Why write this review?
Like many of you, I participate in several photography discussion groups in the Fujifilm community. One topic that comes back recurrently is whether the Fujinon teleconverters (TC) are recommendable. Fuji photographers wonder if the teleconverters perform well, whether they degrade image quality and autofocus, whether they are worth their price and which of the two converters are appropriate for a specific lens or use case.
With this review, I intend to share my real-world experience using the Fujifilm teleconverters. My objective is not to influence readers in making or not making a specific purchase, as each photographer may have different needs. However I hope everyone reading this can use this review as input in their own decision making process.
What is a teleconverter for?
A teleconverter is essentially a very small lens. It attaches between a compatible lens and the camera body. It is capable of multiplying the focal length of the mounted lens, typically by a factor of 1.4 times or 2 times, providing you with additional reach for capturing subjects that may be beyond reach.
A teleconverter provides several advantages. The most obvious one is that you can increase the usable range of your existing lenses with very little weight or size penalty compared to carrying another full-size lens. Using a teleconverter is typically a favourable tradeoff compared to excessive cropping in post-processing. Most teleconverters also preserve your camera and lens’ weather resistance and maintain image and sensor stabilization.
Using a teleconverter comes with a few drawbacks. The most important is that it reduces the amount of light entering your lens, generally by 1 or 2 stop(s) of light depending on the teleconverter. This can be a hindrance when shooting in low light conditions. TCs can also have small to moderate negative impacts on image sharpness, autofocus speed and autofocus accuracy.
Technical specifications and compatibility
The two teleconverters under review are the Fujinon XF1.4X TC WR and Fujinon XF2X TC WR, for the X Mount system.
The XF1.4X TC multiplies the lens’ focal length by 1.4 times and increases the aperture by one f-stop. The XF2X multiplies the focal length by 2 times and increases the aperture by two f-stops. For example, if your lens is set to a focal length of 100mm at F2.8, your effective focal length and aperture becomes 140mm F4 with the 1.4X TC and 200mm F5.6 with the 2X TC. The camera will accurately record the effective aperture and focal length when the teleconverters are mounted.
In terms of dimensions, both teleconverters have a diameter of 58mm. The XF1.4X weighs 130g and is 15mm long while the XF2X weighs 170g and is 30.2mm long. Both are compatible with the following lenses :
- XF80mm F2.8
- XF50-140mm F2.8
- XF70-300mm F4-5.6
- XF100-400mm F4.5-5.6
Be aware that Fujinon produces a third teleconverter for the X Mount system, the Fujinon XF1.4X TC F2 WR, which we will not review here. It is very similar to the regular XF1.4X TC, except it has different optics and adds compatibility with the mighty Fujinon XF200mm F2 lens.
Samples
I have real-world experience with both the XF1.4X and XF2X teleconverters, having owned them both at various stages. I used them both with the XF50-140mm and XF100-400mm, with various levels of success. The below samples summarize my experience.
Unfortunately, I don’t own the XF80mm F2.8 and as such cannot provide samples. I can only hypothesize that its performance with the teleconverters would be close to the XF50-140mm, as they have a similar aperture and range.
XF50-140mm
We know that this lens is great, sharp and fast. It is my favorite X Mount lens.
XF50-140mm + XF1.4X
Paired with the XF1.4X, this lens still performs great. The converter doesn’t degrade the images much to my eyes. In both cases, I stopped down the lens as there was bright sunlight.
XF50-140mm + XF2X
The XF50-140mm can deal with the XF2X really well, because it performs great even when shot wide open. I’m favorably surprised by the number of excellent shots I produced with this combo.
XF100-400mm
This lens outputs excellent images. All three images are shot wide open and cropped slightly, but the quality remains excellent. You do already see the ISO going up on some of these images, under dim lighting conditions.
XF100-400mm + XF1.4X
The image quality remains excellent with the XF1.4X, but you do see the ISO increasing. The teleconverter allows to fill the frame with your subject, it is a great combo again.
XF100-400mm + XF2X
I shot hundreds of images with this combo and struggled to find some images I was willing to post. We can start seeing some softness in the image due to the XF2X. You will also need a fast shutter speed at this focal length to avoid shake, consequently you end up raising ISO and degrading your images even further. It could be my skills, but you do see a marked difference in image quality compared to the previous samples.
Usage impressions
The first thing to keep in mind when interpreting these results is that you will typically use a teleconverter with the lens zoomed near its maximum focal length, as the goal is to extend your reach for far away subjects. There is no real point in using a teleconverter when the effective focal length will be lower that the maximum focal length of the lens, without a converter.
As you can see from the samples provided with this review, both the XF1.4X and XF2X teleconverters perform extremely well when paired with the XF50-140mm F2.8 lens. The fast F2.8 aperture provides plenty of light to counteract the f-stop penalty imposed by both teleconverters. The lens also produces excellent image quality at its long end, 140mm, even when shot wide open at F2.8. The XF1.4X TC has no perceivable impact on image quality. With the XF2X TC, you do notice the loss of light a little more than with the XF1.4X TC, but it is still usable.
With the XF100-400mm F4.5-5.6 lens, the story is a little different. The lens has a variable aperture and it is much slower than the XF50-140mm. It is also generally preferable to stop down this lens by 1-2 stops when shooting at 400mm, to get optimal performance. You probably see me coming :
- The XF1.4X teleconverter continues to be a useful combination with this lens, imposing very little penalties to image quality. You do start searching for light at 560mm, with the minimum aperture being F8. You will need to shoot in generally bright conditions, particularly if you stop down to F11.
- With the XF2X teleconverter, things get complicated really fast. At 800mm, the minimum aperture is now F11. You will need to keep a high shutter speed at that focal length to minimize shake and preserve subject sharpness. To reach an acceptable exposure, you will then either need to shoot with the aperture wide open or increase your ISO, both of which will negatively impact image quality. This mean that the XF2X TC is really only usable in very bright conditions and with very careful technique.
TL;DR. Just get on with it.
From my experience using the two Fujinon teleconverters, the XF1.4X TC is excellent with all lenses, with no negative impacts on image quality or camera functions. It is a very useful addition to your camera bag, particularly if you own a few of the compatible lenses.
The XF2X TC performs acceptably on the XF50-140mm, but it does not perform as well with the XF100-400mm and I was constantly disappointed with image quality. In terms of overall value, you might not use the XF2X TC as much as you would hope, and for that reason I have difficulty recommending it.
Sebastien Hinse - Blog 