Dienstag, 2. Dezember 2014

RJ Lens Turbo Review

Probably most of you are familiar with the principle of Focal Reducers. If you are not, you might find this short explanation very inspiring.
Whilst the first product of this kind, the metabones speed booster, conmes up with a rather high price tag, there are already some lower-end alternatives and I have decided to go for one of those myself. The product I have picked in the end is the Speed Booster / Lens Turbo from RJ because you can find many positive reviews and it offers two special features: The
first is an aperture control ring for Nikon G lenses which is essential if you are going to use modern lenses. The second thing is the tripod mount shell which comes with the adapter and is important if heavy lenses will be used.

Those facts imply that the RJ should be a good pick, alright? So let us go a bit further and take a look at the actual performance and build quality of the adapter!

1. Build quality
The Adapter consists of a massive metal body that feels well made. There are some reports about other products revealing a misaligned flange distance as soon as you try to focus to infinity which is a major problem and renders the adapter unusable. 
But the RJ is different: As soon as a little screw, found at the side of the mount, is loosened, you are able to align the optical unit and adjust the flange distance.

There is one important thing to mention: The aperture is controlled mechanically by a little stick which is connected to the aperture Ring. The length of that stick is also adjustable with a little screw and you should alway check that length before you mount a new lens to the adapter. I did not when I mounted my Tamron 17-50mm lens and unfortunately the stick's protrusion was so large that it scratched the inner mount of my lens!

This inconspicuous pin turned out to be nasty!
Turn this to keep the heck in check!
Mounting the camera and lens on the adapter turned out to work very well: The RJ mounts very precisely with little play.

2. Image Quality
After we have seen that the adapter is well made, it is time to face the most important aspect: The image quality.
You can find many sample images from the adapter in the internet and examining them will most probably lead you to an impression that correlates with my findings: The adapter produces quite sharp images even at wide apertures. Yet, at higher aperture values there will appear a special kind of lens flare in the shape of a blue spot in the center of the image if there is a light source in front of the camera. This is not an issue in real life if you are not a landscape photographer who is dependent on small apertures, but should be mentioned. There is also a slight green cast introduced by the adapter which does not pose difficulties also, because it may be corrected in post very quickly and even on many cameras on set.

Yet, while the most Sample Images tend to look very promising, tack sharp from corner to corner, I have encountered serious edge softness with my copy on Micro Four Thirds cameras. Though the image center appears really sharp, there is a noticable decease of resolution in the corners, coming along with strong vignetting and distortion!

This issue is most present on short focal lengths with my Tamron 17-55mm, but still a bit noticeable with longer lenses.
After I had written to the RJ support regarding the Image quality, they recommended to try the flange distance adjustment. Unfortuntely I was unable to achieve an improvement by doing so and in consequence I decided to write an other email to ask about the fact that the most images in the web appear to be flawless and get an explanation if either I could have gotten a bad copy or there is a general problem with the quality of their adapters.
I have written to them two times and haven't gotten an answer in over one month. I guess that it is up to you to decide about the integrity of that company for yourself.
As you see on those samples, the adapter is unusable for serious use on mft cameras for which it is constructed and advertised.

So is it all bad in the end? Fortunately not because the adapter DOES produce a really decent image in the center and I found out that my Black Magic Pocket Camera, thanks to it's Super16mm Sensor, does only cover the sharper center of the Image so that the RJ Speed Booster turned out as a superb match for that camera! My Tamron gains one full stop of light and an usable amount of wide angle on the BMPCC. That is the reason why I am still satisfied with that product in a certain way.

But would I buy the RJ again or even recommend it to somebody?
No, I wouldn't because I feel cheated due to the lack of optical quality and the "unreliable" support. In the end this experience implies the conclusion that it might be worth spending some more money to get a reliable product from a more trustworthy company.

By the way:
As you can read in the right column of my blog, if you would like to say "thank you" for the hopefully useful posts, you can easily do this by making your next Amazon purchase using the links provided in the "Note" box. It won't cost you anything more, but helps me keeping this blog running! Thanks! :)