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  Reviews by: johnhopkins  

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Acratech ballhead

57ballhead_1_
Review Date: Jul 16, 2006 Recommend? yes | Price paid: $300.00 | Rating: 9 

 
Pros: Lightweight. Does the job.
Cons:
Some slight creep. Limited degree of rotation.

I use my Acratech Ultimate ballhead on two Gitzo CF tripods; the G1228 and the tiny G0027 for ultra lightweight travel. It is superb for travel easily fitting (with the G0027!) inside my Lowepro Mini Trekker AW with 6 lenses. I have however not used it to support anything heavier than the 950g of the 24-70L or longer than the 70-300 DO for which the ballhead is far more than sufficient. The light weight was a big factor in me choosing this ballhead as I have taken it places (like Himalayan hill-stations) where every gram counts.

On the G1228 it is a super stable setup with all my lenses. With the G0027 I also find it provides adequate stability for me so long as I extend the legs from the minimum position. With the legs in the minimum position it is OK for smaller lenses but I have to take care with the 24-70L. But they are issues with a very small set of legs – the Acratech ballhead is more than up to the task.

I have noticed some slight creep but you do get used to setting it up a little higher than you need knowing it will settle very slightly after you have tightened everything up.

Others have commented on the stylish but unorthodox design with its limited degree of rotation. The diagonal support bar looks very cool but restricts the movement of the camera. It is fine if you want to move through 90 degrees, i.e. rotate the camera from portrait mode to landscape, but will stop you continuing to rotate it further (i.e. to portrait again but upside down from the original position). Very often that is not an issue and even when it is you can simply twist the entire tripod around. But I am sure some people would not like that especially if they have a heavy setup.

It is not easy to find this ballhead in the UK. I ordered direct from the manufacturer’s website in the US but got stung an extra £50 (~US$90) for import fees.

Overall I am very happy with the Acratech Ultimate ballhead and would recommend it to others who put a premium on low weight.


 
Canon EF 24-105mm f/4L IS USM

24-105lisusm
Review Date: Jan 6, 2006 Recommend? yes | Price paid: $1,250.00 | Rating: 9 

 
Pros: Very close optically to 24-70L. Excellent performance wide open. Lightweight. IS. Range.
Cons:
Slight corner softness at 70mm (relative to 24-70L) and longer. High price for f/4.

A friend of mine recently got a 24-105L and I tested it against my 24-70L and 16-35L. I set up the tripod and took test shots at 24mm, 35mm, 50mm and 70mm at f-stops between f/4 and f/11. For good measure I took extra test shots at f/4.5 and f/5 expecting this to be the range where differences would be most apparent. I tested with a 1.6x crop sensor using 8.2 mega pixel JPEGs with no post-processing.

My summary result is that 24-105L and the 24-70L were almost identical optically at 24mm and 50mm. I gave the 24-105L a slight advantage at 35mm and the 24-70L a bigger advantage at 70mm. Both standard zooms were consistently slightly ahead of the 16-35L at 24mm and 35mm. The thing that surprised me most was the excellent sharpness of the 24-105L wide open in the 24-50mm range.

At 24mm the 24-105L was a bit better at f/4 and the 24-70L a bit better at f5.6-f/11. But the differences to the eye were very slight. Using averaged JPEG file sizes as an objective proxy for resolution the differences at 24mm was a negligible 0.4% advantage to the 24-105L. Call it a draw.

At 35mm the 24-105L was a winner at all apertures from f/4 to f/8. JPEG file sizes produced by the new zoom averaged 2.8% larger. Comparing the images carefully those from the 24-105 seemed very slightly sharper but also a little brighter.

At 50mm there was nothing between the 24-70L and the 24-105L. The averaged JPEG files were practically identical and my eye could not see any difference in the images. I took some further test shots with a 50mm 1.4 prime and it was no surprise to see that it was a bit better than either zoom. JPEGs produced with the 50mm prime averaged 3.5% larger than the zooms and the eye could see some finer details.

At 70mm the 24-70L was a clear winner at all apertures especially f/4 through f/8. The JPEGs from the 24-70L averaged 6.5% larger than the 24-105L and this is readily visible to the eye. The 24-70L was a bit sharper in the centre but the bigger difference was the corners (even using a 1.6x sensor) where the 24-105L was noticeable softer than the 24-70L. I couldn’t test with a full-frame camera but I can imagine the corners could only get worse. At 105mm there was again decent centre sharpness but some softness in the corners.

My conclusion is that the 24-105L is a very good lens especially at the shorter focal lengths coming very close to the 24-70L optically. Which medium range L zoom you prefer probably comes down to your desire for the wide-aperture ‘look’ of f/2.8 versus the low weight, IS and usefulness of the extra range of the 24-105L within the context of your lens collection. For those who want only one high quality lens that never comes off the camera, and is not heavy; the 24-105L is a great choice.


 
Canon EF 28-80mm f/3.5-5.6 II

ef_28-80_35s_1_
Review Date: Sep 20, 2005 Recommend? yes | Price paid: Not Indicated | Rating: 7 

 
Pros: Cheap. Small. Light. Decent performance at 28mm and good resolution anywhere in its range at f/11.
Cons:
Poor performance towards 70mm especially in the corners (except at f/11). Colour not the best.

I tested a friend’s 28-80 recently against my Canon 24-70L and a Sigma 28-70 mm f/2.8 DG. The results make me think this lens’ lowly rating on this forum is overdone. The Canon 28-80 may be a kit lens but it comfortably outperformed the Sigma zoom in my tripod-mounted test shots at all apertures within its limits at 28mm, 50mm and 70mm.

The 28-80 could not match the Canon 24-70L in colour and contrast, but at f/11 there was no difference in resolution anywhere in the zoom range. At 28mm the 28-80 performed pretty respectably (though not as well) relative to the L zoom. Resolution at f/11 was identical to the L and only a little worse at f/5.6-f/8.

Performance drops off further in the zoom range. At 50mm the 28-80 performed as well as the 24-70L at f/8-11 but resolution tailed off at f/5.6 and especially at f/4.5. The corners especially were poor.

At 70mm the 28-80 only really performed well at f/11. Resolution was still OKish at f/8 but tailed off badly at f/5.6. It might still be OK for 4x6 prints but the corner sharpness (even on a 1.6x digital) becomes very bad at f5/6 & 70mm and is very noticeable on a monitor or large prints.

I came to a three conclusions regarding this lens:-
1. If used at f/11 anywhere in its zoom range or at f5.6-f/11 at 28mm then this lens can produce very decent results. Set the camera to Aperture Priority f/11 and leave it there if possible.
2. An inexpensive 50mm prime would be a really nice complement to this zoom making up for its deficiencies at the longer end and giving a low-light option.
3. If you do upgrade from this lens be prepared to go for real quality. Otherwise you may spend quite a reasonable amount of money (the Sigma 28-70 is £250 on the UK high street) and actually end up with something that is worse.


 
Canon EF 50mm f/1.4 USM

ef50mmf_14usm_1_
Review Date: Aug 25, 2005 Recommend? yes | Price paid: $300.00 | Rating: 9 

 
Pros: Very sharp from f/2.8, USM, FTM, Bokeh, Good portrait lens on 1.6x digital, light weight, cheap.
Cons:
Not really usable at f/1.4. Soft at f/2.

I did a series of tripod-mounted test shots recently at 50mm with the 50 f/1.4 against the Canon 24-70L, Canon 28-80 f/3.5-5.6 kit lens and Sigma 28-70 f/2.8 DG. Perhaps not surprisingly the 50 f/1.4 was sharper than all the zooms, but I was surprised how well it performed even against the 24-70L. The 50 f/1.4 was as sharp at f/2.8 as the 24-70L at f/8 (its sweet spot). The JPEGs produced with the prime were ~5% larger than the L-series zoom at any given aperture between f2.8 and f/8 (the gap narrowed at f/11 and was gone at f/16) and this difference in file size was visible to the eye as extra detail.

The performance of the 50 f/1.4 against the Canon kit zoom lens was even better … and against the Sigma it was simply no contest.

Centre sharpness at f/2 is OK but the edges are soft and the colour and contrast is going. I would not want to use this lens at f/1.4.

I got his lens for its low-light performance and it delivers outstanding results at f/2.8 in a lightweight and low-cost package. The sharpness from f/2.8-11 is a sensational bonus and I would strongly recommend this lens to anyone.