Fast wide angle lens to use with GH1

shaveblog said:
Once more with feeling: all lenses, even the native m43 ones currently being produced, double their equivalent focal length when used on a camera with 2x crop factor. So the 20mm pancake sees the world as a 40mm lens would on a 35mm film camera, which is the reference point for equivalency. A 35mm Canon lens becomes a 70mm when I put it on my GF13, a 50mm lens becomes a 100mm, and so on.
Click to expand...
Sorry, but you're mistaken. A 20mm lens is a 20mm lens regardless of which camera you use it on. The only thing the GH1 does that is different from a full-frame still camera is to crop out the center rectangle of the 35mm still frame, producing an image with a 50% crop (i.e. a 2x crop factor). This does not change the focal length of the lens at all, it simply crops the resulting image.
 
skulpt said:
There aren't many wide options at all. Even the 20 1.7 isn't wide with the 2x crop factor.

If only the Nikon 14-24 2.8 could have manually controllable aperture.... It's expensive, but it covering 28-48mm 2.8 is a good fit for wide to normal. Of course with it's protruding front lens element, you would have to mount a ND filter differently, but....
Click to expand...

There are nikon adapters that allow you to control the aperture.
 
lpowell said:
Sorry, but you're mistaken. A 20mm lens is a 20mm lens regardless of which camera you use it on. The only thing the GH1 does that is different from a full-frame still camera is to crop out the center rectangle of the 35mm still frame, producing an image with a 50% crop (i.e. a 2x crop factor). This does not change the focal length of the lens at all, it simply crops the resulting image.
Click to expand...

You're right lpowell, 20mm is 20mm is 20mm but I liked his post and I think he knows the science, meaning he knows that it is the field of view that changes with frame size, but is putting it a funny way. Anyway, I like that his post cut through the list of posters that preceded him, each supporting the last in their nonsense idea that 24mm will be perceived as wide on a 4/3 crop. Also, what is this gumph about "they rarely ever shoot wider than 18mm in motion pictures." Codswallop! They do for establishing shots all the time.

Actually, this should be our frame of reference - if our 4/3 frame is very close to 35mm motion film, and we are film-makers, just what is a standard prime set for 35mm motion picture?

Well, on the one occasion I shot a 35mm picture, we hired a standard Cooke set from Arri, and it was this: 14, 18, 24, 32, 40, 50, 75, 100, 135.

The larger Zeiss set have different lengths but are: 10mm, 14mm, 16mm, 20mm, 24mm, 28mm, 32mm, 40mm, 50mm, 85mm, 100mm, 135mm

So what do we learn from this? They do shoot 10mm and 14mm in motion pictures, of course. Rarely, perhaps, but for some shots it's a must. In landscape photography, use of the 20mm lens in 35mm Vistavision is pretty standard, and any landscape in film will require the same angle of view, this being a 10mm lens. Halve the values - that's what we learn. Simples.

I just sold my Canon 5D Mk1 to downgrade (photographically) to the GH1, for the addition of HD video, and my standard set of Zeiss/ Yashica (mixed) 20mm, 28mm, 50mm, 90mm, 135mm & 200mm is now kind of desperate for a 10mm and a 14mm, though I do have the kit lens, which I like a lot. The wides don't need to be fast for me, because I think wide establishing shots and landscapes are a rare example of shot that usually work better with a greater depth of field and super-sharp rendition.

The Panasonic 7-14 f4 looks interesting to me.
 
Last edited:
Lucas Adamson said:
Also, what is this gumph about "they rarely ever shoot wider than 18mm in motion pictures." Codswallop! They do for establishing shots all the time.

So what do we learn from this? They do shoot 10mm and 14mm in motion pictures, of course. Rarely, perhaps, but for some shots it's a must.
Click to expand...

You just contradicted yourself. Lenses wider than 20mm or 18mm tend to have a lot of distortion to them, so no they don't really use wider lenses than 18mm that often, even for establishing shots. Establishing shots are just further away. You physically move the camera back.
 
Mike@AF said:
$899 for a 25mm f/0.95 lens with 10 blades seems pretty cheap to me. Almost a steal. The Zeiss ZF 25mm f/2.8 with 9 blades is about $825. Granted the Voigtlander is no Zeiss, but it's still a great lens and f/0.95 is sort of unheard of.
Click to expand...

Have a look around the internet and you will find that Voigtlander and Zeiss lenses are actually manufactured by Cosina in Japan. Yes, they both sound like German brands and the Zeiss optical designs are still done in Germany, but the production is done by Cosina. Check out this comparison between Voigtlander and Zeiss macro lenses that both come from the Cosina factory:

http://thepictorial.com/reviews/clash-of-the-titan-macros/

So, it is legitimate to directly compare Zeiss and Voigtlander lenses.
 
Lucas Adamson said:
The Panasonic 7-14 f4 looks interesting to me.
Click to expand...

I just recently picked up the 7-14 even though the shoot I'll need it for isn't for a couple of months. Figured with all the positive attention that lens is getting over on the AF100 forum it may soon be in short supply. Anyway, it's a totally sick lens. I love it!

Had previously shot with a friend's Tokina 11-16 and the difference in width between that lens at 11mm and the Panny at 7mm is HUGE. You really need to experience the 7-14 to fully appreciate just how wide it is and the rectilinear correction they do with it compared to something like the 8mm fisheye.
 
NPrincen said:
Have a look around the internet and you will find that Voigtlander and Zeiss lenses are actually manufactured by Cosina in Japan. Yes, they both sound like German brands and the Zeiss optical designs are still done in Germany, but the production is done by Cosina. Check out this comparison between Voigtlander and Zeiss macro lenses that both come from the Cosina factory:

http://thepictorial.com/reviews/clash-of-the-titan-macros/

So, it is legitimate to directly compare Zeiss and Voigtlander lenses.
Click to expand...

I knew the Zeiss ZF were made by Cosina, but not the Voigtlander. Good to know. Thanks for that bit of info. I already have a Voigtlander on order so it makes me feel even better.
 
Mike@AF said:
You just contradicted yourself. Lenses wider than 20mm or 18mm tend to have a lot of distortion to them, so no they don't really use wider lenses than 18mm that often, even for establishing shots. Establishing shots are just further away. You physically move the camera back.
Click to expand...

I don't want to get into a "thing" with you about this, but if I contradicted myself, what you stated as fact here rather undermines anything else you might say about lenses:

Mike@AF said:
I don't think it's just about the FOV you get in a cinema vs photography camera or situation. It's also the depth perception and how far away the background appears to be from the subject. That all changes when you change the focal length of the lens and the lens distance from the subject. I don't know anyone that would consider a 25mm lens to be normal, even though the FOV of a 25mm lens on a m4/3 camera will be similar to a 50mm lens. It's still a 25mm lens, still a 25mm focal length, and thus is still a wide lens. Normal lenses are typically going to be your 35mm and 50mm. Smaller focal lengths are wide and longer focal lengths are tele. I understand where you're all coming from though, because you're not used to the 2x crop factor. It didn't really seem like anything new to me though for some reason, even though I've never shot 35mm cinema before.
Click to expand...

I'm sorry, but his is just hogswallup! Perhaps that's harsh, but you can't get away with that kind of comment without it being put up to the light. Compare a 6x7 medium format shooters standard lens set, a 35mm photographers standard lens set and a 35mm motion picture standard lens set. All different. Their ideas of what a 25mm lens is are totally different, and it's based purely on FOV. I have always enjoyed occasionally using a 20mm ultra-wide on my 35mm stills cameras, and to continue to enjoy a similar experience on a 4/3 camera will inevitably require the purchasing of a 10mm(ish) lens. There's no way to get around that, I'm afraid. That stuff about the relationship between focal length and distance from the subject doesn't pan out in reality (ie in science or practice). The only difference with my 10mm on 4/3 compared with 20mm on 35mm Vista, is greater depth of field, always associated with smaller frame size.
 
Last edited:
Mike@AF said:
I knew the Zeiss ZF were made by Cosina, but not the Voigtlander. Good to know. Thanks for that bit of info. I already have a Voigtlander on order so it makes me feel even better.
Click to expand...

Enjoy your "normal FOV" ultrafast lens Mike! It's a beauty ;P
 
There seems to be an issue then with 4/3 systems. You can say that 20mm is 20mm no matter the crop, but try saying that to someone wanting to frame a shot in a tight room. Sometimes 40mm doesn't cut it. You can have a certain 20mm look with the dof and so on, but that doesn't address framing the shot.

To get the ideal 35mm framing, you'll need an 18mm lens. One that probably starts distorting more readily than a native 35mm lens on a full frame or a 24mm lens on a 1.5x crop.

So for me at least, a 20 1.7 is more of a 40 1.7. :) This 2x crop thing is a blessing and a curse depending if you want 35mm framing and wider or not. You're almost going to need a fisheye lens to get wide and bright and into this 28mm realm or wider.
 
shaveblog said:
I don't believe your information is accurate. There have been countless threads about this on every camera forum since m43 cameras hit the market, and some people still don't understand what the format's 2x crop factor does to the look and behavior of a legacy lens which has been adapted to an m43 camera like the GH1.

Once more with feeling: all lenses, even the native m43 ones currently being produced, double their equivalent focal length when used on a camera with 2x crop factor. So the 20mm pancake sees the world as a 40mm lens would on a 35mm film camera, which is the reference point for equivalency. A 35mm Canon lens becomes a 70mm when I put it on my GF13, a 50mm lens becomes a 100mm, and so on.

Where this subject inflames pedants is in their framing the "debate", if such settled argument can be called that, as a clash between those defenders of absolute scientific fact and the great unwashed who aren't actually strangling puppies but they might as well be because they're saying 20mm lenses magically transform into 40mm lenses and that's a tragic oversimplification of the vectors involved because sine cosine angle vector victor one niner one niner mayday mayday we're going down.

For the rest of us who just want to shoot images, it's a simple, settled fact. Double your lens's rated focal length and you'll know how it's going to behave on your m43 camera. It's really that simple. Anyone who tries to tell you that a 25mm lens still presents a wide angle view when used on an m43 camera is guilty of one or more of the following:

1, They've never actually tried it, and are just extrapolating their old experience with film cameras;

2. They have tried it, but have never used an actual 25mm lens on a 35mm camera so they don't know what a true wide angle lens view looks like:

3. They do know what it looks like, and they have tried a 25mm lens on their m43 camera, but they disregard the obvious and gross optical differences between the two because it doesn't gel with their entrenched assumptions. Also, some people are just contrarian.

This isn't a subtle thing, so it continues to surprise me that some people persist in debating it. Like the man said, I've seen things. I've seen what a 25mm lens sees on a 35mm film camera, and I've seen what a 25mm lens sees on an m43. They are not the same thing. Swap the film camera's lens for a 50mm, though, and they are the same thing.
Click to expand...

Well, I think the additional confusion comes up because people seem to think that still 35mm is the same as film 35mm. As has been stated many times when this topic is debated, m43's crop factor is quite close to the crop factor of 35mm motion film. The FOV is obviously doubled compared to 35mm stills but since motion picture film was already close to the side of m43 the people who are used to mentally adjusting for crop factor in film are already quite close for m43. For stills you have to consider the FOV as doubled compared to a Full-frame camera. Even then, most people don't have full-frame digital cameras. I came from a 30D to the GH1, so the crop factor difference was there but it wasn't nearly that significant.
 
Vitaliy Kiselev said:
I do not agree here :-)
20-25mm are normal lenses on m43.
Perspective changes only with camera position relative to object.
And lens only crop necessary part according to its FOV (if it is perfect distortion free lens).
This is simple basics.
So, all this theory of 25mm being 50mm FOV, but still 25mm feel is crap.
Click to expand...

FOV changes but z-axis spatial distortion doesn't. 20mm on GH1 distorts space the same way as a 20mm on a full frame camera. Objects in this lens are closer than they appear. Get a foreground object same size on a 20mm and a 50mm and the background object will seem much further away on the 20mm.
 
There seems to be more debate on the m43 crop factor than there is on the off side rule lol
If you want to shoot on an a system, then learn how it's FOV relates to focal lengths on that system.
Some of the wide fast lenses available are

Panasonic 14mm 2.5
Olympus 17mm 2.8
Olympus 11-22mm 2.8-3.5
Olympus 14-35 2
 
Revelations to real life, after reading this thread, next time we need not "laugh" at the young ones when they put on the left shoe on their right feet and vise versa, to them is the same scenerio as we see here :-)
 
LPowell, I have too much respect for your accomplishments to argue with you. Also you're much smarter than I am, so there's that, too.

If I'm missing something here, what is it? Am I perhaps not phrasing things accurately? I once got sucked into a similar argument with a pedant whose sole objection to my position regarding 2x crop factor as it relates to FOV was that it's impossible for a lens to literally physically change into a longer focal length, which of course no one has ever claimed but it does make for a nice straw man.

My eyes tell me that a 20mm lens on an m43 camera behaves more like a 40mm lens on a traditional 35mm camera than a 20mm lens on that film camera does. The math behind the 2x crop factor seems to support what my eyes see, and even the manufacturers themselves have agreed, across the board, to describe, say, a 20mm lens designed for m43 as a "40mm equivalent" or "40mm effective". All of this fits together nicely, and is repeatable when I mount a 50mm lens on my GF1 and the resulting image looks like that of a 100mm lens on a 35mm film camera.

But still there are some like you who dismiss the above and maintain that a 20mm lens always behaves like a 20mm lens no matter what the crop factor is. That merely cropping the image to the center portion of the lens doesn't result in the effective doubling of FOV. I have to admit that most who fall in this camp don't impress me with their arguments, which seem a sort of catch-all grumpiness about the digital erosion of photography in general. But you're not one of these folks, and I take what you say very seriously.

What's getting lost in translation here? I'm all ears. Thank you.


lpowell said:
Sorry, but you're mistaken. A 20mm lens is a 20mm lens regardless of which camera you use it on. The only thing the GH1 does that is different from a full-frame still camera is to crop out the center rectangle of the 35mm still frame, producing an image with a 50% crop (i.e. a 2x crop factor). This does not change the focal length of the lens at all, it simply crops the resulting image.
Click to expand...
 
GrahamH said:
Nicely done site. But the crop factor diagram is for 4:3. In 16:9 mode the GH2 maintains the same diagonal, whereas the APS sensors have to crop top and bottom: the effective crop factors are consequently much closer than 2.0X and 1.6X would suggest.
Click to expand...

I guess I should point out that it's not my site. I was just too lazy to explain it myself. You're right about the crop factor, but that part of the site wasn't really what was relevant to Ben_B's argument. I was refering to the "Perspective" part of the site that illustrates with actual photos the difference (or lack of) between fullframe and crop sensor images with the same FOV. It shows that the size difference of foreground and background objects is the same despite the difference in focal length. As long as the lens&sensor combo has the same FOV this relationship will be the same.
 
Last edited:
So I guess my 55mm wide angle from my Pentax 67 will still be a 55mm wide angle on my GH2 , r i g h t.
 
joe1946 said:
So I guess my 55mm wide angle from my Pentax 67 will still be a 55mm wide angle on my GH2 , r i g h t.
Click to expand...

Sarcasm noted. Point agreed. Nice example.

I think another thing people are getting confused about on here is the whole dof vs fov issues. Of course it is true that dof will be the same with this 55mm lens on either camera at the same shooting distances, but the GH2 will be a massively cropped version of the 67 frame, so in a sense there is an equivalency. So perhaps people are arguing that to compensate for the increase in depth of field, we should be using longer lenses. Anyway whatever, people should study cinematography before teaching it I guess.
 
You must log in or register to reply here.
Back
Top