Venus Optics Laowa 7.5mm f2 lens for MFT User review 4 December 2019

The full name  of this lens is Venus Optics Laowa Compact Dreamer 7.5mm f2.0 Ultra wide angle lens for the Micro Four Thirds mount, standard weight.

Spoiler alert…..this is a very good lens.

Read on for the details…………

As described on the Venus Optics website, Anhui Changgeng Optics Technology Co was established in 2013. The growing organisation has 131 employees at the time of posting, located at Hefei China.

There are currently 10 Laowa lenses in production with more promised soon. These are mainly manual focus, manual exposure ultra wide and macro lenses for MFT and Sony APS-C.

Update:  I notice that Laowa is now offering lenses for the Canon RF and Nikon Z mounts.

Both these lens types are suitable for Venus Optics’ strategy of offering manual focus, manual exposure models with no electrical contacts, no AF and no stabiliser.

This has allowed the designers to concentrate on producing lenses with excellent optical qualities at a very reasonable price.

Which brings us to the subject of this post.

The 7.5mm f2 is a native MFT lens not something originally designed for APS-C. It can be mounted and used on any MFT camera body.  I recommend one with IBIS (in body image stabiliser) but this is not essential.

It is an ultra wide angle non zooming lens with some very appealing qualities.

It manages to combine an unusually wide aperture of f2 with very good optical characteristics right from f2 in a tiny package. It can even accept a thin 46mm screw in filter and comes with a small petal type removable lens hood. 

I paid AUD620 for my copy new, retail in Sydney.  This is for the standard weight version at 170 grams with front and rear caps and hood, no filter.

There is also a lightweight version said to weigh in at 150 grams selling for AUD857 at my last check. This is intended for drones where presumably every gram is important.

Why an ultrawide ?

There are some types of subject which lend themselves to an ultrawide lens. These include interior and some exterior architecture, the night sky, low aerials, drone photography and landscape.

It can also be fun to use an ultrawide in other situations for the dramatic perspective achieved.

My experience with ultrawides for MFT includes the Olympus 9-18mm and the Lumix 7-14mm.

Why a prime ?

I found when using these zooms that I almost always set them to the widest available angle of view.

The reason for this is simple enough. The party trick (a.k.a. unique selling point) which these lenses bring to photography is their ultrawide capability. If I want a 12mm lens on MFT I will prefer a 12-35 or 12-60mm zoom over the long end of a superwide.

So a prime ultrawide makes sense even for an architectural photographer who can usually use their “two foot zoom” to achieve the desired framing.

I also like manual focus in a ultrawide because it enables the focus distance to be set by scale. This is obviously very useful for astro and aerial photography where you want the focus distance locked at infinity but is also useful in more terrestrial circumstances when an ultrawide is very suitable for zone focussing.

MFT ultrawide offerings

The MFT system offers many options in the ultra wide rectilinear (meaning it draws straight lines in the subject straight or just slightly curved in the picture) lens category, with several options for fisheyes as well.

None of the ultrawides includes a stabiliser in the lens. Olympus and Pana/Leica  models have autofocus.

None of the autofocus models has a distance scale and none of them allow the focus to be set to a specific distance by scale. Rectilinear options include

From Olympus

*  9-18mm f4-5.6 zoom with 52mm filter. This is very compact but optical quality is not up to the standard of the other lenses listed here and the aperture is smaller than the others. AUD685.

*  7-14mm f2.8 Pro. This has a dome type front element preventing the use of ordinary screw in filters. AUD1450.

From Pana/Leica

* Lumix 7-14mm f4. This is another lens with a dome type front element. Mine was optically very good. AUD994

* Pana/Leica 8-18mm f2.8-4. This takes a standard 67mm filter. It is reported to be very good optically. AUD1350.

Laowa 7.5mm f2 specifications and features

Ultrawide angle lenses have traditionally been large things with a huge front element, particularly when designed for SLR/DSLR cameras which require a retrofocus formulation.

Mirrorless cameras allow the rear element of the lens to be placed much closer to the sensor which enables a more compact design to be used for wide angle optics.

The optical construction is quite elaborate with 13 elements including 2 glass aspherics and 3 of  extra low dispersion.

The rear element moves with focus.

The front element has the Laowa “frog eye” coating. This is water repellent. I have not tested this on my lens but have seen videos which suggest it works well. The coating might be similar to the “Multi resist” feature on B+W filters.

The “C” in the name stands for compact, which it certainly is.

The meaning of the “Dreamer” designation continues to elude me. Maybe it is a reference to the character of the bokeh (out of focus rendition) produced by the lens which looks nicely smooth in my tests.

A petal type lens hood is provided and it does provide some protection for the front element. 

Unfortunately there is insufficient clearance between the hood and the front cap so every time I remove the hood this pulls off the front cap.

I glued two little metal lugs to the finger grips on the front cap so I can remove the cap when the hood is mounted facing forward.

The 7.5mm f2 is tiny. With the lens cap fitted and hood reversed the lens is 48mm long with a diameter of 55mm including the hood. It takes 46mm screw in filters. Thin models are preferred to prevent vignetting. I have not tried a polariser on this lens. Mass is 170 grams.

The aperture ring has clicks at whole stop intervals from f2-22. The ring is thin and very close to the camera body making it rather awkward to use. Changing aperture is therefore something to be considered in the Prepare Phase of use not in Capture Phase.

There are no contacts so you cannot see the aperture in the viewfinder. Shutter speed and ISO are displayed as usual.

My rule of thumb is to use

f2 for low light indoors

f2.8 for bright light indoors

f4 for general photography outdoors

f5.6 for landscape in landscape orientation with the near subject close to the camera

f8 for landscape in portrait orientation with the near subject close to the camera.

Achieving correct exposure

This lens requires the user to understand and be able to work with lens aperture (f stop), shutter speed and ISO sensitivity to achieve an appropriate “firing solution” for each photographic situation.

For users accustomed to automatic camera operation a new learning experience is required. I recommend a visit to https://www.cambridgeincolour.com/  for some useful tutorials.

You set the aperture on the lens.

Set the Mode Dial to M (manual)

Work out which dial changes shutter speed in M Mode. I have it on the rear dial of my G95.

Now there are two main ways to proceed:

a) set a specific ISO sensitivity, for instance 200 outdoors and control exposure with shutter speed, viewing the analogue exposure +/- indicator in the viewfinder

or

b) set a specific shutter speed and allow auto ISO to adjust the exposure.

I find method a) works best for me most of the time because it allows me to use the zebras to control exposure compensation by changing shutter speed. Changing shutter speed does not alter the character of the image. Changing either aperture or sensitivity will do so.

However sometimes method b) is more useful. I used this in the cathedral indoor picture, setting the aperture at f2, shutter speed at 1/30 second hand held and allowing the camera to select an appropriate ISO setting which was 1600.

Infinity focus

Focus at 1.5 meters

Focus at 1 meter

Focussing

The autofocus revolution in the 1980’s was in many ways a wonderful thing but it led to the loss of scale focussing. Manual focus lenses with a scale can be very useful when you want focus to be set at a specific distance from the camera.

Ricoh cameras have used Snap Focus for years. This is the electronic equivalent of scale focus. It works really well on the GR compacts and I do not understand why the feature is not available in all digital cameras.

Wide angle lenses with a distance scale can be used for zone focussing which can be very useful in street, documentary architecture and landscape work.

This uses the depth of field available at a given lens aperture to ensure everything from a near point to infinity or some far point is sharp enough for the photographic task in hand.

With the 7.5mm lens my rule of thumb is as follows:

For all general photography and everything except close-ups I use scale focussing.

For close-ups which I roughly define as a subject less than 0.5 meters from the camera I focus in the viewfinder or on the monitor using picture-in-picture image magnification. 

I don’t use peaking because on the G95 this just spreads the peaking color all over the frame to the extent that I cannot see the image preview properly.

Most photos however will usually be of a subject more distant than half a meter and in addition will often find best expression when everything in the frame is perceived as sharp.

Which brings us to scale focussing.

Before going on I need to point out a few things about modern cameras and lenses.

First, modern lenses including the subject of this post are capable of reproducing an amazing amount of fine detail the like of which I never saw in the days of 35mm film. The corollary of this is that even slight deviation from optimal focus will produce a slightly unsharp result.

The way that out of focus parts of an image are perceived will depend on the viewers expectations. If focus is on a close subject and the background is completely blurred this will generally be perceived as looking “right” because it conforms to the viewers expectations.

But if a landscape is presented with the near and mid parts of the scene sharp and the background slightly unsharp it may well be perceived as “not right” because it is at odds with the viewers expectations. It also presents an internal inconsistency with extremely high sharpness in the near and mid range but not in the distant parts of the scene.

Second a MFT camera/mount/sensor/lens system must be manufactured to extremely fine tolerances. There is the potential for deviation from specification at many points along the way. These include the camera mount to sensor distance and parallel alignment, lens mount to camera mount fitting, distance from lens rear element to sensor and lens centering.

With an autofocus lens a small deviation from specification in the lens to sensor distance will be masked by the AF which in a mirrorless camera is achieved on the sensor allowing (if everything is working properly) perfect focus to be achieved every time.

But with a manual focus lens if all the potential errors in the system trend one way you could end up with best focus at infinity falling somewhere other than exactly at the infinity mark marked on the lens barrel.

Note: My copy does not have a hard stop at infinity. Apparently early copies of the lens did have a hard infinity stop. In either case the following procedure is recommended.

Finding exact infinity focus

Set the lens to f2 and the sensitivity to ISO 200 and take a series of photos which include a clearly rendered distant subject. I recommend something more than about 50 meters from the camera. Set the focus ring just to one side of the infinity mark, then at the middle of the mark, then at the other side of the mark. Keep notes.

Look at the resulting images on a sharp screen at 200%. See which focus ring position gives the sharpest result. Extend the range of focus ring movement if required.

When I did this I was surprised to find that even one millimetre rotation of the focus ring (which is about the dimension of half the infinity symbol) produced a perceptible change in image sharpness at infinity.

You need to determine where exactly is the best position of the focus ring for infinity focus with your copy of the lens on your chosen camera body (it might be slightly different on a different body).

Now repeat this test for shorter subject distances. I chose 1.5 meters and 1 meter. Keep careful notes as you go.

I got lucky and found that the optimum position for infinity focus on my gear is with the red line pointing at the middle of the infinity symbol.

For 1.5 meters the best position places the infinity symbol between the red line and f2.8 marks.

For 1 meter the best position has the infinity symbol between the f2.8 and f5.6 marks.

For most subjects most parts of which are more than a meter from the camera and particularly if any part of the subject will be more than about 10 meters from the camera I just set the lens with the red line pointing to the middle of the infinity symbol.

If the foreground will be close to the camera, say, around 0.5 meters but there is also a mid ground and background I set the lens for 1.5 meters and use f5.6 or f8.

Note that the depth of field markings on the lens barrel give equal weight to the foreground and background.

In practice you need to deliberately bias focus towards the background. The reason for this is partly explained in the discussion above but is also partly because near objects appear much larger in the frame than far objects. So a degree of unsharpness which has little perceptible effect on near objects will have a very obvious effect on distant objects.

The standard “rules” for depth of field and hyperfocal distance focussing such as you will find in a textbook or online source such as dofmaster.com  do not give the best result.

You can read more about this topic here https://photographylife.com/depth-of-field-myths-the-biggest-misconceptions

And, when completely bamboozled by all that just stick to the reasonably simple guidelines in this post.

Lens performance

So now we have hopefully got the lens focussed right and got the exposure right, what about the results ?

Sharpness/resolution

This is very good in a large center zone of the frame right from f2, improving to excellent from f2.8 with diffraction effects starting to appear with f numbers larger than 8. In practice I see no reason to use an aperture smaller than f8 for the great majority of subjects.

The edges and corners are slightly soft at f2 cleaning up to very good by f4 and excellent at f5.6.

The lens focusses correctly on a flat test subject  with the center and edges both in focus suggesting minimal field curvature.

Distortion

There is mild barrel distortion which fortunately is evenly curved and is easily corrected with +9 in the Lens Correction panel in Adobe Camera Raw.

Color fringing

Mild color fringing can sometimes be seen at high contrast edges near the frame corners. This is easily corrected in Adobe Camera Raw.

Corner shading

This is obvious at f2 although correctable in Adobe Camera Raw, becoming negligible by f5.6.

Flare

The lens generally handles light sources in and just outside the frame decently well. However some veiling and other kinds of flare can occur with very strong light sources, like the sun.

I did not test for coma which is relevant to astrophotography but others have done so and apparently it can be seen in the outer parts of the frame.

Note: JPG vs Raw

If you mount a Panasonic lens on a Panasonic camera they talk to each other. The camera can apply software corrections for distortion, color fringing and other aberrations.

In the case of the Laowa lens, the camera recognises there is a lens mounted but has no other information. You have to set the correct focal length when prompted so the IBIS can work properly. No in camera corrections are applied.

So I always shoot Raw and make corrections as required in Adobe Camera Raw.

Summary

Good things sometimes come in small packages. The Laowa 7.5mm f2 is one such.

I would guess it is most likely to be used by a MFT owner who only occasionally has need of an ultrawide lens. But the optical quality is certainly good enough for professional use.

Lenses like this are part of the reason I am still using MFT cameras.

The Laowa 7.5mm is small, light, optically excellent and very reasonably priced. Packaged with the Lumix G95 it allows the thoughtful user to access very high imaging quality without breaking back or bank.