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Topics - AlanF

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Lenses / lensrentals:-100-400-is-l-mk-ii-teardown-best-built-lens-ever!!!
« on: February 12, 2015, 04:56:49 PM »

Roger has stripped down the 100-400 II and reckons it could be the best engineered lens ever. Perhaps one reason why it is twice as expensive as the Tamron 150-600mm or the Sigma C.

I want to take a week's break at the end of March for bird photography in Cyprus, most probably in Paphos. Any suggestions for a hotel etc and advice, please?

Lenses / Inconsistent reviewing of lenses
« on: January 21, 2015, 09:08:40 AM »
We read reviews and draw our own conclusions, and generally have a feel for the sites that are reliable. This review of the 100-400mm II, however, takes the cake for contradicting itself.


Tamron 150-600
Both centre and edge sharpness are excellent stopped-down at f/8 through to f/16
Both centre and edge sharpness are excellent stopped-down at f/8 through to f/22
Both centre and edge sharpness are excellent stopped-down at f/8 through to f/22
Both centre and edges aren't critically sharp until you stop-down to f/11, which means that you should only use the 600mm focal length sparingly if sharpness is your number one priority.

Score for IQ 4.5/5

Sigma 150-600
Centre and edge sharpness are commendably good wide-open at f/5, and remain high through from f/5.6 to f/16
Centre and edge sharpness are commendably good wide-open at f/5.6, and remain high through from f/8 to f/16
Centre sharpness is commendably good wide-open at f/6.3, and both the centre and the edge remain high through from f/8 to f/16
Centre sharpness is commendably good wide-open at f/6.3, and both the centre and the edge remain high through from f/8 to f/16.
Centre sharpness is commendably good wide-open at f/6.3, and both the centre and the edge remain high through from f/8 to f/16.

Score for IQ 5/5

Canon 100-400 II

Both centre and edge sharpness are both excellent wide open at f/4.5, and outstanding between f/5.6 and f/11.
Both centre and edge sharpness are both excellent wide open at f/4.5, and outstanding between f/5.6 and f/22.
Both centre and edge sharpness are OK wide open at f/5, and outstanding between f/8 and f/16.
Both centre and edge sharpness are OK wide open at f/5.6, and outstanding between f/8 and f/16.

Score for IQ 4.5/5

Firstly, the 100-400 beats the other two in his own descriptions and yet gets rated lower than the Sigma and the same as the Tamron. Secondly, photozone, which actually measures the sharpness quantitatively, has the centre sharpness at 300mm close to the top of the chart, and wide open is sharper at f/5.6 than f/8 for 200-400mm.

Very odd comments: “While you could use it (100-400) on a smaller APS-C body for a 160-640mm equivalent angle of view, it won't balance very well at all - as demonstrated by the images below, it's a much better match for a professional-grade full-frame camera like the 5D Mark III”.
an excellent telephoto zoom lens for Canon full-frame DSLR owners

But, the APS-C 7D II is only a couple of mm smaller in 2 of the dimensions and larger in the 3rd, and weighs 910g versus 950g for the 5D III. I can’t tell any balance difference between the lens on the 5D III and 7D II. The Tamron and especially the Sigma are far more unbalanced

Lenses / Canon EF 400mm f/4 DO IS II USM Lens Review
« on: January 13, 2015, 05:39:44 PM »
The first review of the EF 400mm f/4 DO IS II has just appeared in ePhotozine

The sharpness at f/4 is phenomenal. The sharpness falls off with increasing f number, and rapidly above f/11.  From the Canon MTFs, at 560mm with the 1.4xTC it is probably sharper than the 300mm f/2.8 II at 600mm with the 2xTC and slightly lighter. It is a superb lens - pity it is so expensive.

Reviews / Photozone review of 100-400 L II
« on: December 19, 2014, 02:50:20 PM »
The review I have been waiting for:

The measured MTFs are just so good. It is exceptional in the centre at 100-300mm, and still very high at 400mm. At 200mm, it nearly out resolves the 5DII sensor with a score of 3700 LW/PH out of a maximum of 3800, far better than the 70-200mm IS II. At 400mm, it resolves 3450 LW/PH. The sharpest aperture is f/5.6.


Comparing with the Mk I, it is way ahead for 100-300mm and significantly better in the centre at 400mm.



It's even better than the 400/5.6.

Lenses / EF 100-400mm II - first impressions
« on: December 16, 2014, 05:51:32 PM »
My 100-400 II arrived today at the local store, collected it at 2.45 pm, adjusted microfocus on Focal by 3.45, when it was nearly dark here, ± 1.4xTC.

I fired 6 quick shots of the local chimney in the near dark at 560 mm (with the 1.4xTC) at f/8, iso 2500 and 1/25 s. All were spot on sharp. The IS is excellent, at least 4 stops, compared with 3 on my Tamron at 600. The image looks really sharp. I couldn't do any extensive testing as I had to photo all the kids at a Christmas party, but I have just done some quick shots of the centre of the iso 1223 chart to compare with the 300/2.8 II and Tamron on the 5DIII. (My 70D is at WEX being assessed for part exchange).

1. At 400mm and f/5.6, it is not as sharp as the 300 + 1.4xTC at 420mm and f/4. I was only at about 8m from the target, and the focal length appeared to be only about a real 370mm.
2. At 560mm and f/8 with the 1.4xTC it is really sharp, and much better than the Tamron 150-600mm at 600mm and f/8.

I am really surprised about how good it is with the 1.4xTC.  With it's superb IS and performance at 560mm, I am really pleased I bought it. A little disappointed at 400mm, but maybe microfocus isn't quite right yet. I'll play around with it more in the next few days to see how it shapes up at 400.

Left hand side shots are raw converted to jpeg with no sharpening whatsoever. Right is applying unsharp mask at 0.9 px and 100%.

EOS Bodies - For Stills / 70D/7DII vs 5DIII + TC
« on: December 09, 2014, 06:16:10 AM »
This is not yet another of the endless crop vs FF (famous last words) but a focus on a particular situation, which is of interest to some of us nature photographers who slap TCs onto our telephotos and plug them into a 5DIII or 1DX. How well would we do if we use the 7DII or 70D instead of a 1.4xTC, or a 7DII or 70D + 1.4xTC vs 5DIII + 2xTC?

The answer will depend to a large extent on how sharp the bare lens is because the crops are very intolerant of soft lenses. So let's do this for really good lenses. The addition of a 1.4xTC will cause a small degradation of image but cut the light for a factor of 2 on the FF, compensating for the smaller pixels in the crop sensor. First is a photo (100%) crop of my favourite medieval brick chimney. The 300mm/2.8 II + 1.4xTC III on my 70D at iso640 is at least equal to my 300mm/2.8 II + 2xTC III on my 5D III at iso1250.

Below, are centre crops from the standard chart (printed out on rough photocopy paper). Again, The 300mm/2.8 II + 1.4xTC III on my 70D at iso640 is at least equal to my 300mm/2.8 II + 2xTC III on my 5D III at iso640.

Two further points. The 300mm/2.8 II + 2xTC III on my 70D has lost some IQ, and it is probably worth sticking to the 1.4xTC. The Tamron at 150-600mm at 400mm on the 70D is quite good and is much better than at 600mm on the 5DIII.

So, these tests have made up my mind for me. I am going to use the 100-400 II on a 70D or 7DII as my hiking/birding lens. I think that the new 400 DO II on the 7D II will be better than the 300/2.8 + 2xTC on the 5DIII for hiking/birding. Let's wait and see.

Third Party Manufacturers / Sigma 150-600 Sport vs Tamron 150-600mm
« on: October 29, 2014, 06:58:27 PM »
Lenstip, bless them, have done the first review of the Sigma 150-600mm sport. The MTFs are very impressive, and beat the Tamron. But it is a monster, heavier than the Canon 300/2.8 II + 2xTC. It weighs 2860g vs 1951 of Tamron. It is 120 x 290.2mm vs 105.6 x 257.8mm. (The 300/2.8 II is 128 x 248mm, 2350g)

It's a better lens than the Tamron but it is too large and heavy for me as it would be easier to carry and pack the admittedly much more expensive 300/2.8. Nevertheless, a very impressive lens.

PowerShot Cameras / SX60 HS
« on: October 15, 2014, 04:04:26 PM »
The first reviews are trickling out, e.g, http://cameras.reviewed.com/content/canon-powershot-sx60-hs-digital-camera-review

It handles better than the SX50, it is reported. The local shop had one in today, which gave me the chance of a few shots side-by-side with the SX50. The evf is a real improvement and seemed more responsive, but I was more interested in the IQ at 1365 on the SX60 vs 1200mm.

I used iso 320 and RAW. Unfortunately, DxO doesn't have a raw converter for the SX60 yet but the latest DPP for Powershot works. The SX60 was very noisy, much noisier than the SX50, and the SX50 gave better results.

Site Information / Noisy obtrusive ads
« on: September 15, 2014, 07:32:18 AM »
Audio/video ads are being posted by Google that are activated simply by moving unintentionally the cursor over them without clicking. This activation happens when scrolling and the cursor slides over the ad. They are horribly noisy. Admin please get rid of them.

Lenses / What telephotos do we own?
« on: September 15, 2014, 07:20:46 AM »
With new telephotos being announced, questions asked about how many telephotos are sold, and the usual arguments about about which are better, it may be interesting to know the numbers and choices of CR members. To keep the options down, I haven't divided into I and II series.

Here is a way of calculating the effective extra reach or resolving power of a crop body versus FF, which will amuse the geeks among us.

Measure the MTF of a lens on the crop (= MTFcrop) and the same lens on the FF (= MTFff). The ratio of the MTFs, MTFcrop/MTFff, gives the relative resolving power of the bodies with that lens. However, the crop body can be placed 1.6x further away to give the same field of view. Therefore, the true effective relative resolving power, R, is given by:

R = 1.6x MTFcrop/MTFff.

Photozone lists measured MTFs for a set of lenses on the 5DII and 50D. I calculated their ratios for the Canon 200mm f/2.8 II, 85mm f/1.2 II and 35mm f/2 at wide apertures below the DLA. MTFcrop/MTFff is very close to 0.726 in all cases.

This gives R for 50D/5DII = 1.16.

So the effective extra reach is 16%.  (Based on the ratio of their pixel sizes, a value of 36% is expected.

The dpreview widget gives values for the 5DIII and 7D only for a few lenses. I did the same calculations with the Tamron 150-600mm (between 150-400mm), the Canon 200-400mm and the Sigma 50mm f/1.4 A at wider apertures below the DLA. In all cases, MTFcrop/MTFff is close to 0.742.

This gives R for 7D/5DIII = 1.19.

So, the effective extra reach is 19%. (Based on the ratio of their pixel sizes, a value of 45% is expected).

There are always arguments about using MTFs quantitatively, but I think in this particular calculation it is reasonably valid to use them. It fits in reasonably well with experience - Jon has shown there is better resolving power in photos of the moon with the 7D, but it doesn't look 45% better. And my own experience is that the 7D and 70D aren't much better than the 5DIII, certainly not 1.6x.

Animal Kingdom / Tamron 150-600mm bird pics
« on: August 19, 2014, 07:47:15 PM »
I have been on holiday in Canada for two weeks, walking with my Tamron 150-600mm and 5DIII. The birds are difficult to find - you suddenly come across small birds who will be around for a few seconds or minutes and then disappear. To get any photos you need a portable, reasonably long lens that you can swing into action in seconds. The birds are often hiding in bushes and you need IS for long exposures. My 300mm f/2.8 II + 2xTC III would have been the best solution, but the Tamron 150-600mm was more than good enough and more suitable for a holiday combining a family visit with the odd day for birding. Those knockers who have dismissed the Tamron in favour of a 400mm f/5.6L + 1.4xTC would have been completely stranded without IS - one of the exposures was as low as 1/50s and many in the 1/250 range. The 100-400mm would have been too short. The exifs are on the photos, which are all 100% crops, ie 1 pixel on the image = 1 pixel on the uncropped full frame. I was pleased with the haul. Most of the photos were in the Hammonds Plain area of Halifax NS.
The first 4: Canada Warbler 1/50s, Cedar waxwing, Black-capped chickadee, Ovenbird.

Please post images of your own from the 150-600mm Tammy.

Finally packing to go to Boston then Halifax next week. I was given helpful advice of places for bird photography and nature in http://www.canonrumors.com/forum/index.php?topic=19255.msg360984#msg360984

Any updates, more help and advice of where to go would be much appreciated.

I don't know whether to take my 300mm f/2.8 II plus extenders or settle on the Tamron 150-600mm for lightness and versatility at the expense of IQ at 600mm. What a terrible dilemma!

Photography Technique / Tour de France crops
« on: July 08, 2014, 10:11:24 AM »
Yesterday afternoon a stage of the Tour de France started from Cambridge, and I wanted a record of the parade coming out in front of my college, the tall Gothic building with the spire. So, I hung out of a 2nd floor window, with my right leg wedged between the wall and an armchair, on which my wife was instructed to sit and not get up. I used the 5DIII with a 70-200mm f/4 L IS at f/8 to increase the DoF and iso640 for a decent shutter speed. All images are reduced to fit.

I would like advice on the composition. Top is the uncropped image. Below a narrow crop to remove the spectators just below me and the wall of the building, and reduce the foreground. However, the Gothic building is rather to the right. Next is a squarer crop, which has some wall and faces, but the Gothic building is exactly 1/3rd way in. I like this version, despite the faces on the right. Bottom, is just to show the yellow and green jersyes as they went past (the 70-200mm is just so sharp).

Advice please on the best crop or left alone, bearing in mind the Gothic building is important?

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