| Showing all 3 reviews by DSG | |
| Review of: Sigmatel "Multi Scalematic" Y/S 135mm F1.8 by DSG on Mon February 27, 2012 | Rating: 9 | View more reviews | |
Views: 30982
Reviews: 2
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I bought this lens practically mint, for less that £55, including delivery back in 2008.
I was'nt really expecting it to be any good as I had been lead to believe that all the old 135mm f1.8 lenses that are available were optically one and the same, and I'd seen some pretty awfull wide open samples from lenses like the Spiratone 135mm f1.8.
However, I have subsequently discovered that it has completely different optics from all the other 135mm f1.8 lenses out there, like the Spiratone, and the Soligor, except for the optically identical Sigma XQ version. The Sigmatels optical design proved so effective that Pentax decided to borrow most of it when they produced their SMC-A version.
Here you can compare six optical diagrams used in various 135mm f1.8 lenses, including the Sigmatels:
http://imageshack.us/a/img715/1344/135mmf18optics.jpg
Both Spiratones and the Soligor version have an 82mm filter thread and weight about 1.2kg but the Sigmatel, which is physically smaller, has a 77mm filter thread, so the Sigmatel can use cheaper and easier to find filters and lenshoods, and it only weighs about 820g too.
I use a "Sonia Brand" 77mm lenshood which I keep on it at all times. Here is how it looks with the hood when fitted to my camera:
http://img202.imageshack.us/img202/8408/sigmatel1c.jpg
It performs best between f4-f5.6...Here are some handheld samples, some taken at f4 and some at f5.6:
http://img3.imageshack.us/img3/339/sdim3217bc.jpg
And a 100% crop:
http://img851.imageshack.us/img851/3996/sdim3217bcrop.jpg http://img829.imageshack.us/img829/1771/sdim3164ps1c.jpg
And a 100% crop:
http://img190.imageshack.us/img190/1315/sdim3164ps1crop.jpg http://img26.imageshack.us/img26/3446/sdim3341ps1c.jpg
And a 100% crop:
http://img153.imageshack.us/img153/9112/sdim3341ps1crop.jpg http://img826.imageshack.us/img826/1184/sdim3238ps1c.jpg
And a 100% crop:
http://img849.imageshack.us/img849/7528/sdim3238ps1crop.jpg
I highly recommend this lens, if you can find one that is, because they are pretty rare these days.
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| Review of: Carl Zeiss Jena Tessar 50mm F2.8 by DSG on Sun February 26, 2012 | Rating: 1 | View more reviews | |
Views: 287246
Reviews: 18
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Avoid this lens like the plague! The worst 50mm lens I've every used, and I've tried dozens. You can get much better lenses for less money.
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| Review of: Sigma 14mm F3.5 by DSG on Mon October 24, 2011 | Rating: 8 | View more reviews | |
Views: 25034
Reviews: 3
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Length (without front and rear caps): 80mm. Diameter: 81mm. Weight: About 475 grams. Number of Iris blades: 6. Max and min f-stops: f3.5-f22. Minimum focus distance (MFD): Between 50-75mm.
This lens offers a lot of value for money. In fact its probably the cheapest and widest, fully rectalinear, full frame (FF) prime available on the used market...On crop format DSLR's, fisheye distortion is so low that its not even noticable!
I have'nt tested it on a FF DSLR so its possible that there might be some noticable fisheye distortion on FF cameras, at least at the extreme edges of frame.
It has a permanently built-in petal hood, but its too shallow to stop all stray light hitting the bulbous, protruding front element. On crop format, contrast is OK across the frame but with its large and exposed front element it is sensitive to the direction of the sun...Shoot into the sun and veiling coma can become a problem, noticably reducing the contrast right across the frame. Shooting with the Sun behind you and adding some extra contrast in post processing is a good solution.
Sharpness is very good at centre of frame, tailing off slightly towards the extreme edges of frame.
Some CA can be noticable at the extreme edges of frame, with high contrast subjects, but across most of the frame its is well controlled and not noticable at all. Normally the CA takes the form of slight red/purple fringing on the left of high contrast objects, like tree branches, and blue to the right. The maximum width of the CA is only a few pixels though so its easy to remove in post processing.
Colours are slightly warm with this lens, but otherwise look quite natural.
Its minimum focus distance is around 2-3 inches from subject, where even with its inherrantly deep DOF, some subject isolation is possible and semi macro shots are possible. It has a six blade Iris, with positive click stops at half stop intervals.
Its lenscap comes in two pieces...A cylindrical collar, approximately 25mm deep, that slides over the petal hood and a conventional 72mm lenscap which clips into the hole at the front of the collar...Together they offer good protection of the whole of the front of the lens.
If your looking for a reasonably good UWA lens for very little outlay then I'd recommend you take a serious look at this lens.
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