Saturday, 4 October 2014

Lens Review - Mitakon 50mm f/0.95


I usually concentrate my lens reviews on how well they cope with infra-red photography on the Sony A7, but for this one I'll try to appeal to a broader audience. **Spoiler Alert** - For those of you with short attention spans: here's a quick summary of the conclusions (Skip to the 'Notes' section if you'd rather find out more first)...

    Pros (rated out of 10 for how awesome they are)
(9.5) - Amazing sharpness (even wide open)
(9) - Cheap (for a full-frame 50mm f/0.95)
(8) - Focuses to 50cm (although there is also a negative aspect here)
(8) - Good feedback from focus and aperture rings
(7) - Good construction (All metal and glass)
(7) - Great colours and contrast
(5) - Comes in a nice case
(2) - Lens hood is a nice touch (although doesn't fit well, almost a negative point)

    Cons (rated out of 10 for how annoying they are)
(9) - Moderate hot-spot with infra-red
(8) - Focusing 50cm-1m produces haziness
(7) - Bokeh aesthetics more nervous than dreamy
(7) - Extreme lens flare (although can look cool)
(7) - Extreme Ghosting
(5) - Infra-red can lack contrast
(2) - Focus ring would be comfier at the front
(1) - No exif data communicated to camera body
(0) - No AF (Not really a con, but some won't like this)

    Notes
After a year on the market the Sony A7 series (FE mount) lens options are still extremely limited. Despite new models being announced at Photokina 2014, its poor aperture & extremely over-priced lenses still make this mirrorless system one of the hardest to recommend, even with it's full-frame sensor. I sold my Nikon D3 to get the Sony A7 and don't regret that, but only because I'm happy using old manual lenses.

Now we have a Chinese company (Mitkaon / Zhongyi / ZY Optics?) stepping in to make a new lens directly for this mount and for a very reasonable price. The cost of the Mitakon 50mm f/0.95 undercuts the Zeiss 55mm f/1.8 by quite a bit. Of course, this is a manual lens that doesn't communicate with the camera body at all. On the other hand, the (almost) two extra stops of aperture offered by the Mitakon are something you'd normally pay thousands more for (£ or $) and this lens is all metal and glass. Despite the fake, plastic zeiss having autofocus, many would argue that this price difference is insanity and I'd have to agree. The big question is: Can the Mitakon's optical performance really stand up to a respected 'high quality' lens?



I'm a big fan of shallow depth of field, so when I saw the Mitakon going up for pre-order I jumped at the chance to own this specialist lens for a relatively low price (£480). I ordered it from 'MX Camera' (the official seller), only a day or so after it was announced. At that time shipment was suppose to be a couple of weeks away. well, after several weeks I heard nothing so I sent a few emails and was eventually given another date. After four more dates slipped by without notice I got rather upset and posted a very blunt message on MX Camera's Facebook page. Magically, my order finally materialised - a total of four months from my order date.

The 'Speedmaster' lens (oh yeah, it's called that by the way) is now apparently called 'Dark knight' as well, although this is not written anywhere on the products themselves. During a manufacturer switch (hence the huge delay) the lens had been updated with better coatings and a lens hood. The overall shape of the lens had been modified and the inclusion of a hood connection meant the filter size was now 9mm larger (making 3 filters I'd bought in the mean time rather useless). Apart from this, it seemed largely the same lens.



    Image Quality Issues (IR & Colour)
OK, let's get this stuff out of the way first, shall we? The Mitakon 50mm does have a lot of issues shooting infra-red. That has been quite a disappointment for me, especially after a 4 month wait. Although not as bad as the Voightlander 35mm f/1.4 images were, the Mitakon does unfortunately suffer from the dreaded IR 'hot spot' issue (about 20% of the time).


▲▲ Generic 850nm IR filter @ 1/320th, f/2.8, iso 100 ▲▲


At f/2.8 (Above) you can get a fuzzy highlight in the middle of the frame, growing in size as the aperture opens up to cause a second layer of vignetting. 


▲▲ B+W 093 IR filter @ 1/25th, f/16, iso 100 ▲▲

At f/4 and above the hot-spot gets smaller and quite harsh, especially against darker backgrounds. This can be quite difficult to blend out with an exposure offset. If you're not familiar with IR hot-spots and you see the above example as a lens flare, think again - this was shot facing directly away from the sun. It doesn't always happen, as it's related to the brightness of the scene, dynamic range and a few other things, but it's annoying when it does. This makes me wish I was using a different lens when shooting IR landscapes.


▲▲ Generic 850nm IR filter @ 1/320th, f/0.95, iso 100 ▲▲


Shooting at wider apertures generally produces low contrast images and it's difficult to expose, or compensate for this and the double layer of vignetting in post. It can also produce noticeable levels of noise trying to fix all this. Above is an example before and after fixing the contrast in ACR (Adobe Camera RAW). I often need more than 100% contrast for this, so I tend to use the curves adjustment instead (also in ACR). This can be useful for redistributing the tone in a more pleasing way as well, so it's not a huge pain that you need to get used to this, other than how far you have to push it at times.

With pure IR images like this the corners are not only doubly vignetted, but they're also rather soft / blurred. This seems to be an issue with the filters interacting with the lens. This happens even with good quality filters that work fine on other lenses. This issue doesn't go away when stopping the aperture down and the lens doesn't suffer from this when shooting 'normal' colour (visible spectrum) images. There seems to be a combination of things going on here, perhaps the shallow flange distance is amping up other issues. 


▲▲ B+W UV/IR Block filter @ 1/100th, f/0.95, iso 100 ▲▲

What is consistent with its colour performance is possibly the most obvious flaring I have ever seen in a lens. I hesitate from saying "worst", because sometimes I do actually kind of like it. This flaring changes shape when stopping the aperture down, but it never fully goes away (unlike most other lenses) and this is the same situation with IR.


▲▲ B+W UV/IR Block filter @ 1/50th, f/1.4, iso 4000 ▲▲

Above is an example of the kind of flare you can expect at night. This is a worst case, it doesn't always look this bad. At least with the EVF you can see pretty much what you're getting, so you can do your best to minimise this while shooting.


▲▲ B+W UV/IR Block filter @ 1/100th, f/1.4, iso 600 ▲▲

Another bad issue that affects colour and IR equally is 'ghosting' - harsh highlights getting mirrored across the frame. Similar to the flaring, this is worse on the Mitakon than I've ever seen elsewhere. The above example is only a moderate case of it too, it can easily ruin a shot.


▲▲ B+W UV/IR Block filter @ 1/50th, f/1.4, iso 1600 ▲▲

And finally - colour fringing. Yes, it happens here at times and occasionally it can be rather obvious, but the up side here is that with the tweaking of some RAW sliders you can make it almost completely disappear. One word or warning though; if you do a lot of adjustment here, just do a quick check around other areas of your photo that might contain similar colours because it can do nasty things to them too.

So, Infra-red performance might seem rather meh because it suffers from all of the above issues, but would I avoid using it purely for IR? Well no, not quite. To be fair most of the issues I've mentioned don't always happen and the amazing shallow depth of field still brings a lot to the table. In my case, having a full-spectrum conversion is also useful, as I can switch to colour when I want (to avoid hot-spots and blurry / dark corners), but if you have a straight up IR conversion I'd be less inclined to recommend it (despite the blurry corners probably not being an issue), unless you're an absolute bokeh whore, like me.

    Handling
This lens is only slightly bigger than the Zeiss 55mm f/1.8, or the Nikon 50mm f/1.4 (including the Sony adapter), albeit a bit thicker than either of those offerings. The real problem is not its size though, it's the weight. If you're used to a 'normal' 50mm prime, or a cheap zoom then 800g (or 1240g incl. the camera) will outright shock you on a mirrorless camera. There's a lot of metal and glass here, but, of course, this is also a good thing.



The weight distribution is extremely front heavy, so I wouldn't recommend holding the camera by only it's grip when this lens is on. For this reason it really scares me to put it on a tripod, because it feels like it could rip the mount off. A tripod mount on the lens would have been better, but I can also see why that would have been annoying for normal use.

After getting screwed on the filter thread change, I decided to make do with what I already had and adapted a few 77mm filters. Unfortunately this meant ditching the included plastic lens hood, which doesn't fit on the lens very well anyway (well, if it goes on, it's extremely hard to get off). So, instead I've been using the screw on metal hood that came with my Nikon 85mm lens, although this doesn't help with weight or size.



    Aperture
The aperture ring being at the front feels a little weird to me. It falls at my comfortable handling position, which is a shame because I rarely want to move it. The saving grace here is that it's really stiff to turn, so I find that I don't move it by mistake. The step-less aperture is fascinating to turn and watch the blades moving, but more useful would be it's application for video (which I haven't tried yet). The spacing between the aperture values is a little odd. There is a lot of room between the first three full stops and almost nothing between f/8 & f/16. f/11 isn't even shown.

I didn't find there to be a complete stop of light going from f/1.4 to f/0.95 on the Mitakon 50mm. The size of bokeh also doesn't grow much (it mostly just gets less circular). These aspects felt rather disappointing considering it's kind of why you justify buying a lens like this over a smaller, lighter, cheaper version. So, I decided to compare it to a couple of 50mm f/1.4 lenses I had on hand:


  • Pentax-M 50mm f/1.4
  • Nikon 50mm f/1.4 AF-D

Here is the sample scene I used for the comparisons (this frame is from the Mitakon @ f/1.4):



And here are some crops from each lens:


 100% crop to show bokeh

100% crop to show sharpness

These were all set to iso 100, with the same shutter speed on all the f/1.4 values (1 stop faster shutter on the f/0.95 value - right). Focus was set as carefully as I could, using the 200% zoom function on the EVF. Click on these two images to see larger samples.

As you can see the bokeh shows almost no halo effect on the Mitakon. Perhaps more interestingly it seems that the f/1.4 marking behaves more like f/1.2 and it gives the most circular bokeh. More than f/1.4 starts to show the blades (9), although they are a little curved. This aperture is also a good sweet spot for sharpness. With the Mitakon's aperture fully open (f/0.95) the bokeh gets very 'cat's eye' shaped (even close to the frame center). It also doesn't appear to give a full extra stop of light. That said the f/1.4 was also brighter on the Mitakon, compared to the Pentax or Nikon, so I think the 't/' value (transmission) at f/1.4 is more like t/1.2 as well. It may not sound as sexy, but this alleged f/1.4 marking seems to provide the best 'sweet spot' of bokeh and sharpness.

    Focusing
The focus ring of the Mitakon's being at the back is easy to miss for me as my hands gravitate more towards the aperture ring. This could be related to my frequent use of old manual lenses on the Sony (via adapters), which pushes the focus mechanism even further forward.

When you do find the focus ring it's nice and easy to turn. It's just stiff enough not to get jogged out of position too, so it's a good level of friction. It's not beautifully smooth throughout the turn, but it's not bad at all. At points it feels a tad scratchy, but this depends on the angle you're holding it. I wouldn't say this makes it feel cheap, in general it feels very solid and well put together, but I have slight concerns for long-term reliability.

The spacing of distances throughout the focus turn is about as exponential as the aperture ring. There's a huge amount of play with close distances and almost nothing between 7m - infinity. This is more common than the aperture ring spacing however, but it's not great for video use.

The hard truth is that focusing accurately with this lens (wide open, or at f/1.4) is hard. Even with focus assistance like zoom and/or peaking it's so easy for your subject to move out of the focus zone. A lot of your shots will be blurry and it won't be the lenses fault.

    Sharpness
It's worth baring in mind that the sharpness of any super wide-aperture lens will not be it's strength. What you get here is the relative sharpness compared to the amount of out-of-focus blur, the depth of field, or 3D Pop from the subject.

Usually a slightly less wide aperture version of the same lens performs better on sharpness, even at the same apertures. For example a 50mm f/1.8 is sharper at f/1.8 than the f/1.4 version, so if it's only sharpness that you're after save your money and get the significantly cheaper lens. That said, the construction of the Mitakon lens is significantly different to any common 50mm f/1.4 or f/1.8 and thus it's not easily comparable, although the same rough rules apply here.

So, considering it's maximum aperture, I found this to be a very sharp lens. It's surprisingly good wide open (if you can focus properly) and it's extremely sharp at f/1.4, which acts more like f/1.2 anyway. This lenses center sharpness has beaten all of the other 50mm lenses I've tried so far. I think it would be very interesting to compare it to the Leica Noctilux (50mm f/0.95), but also the Zeiss Otus 55mm. I'm not saying that it will beat them, or even necessarily match them, but I think it will surprise people... Just not flaring :P. Neatly bringing me onto my next point...

    Bokeh
I didn't find the rendering of the bokeh from the Mitakon to be particularly pleasing. By it's nature it has a lot of it and, at times, that can save shots, but it just seems too nervous when it's subtle. This made too many images fall rather flat for me. Some of this relates to the heavy squashing of the bokeh shapes when fully open, so I mostly recommend not going wider than f/1.4, but I still think it's OOF rendering doesn't hold up to the great bokeh lenses aesthetically.

When maximising the 3D pop factor I found that shooting your subject between 1-3m produced the nicest results because you get a great sense of isolation! At f/1.4 you still get nice, big & flat, rounded bokeh shapes too, so I advise caution in going wider than this.

    Competition
It will seem quite expensive to some people for a 50mm, but for one with this aperture it's really rather cheap. The Leica Noctilux being about £7500 and even other Chinese brands like the SLR Magic Hyperprime are going to set you back £2400, making the Mitakon seem like a bargain. Of course there are other options, like adapting a second hand Canon 50mm f/0.95, but that's still likely to cost you over £1000. The Mitakon 50mm may just be one of the best value super-wide aperture, full-frame lenses ever made!

    Samples
Here are some 'colour' images that I've taken with the Mitakon 50mm...


 ▲ B+W UV/IR Block Filter (Colour) @ 1/320th, f/0.95, iso 100 ▲▲

 ▲ B+W UV/IR Block Filter (Colour) @ 1/500th, f/0.95, iso 100 ▲▲

 ▲ B+W UV/IR Block Filter (Colour) @ 1/60th, f/1.4, iso 640 ▲▲

 ▲ B+W UV/IR Block Filter (Colour) @ 1/60th, f/0.95, iso 2000 ▲▲

▲ B+W UV/IR Block Filter (Colour) @ 1/640th, f/0.95, iso 100 ▲▲


▲ B+W UV/IR Block Filter (Colour) @ 1/50th, f/1.4, iso 2000 ▲▲ 

▲ B+W UV/IR Block Filter (Colour) @ 1/3200th, f/1.4, iso 100 ▲▲

Here are some 'infra-red' images that I've taken with the Mitakon 50mm...


 ▲ Generic 850nm IR filter @ 1/320th, f/0.95, iso 100 ▲▲

▲▲ Generic 850nm IR filter @ 1/100th, f/4, iso 100 ▲▲

 ▲ B+W 093 IR filter @ 1/1600th, f/0.95, iso 100 ▲▲

 ▲ B+W 093 IR filter @ 1/80th, f/1.4, iso 100 ▲▲

▲ B+W 093 IR filter @ 1/320th, f/1.4, iso 100 ▲▲

As you can see infra-red is not a complete bust with this lens. Most of these examples are shot using f/1.4 or wider to avoid the hot-spot, not that I would use another setting on this lens often anyway. That said the second sample (Prince Albert Monument), which was shot at f/4, did have a slight hot-spot, but I tried quite hard to compensate for it here. 

    Bokeh Panoramas
Here are a couple of bokeh panoramas that I've taken on the Mitakon. This technique involves taking a bank of photos at (or close to) the widest aperture, while rotating the camera on the lenses entrance pupil. These are then stitched together to make a larger, wider angle photo with shallow depth-of-field. On average I take about 25 images for each panorama when using the Mitakon 50mm. The results are roughly equivalent to a single shot taken with a 24mm f/0.7 lens (on the full-frame format). If it existed a lens like this would be too large, heavy and expensive to warrant using/buying. It would also be extremely difficult to make it perform to the same quality.


 ▲ B+W 093 IR filter @ 1/640th, f/0.95, iso 100 ▲▲

▲ B+W UV/IR Block filter (Colour) @ 1/2000th, f/0.95, iso 100 ▲▲

    Notes About Extreme Wide Aperture Lenses
It seems that harsh opinions are all too easily formed about relatively cheap, extreme performance lenses (such as this). Expectations are often unrealistic and limitations not fully understood. The truth is that almost all super-wide aperture glass performs poorly and has numerous aberrations when pixel peeping. The same is true of the £7500 Leica Noctilux for example, but to concentrate on this would be missing the point of these great lenses. It's also worth remembering that they're surprisingly hard to use. They will frustrate amateur photographers intensely, so if you're not quite sure you want one - it's not for you.

    Conclusion
Normally I'd call a good 50mm a general purpose lens, perhaps even the only lens you need to own, but in the case of the Mitakon it failed me for a few reasons.  I wouldn't want to take this lens on holiday for example, because it's both extremely heavy and requires a lot of attention to get good results. That said, this is true of any 50mm f/0.95 lens and some cost more than ten times what this does. 

When focusing on close up subjects the amount of blur produced by the Mitakon is stunning, but there are a couple caveats to that. firstly; the widest aperture gives very odd shaped light bubbles, so I advise sticking to f/1.4. Next up; focusing very close (50-100cm) can often cause an overall haze, even if you manage to nail focusing. Lasty; when your subjects drifts beyond 3m the drop in the amount of blur your background is getting doesn't render the prettiest bokeh quality.

Sharpness is this lenses killer feature as far as I can see and I wasn't expecting that at all given the extremely reasonable price. Although the corner performance drops off considerably (no good for a landscape photographer), the centre is very impressive, stretching out to a radius of 10-12mm (18mm being the very corner). Usually wide aperture primes are worse at resolving ultimate detail the wider apertures they're capable of, but this lens beats any standard f/1.2 and any f/1.4 I've tried. Even next to the Zeiss 55mm f/1.8 (not testes myself) and it's resolution is not far off - that's crazy! 

I wish the Mitakon was better at extreme lighting conditions, but the sun (or lights at night) can cause some rather horrific flaring / ghosting. Whether this, or any of its other issues can be written off in the name of 'character' will be up to you. This lens is far from perfect, but for us shallow depth of field junkies on a budget it's a masterpiece of engineering despite its flaws. it enables us to reach new levels of subject isolation and light gathering that would have otherwise been off limits and it brings with it some really quite unexpected positive aspects too (like build quality and centre sharpness). This has been one of the most challenging lenses to use but it's also the most interesting and exciting too.

    Scores
Optical Issues (Lack of): 5/10
Sharpness (Middle): 9.5/10
Sharpness (Edges - FF): 6/10
Sharpness (@ f/0.95) - 9/10
Sharpness (@ f/1.4) - 9.5/10
Bokeh quality: 7/10
Bokeh amount: 9.5/10
Size & weight: 4/10
Lens Markings: 9/10
Versatility: 7/10
Value (used): -
Value (new): 10/10

Overall Score (Colour): 9.5/10
Overall Score (Infra-red): 6/10
Extremely Highly Recommended (perhaps not for IR though)

8 comments:

  1. I have read countless lens reviews over the last 10 years. I hadn't found a review that covered everything I wanted to know about a lens, up until I came across yours. Keep up the good work.

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    1. Thanks very much for the high praise and kind comment! I really must get on and do some more reviews soon. Next up will be the Konica 40mm f/1.8 pancake lens.

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  2. I agree, great review... Think I'll go for the CV 35mm f1.2 first..

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    1. This comment has been removed by the author.

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    2. Thank you! Oh I am very curious about that lens. I wish you luck with it, I've heard great things. At the moment I am thinking about saving up for the Zeiss 35mm f/1.4 FE lens as my first actual Sony AF lens. I just bought the Canon 40mm f/2.8 pancake lens with a Chinese AF adapter and it works better than I expected. The STM lens makes the slow AF bearable I think, but it's still pretty slow.

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  3. Nice review. I wonder how good is this lens for astrophotography.

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  4. Wow!

    Great review :D I have that same lens and I LOVE it, even I miss a lot of pictures because of the manual focus.

    I was thinking of buying a filter, the first one indeed, and I have seen that for your color images you have used a "B+W UV/IR Block filter". Could you tell me a bit more about it?

    Thanks!!! :)

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    1. Thanks, I'm glad you liked it! Since you have not used filters before you're probably not in the same position as me I think. I need filters to shoot any spectrum because my camera has been converted to full spectrum. Without any filters in front of the lens my colours would be a washed out mess (not necessarily ugly). At the time I made this review I used a UV/IR blocker because I thought it was the best way for me to shoot normal colour photography, but I was wrong. I now know you can get hot mirrors, which block UV & IR properly for full spectrum cameras by absorbing unwanted parts of the spectrum rather than reflecting it. If you don't need a filter for a specific visual purpose then I wouldn't recommend using one at all. They will only degrade your image quality, especially with strong lighting in high dynamic range scenes.

      I hope that answers your question somehow, but if not just reply back :)

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