Let's talk glass: Lenses for the AF100!

Cosina Voitlander Nokton 25mm f/0.95

Cosina Voitlander Nokton 25mm f/0.95

One lens to rule them all... and in the darkness, find them...

http://www.cosina.co.jp/seihin/voigt/v-lens/micro-ft/index.html

Looks like a great response to the c mount activity we're seeing (of which I'm now a proud member). :beer:

Available in October for 92,000 yen (US $1,075 at current conversion rate). Add a decent X.5 and X2 conversion lens and maybe a few extension tubes for macro work and I think it would make a nice little starter kit.

Thoughts?
 
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Barry,

Did you say that you heard someone was developing a Nikon-MFT lens adapter that permitted one to have full control of the G-type lenses?

If it is true, than any G lens would work, right? Including the DX lenses ?

Like this one:

http://www.nikonusa.com/Find-Your-N...AF-S-DX-Zoom-NIKKOR-17-55mm-f/2.8G-IF-ED.html


I have used this lens -- it is very sharp, has a smooth mechanism, and features a constant f/2.8 throughout the zoom range, which according to what I have read here, would provide the equivalent of a 32-104mm lens.

Does this sound right?

Regards,
Paul Vicente
 
Zuiko Digital
14-54mm
F2.8-3.5 II
$599.99

Has anyone used this little guy? Nice price, not constant aperture but you only lose about a half stop.
 
Help me with my math!

So on my 7D, I use the 30mm F1.4 Sigma a lot. I'm trying to understand the extra bit of cropping on the 4/3 sensor I am going to get. I am also familiar with the 50mm F1.4 Sigma as well. With the 30mm on the AF100, how do I convert to what size focal length would give me the same FoV on the 4/3? Does that make sense?

Essentially, when I was buying the 30mm, I went off the use of a 50mm on a FF lens. While 30mm is not exactly equivalent, it was the closest I could find that was fast.

I've never gotten a great grasp on how to convert between sensor sizes and focal lengths for the same FoV, although I should by now! :)
 
grimepoch said:
Help me with my math!

So on my 7D, I use the 30mm F1.4 Sigma a lot. I'm trying to understand the extra bit of cropping on the 4/3 sensor I am going to get. I am also familiar with the 50mm F1.4 Sigma as well. With the 30mm on the AF100, how do I convert to what size focal length would give me the same FoV on the 4/3? Does that make sense?

Essentially, when I was buying the 30mm, I went off the use of a 50mm on a FF lens. While 30mm is not exactly equivalent, it was the closest I could find that was fast.

I've never gotten a great grasp on how to convert between sensor sizes and focal lengths for the same FoV, although I should by now! :)
Click to expand...

http://en.wikipedia.org/wiki/Crop_factor
 
LoganMackay said:
Please, please, please... type the word "crop" into the search.
Click to expand...

Have you ever searched for the term 'crop' at dvxuser? I suggest you try it before suggesting it. You will see, as I have, that EVERYTHING shows up except what I was asking. :) But, you are right, I should have searched at least on google first!

I was trying to get away from comparing everything to a FF sensor, but I guess that is just not possible since everyone already speaks in crop factor.

Okay, so if the aps-c is 1.6, and the 4/3 is 2.0, then for the equivalent FoV of 30mm on the 4/3 as compared to the aps-c, would that be:

30mm x 1.6 / 2.0 = 24mm

and therefore my other lens sizes

11mm = 8.8mm
16mm = 12.8mm
50mm = 40mm
85mm = 68mm

Thanks for the pointer to the Wiki page though, not sure why I was brain dead first and didn't think to just search for crop factor. :)

I guess that 24mm F0.95 is looking VERY good to me right now as I really do like that FoV. Of course, I am intrigued now at how the 30mm will feel right between what the 50mm and 30mm already feel on my aps-c sensor. Or was that for a smaller crop factor? I couldn't understand the language on that page! :)
 
grimepoch said:
Have you ever searched for the term 'crop' at dvxuser? I suggest you try it before suggesting it. You will see, as I have, that EVERYTHING shows up except what I was asking. :) But, you are right, I should have searched at least on google first!

I was trying to get away from comparing everything to a FF sensor, but I guess that is just not possible since everyone already speaks in crop factor.

Okay, so if the aps-c is 1.6, and the 4/3 is 2.0, then for the equivalent FoV of 30mm on the 4/3 as compared to the aps-c, would that be:

30mm x 1.6 / 2.0 = 24mm

and therefore my other lens sizes

11mm = 8.8mm
16mm = 12.8mm
50mm = 40mm
85mm = 68mm

Thanks for the pointer to the Wiki page though, not sure why I was brain dead first and didn't think to just search for crop factor. :)

I guess that 24mm F0.95 is looking VERY good to me right now as I really do like that FoV. Of course, I am intrigued now at how the 30mm will feel right between what the 50mm and 30mm already feel on my aps-c sensor. Or was that for a smaller crop factor? I couldn't understand the language on that page! :)
Click to expand...

Yes, I searched crop and the first page had the info you were looking for.
 
Well anyways, glad you have it all figured out now.

I picked up a Nikon 17-35 2.8 the other day and I think I might be happy with 17 as my widest...
 
Haha, thanks! Yeah, although I have a lot of EOS glass, I am starting to look outside that now. I don't buy any lenses slower than 2.8 and am pretty happy with that bottom end range.

I see both Canon and Nikon have a 24mm F1.4 although the Canon seems to be cheaper.

As for the super wide angle, I doubt I am going to find anything around 8mm F2.8 and will just have to live with the 11mm.
 
Yeah the whole crop factor thing has a lot of video oriented folks in a tizzy. Just remember it is a still photographer reference, for the most part. While I had a 35mm still camera, BITD... it has never been my point of reference for FOV. I learned on film (Super 8 and 16mm) and still, really, think about FOV in reference to 16mm film lenses (4:3 regular 16mm). Since then I have shot most of my video stuff on 1/3" sensors, with fixed lens cameras and never really thought about the lens focal lengths. Since getting a HD-DSLR, with an APS-C sensor, that is quickly becoming my point of reference. The FOV difference between that and the 4/3 sensor is so relatively small that getting used to it should not be a problem.
 
That's what everyone has said in reference to 4/3 vs aps-c. I know the best thing to do would be just rent a GH1 for a few days just to wrap my brain around it. Seeing is believing :) Of course, I am waiting on any news from Birger about when the availability of their electronic mount will available so I can use my lenses. One thing I have found is all the reading in the world doesn't help as much as getting behind the lens/sensor.

We do a lot of martial arts and stunts in some of our films. I started researching lens lengths that I wanted to use to flatten out the image AND still be not horrendous on the DSLR rolling shutter issue AND be good for low light. After going to a local shop and playing with an 85mm F1.4, I was sold. I think I spent like an hour in the store pretending customers were about to get into a fight and moving around them :)
 
Paul Vicente said:
Barry,

Did you say that you heard someone was developing a Nikon-MFT lens adapter that permitted one to have full control of the G-type lenses?
Click to expand...
That's more details than I think I heard. Basically Birger said they were going to produce a mount that did electronic control of Nikon and Canon lenses, and that they would have the Canon version done first. That's about the extent of the details that I know. They should be making an announcement within about a month where a whole lot more will be known.
 
grimepoch said:
So on my 7D, I use the 30mm F1.4 Sigma a lot. I'm trying to understand the extra bit of cropping on the 4/3 sensor I am going to get.
Click to expand...
If you want the same FOV on the AF100/GH1 as you get on the 7D with a 30mm lens, then you'd need to use a 25.5mm lens on the AF100/GH1. The Cinema Crop Factor is 1.18.

So for a 50mm lens on the 7D, you'd use a 42.4mm lens on the GH1/AF100.

Basically, if you know the exact look you're looking for on the 7D (which is a Cinema Crop Factor of 1.00), then you'd divide that focal length by 1.18 to get the same field of view on the GH1/AF100.

Note that this is not the same as with other 4/3rds cameras. The 4/3rds standard calls for a 17.3mm wide sensor, but the GH1/AF100 use an oversized 19mm wide sensor, so the CCF is less.
 
Barry_Green said:
If you want the same FOV on the AF100/GH1 as you get on the 7D with a 30mm lens, then you'd need to use a 25.5mm lens on the AF100/GH1. The Cinema Crop Factor is 1.18.

So for a 50mm lens on the 7D, you'd use a 42.4mm lens on the GH1/AF100.

Basically, if you know the exact look you're looking for on the 7D (which is a Cinema Crop Factor of 1.00), then you'd divide that focal length by 1.18 to get the same field of view on the GH1/AF100.

Note that this is not the same as with other 4/3rds cameras. The 4/3rds standard calls for a 17.3mm wide sensor, but the GH1/AF100 use an oversized 19mm wide sensor, so the CCF is less.
Click to expand...

Now I'm even more confused :) Is the crop factor from FF35 not 2.0 then on the Panny 4/3? Are you meaning in terms of the width as opposed to the diagonal which crop factor doesn't really take into account so well?
 
grimepoch said:
Now I'm even more confused :) Is the crop factor from FF35 not 2.0 then on the Panny 4/3? Are you meaning in terms of the width as opposed to the diagonal which crop factor doesn't really take into account so well?
Click to expand...

Here's referring to the Canon 7D which isn't a FF35, it's an APS-C sensor which has a crop factor of 1.6 over FF35. The MTF has a crop factor of 2 over FF35. To be honest, I agree that comparing APS-C to MTF is confusing, too many number to be multiplied and divided. "I graduated from school so I wouldn't have to do fractions anymore."

The de facto is FF35 and should be everyone's starting point cause it's easier. A 50mm on a 5D is ROUGHLY a 35mm on a 7D (50 divided by 1.6), and a 25mm on a GH1 (50 divided by 2). :beer:

Now, how about that 25mm Voitlander, folks? The reviews of the Voitlander 50mm f/0.95 for M mount as pretty frickin' stellar. For a thousand bucks, this should make an awesome MTF lens -- like seriously, the first native pro lens, no? :thumbup:

Looking forward to trying it out on my GH1 in the next couple of months.
 
grimepoch said:
Now I'm even more confused :) Is the crop factor from FF35 not 2.0 then on the Panny 4/3?
Click to expand...

Not when shooting 16:9. To recap in general terms from the beginning:

A 35mm still (photography) frame (no soundtrack) is larger than a 35mm motion picture frame (w/ soundtrack). Since the folks here are generally more concerned with video, Barry came up with "Cinema Crop Factor" to be more relevant. Turns out that APS-C sensors are pretty close to 35mm motion picture frame size so they have a CCF of 1.

Now when the GH1 is shooting 4:3 it uses the standard m4/3 sensor size/area and therefor has a CCF of 1.25 (and a 35mm photography frame crop factor of 2.0). But the GH1 (and it appears the GH2 and AF100) are equipped with an oversize sensor, so when they shoot 16:9 (which is what most folks here do) it uses a wider area of the sensor which results in a lower CCF of 1.18 (and lower 35mm photography frame crop factor of ~1.91).

HTH - Mark
 
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