Pocket Camera + MFT lens = crop factor?

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alexandr.pervi

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Pocket Camera + MFT lens = crop factor?

PostSun Apr 14, 2013 3:30 pm

if this topic is already there, I'm sorry, but I have not found the answer ..
for example: Pocket Cinema Camera + Olympus ED 12mm f/2.0, what focal length I get? 34.5 or 16.6?
please tell me .. who knows :)
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Dillan Stockham

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Re: Pocket Camera + MFT lens = crop factor?

PostSun Apr 14, 2013 5:28 pm

alexandr.pervi wrote:if this topic is already there, I'm sorry, but I have not found the answer ..
for example: Pocket Cinema Camera + Olympus ED 12mm f/2.0, what focal length I get? 34.5 or 16.6?
please tell me .. who knows :)


you would get probably a 35mm or 36mm out of it.
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Ryan Jones

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Re: Pocket Camera + MFT lens = crop factor?

PostMon Apr 15, 2013 12:20 pm

So does that make crop factor 3x?

Which makes a 20mm lens appear like a 35mm equivalent 60mm?

I'm trying to compare to what I know. I know what my 7D looks like with a 17-50mm lens, and I know what my NX5 looks like, which has a 35mm equivalent 29.5 to 590 mm.

I also know what I really want at this point is a small AF lens I can put on the camera and mount it on a windscreen facing a driver, and a larger lens, AF or manual, better suited to documentary/interview work.
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Joseph Ciccarella

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Re: Pocket Camera + MFT lens = crop factor?

PostMon Apr 15, 2013 1:29 pm

Actually, this topic has been discussed ad nauseum in the sticky for this camera.
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Ryan Jones

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Re: Pocket Camera + MFT lens = crop factor?

PostMon Apr 15, 2013 1:57 pm

So yes is the answer. Thanks for that. There is a lot of conflicting info in that thread, I figured it easier to clarify in another thread.
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Re: Pocket Camera + MFT lens = crop factor?

PostWed Apr 17, 2013 4:40 pm

bigkevracer wrote:So does that make crop factor 3x?

Which makes a 20mm lens appear like a 35mm equivalent 60mm?

I'm trying to compare to what I know. I know what my 7D looks like with a 17-50mm lens, and I know what my NX5 looks like, which has a 35mm equivalent 29.5 to 590 mm.

I also know what I really want at this point is a small AF lens I can put on the camera and mount it on a windscreen facing a driver, and a larger lens, AF or manual, better suited to documentary/interview work.


Yessir - 3X

Are you talking about wanting an autofocus lens for the BMPocketCC?
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Re: Pocket Camera + MFT lens = crop factor?

PostThu May 02, 2013 11:11 pm

Okay, I know CF is like voodoo math. I get that. But I always thought CF had as its baseline the area covered by a full frame still camera lens. Otherwise, there's nothing to base the "factor" on.

So my question is: If the PC is designed for an MTF lens, does one need to apply the 3.02 factor to that lens or only full-frame lenses? It seems that if an MTF lens is designed for a smaller sensor and a "full-frame" lens is designed for a larger sensor, the two should not have the same CF and the MTF lens ought to come closer to matching the sensor size. Yes? No?

Is it fair to say that CF really means that only a portion of the middle of the "projected image" from a given lens falls on the sensor and the rest falls outside the sensor? So the image seems to have been virtually zoomed in.

Too much info, not enough conclusions. :-D

Thanks!
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Joseph Ciccarella

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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 12:23 am

pointsource wrote:
Too much info, not enough conclusions. :-D



Or maybe you don't like the conclusions ;)

All (correction MFT) lenses are marked according to a full frame of 35mm.
The smaller lenses have less glass and a shorter flange which makes them great for smaller cameras. But, they're still marked and measured according to FF35.

If it makes you feel better you can always measure to S35.
But the standards will stay the same.

On the BMCC it would be about 1.6x crop to S35 and 2.3x to FF35
On the Pocket it would be about 2x crop to S35 and 3x to FF35.

Even S35 is a crop from FF35 it's about 1.4x

Edit: Distinguished that I'm talking about MFT lenses. Thanks.
Last edited by Joseph Ciccarella on Fri May 03, 2013 6:50 am, edited 1 time in total.
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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 12:25 am

pointsource wrote:
Is it fair to say that CF really means that only a portion of the middle of the "projected image" from a given lens falls on the sensor and the rest falls outside the sensor? So the image seems to have been virtually zoomed in.



Yes :)
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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 1:15 am

Joseph Ciccarella wrote:
All lenses are marked according to a full frame of 35mm.



No they're not.

I hate the phrase full frame. What does at make a medium format camera ? M
"more full frame " since when was the 135 the golden standard by which all are measured.

lenses are lenses. They have a focal length and a target image circle they are designed for.

Its only us idiots who make it complicated by using crop factors.

They do more harm than good.

JB.
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rick.lang

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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 1:20 am

pointsource wrote:Okay, I know CF is like voodoo math. I get that. But I always thought CF had as its baseline the area covered by a full frame still camera lens. Otherwise, there's nothing to base the "factor" on.

So my question is: If the PC is designed for an MTF lens, does one need to apply the 3.02 factor to that lens or only full-frame lenses? It seems that if an MTF lens is designed for a smaller sensor and a "full-frame" lens is designed for a larger sensor, the two should not have the same CF and the MTF lens ought to come closer to matching the sensor size. Yes? No?

Is it fair to say that CF really means that only a portion of the middle of the "projected image" from a given lens falls on the sensor and the rest falls outside the sensor? So the image seems to have been virtually zoomed in.

Too much info, not enough conclusions. :-D

Thanks!


Joseph's conclusions are essentially correct, but there is another way to look at it from your perspective. You know a normal lens (50mm) on a full frame camera gives you an angle of view of 39.6 degrees. To get that same angle of view so it looks 'normal' on a true MFT camera, you know you need to use a 25mm MFT lens. And to get that same 'normal' angle of view from an MFT lens mounted on the BMPCC camera, you just apply a crop factor if you wish of almost 1.4x so that a 17-18mm lens will be required. Hope that helps. But you see you get the same result I believe. Correct me if I am wrong, please! I don't have an MFT camera and lens to verify this so going out on a limb here.

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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 1:33 am

Joseph Ciccarella wrote:All lenses are marked according to a full frame of 35mm.

The smaller lenses have less glass and a shorter flange which makes them great for smaller cameras. But, they're still marked and measured according to FF35.



That doesn't make any sense. The focal length of a lens doesn't change with sensor size.
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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 1:41 am

Pocket cinema camera crop factor 2.88x
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Joseph Ciccarella

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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 2:53 am

Tamerlin wrote:
Joseph Ciccarella wrote:All lenses are marked according to a full frame of 35mm.

The smaller lenses have less glass and a shorter flange which makes them great for smaller cameras. But, they're still marked and measured according to FF35.



That doesn't make any sense. The focal length of a lens doesn't change with sensor size.


You're right, focal length doesn't change, and that's not what i said. But how much of the image is projected on the sensor does.
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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 3:02 am

John Brawley wrote:
Joseph Ciccarella wrote:
All lenses are marked according to a full frame of 35mm.



No they're not.

I hate the phrase full frame. What does at make a medium format camera ? M
"more full frame " since when was the 135 the golden standard by which all are measured.

lenses are lenses. They have a focal length and a target image circle they are designed for.

Its only us idiots who make it complicated by using crop factors.

They do more harm than good.

JB.


The lens manufacturer uses crop factors and crop factors were developed because of the crop sensor we find in DSLR's.

It's really just angle of view as Rick discusses above. But it exists so that we can understand when picking up a lens what we're going to get out of it.

I don't think it's complicated it just is what it is. I think it's helpful.
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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 3:04 am

Rocket wrote:Pocket cinema camera crop factor 2.88x


Correct! Even BMD has been putting out the wrong numbers(3.02x) because I suspect they are comparing the 16:9 diagonal on the BMPCC to the 3:2 diagonal of full frame. That's not a meaningful comparison of the frames that are used for any video projection.

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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 3:09 am

Joseph Ciccarella wrote:
Tamerlin wrote:
Joseph Ciccarella wrote:All lenses are marked according to a full frame of 35mm.

The smaller lenses have less glass and a shorter flange which makes them great for smaller cameras. But, they're still marked and measured according to FF35.



That doesn't make any sense. The focal length of a lens doesn't change with sensor size.


You're right, focal length doesn't change, and that's not what i said. But how much of the image is projected on the sensor does.


Actually, it IS what you said, where you wrote, "All lenses are marked according to a full frame of 35mm."

That strongly implies that their marking, which happens to be their focal length, is dependent on the size of the sensor they're designed for. My large format lenses use the same measurements as my MFT lens, my a-mount lenses, and my e-mount lenses.

They're marked according to their focal length.
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Joseph Ciccarella

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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 3:14 am

Tamerlin wrote:
Joseph Ciccarella wrote:
Tamerlin wrote:[quote="Joseph Ciccarella"]
All lenses are marked according to a full frame of 35mm.

The smaller lenses have less glass and a shorter flange which makes them great for smaller cameras. But, they're still marked and measured according to FF35.



That doesn't make any sense. The focal length of a lens doesn't change with sensor size.


You're right, focal length doesn't change, and that's not what i said. But how much of the image is projected on the sensor does.


Actually, it IS what you said, where you wrote, "All lenses are marked according to a full frame of 35mm."

That strongly implies that their marking, which happens to be their focal length, is dependent on the size of the sensor they're designed for. My large format lenses use the same measurements as my MFT lens, my a-mount lenses, and my e-mount lenses.

They're marked according to their focal length.[/quote]

And that focal length is consistent with the angle of view on a 35mm camera, not an MFT camera. So, where did I say the focal length changes?
And why are your panties in a bunch?
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Rakesh Malik

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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 3:35 am

Joseph Ciccarella wrote:And that focal length is consistent with the angle of view on a 35mm camera, not an MFT camera. So, where did I say the focal length changes?
And why are your panties in a bunch?


Looking at a mirror while you type?
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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 3:48 am

Tamerlin wrote:
Joseph Ciccarella wrote:And that focal length is consistent with the angle of view on a 35mm camera, not an MFT camera. So, where did I say the focal length changes?
And why are your panties in a bunch?


Looking at a mirror while you type?


Don't be like that. If you want to have a discussion about these things than discuss. I'm asking why you're so persistent in making your point when you can easily see that's not what I said.

There's article upon article about this stuff, i'm not making it up for the sake of argument.

And referring to john's medium format comment, let's be real. These cameras were developed to take over the DSLR shooter market. Not the 645 market. So, the probability that those concepts should apply to this camera are completely valid. The fact that BMD chose EF and MFT mounts speaks volumes about the demographic they were interested in. So the term crop factor and full frame are completely reasonable and in fact appropriate.

When they start going after the 70 mil crowd than we can bring up medium format.
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Rakesh Malik

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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 6:01 am

Joseph Ciccarella wrote:
Don't be like that. If you want to have a discussion about these things than discuss. I'm asking why you're so persistent in making your point when you can easily see that's not what I said.



It was actually a correction.


And referring to john's medium format comment, let's be real. These cameras were developed to take over the DSLR shooter market. Not the 645 market. So, the probability that those concepts should apply to this camera are completely valid. The fact that BMD chose EF and MFT mounts speaks volumes about the demographic they were interested in. So the term crop factor and full frame are completely reasonable and in fact appropriate.


You're right, the concepts are in fact identical. That means that the markings, which indicate focal length and aperture, neither of which has any relationship to do with their format. You can use lenses for 6x6 and 645 on any of the BMD cameras, so the medium format comment IS relevant, and you actually cited a reason that supports that statement.
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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 6:44 am

Tamerlin wrote:
Joseph Ciccarella wrote:
Don't be like that. If you want to have a discussion about these things than discuss. I'm asking why you're so persistent in making your point when you can easily see that's not what I said.



It was actually a correction.


And referring to john's medium format comment, let's be real. These cameras were developed to take over the DSLR shooter market. Not the 645 market. So, the probability that those concepts should apply to this camera are completely valid. The fact that BMD chose EF and MFT mounts speaks volumes about the demographic they were interested in. So the term crop factor and full frame are completely reasonable and in fact appropriate.


You're right, the concepts are in fact identical. That means that the markings, which indicate focal length and aperture, neither of which has any relationship to do with their format. You can use lenses for 6x6 and 645 on any of the BMD cameras, so the medium format comment IS relevant, and you actually cited a reason that supports that statement.


So, you agree with me. Good, i'm glad you see it my way.
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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 9:03 am

Lens focal lengths are marked according to the focal length of the lens nothing else, and the sensor/film size in no way affect the marked focal length as focal lengths are ABSOLUTE not relative. Saying they are marked with regards to anything other than focal length is complete rubbish.

This means that assuming you could mount them all to the BMPCC a Medium format 50mm, a FF35 50mm a Super 35 50mm and a Super 16 50mm would all be identical in field of view (you may find light pollution issues on the larger lenses though).

Crop factors give a way of calculating what lens you need to use to get the same FoV as a given lens produces when the sensor sizes differ.
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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 10:19 am

Joseph Ciccarella wrote:
I don't think it's complicated it just is what it is. I think it's helpful.


It's only helpful to compare to a 135 format camera.

More get this wrong than right. Look at the very discussion we're having here in this thread. Look at the other threads here and the endless discussion on my vimeo of the pocket and other forums.

I see a lot of confused people. Not a lot of helpful.

You saying "All lenses are marked according to a full frame of 35mm." it's totally misleading, wrong and again cements this idea that 135 somehow has primacy over all other formats.

Noone else thinks this other than those that have started their careers shooting on 5Ds.

jb
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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 10:27 am

"John Brawley

Noone else thinks this other than those that have started their careers shooting on 5Ds.

jb


Which is precisely what BMD has aimed for all along, targeting their cameras to the 5D crowd.
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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 10:43 am

Taikonaut wrote:
"John Brawley

Noone else thinks this other than those that have started their careers shooting on 5Ds.

jb


Which is precisely what BMD has aimed for all along, targeting their cameras to the 5D crowd.


In part, not in total. The GH2/3 markets hardly insignificant either in the transfers to BMCC, and thats just looking at DSLR converts, who won't make up everything
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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 11:09 am

The current popularity in budget filmmaking is in no small part to dSLRs.
Even established filmmakers using high end Arri and Red cameras have reached out to dSLR crowd to esatblish a name for themselves. dSLR users are changing the video industry, not the other way round.
Soon everyone including videographers will be thinking of in terms of dSLR 35mm as FF not 135.

It is bottoms up.
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Pete Proniewicz-Brooks

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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 11:29 am

Taikonaut wrote:The current popularity in budget filmmaking is in no small part to dSLRs.
Even established filmmakers using high end Arri and Red cameras have reached out to dSLR crowd to esatblish a name for themselves. dSLR users are changing the video industry, not the other way round.
Soon everyone including videographers will be thinking of in terms of dSLR 35mm as FF not 135.

It is bottoms up.


But a fair whack of the DSLR filmmaker market don't use FF35, Panasonic GHs and 7Ds are a significant portion of the DSLR video market. the 7Ds sensor is within a nats whisker of S35.

This camera we are talking of here is using another CINEMA aspect ratio of S16.

The whole reason for the DSLR video boom was the 5Dmk2s FF35 sensor giving an image so much more like S35 cinema cameras than anything else in a similar price range. It was the desire to get to be like the S35 that did it.

Video and Cinema could expand to include FF35 focused, but a wee look at history suggests that cinema likes multiple formats, there is plenty of variation in the S35 theme after all.

The BMD camera range seems to be mostly (but by no means entirely) aimed at DSLR shooters wanting the next step in getting more like cinema, not in making the cinema look more like DSLRs.
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Re: Pocket Camera + MFT lens = crop factor?

PostFri May 03, 2013 11:44 am

Not this again.

Image

Crop factor was created to help people gauge comparable FOVs. That's it.

12mm on a BMPCC S16-sized sensor, is 12mm.

12mm on FF sensor is 12mm.

A lens' focal length doesn't change. Different formats, yield different fields of view. When you're using the now "ever fashionable" :roll: "crop factor" lingo it's just giving you comparable information.

A 25mm lens on a GH3 that has a "2.0x Crop Factor" gives you a FIELD OF VIEW, comparable to 50mm lens on a FF format. The lingo thing is ever-so slightly complicated, but damn is it annoying.
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