The OptMag TL-OM14F 1.4x expander from Musashi Optical adapts your Super 35 lenses to cover large format sensors with an image circle up to 44mm. This covers the traditional 36x24mm sensor size and smaller. Its optical design was created to minimize the impact on the optical character of the taking lens with the only downside of the reduction of 1 stop in speed.
The expander increases your focal length and image circle by 1.4x and reduces your light by just 1.0 stop. This is how the Musashi Optical OptMag Expander can convert a Super 35 lens to cover large format sensors. Compared to other expanders of known brand the Musashi is the top of the bill and will outplay all the competition in terms of optical performance.
The 1.4x expanders sets up easily with its own integrated flange back adjustment, no shimming necessary, just loosen a screw and dial in the backfocus, by twisting the barrel.
One other unique feature of this adapter -which made Gafpa Gear pull the trigger to sell this adapter- is the unique physical size of the adapter which lets you use a broad variety of lenses including many vintage lenses. So far we haven’t found a lens that can’t be adapted, from 18 mm lomo standard speeds, to super baltars, to cooke varotal zooms. If you are uncertain if this adapter will fit your lens contact us and we will figure out if it will work, or we can even send you a demo adapter to try it out yourself.
It should also be noted that the super 35 lens must have an image circle of at least 31mm. 1.4X is a great focal expander factor to employ s35 lenses on a large format camera. Since most lenses have a generous enough image circle 1.4X is the sweet spot, however if you use vintage wide angle lenses which are designed for academy film, you might be better off with the Musashi 1.7X, or if you favour your vintage lenses a bit more cropped to reduce edge unsharpness, or soft vignetting the 1.7X might be also the better weapon of choice.
We made a few tests with an Arri/Zeiss Ultra Prime on a s35 image sensor without the expander and on a large format sensor with the expander.
The test can be downloaded in 6K from our dropbox HERE
As you can see both on the s35 sensor and expanded the Ultra prime has some corner fall off both in illumination and mtf when being wide open at t1.9 however the Ultra Prime gets nice and sharp from t2.8 and so on. Best is to dismiss the t1.9 images because both with and without expander this is not the best example. We will soon try to get a hold of master primes, which are a tad sharper, especially wide open. Our conclusion is that there is barely any difference between the lens without expander and with. We noticed the same when projecting the lens, which is of course a better way because it excludes the artefacts produced by a sensor design and inherent resolution and OLPF.