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Andrew Reid

Fast apertures on the GH5 = Full frame

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16 hours ago, noone said:

That depends.     The lenses have to be considered with the camera used.

In any case, I think I much prefer the (cheaper) Sony Zeiss 55 1.8 to the Olympus 25 1.2. (yes it is not 50 but it is close enough).

I have had a LOT of normal lenses including a Canon FD 50 1.2 I loved and Pentax 50 1.2 that I loved to death (it eventually fell apart on me) but the Sony Zeiss has cured me of all of those others.

I also think the FE 85 1.8 is the biggest bargain going in photography for any brand and used on a FF camera I would also prefer it to the Fuji 56 1.2  and the FE 85 is also cheaper than the Fuji.      The FE 85 IS an absolute bargain but it is also an excellent lens and has similarly cured me of all the other 85s I have had (still have an FD 85 1.2 L).

Just my opinion.

EDIT and a couple of other reasons they are even bigger bargains.

Both those lenses (55 1.8 and 85 1.8) can be used as 2x virtually lossless zooms in video (as any other lens can and also for Jpeg stills) and also be used both FF and APSC on the FF Sony E mount cameras.

I have used a lot of standard lenses too. I'm not bashing standard lenses. I'm sure the Sony standards are nice. What I am saying is that people forget that the 135 format lenses of the same class as for example the Olympus Pro are often more expensive. The Nikon 58mm 1.4 or Zeiss Otus comes to mind. These are no compromise lenses, much like the mentioned Olympus lens. (no holds barred, heavy, large and costly). To get this kind of no compromise lens is typically cheaper the smaller the format. As it should be. 

 

14 hours ago, Damphousse said:

The Olympus 25mm f1.2 is an $1,100 lens!

No.

See my previous reply. The Nikon 58mm 1.4G is 1600$. The top quality Sony primes are around 1500$. The top end lenses for smaller sensors are typically less costly. Nothing weird with this. I worked with 120 for many years and those lenses are more expensive. Then we have large format lenses and so on. Step up in film size and costs, weight, et c increases. 

There is more to cameras and lenses than "equivalence". I may be old school but to me how a system feels to work with is the most important.  

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1 hour ago, KnightsFan said:

I'm probably wrong, I'll need to read up more on lens design. It was an intuition based on the fact that scaling an object doesn't change any angles--but again, I am not sure it's right. I hoped someone could explain why it was right or wrong.

Are you thinking about the distortion that you get with planar projection where the edge get "stretched" which do worsen as the angle get wider?

 

Also things get really hard as aperture increases so a 50mm f2 is a lot easier than a 25mm f1. So a large aperture lens, especially wide angle it reeeely hard. Which is probably why you don't see many of them.

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48 minutes ago, no_connection said:

Are you thinking about the distortion that you get with planar projection where the edge get "stretched" which do worsen as the angle get wider?

 

Also things get really hard as aperture increases so a 50mm f2 is a lot easier than a 25mm f1. So a large aperture lens, especially wide angle it reeeely hard. Which is probably why you don't see many of them.

Likewise, designing a lens with a smaller image circle is a lot easier. After all, we've all got 4.5mm f/1.7 lenses, in our smartphones. That's of course not counting for the same depth of field, which would make it a lot harder again, just as you pointed out.

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12 minutes ago, Castorp said:

Worth noting that Mattias Burling made a great video about this. 

I don't find it that great.

First of all because especially cinematographers need to know and adjust the DoF, FoV and perspective. That means then need to know the equivalent focal length for all different cameras with different sensor sizes. If you had a m4/3 camera with the 25mm @f/1.4 and you wanted to match the image with a FF camera then you would have to use a 50mm @f/2.8. You then use ISO/NDs/Lights to control exposure. 

 Second is because he was ad nauseam saying you cannot get the same look from different sensor sizes no matter what, even when people provided him with proof. He then he made a youtube video twisting the argument and saying exposure is everything. 

Lets not go back to that bitterness. 

Hopefully this is the last thread about it but lets say it one more time: Perspective only depends on the distance from the lens. You can then adjust the focal length/aperture for a given sensor size to get a specific FoV and DoF. 

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35 minutes ago, Don Kotlos said:

Hopefully this is the last thread about it but lets say it one more time: Perspective only depends on the distance from the lens. You can then adjust the focal length/aperture for a given sensor size to get a specific FoV and DoF. 

Cheers Don. Understanding equivalence was a super useful, practical insight for me. So if a thread keeps a constructive and inquisitive tone, I am glad to see people explaining and listening to each other :blush:

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2 hours ago, Timotheus said:

Cheers Don. Understanding equivalence was a super useful, practical insight for me. So if a thread keeps a constructive and inquisitive tone, I am glad to see people explaining and listening to each other :blush:

Ok than :) If you look the initial provided comparison in A. Read's article, apart of nominal/objective perspective equivalence it is also noticeable (as one poster already noted) that aesthetic impression of depth of field is not the same. Plans in perspective looks closer or further, so in one case there's impression of stronger 3d quality, or a even deeper background in whole. That is result of inner construction qualities of lenses - and that's the one of the reason, between others, why some lenses cost more and being acclaim as more precious. That fact I used as argument in statement that it is note quite correct to compare very high-end and very precise thought-out m43 lens with their cheaper FF contrepairs based only on the mathematically same DoF.

For example, Voigt 17.5 here used in comparison, as also others in the Nokton m43 lines, are extremely precise constructed to be able to provide specific chosen (and of course subtle) distinctive effects. It is as secret receipt of chosen accentuation and inevitable compromised weaknesses - on which distance image is most detailed with smooth back-and-side rollofs or bokeh nuances; which distance-sharpness to sacrifice to achieve wanted strong effects at other favorable distance; on which aperture and why lens get highest sharpness and where (center and peripheral distribution of sharpness); how to play with color shifting and contrast across aperture range; how to render (faster) movements vs static shots etc.  We can appreciate it or not, being exalted or not depends of taste and personally search specific attributes - but it is without doubt that very sophisticated know-how experience and long tested elaboration, as also higher quality glasses, are involved in construction of these lenses - so, are they really pricey or not, it is very disputable. Having opportunities to compare them with actual results of much higher price cine-lenses (apart of more technical traits as level of focus breathing etc) - I'd say that nowadays these voigts are very moderate or even cheap in price.

By reports and tests it looks that the same is applicable to, say, Veydra line, for their chosen and accurately aimed/provided qualities - some relevant testers claim that they are even better than Zeiss Primes, but double or triple cheaper.

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17 hours ago, blondini said:

Ah cool, thanks for this. It was a piece of misinformation that an older DoP passed on to me and I've held on to for a while now. But you've explained this very well. I think its the way I use different focal lengths that has helped hard wired in this instinct. And it's actually and instinct of proximity rather than focal length.

Another thing that occurred to me regarding this is the physical qualities of lenses of different focal lengths. One of the things that distinguishes wide from telephoto lenses is their focusing characteristics. Wide lenses focus closer and hit infinitely sooner. A 17mm lens is likely to be at infinity by 3 or 4 meters, where as a 50 might still separate the infinity from a subject at 20 or 30 meters. This is not strictly an issue of perspective, but it is a focal-length-dependent characteristic of rendering space. I have no experience of using short focal length lenses designed specifically for MTF sensors, but I would presume that those physical characteristics still hold true? Hence a 17mm on and crop sensor is not truly equivalent to a full frame 35mm and so on, because they do not focus through space in an equivalent way.

Or maybe I'm just suffering an esoteric crisis because I'm some kind of flat earther.

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4 hours ago, Castorp said:

See my previous reply.

Okay.  This is what you said...

23 hours ago, Castorp said:

I don't see any 135 format 50mm 1.8 compare at all with for example the Olympus 25mm f1.2 Pro in terms of quality.

All the Nikon and Canon 50mm 1.8 lenses I'm familiar with are around $100 or less!  I just don't understand this apples to oranges comparison.  You bring me a 50mm 1.2 Canon lens and yes it will be $1,100 but now it is capable of bokeh that the Olympus can't do.  So either way you are wrong.

 

5 hours ago, Don Kotlos said:

But the differences that are visible in that test are mostly due to perspective and not distortion, which is really a problem when shooting architecture (both stills & video). 

In any case, I believe the m4/3 still has its place.

I think dismissing the inherent barrel distortion, etc with wide angle lenses particularly when you don't know the exact specific characteristics of each lens in the test is a bit disingenuous.  Everything you are seeing in those pictures is not 100% due to distance.  The exact ratio of what is affecting what we can debate but just glossing over a fact that doesn't support your argument isn't the way to help someone learn.

I also stated that M43 has its place.  I own a BMPCC and it is super 16.  There are pros and cons to the camera.  If someone asks me I tell them the truth.  All these things are just tools.  They all have their place.

4 hours ago, Castorp said:

To get this kind of no compromise lens is typically cheaper the smaller the format. As it should be.

No.  You are wrong, at least about OEM M43 lenses.

It might be easier to make a smaller lens but that is not the only factor in the equation.  Four things...

1)  It is easier to make a smaller lens.  POSITIVE

2)  To get the same field of view you have to use substantial wider angle lens.  NEGATIVE

3)  To get the same level of bokeh you have to use a larger aperture.   NEGATIVE

4)  ALL nonCanikon lenses are produced at lower volume (excludes smartphones) and do not have the same mass production cost benefits.  NEGATIVE

So one positive and three negatives.

Also there is something you are being very disingenuous about.  M43 OEM lens manufactures use software interpolation to correct defects in their lenses.  In many cases they make optically inferior lenses and use in camera software to do the last bit of heavy lifting.  One can argue about how much difference there is between the software corrected and uncorrected images but full frame lens manufactures going the extra mile to correct as much as possible with glass needs to be acknowledged.  People need to tell the whole truth and do apples to apples comparisons.

Cutting corners to hit a particular price target and then relying on a software crutch is fine but don't turn around and say a fully optically corrected full frame lens is some kind of rip off.

When you see lists of the sharpest lenses there are two things you don't see M43 lenses and a bunch of lenses wider than 35mm.   Ever ask yourself why?

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7 hours ago, Castorp said:

I have used a lot of standard lenses too. I'm not bashing standard lenses. I'm sure the Sony standards are nice. What I am saying is that people forget that the 135 format lenses of the same class as for example the Olympus Pro are often more expensive. The Nikon 58mm 1.4 or Zeiss Otus comes to mind. These are no compromise lenses, much like the mentioned Olympus lens. (no holds barred, heavy, large and costly). To get this kind of no compromise lens is typically cheaper the smaller the format. As it should be. 

 

See my previous reply. The Nikon 58mm 1.4G is 1600$. The top quality Sony primes are around 1500$. The top end lenses for smaller sensors are typically less costly. Nothing weird with this. I worked with 120 for many years and those lenses are more expensive. Then we have large format lenses and so on. Step up in film size and costs, weight, et c increases. 

There is more to cameras and lenses than "equivalence". I may be old school but to me how a system feels to work with is the most important.  

You are missing the point.

The Sony Zeiss 55 1.8 IS a premium lens, it just happens to be one that is 1.8 instead of 1.4/1.2 or f1.        It has often been described as a mini-Otus and it isn't a "normal" normal lens (3 aspherical elements).

It is very much in the league of the Oly 25 1.2 and if it was a Canon lens it would no doubt be a Canon L lens.       Its biggest problem is LOCA but no lens is perfect.

It often gets called for being too expensive (for a 1.8 normal) but to many people, it is worth every cent and it IS cheaper than the Oly for similar performance.

Many of the Sony premium lenses ARE more expensive but then they are faster and NOT being matched with any M43 lenses.    

The Sony Zeiss 55 1.8 CAN be matched (as can the FE 85 1.8) but that doesn't take away how good these lenses are.

Many prefer the cheap 85 1.8 FE over the more expensive Zeiss Batis 85 1.8 (which is also a very nice lens).

Not taking away anything from the premium M43 lenses but don't undersell those "cheaper" FF E mount lenses and mated with decent sensors, they shine.

http://www.stevehuffphoto.com/2016/11/09/crazy-comparison-sony-a7rii-and-55-1-8-vs-olympus-pen-f-and-25-f1-2

 

https://www.dxomark.com/Lenses/Compare/Side-by-side/Sony-FE-Carl-Zeiss-Sonnar-T-STAR-55mm-F18-on-Sony-NEX-7-versus-Olympus-MZUIKO-DIGITAL-ED-25mm-F12-PRO-on-Panasonic-Lumix-DMC-GX7__1252_736_1774_901/

The Sony Zeiss 55 1.8 also does well as an APSC lens too (plus as I said can be used as a 2x zoom for video and jpegs)

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7 hours ago, no_connection said:

Are you thinking about the distortion that you get with planar projection where the edge get "stretched" which do worsen as the angle get wider?

No, we were talking about pixel vignetting, which is caused by pixels being recessed. Oblique rays of light get occluded by the "rim" of the pixel. The farther from the center of the image, the more oblique the rays that strike that pixel. Thus, more light is occluded by the "rim" at the corners which causes vignetting. My thought was that if you simply take a design and scale it down, none of the angles will change. So the light rays passing through a 50mm on full frame will have the same angles as they would through a 25mm on MFT, if measured at corresponding points on the sensors.

Now, I just did a back-of-the-envelope calculation that implies that I was wrong, since we are measuring at equivalent DOF, which interestingly makes the diameter of the aperture equal. (Maybe that's obvious to all of you, but I found it interesting). But I don't know enough about optics to be sure that any of my thought process is correct!

 

 

2 hours ago, blondini said:

A 17mm lens is likely to be at infinity by 3 or 4 meters, where as a 50 might still separate the infinity from a subject at 20 or 30 meters. This is not strictly an issue of perspective, but it is a focal-length-dependent characteristic of rendering space.

True! That is why Andrew compared  a 17.5mm f0.95 to a 35mm f2.0. Halving the focal length requires an extra two f-stops wider aperture for equivalent depth of field.

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1 hour ago, noone said:

You are missing the point.

The Sony Zeiss 55 1.8 IS a premium lens, it just happens to be one that is 1.8 instead of 1.4/1.2 or f1.        It has often been described as a mini-Otus and it isn't a "normal" normal lens (3 aspherical elements).

It is very much in the league of the Oly 25 1.2 and if it was a Canon lens it would no doubt be a Canon L lens.       Its biggest problem is LOCA but no lens is perfect.

It often gets called for being too expensive (for a 1.8 normal) but to many people, it is worth every cent and it IS cheaper than the Oly for similar performance.

Many of the Sony premium lenses ARE more expensive but then they are faster and NOT being matched with any M43 lenses.    

The Sony Zeiss 55 1.8 CAN be matched (as can the FE 85 1.8) but that doesn't take away how good these lenses are.

Many prefer the cheap 85 1.8 FE over the more expensive Zeiss Batis 85 1.8 (which is also a very nice lens).

Not taking away anything from the premium M43 lenses but don't undersell those "cheaper" FF E mount lenses and mated with decent sensors, they shine.

http://www.stevehuffphoto.com/2016/11/09/crazy-comparison-sony-a7rii-and-55-1-8-vs-olympus-pen-f-and-25-f1-2

 

https://www.dxomark.com/Lenses/Compare/Side-by-side/Sony-FE-Carl-Zeiss-Sonnar-T-STAR-55mm-F18-on-Sony-NEX-7-versus-Olympus-MZUIKO-DIGITAL-ED-25mm-F12-PRO-on-Panasonic-Lumix-DMC-GX7__1252_736_1774_901/

The Sony Zeiss 55 1.8 also does well as an APSC lens too (plus as I said can be used as a 2x zoom for video and jpegs)

Forgot to add, that while the Oly is an F 1.2 lens, it has a T stop of 1.8 which is the same as the Sony Zeiss 55 1.8 used on FF cameras.

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2 hours ago, noone said:

Many prefer the cheap 85 1.8 FE over the more expensive Zeiss Batis 85 1.8 (which is also a very nice lens).

Not taking away anything from the premium M43 lenses but don't undersell those "cheaper" FF E mount lenses and mated with decent sensors, they shine.

http://www.stevehuffphoto.com/2016/11/09/crazy-comparison-sony-a7rii-and-55-1-8-vs-olympus-pen-f-and-25-f1-2

I'm in that camp, the B85 has swirly cat-eye bokeh wide open - especially when the background is trees/foliage. I much prefer the FE 85. The B135 does the same thing, hate it. The B25 and B18 OTOH are flat out awesome. I have the FE 28 and 85, and sold the Batis 25/85 to get them.

The Huff comparison demonstrates exactly what some make so overly complicated - play the equivalence game with aperture/FL and you get the exact same image across various sensor sizes. Though Huff's fanboy "Olympus has better rendering" with a drill shot is just silly.

FF's advantage over m43 is even with a moderate aperture lens like a 1.8, you get DOF that requires pretty expensive m43 glass. With the cost of top shelf m43 and aps-c bodies hitting $2000, you really have to evaluate the entire system and your needs because the difference in price isn't that much - especially if you're buying f/1.8's in FF-land and faster glass in m43-land.

Used prices also level the playing field quite a bit. I saw an a9 for $2600, a7r3's are dropping to about that level too. Other bodies are far less. If you're shopping Sony, the F/4 zooms have been around awhile and so on.

Cheers

Chris

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7 hours ago, KnightsFan said:

No, we were talking about pixel vignetting, which is caused by pixels being recessed.

If you look at Nikon lenses the large flange distance means the angle can't be too high simply due to the distance. (ignore the wonky ultra wide angle that had a long element stick in under the mirror).

Sony on the other hand had a huge problem with the a7s giving a red cast with some wide angle lenses.

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23 hours ago, KnightsFan said:

 

True! That is why Andrew compared  a 17.5mm f0.95 to a 35mm f2.0. Halving the focal length requires an extra two f-stops wider aperture for equivalent depth of field.

Except I'm not talking about a generic calculation of equivalent depth of field per se. My question is whether, using the 17mm lens on a mtf sensor, it is even possible to film a subject at, say, 15 meters and still differentiate them from the infinity plane as you could with a 35mm lens. I'm just looking at a few barrel markings on some lenses I own, a 20mm which hits infinity just beyond 4 meters, and a 35mm lens which hits infinity past 30 meters. 

 

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22 hours ago, Trek of Joy said:

I'm in that camp, the B85 has swirly cat-eye bokeh wide open - especially when the background is trees/foliage.

One factor in favor of the B85 is that it has OIS. I find Sony lenses with OIS provide smoother stabilisation (when combined with IBIS) in video than lenses without OIS. Certainly the Batis is better than the GM85.

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2 hours ago, blondini said:

Except I'm not talking about a generic calculation of equivalent depth of field per se. My question is whether, using the 17mm lens on a mtf sensor, it is even possible to film a subject at, say, 15 meters and still differentiate them from the infinity plane as you could with a 35mm lens. I'm just looking at a few barrel markings on some lenses I own, a 20mm which hits infinity just beyond 4 meters, and a 35mm lens which hits infinity past 30 meters. 

 

I'm not 100% sure I'm following you. If you mean that the focus throw of the lens is too short to accurately pull focus, that is entirely due to the construction of the lens. You can make the same optics have a focus throw of 5 degrees or 300.

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17mm on M43 at f1.2 with a subject distance of 15m will have DOF with everything in focus from about 8m to 200m.

Take a step back to a subject distance of 17m and everything from just over 8m to infinity will be in focus.

Stop down all the way to f 1.4 and you have infinity from around 7m to infinity with a subject at 14m..

FF and 35mm you get infinity with a subject distance at 15m at 2.8 so all is as it should be.

If you use 17mm FF, you have infinity focus from around 3.5m at f1.4 with a subject at just 7m (and my 17mm f4 TS-E is infinite at f4 from under 1.5m with a subject at just 3m).

http://www.dofmaster.com/dofjs.html

 

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We are living in a post-truth / alternative facts world now so while it may be factually provable by optical calculations and various laws of physics that the only thing that determines perspective is the subject to object distance it is also equally valid to say a 'wide angle' lens has a certain 'look' that is independent of the format and personal belief in this or any other similar notion is just as valid. Indeed there is evidence to be had that there is a vast conspiracy involving all the camera manufacturers and scientists in the world to promote the idea of 'perspective' to sell more cameras and lenses. For many years now we have all been ready to accept the scientists opinion that the world is round but thanks to a growing number of brave and pioneering individuals and groups around the world the truth is finally emerging that the world is infact flat. Only just recently was I able to satisfy myself that this was indeed the case when I took my old school ruler down to the sea and held it up to the horizon - no so-called expert can argue with that can they!

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