review image comparison widget.

10
Lenses / Re: Another thread about AF problems with Sigma 35A
« on: September 25, 2014, 07:34:36 AM »
switters:  What camera are you using?

11
Thanks for the info!  Do you guys happen to remember if the Sigma outlet store charged you sales tax?

12
Ah, thanks Mt. Spokane!

I checked out prices for the 50 and 35 Art lenses...  The 50 is not available at all.  The 35 Art is available for $679, but.... it's only available in the Pentax mount!  LOL

So I guess we still haven't figured out where all those returned Canon mount Art lenses are going.

Perhaps the percentage of returned lenses is much less than what one would guess from reading online reviews and blogs?

13
Third Party Manufacturers / What happens to all those returned Sigma lenses?
« on: September 24, 2014, 07:29:07 PM »
I'm considering a Sigma Art lens and doing a lot of online research.  One thing that shows up a lot are reports of photographers sending back a lens to exchange for another that will hopefully focus better.  Sometimes there are three or four exchanges before they either give up or get a lens they are happy with.

You guys know that already, but what I'd like to know is what happens to all those returned lenses?  Does Sigma have a place where they sell refurbished lenses?  Do they destroy them as a tax write-off?   Disassemble them and re-use the parts to make new lenses?

Just curious!

14
Third Party Manufacturers / Re: Sigma Opens Up About Their Roadmap
« on: September 22, 2014, 09:23:15 PM »
How about hiring some Chinese hackers to gain access to the Canon autofocus algorithms?   All the sharpness in the world does me no good if my images are not precisely focused.

Manual focus?  No way!  Have you ever tried to get a nude model to hold perfectly still and smile while you manually focused your favorite portrait lens?

15
Lenses / Box for sale on Craigslist
« on: September 21, 2014, 11:32:34 PM »
If you happen to need a box for a 5D2, a guy has been offering one on Craigslist (Portland, OR) for $30.  Either he has more than one box or he keeps advertising the same one for the last few months.  Maybe people think it isn't playing fair if you buy someone else's box?   LOL

I only keep boxes if I think there's a good chance I will wish to sell or return a product.

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