Lumix X 35-100mm f/2.8: Expensive, but fantastic

The long f/2.8 zoom is a standard part in a pro photographer's lineup. Back in the time of the film SLRs, these lenses were typically around 70-200mm f/2.8. With the 2x crop factor of the Micro Four Thirds format, the corresponding focal length range becomes 35-100mm, and Panasonic have conformed to the tradition here.

Here is the Lumix X 35-100mm f/2.8 (left) seen together with the Pentax version of the same lens type, the Pentax DA* 50-135mm f/2.8 (right):

As you can see, the Lumix lens is much smaller, due to the larger crop factor of the Four Thirds sensor, compared with the APS-C sensor size the Pentax lens is designed for. The Lumix lens is also remarkably light for a lens of this type.

Specifications

Here are the specifications, compared with some similar lenses:

Lens	Sigma 60mm f/2.8 DN	Lumix X 35-100mm f/2.8	Lumix X 12-35mm f/2.8	Olympus 40-150mm f/2.8 Pro
Announced	Jan 19th, 2013	Sep 17th, 2012	Mar 21st, 2012	Sep 15th, 2014
Lens elements/groups	8/6	18/13	14/9	16/10
Aperture diaphragm blades	7	7	7	9
Minimum focus	0.5m	0.85m	0.25m	0.70m
Diameter	61mm	67mm	68mm	79mm
Length	56mm	100mm	74mm	160mm
Filter thread	46mm	58mm	58mm	72mm
Weight	190g	360g	305g	880g
Hood included	Yes, but wide and pretty useless	Yes, well designed	Yes, well designed	Yes, well designed
Optical image stabilisation	No	Yes	Yes	No
Price	$220	$1250	$1000	$1500

Physical

Below I have placed the Lumix X 12-35mm f/2.8 (my review) together with the Lumix X 35-100mm f/2.8 below. The 12-35mm lens is the little cousin of the 35-100mm lens, and as you can see, they are designed very similarly, both with hoods mounted:

Both lenses have a metallic like barrel at the base, with a somewhat cheesey, glosse purple finish. I would have preferred to see a more matte and grip friendly surface being used here.

On the positive side, both lenses have a generously rubberized zoom ring, which is well dampened and easy to handle. I really like the zoom rings of these lenses. Besides, the 35-100mm lens does not extend when zooming, which makes it feel very solid.

The focus rings are made of some plastic material, and are not as well dampened as the zoom ring. They operate quite ok.

Focus speed

I have compared the focus speed head to head with the Sigma 60mm f/2.8 DN here. The test was done by placing a figure about 1m from the camera, and seeing how long time it takes from pressing the shutter until the picture is snapped. The light was quite dim, around EV7 (corresponding to a city night scene).



The shutter delay is 0.25s at 60mm and 0.33s at 100mm, which is very good. The autofocus speed is not likely to be a problem with this lens.

Here is a test of the autofocus speed during video recording, using the GH3 and GH4 cameras. With the GH4, the lens performs quite well.

Image quality

With tele zoom lenses, the image quality is often the most problematic in the long end. That is why I start by testing the lens at 100mm.

@ 100mm

I tested the lens by mounting it to the Lumix GH4 camera (my review) set on a tripod, at base ISO, and with OIS turned off. I used 10s shutter delay to avoid camera shake. For reference, I tested the lens against the Lumix G 100-300mm f/4-5.6 (my review). I focused on the blue sign in the centre:

Lumix X 35-100mm f/2.8 @ 100mm f/2.8	Lumix G 100-300mm @ 100mm f/4

To better compare the sharpness, here are 100% crops from the centre at various apertures (click for a larger image):

Looking at how well defined the blue sign is, I would say that the Lumix X 35-100mm lens is the sharpest at f/4.

Another test at 100mm:

Lumix X 35-100mm f/2.8 @ 100mm f/2.8	Lumix G 100-300mm @ 100mm f/4

And here are 100% crops from the lower centre area:

From the extreme lower right corner:

In this example, we see one weakness of the lens. While it is very sharp in the centre at 100mm, it is not so good wide open outside of the centre. The performance becomes better when stopped down, though. We shall see later in the tests that the lens does better even in the corners at shorter focal lengths.

@ 60mm

At 60mm, I use the Sigma 60mm f/2.8 DN as a reference lens. With both lenses being very well regarded, it is interesting to do a comparison of them. Here is a photo of some trees quite far away:

Sigma 60mm @ f/2.8	Lumix 35-100mm @ f/2.8

To better compare the image quality, here are some 100% crops from the centre of the images (click for larger images):

And from the lower right corner:

Here is another comparison, also taken from a fair distance:

Sigma 60mm @ f/2.8	Lumix 35-100mm @ f/2.8

It is easier to see the differences by enlarging the images from the centre:

And from the left frame:

Both lenses are performing very well here, and it is difficult to compare them. In the centre, they are pretty much flawless already wide open at f/2.8. Perhaps the Sigma 60mm lens looks a bit better at f/2.8, but the difference is very minor.

In the corners, the Sigma 60mm lens appears to be somewhat duller, and does not sharpen up even when stopping down to f/5.6. The Lumix 35-100mm, on the other hand, is quite impressively sharp already from f/2.8, and becomes even better when stopping down to f/5.6.

Still, it is fair to say that both lenses do very well, and would satisfy most conceivable needs in terms of sharpness.

@ 45mm

Here is a collection of M4/3 lenses covering 45mm, both primes and zoom lenses:

From left to right: Lumix X PZ 45-175mm f/4-5.6, Olympus 45mm f/1.8, Lumix X 35-100mm f/2.8, Panasonic-Leica 45mm f/2.8 1:1 macro (custom hood solution)

The Lumix X PZ 45-175mm f/4-5.6 is a compact tele zoom lens with power zoom. The zooming can only be operated electronically, which is good when you want to zoom while recording videos. It also works well for stills, as you can use the zoom ring much like a normal mechanical zoom ring. The lens is very good optically, and is a good choice for those who would like a compact tele zoom lens, at a somewhat steeper price. There are also more moderately priced alternatives.

From Olympus, the first dedicated portrait lens for Micro Four Thirds, the Olympus 45mm f/1.8. It is reasonably priced, quite good in terms of sharpness and bokeh.

Launched with the GH3 in 2012, the Lumix X 35-100mm f/2.8 is Panasonic's interpretation of the classic pro tele zoom lens. Sporting a constant f/2.8 max aperture across the focal length, it is generally regarded as a very good lens. It is also one of the most expensive Micro Four Thirds lenses available.

Finally, the Panasonic-Leica 45mm f/2.8 1:1 macro is responsible for a lot of firsts in the Micro Four Thirds lens lineup: The first Leica co-branded lens, the first macro lens, the first prime lens with OIS, the first portrait focal length prime. It is fairly expensive, and Olympus users are probably better off getting the Olympus 60mm f/2.8 for macro capabilities.

In my previous comparison, I tested the lenses at pretty close focus distance. This time, I chose to use a longer distance. The focus distance is about 20m, practically infinity. I had the camera, the GH3 on a tripod, and used the 2s shutter delay to avoid camera shake. I set ISO 200.

Here are the test pictures taken:

Lumix 45-175mm @ 45mm f/4	Olympus 45mm f/1.8
Lumix 35-100mm @ 45mm f/2.8	Leica 45mm f/2.8

To better compare the image quality, I have collected 100% crops from the images at different apertures. These are from the centre:



Based on the centre crops, we see that all lenses do very well. The Olympus 45mm f/1.8 is a bit soft wide open at f/1.8, and further improves at f/2.8 and f/4. This is quite normal for a fast prime lens. Even the best lenses cannot be expected to be very sharp wide open. For a reasonably priced fast portrait lens, it is doing very well.

The Lumix 45-175mm is quite sharp at f/4, and improves marginally at f/5.6. When testing lenses at 100mm, I was disappointed with the Lumix X 35-100mm f/2.8. This time, however, I am happy to see that it performs well.

Finally, the Leica 45mm f/2.8 1:1 macro is sharp already wide open, as I think most would have expected.

And from the lower right corner:



The corner performance is usually much more challenging for lenses, and this is where we are more easily able to separate the good from the less good. We can also see which lens has vignetting issues: They will have darker corner crops.

Is is no surprise that the Olympus 45mm f/1.8 needs to stop down to f/4 for the best performance. But considering that it is a fast prime, I don't think the f/1.8 image is that bad. Considering the price, I think it is doing well.

The Lumix 45-175mm vignettes a bit at f/4, but doesn't really get much sharper at f/5.6. For a compact tele zoom, I think the corner performance is quite adequate wide open.

It is a bit disappointing to see the vignetting at f/2.8 from the Lumix X 35-100mm f/2.8. However, the sharpness wide open is very good, even in the corners.

One would perhaps have expected the Leica 45mm f/2.8 1:1 macro to perform the best in this test, given that it is the most expensive of the prime lenses. However, it appears to need to be stopped down to f/4 for the best corner performance. That also takes care of the vignetting issue.

Bokeh

The Lumix X 35-100mm f/2.8 one would typically use wide open for the selective focus look. Hence, it is important that it are sharp wide open, which I tested in the previous section.

It is also important that the out of focus rendering (bokeh) is pleasant. To test this, I took these photos using the 35-100mm lens and the Sigma 60mm lens. I focused on the power outlet to the right. The focus distance is about two meters, a suitable distance for a people portrait with these lenses. Here are the full images:

Sigma 60mm @ f/2.8	Lumix 35-100mm @ f/2.8

And some closeups on the out of focus rendering:

Both lenses do quite well here in terms of bokeh. The Sigma 60mm f/2.8 DN probably has the upper hand here, though, as the out of focus highlights are more round. But the differences are fairly small. Both lenses do very well.

Like many Panasonic lenses, this one also has non-round out of focus highlights outside of the centre. You can see this in the examples below, click for larger images:

Lumix 35-100mm @ 35mm f/2.8	Lumix 35-100mm @ 100mm f/2.8

As you see, the corner out of focus highlights are elliptical-like in shape. So is this a problem? Probably not, it depends on how you plan to use the lens. If you use it outside at daytime, with less contrast, this is not an issue at all.

Alternative lenses

If you are looking for long, fast lenses, there are not that many to choose from. Olympus has a 40-150mm f/2.8 pro zoom lens coming, but it will be quite large, and very expensive.

In the mean time, you could go for the Olympus 75mm f/1.8, which is generally regarded as a very good lens: Sharp, and with a nice bokeh. If you are prepared to pay the fairly expensive price, you can hardly go wrong with this lens.

A lower cost alternative is the Olympus 45mm f/1.8, which is a reasonably priced and well performing portrait lens.

Olympus also have a macro lens specified at 60mm f/2.8. It is generally well regarded, and could be a good choice if you also have an interest in macro imaging.

And as seen previously in this article, the Sigma 60mm f/2.8 DN is a good and cheap alternative.

However, all the lenses mentioned here has one thing in common: They lack optical image stabilization. So if you intend to record video handheld, the Lumix X 35-100mm f/2.8 is going to be your best choice anyway.

Conclusion

The Lumix X 35-100mm f/2.8 is a very good lens. It performs well in comparison with all the lenses I have put to the test here. It is compact and light, and easy to handle. With the constant length (non-extending zoom design), it feels very solid.

The only negative factor I can see, is the price. The Lumix X 35-100mm f/2.8 is not cheap, but I think it is worth the price tag.

Example images

This picture was taken at 100mm, f/7.1, 1/200s, ISO 1250:

This picture was taken at 60mm, f/4, 1/125s, ISO 800: