Focal reducer
May 21, 2017 16:08:27 #
I was interested if anyone here has used a focal reducer, and what do you think about them.
May 21, 2017 17:32:13 #
saside wrote:
I was interested if anyone here has used a focal reducer, and what do you think about them.
Are you talking about a close-up lens, or a wide-angle filter?
May 21, 2017 18:48:52 #
RWR
Loc: La Mesa, CA
saside wrote:
I was interested if anyone here has used a focal reducer, and what do you think about them.
It’s an auxiliary wide angle lens and, unless computed for the lens it is mounted on, very likely will produce unsatisfactory edge distortion.
May 22, 2017 00:34:19 #
neither it's also known as a "speed booster" https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&cad=rja&uact=8&ved=0ahUKEwjqxcHz1YLUAhVKllQKHQeFAX0QFginATAF&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FTelecompressor&usg=AFQjCNFM-lT4NMOQiVmB19MALnRiukKMHA&sig2=ytNjBOMi08xZFzEvoZvKZg
May 22, 2017 04:05:24 #
May 22, 2017 06:03:51 #
saside wrote:
They are the opposite of a teleconverter which spreads light over a larger area of the sensor the speed booster draws in the light from the front of the lens and concentrates it.
Metabones in the USA claimed to have a superior optical system to the chinese producers of essentially the same thing and charged around $400 for them. Some people claimed the cheaper chinese versions also worked well and i think there was some talk of problems with both types. The effect was to increase the effective f-stop of the lens by 1 stop i think.
https://www.dpreview.com/articles/2667195592/first-impressions-metabones-speed-booster
http://www.vintagelensesforvideo.com/lensturbo2-vs-speedbooster/ looking at the video I couldn't see much difference between them for $150 v the $650 cost of the metabones there doesn't seem to be $500 difference in the IQ
It's an odd thing with the focal length they apply a crop factor of 0.71 - 0.72 x but then you have the crop factor of the format to take in as well making a 50mm lens have a crop factor of around a 53mm lens.
For m43 you get to address the problem of a lack of wide angle lenses that can be adapted e.g a 35mm film lens of f2.8 and 28mm focal length normally ends up with the field of view of a 56mm lens. with the adapter maybe effectively 30mm field of view and F2.
The normal kit lens is a 14 - 42mm which has a field of view of 28 - 84mm but is 2 stops slower. It's tempting for the lower priced version but I wonder if the iq was good enough. There is corner softness but if you are going for a thin depth of field does it matter, there is some CA and a loss of contrast but lightroom or photoshop would take care of that pretty much.
Looking on ebay there are quite a few variations on offer but I could only find 2 used ones. They first came to market around 2013 so there must be a fair few sold and if they were trash then most people would be selling them on if possible. Since there is so few second hand i'm tempted to believe that they can't be too bad.
Looking at Amazon reviews doesn't help that much many have no reviews or just 1 or 2 One for canon to sony had 25 reviews 48% were 5 stars the low star reviews were for faulty products pretty much loose lens elements. Vignetting tended to be an issue and one review said they are really good for video and not so good for photography.
My m43 camera is very much under used, I much prefer my hefty K5 if I used it more I think i would be tempted.
However this isn't the post that's needed, it seems like a fair purchase if your budget is limited and especially if you want to make video.
Whats needed is someone who has bought one and uses it.
https://www.flickr.com/groups/lensturbo/pool/
The results from that flickr photo pool seem pretty good on average. For around 150 and having manual lenses to adapt seems to be a fairly good buy. I could see myself using my g5 more if i had the lens turbo 2 ...
May 22, 2017 13:25:10 #
saside wrote:
I was interested if anyone here has used a focal reducer, and what do you think about them.
I tried the MetaBones SpeedBooster adapting Canon EF mount lenses to Micro 4/3 (GH4). The results were awesome, and it retained all automatic features of the lens.
Alas, I was trying it on borrowed equipment. The Nikon version of the same SpeedBooster is strictly manual, and although I have seven old Nikon mount lenses, I'll pass... I don't enjoy stop-down metering ever, or manual focus, unless i'm doing video.
My take is that if you are using Micro 4/3 or Sony or Fujifilm mirrorless, and you have Canon EF lenses, it is a no-brainer if you want to use those lenses. But it does cost about $650. Various combinations are better than others. Consult with the vendor — discuss your lens collection and any known incompatibilities.
There are other focal length reducers on the market, but most of them are not very good.
May 22, 2017 14:12:19 #
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