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Messages - Grummbeerbauer

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1
I had a look at your test shots for 70, 135 and 200mm. What I believe I am seeing is that there is always one corner (or one side) that is definitely softer than the others (lower right mostly, upper right @200mm) but not catastrophically so in each case. This corner then remains visibly worse at f4 and eventually sharpens up at f5.6.
That could indicate some decentering, but could also still be a problem with the test setup. What also made me wonder is the distortion @200mm... the lower border of the test chart shows more pincussion distortion than the other, although the chart seems to be a bit shifted to the top. But then, shouldn't the upper border (being closer to the edge of the frame) show more pincussion distortion?
Point is: your setup isn't perfect (and I doubt it can be with conventional means). Maybe you should check for decentering with a different approach that is less sensitive to test setup, focus issues and shallow DOF: Go outside on a clear day with good light, find far away target (i.e. far away for infinity focus) with good contrast (lone tree in the distance, a tower, tall building, church etc.). Put that into the center of the frame and assure perfect focus (lifeview MF or AF), take test shots at relevant apertures, maybe a few shots for each aperture so that you can rule out camera shake (or better yet, use a tripod ;-)). Now, without changing focus, reframe to put the "test object" in one frame corner, again doing test shots for each aperture. Repeat that for all four corners, making sure that in each shot the test object is roughly the same distance from the image corner.
That should give you five sets of images, one for the center, one for each corner, at each aperture. If you made several shots for each area and aperture, pick the best. Now create a "collage" of the shots of each aperture so that you can visually compare them on one image. The corner shots will likely be darker and a tad less sharp than the center shot, but they should all be roughly equal. If they are not, this is likely decentering.

I couldn't find a good site explaining the procedure in English, but I found this page in German... I think the pictures are pretty self-explantory:
http://www.gletscherbruch.de/foto/test/dezentrierung/dezentrierung.html

2
I used to do my own ISO chart shooting with new lenses, and mine also never looked as crisp as, e.g., those on TDP (I did that also with a 70-200 2.8 IS II that I got once, but I decided that it wasn't worth the extra weight and price over my 70-200 4.0 IS).
What I can tell you is that getting these test chart shots right is really tricky. The chart has to be exactly parallel to the sensor plane, otherwise your corners will be not in focus, in particular when using fast and/or telephoto lenses the DOF is razor-thin. I tried the "mirror trick", which got me probably closest to "exactly parallel" without using an optical bench. For that, you need to put a small mirror in the center of your chart (exactly parallel to the chart itself). Now point your camera at the mirror... once you see the lens front element in the center of the mirror, it should be aligned correctly.
Second, as others have said, for consistent results you need to use live view AF as phase detection AF is usually not consistent enough (and might need some AFMA).

BTW: In the end, it was never my test chart shots that made me keep or return a lens.

3
Lenses / Re: Help me decide: should I buy an EF 135L
« on: November 24, 2014, 09:11:30 AM »
Thanks for the balanced opinions so far. While the vote isn't really clear, it seems that there is a slight tendency advising against buying it despite its merits.

I think I am coming to reason... and getting that little GAS relapse under control again. ;)
Even though the lens it is a steal at "only" 710€, these 710€ are probably better put towards what I am really lacking: more reach!
I am currently waiting for the first reviews of the Sigma 150-600 S (the lenstip.com review sure looks promising) and the 100-400L II and hope to be able to pick up either one sometime in spring.



4
Lenses / Help me decide: should I buy an EF 135L
« on: November 24, 2014, 05:07:00 AM »
Hi,

just stumbled upon a special offer for an EF 135L (brand new) for ~710€. Regular price in my country is 900€.
I know that it is a great lens, so I am really tempted. But do I need it?

I have a 7D with a number of lenses, at least three of which would really be competing for a space in the bag with the EF 135L: 70-200 f4 IS, EF 85 1.8, and the EF 100L 2.8 Macro.

I am afraid that the 135mm FL will be a bit too long for interior shots on APS-C (I find the 100L Macro too long most of the times...)

So is it justifiable to add this lens?
Opinions?

Regards

G


5
Lenses / Re: Introducing the Canon EF 100-400 f/4.5-5.6L IS II
« on: November 09, 2014, 06:50:27 AM »
After Sigma announced their 150-600 siblings, I had almost lost interest in Canon's unicorn lens - after all, with their Global Vision line, Sigma has shown that they can deliver quality at reasonable prices, and at least the Sports variant simply has to be better than the Tamron for APS-C bodies on the long end (first reviews tend to confirm that, e.g. http://www.lenstip.com/417.1-Lens_review-Sigma_S_150-600_mm_f_5-6.3_DG_OS_HSM.html).

But then came today:
100-400LII @2199$ (with probably the usual "rip-off the old worlders" $=€ conversion rate  ::), but cheaper than feared for nonetheless)
+ roughly same price as the Sigma 150-600 S, but for a Canon, not for 3rd party lens
+ red ring ;)
+ less chances of AF gamble (my 18-35 is optically stellar, but AF could still be a tad more reliable on my 7D)
+ fantastically short MFD (<1m versus Sigma's 2,6m, the latter of which could really be annoyingly limiting in practice)
+ roughly half the weight
+ much more compact (94mm x 193mm vs. 121mm x 290mm)
+ (assumedly) better AF speed
- only 400mm

So even if the 150-600S seems to be good as the lenstip review suggests, the question is now, if the 100-400II is good enough to have little practical resolution disadvantage against the Siggy when both are at their long end (I don't think I will be getting a 7DII, so I am not that interested in using a teleconverter)


6
For me, it is actually good that the 70-200 2.8 IS II is not on the list ...
Be careful not to get too close to any of them. They are really sticky ;)
But as you already have the F4 you are very well equiped.
Seems I am not off the hook yet... I just noticed that there is a 300€ cashback if you get a 70-200 2.8 IS II together with the 7D Mk.II... while the verdict on that camera isn't really out for me (waiting for reviews of some more renowned sources), that might make a tempting combination. But even with cashback, that combo ends up well north of 3000€. :-\
Another option would be to get the 15-85 alongside the 7DII - on my last vacation where I had mainly been using the 17-55 2.8 in best lighting (Mediterranean summer sun) were the f2.8 wasn't needed, I always thought that something that goes a little wider and offers a tad more reach might suit that use case much better.
But since only a long tele zoom would be a really an extension of my photographic possibilites, I might be able to keep my GAS in check.  ;)

7
For me, it is actually good that the 70-200 2.8 IS II is not on the list of promoted products. ;)
With the recent price cut to <1900€ in DE and an additional (hypothetical) 200-300€ cashback on top, I would have been very tempted to buy it (despite having a 70-200 F4 IS with which I am very happy). That money would then be missing for buying the Siggy 150-600 S (which is what I really need, as the 70-200 is currently my longest lens).

The only item that I am somewhat interested is the 600 EX-RT. But since I am a flash-on-camera user mostly, I wonder if it would be worth the upgrade from my 580 EX.

8
It will also be interesting how this lens performs compared to the 120-300 2.8 OS S with 2x TC (in particular the new 2x that were also announced by Sigma) ... that combo is said to be good, but not stellar, and will definitely cost more. But you do gain an excellent fast zoom in the process. Could still be a viable alternative for those folks that need 600mm only occasionally.

9
After the Tamron 150-600 turned out a bit disappointing for APS-C users on the all-relevant long end, I was really hoping for Sigma to deliver a product in that FL range - and they did not deliver one, but two! ;D

Since all their recent lenses have been stellar, I am really eager to see the first reviews.

Its a really interesting move to release two lenses with same FL and aperture range at once. Perhaps when their lens designers explored alternative designs for a 150-600 f5-6.3 they came out with two interesting ones, one more pricey to manufacture, but perhaps with better IQ or some other benefits.
And instead of picking the lesser design to win over Canon by price or pick the more advanced design to repeat what they did with their 35A, 50A, and 18-35A (which I have and love), they just decided to do both. Thumbs up for that gutsy call! 8)


10
Is it just me, or do the weight and filter size specs not sound a bit over the top compared to the Tamron with the same maximum aperture and focal length range?
Or is Sigma doing what they did with their 50mm Art, i.e., sacrificing weight and size (and therefore also cost) to get a boost in IQ that would not be possible with a lighter design?
In IT, we call this KIWI (kill it with iron).  :)

Nonetheless, this announcement is exactly what I had been hoping for after the Tamron turned out to be a bit of a let-down for APS-C users in particular on the long end.
If Sigma can deliver the same level of quality of all their recent Sports and Art lenses with this lens as well, and if the price stays well south of 2k€, I might be interested.

11
Wow!  Really F6.3 being marketed as a sports lens?  Maybe on the planet Venus.  Rarely is F6.3 enough to stop sports action.

If you're that close to the sun, an f16 lens will do.

Only if your sport is done in Venus orbit or in some fancy floating city high in the Venus atmosphere. Actually, the surface light level on Venus is very low:

"The cloud cover is such that very little sunlight can penetrate down to the surface, and the light level is only around 5,000–10,000 lux with a visibility of three kilometres. At this level little to no solar energy could conceivably be collected by a probe. Humidity at this level is less than 0.1%.[36] In fact, due to the thick, highly reflective cloud cover the total solar energy received by the planet is less than that of the Earth."

(from http://en.wikipedia.org/wiki/Atmosphere_of_Venus)

SCNR  :)

12
Third Party Manufacturers / Re: A Summary of Sigma Lens Rumors
« on: July 09, 2014, 01:03:36 AM »
I am looking for some halfway affordable longer zoom for occasional birding/wildlife/airshow shooting. The Tamron 150-600 almost had me convinced, but at least on APS-C the long end seems to be bad enough that one should probably use it as an 150-500. That puts me off and the fact that it is on backorder everywhere in .de.  ::)
If Sigma had something in that range (200-600mm?) with better IQ at the long end than the Tamron while keeping the price at a reasonable level (<2000), I might be tempted. I wouldn't even mind f6.3 at the long end if wide-open performance was acceptable.

13
To be honest, I have been considering buying more 3rd party lenses for my Canon bodies recently as Sigma seem to be knocking out some quality glass and their 35mm makes me very happy every time I use it. Looks like Canon are making that decision much easier for me with this news.

According to Wikipedia (read it elsewhere, too, just don't remember where), Sigma's entire production is still happening in Japan in their Aizu plant.
It is good to see that there are still companies that do not put maximizing profit over everything else and therefore do NOT shift production to those places on this planet with the lowest wages, the lowest standards of environmental protection, and/or a questionable human rights situation.

14
Third Party Manufacturers / Re: Tamron to Announce New Tele Zoom Next Week.
« on: November 02, 2013, 04:35:14 AM »
I don't know... I don't really find the "ancient IS" that much of a problem... Guess it depends what you're shooting with it but most of us are shooting wildlife and/or outdoor sports with it.  I've also found the "awkward push-pull zoom" to not be that awkward at all.  In fact when tracking a BIF coming in toward you, it's actually quite natural to slowly draw the barrel back toward you...

There is a reason that this lens is still relevant after all these years without an upgrade.  Here's a few from the old 100-400mm with the "ancient IS" turned on...

At it's price range, I don't think it's a bad option, especially for a "hobbyist"...  ::)  But that's just me!   ;)

I do not doubt that (a good copy of) a 100-400 in capable hands can deliver, and your shots prove that.
Still, I tried this lens a few times and cannot overlook the problems (some of them subjective, like push-pull zoom, others measurable like the IS). Add in that a replacement has been "just around the corner" for about five years now ;). This makes me somewhat hesitant to pay that price for something that might address many of the issues I have with this lens.


My dislike of the 100-400 is not

15
My longest lens is currently a 70-200 F4L IS and I am shopping for something longer for quite some time now.
I don't like the Canon 100-400 with its ancient IS and awkward push-pull zoom design, and optics could be better, too. A successor (if it ever comes into being) will likely cost 2,5k€ and is therefore most likely out of the question for a hobbyist.
The Sigma 120-300 2.8 OS has pretty good optics but is not as long as I would like it to be, heavy as hell and quite pricey, too.
The various Sigron 50/120/150/200-400/500 f4-f6.3 with and without OS/VC also do not cut it optically.
So lets hope Tamron delivers on this one.

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