Sigma 30mm f/1.4 DC DN For Micro Four Thirds

Image © SigmaPhoto

Background

We've reviewed the Sigma 60mm f/1.8 for Micro Four Thirds before and had good things to say about it.  IQ, size and price making it a quality consideration for someone looking for a 60mm focal length (120mm field of view).

Now, we look at another Sigma.  Highly regarded in most places, again for many of the same reasons as the Sigma 60mm.  This new review, though has a much faster aperture, wide open it is an f/1.4 - the Sigma 30mm f/1.4 DC DN with Micro Four Thirds mount is the subject of this review.

Is it as good as the chatter would have us believe?  Let's journey together and find out if this third party lens we got direct from Sigma as a refurb for $259 is worth keeping!

Handling/Size/Weight

The field of view (FOV) on this lens is 60mm on a 135 size sensor camera.  This falls within a competitive range of lenses both OEM and third party.  There are plenty of 20 through 35mm lenses out there for people to choose.

Upon unboxing, I found that the lens was a bit bigger than you'll see lenses like the Panasonic 25/1.7 or Olympus 25/1.8 and even the ZhongYi Mitakon Speedmaster 25mm f/0.95 has a smaller footprint.  It does have a little more weight to it than the above mentioned OEM 25mm, but it is much lighter than the Mitakon 25/0.95.  The Mitakon is 100% metal construction, where the Sigma uses a metal mount with plastics in the construction of the body.

The focus ring is dampened and feels good when you turn it, and this is a focus by wire lens, so power is needed to get it to focus.  There is also no hard stops at minimum focus or at infinity.  The lens also has no focus scale on it.

The front element is 52mm, which is common standard filter thread.

A lens hood is supplied with the lens.

The physical size of the lens is because it was designed around APS-C size sensors.  This can be a benefit to m43 cameras as the "sweet spot" of the lens fits squarely to the m43 sensor.

The lens may seem a little big on smaller m43 bodies, but it feels right at home on a PEN-F or an EM5.2 or larger body. 

Image Quality

No surprises here if this is not your first review of this lens.  Even at f/1.4, this lens delivers the goods!  Sharp wide open and 100% usable for most anything.

I find that Sigma lenses have a unique rendering that I find pleasing when using their lenses on mirrorless cameras.  A bit more contrast and a nice bokeh than some other lenses.

I had wanted this lens to replace the Panasonic 25mm f/1.7 lens I bought and as far as I can tell it will be able to do so.

Yes, the focal length and field of view are different, but if I really need a 25mm, I can utilize the Mitakon Speedmaster 25mm f/0.95 in it's place when I need very low light performance. Otherwise, I can pull out the Panasonic 12-32/3.5-5.6 or the Panasonic 12-35/2.8 when a zoom makes more sense.

Images taken in JPG mode with the Olympus PEN-F

1/1250, f/2.8, ISO 200

1/5000, f/1.4, ISO 200

1/60, f/1.4, ISO 400

1/5000, f/2.8, ISO 200

1/5000, f/4, ISO 200

Focusing

My history with Sigma lenses was severely tainted in DSLR land.   I've had poor luck with them in focus and function, even as recently as a short foray with the Sigma 12-35/1.8 on the Nikon D500.  This combo had severe focus issues with anything outside the middle focus point.

When we come to using Sigma's lenses with Micro Four Thirds mirrorless and have had nothing but great results in IQ, function and focus.

1/60, f/1.4, ISO 200

1/60, f/1.4, ISO 640

1/20, f/1.4, ISO 320

AF speed is excellent in S-AF. While not at the same near instantaneous speed as an OEM Olympus prime lens, it is not very far behind.  I do not use my current m43 cameras for C-AF, so cannot comment on those performance benchmarks.

I've not had an issue with missed focus with this lens, even at f/1.4.

1/250, f/2.5, ISO 200

Bottom Line

So, what is the deal with getting this lens when I already have a lot of other lenses in the same focal length/FOV range?  Yes, I have the Mitakon Speedmaster 25/0.95, but it is an all manual lens.  I did have the Panasonic 25mm f/1.7, but never really bonded with it.  It takes excellent images, for sure....but I was intrigued by the images I was seeing, the other reviews I've read about the Sigma 30/1.4.

The Panasonic 25/1.7 has gone up for sale and I'll be keeping the Sigma 30mm.

Panasonic 25mm f/1.7 Micro Four Thirds Lens Review

Image © Panasonic

Background

The rage as of late has been with the super fast aperture prime lenses.  Olympus has the 25mm f/1.2 that came out a while ago and they just announced that late 2017 and Spring 2018 will give us the birth of the 17mm f/1.2 as well as the 45mm f/1.2

While I do have a fast aperture lens in the Mitakon Speedmaster 25mm f/0.95, I'm not really in the market for any more.  So what is wrong with the f/1.7 or f/1.8 prime lenses?   Well, not a whole lot really.  They tend to be compact and lightweight and cost as little as they weight, relatively.

While it would be great to have the extra stop of light, the weather sealing of the f/1.2 lenses...I just don't see me needing that large aperture in those prime lenses.  Others that specialize in portraiture with their Micro Four Thirds kits will definitely love to see them...and listening to them, it has been a long time coming.

For this review, though - we are going to look at a bargain of a lens, the Panasonic 25mm f/1.7.

This little guy was bought brand new from Midwest Photo Exchange on sale for $150USD.  We'll look at it from handling, image quality and focusing on it's own as well as how I feel about it versus the stellar Olympus 25mm f/1.8.  I used to own the Olympus and really loved it.

Handling/Size/Weight

The field of view (FOV) on this lens is similar to a 50mm on a 135 size sensor camera.  It is not a pancake lens, but it is not large either.

It feels very light and is made from plastics, but the build quality feels very robust.

The focus ring is dampened and feels good when you turn it.

When compared to the Olympus, the Panasonic lens is a bit bigger.    When looking at the spec sheets, the Panasonic comes in lighter, by like 10 grams...not something most people would notice.

Both front elements are 46mm, so would use the same size lens caps and filters.

Panasonic does supply a lens hood with the lens, but it is a little odd to use because you must first remove a ring on the front of the lens. 

Image Quality

This thing is very sharp and at the price you can find them, it makes a whole lot of sense to get this lens if you wanted a 50mm FOV lens. 

I want to say that the Olympus might be a hair sharper in similar situations, but as sharp as both of them are, it's really splitting hairs at this point.

As I like to do, let us leave the proof show through in the images presented here.

1/60, f/1.7, ISO 800

1/125, f/1.7, ISO 200

1/60, f/2.8, ISO 800 (shot through some pretty dirty glass)

1/60, f/1.7, ISO 250

Focusing

As with all contrast detect cameras, when the lens locks in, it is dead on.

I did notice that on the EM5.2 that there were times when the Panasonic would hunt for focus or not lock in properly.  I'll keep an eye on it, but I do notice that this happens every now and again with new lenses.  I think a good lens contact cleaning would benefit here.

Bottom Line

Did I really need another 25mm prime lens?  No, not really.  However, for the price, how can you pass it up?  The Mitakon 25mm performs well, but it is a manual focus lens and that point may not be for everyone.    I love using it and will in the future.  The Panasonic 25/1.7 is a pleasure to use, produces great images, has excellent sharpness and focus' fast.   If maximum performance is desired in an f/1.7 or f/1.8 prime lens and you shoot Olympus bodies - get the Olympus 25mm.  If all things are equal and price is a sticking point - get the Panasonic on sale or used for around $150 - you won't be disappointed!

Panasonic 14-140mm f/4-5.8 Mega O.I.S Micro Four Thirds Lens Review

© PanasonicUSA

Background

We all want the best image quality we can get.  Sometimes we need to make compromises though when going out.  Some gear is to big or heavy, others don't do so good in low light... focus sled can be an issue.

There are times when it is most convenient or conducive to only have one camera and one lens, hopefully it is enough to cover the majority of the situations you'll encounter.

I've been hunting for that one lens solution for my Micro For Thirds lot for a long time.  I've already found a worthy one lens for Nikon DX in the Nikon 18-140mm f/3.5-5.6 VR.  I use it a ton on the Nikon D500.

So far, I've struck out on my selections in m43.  Having tried the best Olympus iteration of the 14-150/4-5.6II.  As much as there was to love about it, with weather sealing and a good range of focal length... It just did not do it for me.  There was something lacking in sharpness and feel.  I've reviewed it here, so feel free to check out that post for more details.

I've had people tell me to try out the Tamron equivalent and I might some day.  One has just not come across my path yet.  The internet does have a buzz about the Panasonic 14-140 lens though.  A local camera store had one for a good price.

Having had experience with the Panasonic pron line of lenses, such as the 12-35 and 35-100 f/2.8 and the great bang for the buck 12-32 pancake soon...I thought I might have a wonder in this all in one.

Keep reading to see how this lens fared in of testing.

© PanasoincUSA

Handling/Size/Weight

I don't really consider this lens heavy.  Honestly even the Olympus 40-150/2.8 Pro lens is not heavy to me.  Coming from all metal Nikon lenses, just about anything in the m43 line up is small and light.

One thing I always give Panasonic credit for is having rubbery like costings on their zoom rings.  I love the functioning of the Olympus lenses, especially the Pro line - however, bring in an environment like Ohio, you having the baking sun in the summer and frigid temps in the winter, having an all metal lens makes it difficult to use sometimes. Definitely will give the Panasonic a not in the positive for the rubbery zoom ring.

Size wise, it is decent, but still unobtrusive.  It felt good in the hand and balanced just fine on both the PEN-F and the EM5.2. 

Image Quality

This is where I really look hard on these lenses.  Having such a stellar line up of both zoom and prime lens offerings I was hoping that I had another diamond in the rough.  Hoping that the lens would be close if not identical to the Panasonic 12-32 through most of the range.

This is where I was let down.  From 14-80mm in the range, the lens performed acceptably well.  It was beyond that where it lost me and fell out of consideration.

I tried everything I could think of to get acceptable image quality.  I shot with anti shock mode, which is something I need to do with a lot of the Panasonic lenses.  No help.  I tried full electronic shutter...still no good.  I even placed the camera on a solid surface...a bit better, but still not passing the grade.

I tried wide open and stopped down apertures, shutter speeds all the way to 1/2000...still not getting there.

Now, I've seen some good stuff coming from this lens and it could possibly be me, for sure.  My best guess is that this might be a bad lens.  Unfortunately, the camera store only had this one copy so I have no other samples to check out.  Alas, though, I feel that this kind of lens is not going to be in the cards for me in m43 mount.

I will some day test the Olympus 12-100/4, but it does not fit the budget or size requirements I am looking for at the moment.

When the images are taken under 80mm focal length, I found the color and contrast very pleasing, as I do with most Panasonic lenses.

As shot image
1/200, f/5.3, ISO 200 @ 41mm

Center crop of above image.  I'm thinking this might not be a bad lens!   Good contrast and decent enough sharpness.

1/1600, f/5.6, ISO 200 @ 15mm

Again, I'm not having a lot of issues here.  The wider to middle focal lengths are showing to be very usable.  Again...my hopes are high.  Now to check the longer end of the zoom range.

1/250, f/8, ISO 250 @ 140mm

And from about 100mm through the end of the range...it just does not cut it anymore.  this center crop at f/8....I was hoping for much more.    The Olympus 40-150/4-5.6R is much better than this.  This is where I'm not sure that the lens is just bad across all the copies or if I have one that has an issue at infinity focus.  Closer focusing at the same focal length gives much better results.

For example, this image was shot from just a few feet away and the IQ is much better.  I do know that the 1/250 shutter speed on the construction worker shots is pushing the boundary....but the IBIS on the PEN-F has handled situations like this much better and I did test the same scenario with a 1/2000 shutter with no appreciable difference in sharpness.
1/1250, f/5.8, ISO 200 @ 140mm

Close up crop of the above.   Very acceptable sharpness here at this closer focusing distance.

Focusing

I can't really complain here.  The focus never really Hunter and felt quick and sure.  The manual focus ring is toward the front of the lens, like many others and I could find it without having to take my eye from the viewfinder.

Bottom Line

Searching for a one lens solution that fits my needs is still ongoing.  The Panasonic is a fine lens from the outside looking in, but the sample I had just let me down. If I ever get the opportunity to try another I certainly will, maybe even check out the newer version with f/3.5-5.6 aperture range.  For now, I'll just stick with a 2 lens solution that I know works for me.

I'm just let down by the focus toward infinity, which is where a lens like this would be working hard for me.  For now, I'll stick with the Olympus 75-300/4.8-6.7II and the Panasonic 35-100/2.8 for my longer lens needs.

Panasonic 35-100mm f/2.8 II for Micro Four Thirds - Review

©PanasonicUSA

Background

Sometimes you just fall into multiple good deals and that is what we found here. not only was I able to find a used copy of the Panasonic 12-35, but got a great deal on this Panasonic 35-100 and will be using it on the Olympus EM5 Mark 2 for our review.

I used to own the Olympus 40-150/2.8 PRO and will provide my thoughts on both the lenses and how they compare.

Handling/Size/Weight

When you think about this lens and its equivalent field of view of something like a Nikon FX 70-200/2.8 VR lens, this thing is absolutely tiny!  Even against the Olympus 40-150/2.8 - we are still in the tiny realm.

©camerasize.com (left to right)
Nikon D700 w/ 70-200/2.8 VR
Olympus EM5.2 w/ oly 40-150/2.8 PRO
Olympus EM5.2 w/ Panasonic 35-100/2.8

One of the differences between the Olympus 40-150/2.8 and this lens is the material that covers the lens. Living in an area where the winters here can be quite brutal, having a barrier between your ungloved hand and the metal of a camera lens is often a welcome thing.  The Olympus is an all metal construction, even the zoom/focus rings are metal.  Panasonic went with a rubbery material around the rings.  This will be a great benefit to me in those cold shooting months.  If you remember, the 12-35 Panny also had this benefit.

1/3200, f/2.8, ISO 200 @ 80mm

Focusing rings are different between the Olympus and the Panasonic lenses as well.  The Olympus has a manual override clutch system (which I prefer).  The Panasonic, you must select manual focus or the AF+MF mode within the camera body.   The focus ring on the Panasonic is well dampened and smooth for those that might have need to use it.

The only switch on the lens is the Power OIS switch.  I leave this on OFF as I allow the fantastic Olympus IBIS (in body image stabilization) to handle my stabilization needs.

1/1600, f/2.8, ISO 200 @ 56mm

The lens is weather sealed as well, so has protection against water, snow, dust and extremes of temperature.  Always remember, though that weather sealing is a an all or nothing concept.  Weather sealing is only at its most beneficial when you have both a weather sealed camera body as well.  The EM5.2 is indeed weather sealed, so makes for a good pairing.

The Olympus has a tripod ring, which is removable.  It can take some getting used to if you are trying to hand hold the lens.  Quite a few people either spin the foot to the top of the lens or remove the tripod foot ring all together when they don't need it.  I spun it to the top.

1/320, f/4, ISO 200 @ 44mm

The Panasonic is 50mm focal length shorter than the Olympus on the long end and 5mm wider on the wide end.  In practice, I never notice this difference in the wider end.  I do find that it is taking me some time to get used to not having that extra 50mm with equivalent 300mm field of view.  The Panasonic only gives you a 200mm field of view.   So long as I have good light, that is not much of a concern as I do have the Olympus 75-300mm f/4.8-6.7II to handle the longer stuff.

Image Quality

I cannot honestly see much of a difference between the images I get from this lens against the Olympus equivalent in regards to sharpness.

Straight out of camera, I might give a slight advantage in contrast to the Panasonic.  However, any differences can be made up for if you have a good grasp of your post processing.  This is very similar to what I experienced with the Panny 12-35 and Oly 12-40 characteristics.

1/640, f/2.8, ISO 200 @ 75mm

One thing to note as a "negative" on the Panasonic.  On the EM5.2, I have issues with all Panasonic lenses of the shutter shock variety.  I've had issues with all these lenses that I've owned and reviewed:
14/2.5, 12-32/3.5-5.6, 12-35/2.8 - the 35-100/2.8 is no different.   I would ensure that any Olympus camera you choose to use this lens on should have an anti-shock mode.

Another point that a lot of people will want to discuss is bokeh quality.  First off, I do conceed that this is a subjective topic.
Now, with that out of the way...

A lot of things contribute to the out of focus rendering. Focus distance, background distance, aperture, type of subject in the background, distance to subject and focal length.

I did find some instances where the Panasonic showed some nervous tendencies in some shots, it seemed less intense than when it was experienced with the Olympus 40-150 PRO.    The image of the dog below is one example.  The OOF background is a little nervous, but in similar situations using the Olympus, I feel the rendition would have been a bit more nervous.

I take this as a fact of how a lot of modern lenses do their thing. Since more and more lenses are pushing maximum sharpness, this seems to be a more common phenomenon.

Focusing

Auto focusing is fast and accurate, as you would expect from a micro four thirds camera and lens of this caliber.  I did notice some times, and they were very few that the 35-100 would miss focus from time to time or hunt and give up.  Maybe it did that 2 times out of the 500 some images I've taken with it so far.    If my memory serves, that seems pretty similar to the ratio I remember with the Olympus 40-150/2.8.  This very well might be a focusing system issue.  I'll do some additional test with the PEN-F and this lens to see of it reacts differently.  The lens is still relatively new to me, so I just may need some more time to get used to using it.

1/1000, f/2.8, ISO 200 @ 89mm

Against the Olympus - while I do not have both to test head to head, I can't imagine if one were faster than the other it is most likely negligible.  My gut wants to tell me that the Oly might be a bit faster.  At least that is what my mind wants to tell me.  Again, we are talking a relatively negligible amount for most applications here.  I'm really picking nits.

Bottom Line

Brand new, the pro line m43 lenses are an expensive proposition if you look at them against the other lenses in the m43 lineup.  However, if you look at them against other systems - even brand new they are a bargain.  A new Nikon 70-200/2.8 VR II lens will run you $2100USD, where are the Oly/Panny field of view equivalents are under $1500/1100 new, respectively!  I was able to pick up this Panasonic lens used for a little more than half the price of a new one!   You are not going to touch even a used 70-200/2.8 lens for that price unless you go third party options like Tamron or Sigma.

1/1600, f/2.8, ISO 200 @ 45mm

If you look at other head to head reviews on the Panasonic/Olympus 35-150 range lenses, you'll see that most people couldn't really give one an advantage over the other from a purely "lens only" view.

However, if you look at the other traits, it might make the decision fall more to one over the other.

If you have an m43 camera with no IBIS, then the Panny makes sense.
If you do a lot of manual focusing but don't like to have your camera in AF+MF mode, then the Oly makes more sense.
Shutter shock is a reality on the Olympus EM5.2 for the 12-35, so keep in mind that used on an Olympus body - ensure that you have anti-shock enabled!
You'll need to decide if you really need that extra 50mm on the long end to pick the Oly over the Panny.  Weight and size wise, the Panasonic has a large advantage.

1/1000, f/3.5, ISO 200 @ 47mm

Unlike the wide to medium telephoto PRO lenses, the differences outside of IQ are a lot more vast and may have a larger impact on your purchasing choices.

So, if you are on the fence on which to get, don't worry about AF speed or image quality.   Consider them equal for all intents and purposes in those regards and look more to the other things like size, weight, cost and additional reach.

I plan on shooting with the 35-100 and the 12-35 and will provide more sample images from it in the future.

Panasonic 12-35mm f/2.8 for Micro Four Thirds - Review

Background

Sometimes you just fall into some good deals and that is what we found here.  A used copy of the Panasonic 12-35 was available when I picked up a gently used Olympus EM5 Mark 2.

I originally had an Olympus 12-40/2.8 so I will not only show sample images from the Panasonic, but I will do some comparisons between the two.

Handling/Size/Weight

When you think about this lens and its equivalent field of view of something like a Nikon FX 24-70 lens, this thing is absolutely tiny!

©camerasize.com
Nikon D700 w/ 24-70/2.8 and Olympus EM5.2 w/ Panasonic 12-35/2.8

One of the differences between the Olympus 12-40/2.8 and this lens is the material that covers the lens. Living in an area where the winters here can be quite brutal, having a barrier between your ungloved hand and the metal of a camera lens is often a welcome thing.  The Olympus is an all metal construction, even the zoom/focus rings are metal.  Panasonic went with a rubbery material around the rings.  This will be a great benefit to me in those cold shooting months.

Focusing rings are different between the Olympus and the Panasonic lenses as well.  The Olympus has a manual override clutch system (which I prefer).  The Panasonic, you must select manual focus or the AF+MF mode within the camera body.   The focus ring on the Panasonic is well dampened and smooth for those that might have need to use it.

The only switch on the lens is the Power OIS switch.  I leave this on OFF as I allow the fantastic Olympus IBIS (in body image stabilization) to handle my stabilization needs.

1/500, f/4, ISO 200

The lens is weather sealed as well, so has protection against water, snow, dust and extremes of temperature.  Always remember, though that weather sealing is a an all or nothing concept.  Weather sealing is only at its most beneficial when you have both a weather sealed camera body as well.  The EM5.2 is indeed weather sealed, so makes for a good pairing.

1/4000, f/2.8, ISO 200

The Panasonic is 5mm focal length shorter than the Olympus.  In practice, I never notice this difference.  I find that I would notice more of a difference on the wider end than the longer.  For example, I can tell a big field of view disparity between 12mm and 14mm.

Image Quality

I cannot honestly see much of a difference between the images I get from this lens against the Olympus equivalent in regards to sharpness.

Straight out of camera, I might give a slight advantage in contrast to the Panasonic.  However, any differences can be made up for if you have a good grasp of your post processing.

1/1600, f/4, ISO 200

One thing to note as a "negative" on the Panasonic.  On the EM5.2, I have issues with all Panasonic lenses of the shutter shock variety.  I've had issues with all these lenses that I've owned and reviewed:
14/2.5, 12-32/3.5-5.6, and the soon to be reviewed 35-100/2.8.  The 12-35/2.8 is no different.   I would ensure that any Olympus camera you choose to use this lens on should have an anti-shock mode.

Focusing

Auto focusing is fast and accurate, as you would expect from a micro four thirds camera and lens of this caliber.  I noticed no hunting or missed focus issues.

1/500, f/4, ISO 200

Against the Olympus - while I do not have both to test head to head, I can't imagine if one were faster than the other it is most likely negligible.  In use, I never had an issue with AF speed with either lens - so fast to the point that if it couldn't have locked on in time, I probably would have missed the shot anyway.

Bottom Line

Brand new, the pro line m43 lenses are an expensive proposition if you look at them against the other lenses in the m43 lineup.  However, if you look at them against other systems - even brand new they are a bargain.  A new Nikon 24-70/2.8 VR lens will run you $2400USD, where are the Oly/Panny field of view equivalents are under $1000 new!  I was able to pick up this Panasonic lens used for $480!   You are not going to touch even a used 24-70 non-VR lens for that price!

If you look at other head to head reviews on the Panasonic/Olympus 12-40 range lenses, you'll see that most people couldn't really give one an advantage over the other from a purely "lens only" view.

However, if you look at the other traits, it might make the decision fall more to one over the other.

If you have an m43 camera with no IBIS, then the Panny makes sense.
If you do a lot of manual focusing but don't like to have your camera in AF+MF mode, then the Oly makes more sense.
Shutter shock is a reality on the Olympus EM5.2 for the 12-35, so keep in mind that used on an Olympus body - ensure that you haev anti-shock enabled!
That's really the only differences that have any real meaning.

So, if you are on the fence on which to get, don't worry about AF speed or image quality.   Consider them equal for all intents and purposes.

Sigma 60mm f/2.8 DN Art Lens for Micro Four Thirds Review

Image © Sigma

Background

I'm going to be very straight forward from the get go on this one.  I've had some pretty bad experiences with Sigma DSLR lenses in the past.   Hunt focusing issues, back and front focus and if you ready any of the forums - plenty of reports of compatibility issues.

However, this is a new era and the mirrorless cameras use a slightly different focusing system.  So, lets say we give Sigma another chance.  How does it fair now with a Micro Four Thirds System?

All images taken with the Olympus PEN-F.

1/320, f/2.8, ISO 200

Handling/Size/Weight

A medium size lens when compared to other m43 lenses.  The focus ring is large and smooth.  There are minimal markings on the lens as well.  The copy I have is the black version.

There is not much weight to the lens.  

When not attached to a camera and powered on, there is a clunking sound.  This is because Sigma is using a floating elements system to align the glass.  This sound is normal and stops once the camera is powered on.

1/125, f/4, ISO 250

1/250, f/4, ISO 200

Image Quality

Even wide open the optical quality for this lens is superb.  While I will not go out there and say that the lens is just as good as the legendary Olympus 75mm f/1.8 to which it is often compared.

Used, I picked up this lens for $130.  When compared to the Oly 75/1.8, which is up near $600-800, this lens is a bargain performer for sure.

Shooting at f/2.8 is great and usually more than adequate.   Colors are rich and contrasty and flare seems well controlled.

Sigma has had a good modern reputation in optics, being as good or better than the OEM equivalents, so seeing the IQ here being so high is no surprise.

1/1600, f/4, ISO 200

1/500, f/2.8, ISO 200

Focusing

The elephant in the room for me.  So how does it perform?

As many know, the benefit of the mirrorless contrast detect AF systems eliminates a lot of the focusing issues that plagued the Nikon F-mount Sigma lenses I've experienced in the past.  This is a great thing!   I've not even noticed any hunting issues.

Kudos for Sigma making this lens perform to a level that I find acceptable.

1/125, f/2.8, ISO 2500

1/1250, f/3.5, ISO 200

Bottom Line

The only major issue that I see with this lens is the roughly 2 second delay from a cold camera start.  While not a deal breaker, it is definitely an annoyance.
The one minor issue I found was the smooth focus ring can make using manual focus a little difficult sometimes.  A  bit of texture for a more positive feedback would be nice.   Even so, not many would probably use this lens in its manual focus configuration anyway - there is not much need to do so as the auto focus works just as you'd hope it would.

The lens is a bargain and a good longer focal length and field of view (roughly 120mm).   For those looking for an alternative to the Oly 75mm this Sigma is a good first choice if you want a lens that retains auto focus. 

ZY Optics Mitakon Speedmaster 25mm f/0.95 Lens Review

Image ©ZYOptics

Background

Dubbed the "Speedmaster" for its fast, f/0.95 aperture, this Micro Four Thirds mount manual focus lens provides a small size lens with fast aperture.  It's main competitor is the Voigtlander Nokton 25mm f/0.95.  All images here are taken with the Olympus PEN-F.

1/100, f/0.95, ISO 6400

Handling/Size/Weight

Even given it's diminutive size, this lens is all metal and glass, making it a bit heavier than you would expect.  When compared to its main competitor, though it is smaller, lighter and half the price brand new.  The ZhongYi Optics comes in around $399 new, while the Voigtlander will put you back $799.

Many other reviewers have compared the 2 and I'll let you explore the internet for those.

The aperture ring is clickless, which, when used for photography can be a bit of a struggle.   Moving the aperture by feel is no longer possible and there are no electronic contacts in the lens, so the actual aperture value is not visible in the EVF.  Having the option to turn the clicks on and off, as in other lenses similar to this one would have been great.

1/6400, f/1.2, ISO 200

The focus ring is in the back and the aperture ring is toward the front of the lens.  They are close together and initially I found myself accidentally turning the wrong ring.  We'll see how long it will take for muscle memory to kick in and rectify that.

Focusing is well dampened and smooth.   Getting exact focus is quite easy for me.   I use a high intensity yellow peaking on the Olympus PEN-F.

Overall the lens feels quality, even with the very basic engravings on it.

For those who subscribe to the Micro Four Thirds ethos of small size matters, then this lens will definitely fit that.

1/640, f/4, ISO 200

3 Image stitched panorama
1/1000, f/4, ISO 200

Image Quality

Some people think that older lens designs, even prime lenses, are not as good as the modern equivalents.  There might be some truth to that statement if we get into a "measurebating" analysis.  I, however, do not fully agree.  While it might be true that on paper one lens may be sharper than another, there is more to a lens than the overall sharpness.  My belief is that there is a threshold of "sharp enough" or acceptable sharpness that is good enough for me.  The 105mm/2.5 AI lens certainly falls into that category and then some.

If we look at the lens at f/2.5, this is probably where the lens is at its weakest.  Even with that, the wide open performance is still plenty acceptable.  Stopped down even a little bit to f/4 and it is very sharp.

I find that I like the rendering of the Nikon 105mm lens as well.

Looking to the Speedmaster f/0.95, I found center sharpness was good to exceptional at all apertures from 0.95 through f/11.  The corners progressively get better as you stop down.

At f/0.95 I expected the lens to be a bit dreamy, like the other ZY lens I have the Creator 85mm f/2.  That does not seem to be the case though.  Optically, this appears to be quite a good performer.

1/4000, f/4, ISO 200

1/2500, f/4, ISO 200

Focusing

As stated previously, I use yellow focus peaking on the Olympus PEN-F.  That can be a challenge when shooting hand held at f/0.95 in low light situations.   Challenging - yes, impossible - no.  Use the zoom function to assist you as well.

The smooth focus ring makes getting exacting adjustments easy to do.

Close focusing distance is useful.  You are not getting macro close, but it should suffice for most peoples usage.

1/2000, f/2.8, ISO 200

1/100, f/1.2, ISO 640

Bottom Line

This is a fun, fun, fun lens to use.  For some people this would be a specialty lens, used for special occasions and most likely wide open.