Beginner Micro 4/3 Bunkum . . . ?

[CJS]

. . . well something like that, what I mean is 'out of focus back ground' . . . ? I'm not what you would call a beginner but do suffer from memory loss and association, so I'm always at the bottom of the heap, but what the hell, I enjoy the climb back. Like now, not held a proper camera for a 3 or 4 years, so all I learened back then has gone or is a haze in the back ground . . . no pun intended, good'un though aint it

Invested in a Lumix GX8 last week, while I have been reading up on 'What and How', I came across the x2 factor applied to micro 4/3 lens focal length. Fair enough even a numpty like me remembers that, however I had not apreciated how this affects the Boken (out of focus back ground) as one increases the size of the apature. Therefor the 'standard f number' we all cling to are x2 out, a 4/3 standard kit lens f3.5-5.6 is actualy f7-10.2, making a good all round focus, but no blured background option to isolate the image you are trying to capture? The recomendation is a fixed prime lens f1.7 or even f1.4 these giving fx2 and good Boken?

Mmm . . . set me thinking, so I have bought a GX12-35 f2.8, as my standard kit/walkabout, still not perfect with its 2x factor, but certaily better. Now I'm looking for a 14mm, f1.4 or 1.7 pancake type that will simply pop in my pocket for those special moments?

CJS

 

[StewartR]

Therefor the 'standard f number' we all cling to are x2 out, a 4/3 standard kit lens f3.5-5.6 is actualy f7-10.2....

No. ... and yes.

No, because the markings on the lens mean what they say. If it's described as f/3.5, then it actually is f/3.5, not f/7. That's important for getting the exposure right. f/3.5 is f/3.5, regardless of which camera or lens you're using.

And yes, in a way, because you'll need to open up the lens by two more stops that you would on a full-frame camera in order to achieve the same depth of field. For example, suppose you're using a 50mm lens at f/2.8 on a full frame camera. Then with a Micro 4/3 camera you'll need a 25mm lens to achieve the same composition from the same place, and to achieve the same depth of field you'd need to be using f/1.4 instead of f/2.8.

 

[CJS]

No. ... and yes.

No, because the markings on the lens mean what they say. If it's described as f/3.5, then it actually is f/3.5, not f/7. That's important for getting the exposure right. f/3.5 is f/3.5, regardless of which camera or lens you're using.

And yes, in a way, because you'll need to open up the lens by two more stops that you would on a full-frame camera in order to achieve the same depth of field. For example, suppose you're using a 50mm lens at f/2.8 on a full frame camera. Then with a Micro 4/3 camera you'll need a 25mm lens to achieve the same composition from the same place, and to achieve the same depth of field you'd need to be using f/1.4 instead of f/2.8.

Mmm . . . I think that is what I was describing that I had gleaned from the reviews and coments I had seen? CJS

 

[Tulipone]

@CJS I have been lusting after the GX8 to replace my aging GX1 - I also have the f2.8 12-35 and really like the combination for a walk around setup. I have read a couple of times what you have written and trying to decide if there is a real world problem. Not sure why you would have an issue with bokeh? The idea of going to a prime with a GX8 would put me off.

 

[Chrisphoter]

I have the Lumix LX100 which has a fixed f1.7 - f2.8 lens. I can get good bokeh with it, but it's more difficult than with full frame. There are certain ways you can work to achieve it :

1. use 'macro zoom', i.e. as near as you can to full telephoto, at wide open aperture
2. increase the subject to background distance as much as you can
3. get as close to your subject as you can, even if using full telephoto

Also, remember that 'crazy' bokeh (so OOF that all context between subject and background is lost) is something of a modern fad, like 'milky' water, so you may actually prefer the more limited bokeh you get using a m4/3 sensor?

 

[CJS]

Whoops . . . sorry peoples, I dont have any issues with bokeh one way or the other. I was simply pointing out the x2 factor has a wider reach than I had realised in my inocent inability. I supose its something I want to have a look at?

I often used primes in my previous life with Nikon full frame cameras, using 'leg zoom' as required. A much older man these day, the legs dont work like they used to, so a sutable zoom lens has to be employed along with the smaller lighter package of Micro 4/3. The GX8 is a little larger than the G1 that I loved, made the mistake of selling! However the GX8 comes to 'my hand' like a glove, the idea of a pancake lens, prime or zoom appeals. The body reminds me of the days my late father used similar looking cameras, going back to the 50's and 60's. So there are compromises I'm prepared to make at this uncompetative stage in my life. I have many slides of my beautiful and photogenic mother that my father took, I remember the reaction they had together, I did not quite understand then of course??? . . . I even have one of his early Kodak cameras, the image quality and composition he produced was stuning, a natural.

So, one way or the other, I'm happy to enjoy my memories, if the GX8 + pancake lens does it for me so be it.

You know what Tulipone, thats the first time I have analised 'why' . . . got a tear in the eye . . .

CJS

 

[woof woof]

Whoops . . . sorry peoples, I dont have any issues with bokeh one way or the other. I was simply pointing out the x2 factor has a wider reach than I had realised in my inocent inability. I supose its something I want to have a look at?

An easy way to rationalise the crop factor in your mind might be to think about a couple of popular 35mm camera focal lengths such as 50mm and 24mm. At any given aperture setting you'd get shallower depth of field with the 50mm lens and deeper depth of field with the 24mm lens if shooting from the same position and distance to the subject. If you took two pictures, at 50mm and 24mm, and then cropped the 24mm shot to give the same field of view as the 50mm shot you'd see deeper DoF with the 24mm shot. That's all the crop factor is.

So, to get the same field of view as you'd get with a 35mm camera and 50mm lens with a MFT camera you use a 25mm lens (or even your old 24mm lens from your 35mm film days) which will give you the same field of view as a 50mm lens on a 35mm camera but it's still and will always be a 24 (or 25mm) lens so the depth of field will still be that of a 24 (or 25mm) lens.

It's not all bad news though as with a 35mm camera you can sometimes find yourself stopping the aperture down to get decent depth of field but with a MFT camera you can get the same DoF at a wider aperture and will be able to shoot with a faster shutter speed or a lower ISO setting. For example if shooting with a 35mm camera and a 50mm lens at f8, you can get the same effect when shooting with a MFT and 25mm at f4. There may be an advantage particularly for handheld shooting and of course once you stop a 35mm camera down to f2.8 MFT can match the DoF with a f1.4 lens.

 

[Chrisphoter]

Yes, I'd just add that the greater DOF you get with m4/3 is a positive boon shooting macro, where quite often full format DOF is so narrow you have to make complicated decisions about what bits you want in focus and what not.

 

[Garry Edwards]

Bokeh, bunkum - much the same thing in reality
The downside of a small sensor camera is that there is much greater depth of field, which of course in some situations can be an upside instead.
Don't get hung up on f/, which is a constant regardless of the focal length and which at its simplest is just about how much light passes through the lens.
What you should be thinking about is aperture, or effective aperture, or actual aperture (same thing). Effective aperture is the actual size of the aperture in the lens that allows the light to pass through it, and an effective aperture of say 10mm will produce the same depth of field in every lens, regardless of f/. It is arrived at like this:
F/f=Ea, where F is the focal length, f/ is the f/number and Ea is the effective aperture so, F100 divided by f/11 = 9, and 9mm is the effective aperture. So, the effective aperture of a 100mm lens when set to f/11 is 9mm.
The same depth of field on a 50mm lens would be achieved by setting the aperture to f/5.6, F50 divided by f/5.6 = 9, and 9mm is the effective aperture.

So, if the effective aperture you need to get the background out of focus is say 9mm, then you'll need to set f/11 on a 100mm lens, f/5.6 on a 50mm lens and if your lens is 25mm you'll need to use f/2.8 to get the same effect.

Of course, it isn't quite that simple in practice, because there are always other factors in play. My smallest camera is full frame, and in theory to get the background seriously out of focus I would shoot with my 200mm lens at f/2.8 - but with that length of lens, I often have to shoot from further away, which in effect creates greater depth of field.