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Messages - AlanF

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406
Third Party Manufacturers / Re: In-Depth Review: Tamron 150-600 f/5-6.3 VC
« on: February 02, 2014, 03:20:28 PM »
There are reports elsewhere that AF for BIF is problematic. Does anyone have experience of this?

There are also rumours that stocks to the big retailers are being withheld while Tamron sorts out the AF problem. Has anyone any knowledge of this?

407
Lenses / Re: Stacked TC IIIs on 300/2.8 II Brief summary
« on: February 02, 2014, 03:12:19 PM »
AlanF, thanks for making the effort to provide this feedback.  Do you think AFMA is a factor here?  I guess the camera wouldn't be able to recognize/remember the combination??

Do you feel the result is better than a crop of less than full stacked?  Did you play with sharpening the stacked result?

Maybe you've answered this previously, but you're gaining more experience daily.  So, assuming you need reach to frame a stationary subject, does the 70D outperform the 5D3 in good light in any regard, considering the various aspects of IQ?

Jack
The AF is so limited for the stack that I used manual focussing through the viewfinder so AFMA doesn't come into it.

When I got good focus, the results were very acceptable. Using a tripod for a static subject, for moon shots etc, I think the stacked TCs could give an advantage. I got a reasonable shot of a bittern in reeds at the very limits of resolution which was at least as good as just using the 2xTC. But, the whole rig is too cumbersome for my hand held shots, which is what I want to do. And the loss of AF is a killer.

The 70D does give better resolution than the 5DIII, with DxO noise reduction and a bit of PP. But, this comes into play when you are cropping so much the results are never going to be spectacular whichever camera you are using. I am very happy with both the 70D and 5DIII, but the 5DIII will be my workhorse. I expect to test the Tamron 150-600 the week after next. My guess is that it will perform significantly better on the 5DIII. Its sharpness is very similar to that of the 100-400, and that lens is much better on the FF than crop. You need a very sharp lens to get the best from crop sensor.

408
Lenses / Re: Stacked TC IIIs on 300/2.8 II Brief summary
« on: February 02, 2014, 10:21:27 AM »
The 5DIII has the same problems with a very limited mid-range AF, not focussing close or far away.

409
Third Party Manufacturers / Re: In-Depth Review: Tamron 150-600 f/5-6.3 VC
« on: February 02, 2014, 10:19:02 AM »
Having read lots of reviews and had several questions answered in this thread (thanks everybody), I have ordered the Tamron. The money I got for my 100-400 and Sigma 400 will more than pay for it. Even if it is not as good as the 300/2.8 II, I have some trips coming up when the advantages of the zoom and the lower weight will be important advantages. But, I am hopeful that stopped down it will rival the 300 + 2xTC.

410
Lenses / Re: Stacked TC IIIs on 300/2.8 II Brief summary
« on: February 01, 2014, 11:19:09 PM »
Same focus limitations as for normal viewfinder (phase detect) AF. It would only AF for the intermediate distances.  It was very accurate then. 

411
Lenses / Stacked TC IIIs on 300/2.8 II Brief summary
« on: February 01, 2014, 12:51:13 PM »
We have been having discussions about stacking 1.4xTC III and 2xTC III on telephotos. I have done some testing using a 70D, and here are some brief conclusions, incorporating what others have already written and discovered.
1. Stacking requires a 12mm extension tube placed between the two TC III extenders.
2. The 2xTC III must be attached to the lens and the 1.4xTC to the camera.
3. The camera exif records only the effect of the 2xTC - the pair attached to a wide open f/2.8 records as f/5.6.
4. The 300/2.8 focusses manually at all the usual distances, and the same is reported for other telephotos.
What I found from the 70D today is:
5. AF works only at intermediate distances (approx 30-80m, give or take) and not closer or at infinity in both live view and phase detect. (The 5DIII also didn't AF).
6. IQ is quite good.

Here are two shots of Egyptian geese at about 20-30m. The stacked TCs required manual focus which I did through the viewfinder, rather quickly, resting the lens on the ledge of a hide. The full shots are reduced to 1200x800, the crops of the heads are 100%. The goose standing is done with just the 2xTC attached. The sitting goose with the 1.4x + 2x.

Both are wide open (f/5.6 with 2x, f/8 with 1.4x+2x), iso 640 and 1/3200 or 1/1000s.

412
That is impressive. What sharpening has been applied?

413
Lenses / Re: Stacked TCs - 1.4x III + 12mm Extension Tube + 2x III
« on: January 31, 2014, 02:55:11 PM »
Jack
The 70D is very good indeed with 300/2.8 II and TCs. I haven't had a chance to use them stacked yet. I don't think stacking is practical for bird photography. With individual TCs, the focussing is fast and accurate, the IQ very good. There is no doubt I am getting better reach than with the 5DIII, but the 5DIII does give slightly crisper and richer images, which makes up for some of the lower reach. DxO PRIME noise reduction without loss of detail is so remarkable that it greatly raises the iso performance of the 70D. Trouble is, the noise reduction takes about 2.5-3 minutes on my MacBook Pro and 11 minutes on my MacBook Air.

414
Most if not all the foregoing discussion centres around the softness beyond 400mm on a F/F body. Using the lens on a F/F camera, one's going to have to stop down to f8 or f11 to maximise sharpness beyond the 400mm focal length.

This is the same for many many other lenses, including those made by Canon.

SO what's the point here?

Dilbert.... Dilbert... Dilbert..... Don't you know that common sense and logic has no place in an emotional argument :)

And seriously, is there ANY lens that is sharpest wide open?

Yes. For example, my 300mm f/2.8 II + 2xTC III analysed by FoCal is sharpest wide open - see chart. The new big whites are often sharpest wide open. However, the Tamron when stopped down is giving the Canon a run for its money, which makes it very attractive. You have to pay a hell of a lot extra to get the sharpest at f/5.6.

415
Like most of us I was interested as soon as I saw the introduction of this lens on CR and dpreview. I searched for sample images and reviews. The images provided by Tamron looked promising and finally the first review came out from Frank Wong which was positive. I then waited to see the price and as soon as this was announced I ordered one from my local camera store.
I tried it out at the Arizona-Sonora Desert Museum and their Raptor Free Flight program and was impressed with the results and have attached thumbnail (reduced resolution) full frame images plus cropped full resolution images to show the sharpness. These were all taken hand held with my Canon 5D Mk III at ISO 1600. The great horned owl closeup was at 600mm at f14, the bobcats at 600mm at f9 and the hummingbird wide open at 600mm and f6.3 and is a little soft compared to the others.


I just registered to be able to show these photos so I am not sure how to add my equipment list automatically below my posts so here is a sampler.
Canon D30, D60, 1D Mk II, 20D, 5D Mk II, 7D, 5D Mk III, SL-1, 24-105 L, 70-200 L f2.8 IS, 100-400 L IS, 28 - 300 IS L, 70 - 300 IS, Tamron 150-600

Thank you! Thank you! Just what I wanted to see. It is really very good stopped down.

416
I am certainly not dissing the lens, and am thinking of buying one. What I want is for someone to show off the lens at its best with birds shot at f/8-f/11 where it looks from MTFs as if it could be really great.

417
Lenses / Re: Stacked TCs - 1.4x III + 12mm Extension Tube + 2x III
« on: January 31, 2014, 09:23:39 AM »
I have only just noticed that TDP has a shot of the moon through a 600mm with stacked extenders.

http://www.the-digital-picture.com/Reviews/Canon-EF-600mm-f-4-L-IS-II-USM-Lens-Review.aspx


418
For all of you birders, here is a pretty amazing review of the lens by a guy comparing it to the 600mm f/4L IS (original version):

http://theamazingimage.com/wildlife/field-test-new-tamron-150-600mm-super-telephoto-zoom/#prettyPhoto

The comparison images of the Red-Tailed Hawk have the bird occupying half the height of the frame. At that size, the image should be extremely sharp with fine details of the plumage visible. You can see that the head of the hawk from the Tamron is soft. All of the images I have seen at 600mm f/6.3 are soft to varying degrees, as you would expect from the measured MTF charts published by different reviewers. However, the lens gets significantly sharper at f/8-f/11 and the lens should be very sharp. So would someone please post some shots at f/8-f/11 so we can see what the lens is really capable of doing. How about it Don?

419
Lenses / Re: Review: Canon EOS 100-400 f/4.5-5.6 L IS USM by DxO Mark
« on: January 30, 2014, 08:57:04 AM »
I sold my excellent mint copy last week while I can still get a good price. Whereas it is OK on FF, DxO gives it a rating of 13 Mpix sharpness on the 6D or 5DIII, it drops to only 6 Mpix on the 7D or 7Mpix on the 70D, echoing what most of us know already that crop requires sharp lenses. And, I found the 100-400 on the 5DIII pretty good and not so good on the 7D,

http://www.dxomark.com/Lenses/Canon/Canon-EF-100-400mm-F45-56L-IS-USM-mounted-on-Canon-EOS-7D__619

A supersharp lens like the 330/2.8 II drops from 21 Mpix on the 5DIII to a still excellent 14 on the 7D and 17 on the 70D. Ok, DxO tests aren't perfect and they can make mistakes, but testing the same lens on different bodies is a pretty fair comparison.

If I want zoom in the 100-400mm region, I am going to use as a stop gap until a new 100-400 or what else the 70-200mm f/4 IS with or without extenders. I found it better or at least as good as the 100-400 on the 5DIII, and you can see this is general on the TDP site or lenstip, and not just me.

420
Studio and landscapes have different requirements from nature and bird photography. For bird photography, we use high iso and the best telephotos we can afford. Canon wins hands down on the lenses (Metabones adaptors aren't good on fast AF)), and their sensors are fine at high iso. If I need more megapixels, I use a crop body like the 70D, which has a pixel density equivalent to a 51.7 mp FF. However, a 36 mp sensor on the 5dIII would give an extra 28% of reach if IQ was not lowered.

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