28mm focal length, but what is the actual field of view after lens correction?

[bob24]

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I saw here that once the Q images are processed by the camera or Lightroom to correct for the lens, a fair bit of the picture is cropped in the process (see below, the tree at the top right is gone from the RAW to the JPEG, and the cloud at the top right is cropped).

Am I correct on thinking that due to this you don't actually get a 28mm field of view but rather something in the 30-32 range? (unless the uncorrected RAWs are wider than 28mm?)

Also, when you are composing, do the screen and the OVF show the uncorrected or the correct version? (i.e. do you need to assume the borders of the frame you are seeing while composing will be cropped by the camera/Lightroom?)

 

[digitalfx]

its a 28mm lens, a 28mm lens is always a 28mm lens.

The amount of cropping is insignificant as demonstrated in your images.

 

BTW- its an ElectronicViewFinder..WYSWYG

Edited June 21, 2015 by digitalfx

[bob24]

its a 28mm lens, a 28mm lens is always a 28mm lens.

The amount of cropping is insignificant as demonstrated in your images.

 

 

I wouldn't call it insignificant at all. On the first image the top left is just blue sky and on the second one it is a tree (and heavy vignetting).

 

 

BTW- its an ElectronicViewFinder..WYSWYG

Well ... you can get two different images depending on whether you are applying correction or not. Which one does the EVF show?

Edited June 21, 2015 by bob24

[digitalfx]

I wouldn't call it insignificant at all. On the first image the top left is just blue sky and on the second one it is a tree (and heavy vignetting).

 

Well ... you can get two different images depending on whether you are applying correction or not. Which one does the EVF shows?

I would as all the properties of a 28mm lens are there. Every 28mm lens fov varies slightly from manufacture to manufacture.

 

The EVF only displays what is recorded as it does on every camera.

[uhoh7]

its a 28mm lens, a 28mm lens is always a 28mm lens.

The amount of cropping is insignificant as demonstrated in your images.

 

BTW- its an ElectronicViewFinder..WYSWYG

 

Did you even look at them? The images show a large crop.

 

Now I have no idea as to the source of them, but my understanding at the moment: the Q 28 is wider than 28 and corrected on camera by the fujitzu jujitsu to 28 "live". You never see the "uncorrected" lens image at all. Raw or Jpeg or in the EVF.

 

The actual FL of the lens, like the sensor maker, is top secret LOL

 

For the record, while I'm astonished at the uncorrected nature of the Q lens, I'm liking many shots from my favorite shooters with the camera. 

 

But in short, to OP: I think the corrected image is 28mm. LR corrections should be minor, since the real correction is with the camera processor.

Edited June 21, 2015 by uhoh7

[digitalfx]

Did you even look at them? The images show a large crop.

 

 

 

Yes, they are as big as Dallas at the top of this thread. Not sure why this matters, you can't see the uncropped image so what is the point? What you are recording is all that matters...if you honestly feel like you are losing a tiny bit of what you assumed was a 28mm FOV then lean back a bit and you have what you lost. You guys are making an issue out of nothing.

 

Put ten 28mm lenses from ten manufactures on a tripod side by side and shoot an image and compare. You will have ten variations of fov. 

 

Lets put this to rest and enjoy the camera.

Edited June 21, 2015 by digitalfx

[Geoffrey James]

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Let's face it,  the view-finders of all M cameras  could generously  be callled approximate.  The only thing that matters is the relationship betweem the raw file and what you see in the EVR,  and in the Q this is going to be either identical or as close as makes no difference.  I always like it that the Ms give you a little bit more than what you see.  You can clean up later. 

[bob24]

Did you even look at them? The images show a large crop.

 

Now I have no idea as to the source of them, but my understanding at the moment: the Q 28 is wider than 28 and corrected on camera by the fujitzu jujitsu to 28 "live". You never see the "uncorrected" lens image at all. Raw or Jpeg or in the EVF.

 

The actual FL of the lens, like the sensor maker, is top secret LOL

 

For the record, while I'm astonished at the uncorrected nature of the Q lens, I'm liking many shots from my favorite shooters with the camera. 

 

But in short, to OP: I think the corrected image is 28mm. LR corrections should be minor, since the real correction is with the camera processor.

 

Thanks, this makes sense.

 

Yes, I was indeed wondering whether Leica was using a lens slightly wider than 28mm and only showing you a slightly cropped version ( given the amount of vignetting on the uncorrected image this is not something they could expect you to use as-is).

 

btw the images are from the review I linked. I would hope the reviewing didn't temper with them but who knows.

 

You guys are making an issue out of nothing.

 

 

 Who said it was an issue? Just want to know what field of view to expect compared to another 28mm which might not bas as corrected and ensure the EVF view includes lens correction...

Edited June 21, 2015 by bob24

[digitalfx]

Like I said you are getting a 28mm lens. All cameras display what they are recording in the EVF.

The image you posted is extracted in means that are not normal, you would typically never see this image...so ignore it.

 

Just to be clear, this isn't happening in LR. You are posting an image that you will never see if you use the camera.

Edited June 21, 2015 by digitalfx

[mjh]

The focal length is a property of the lens, so either it is or it isn’t a 28 mm lens. Whatever the CPU or the raw converter does with the sensor data doesn’t change this. The effective angle of view is a different matter; this does change when corrections are applied. And note that the horizontal, vertical, and diagonal angle of view may change by different amounts.

[microview]

Iridient Developer adds support for the Q in its 3.0.3 version released 19th June.

[jonoslack]

HI There

I did some comparisons with the 28 'lux, and the corrected images on the Q were very slightly wider.

So the field of view is 28mm AFTER correction

 

The lens is probably more like 25mm uncropped.

 

All the best

Jono

[UliWer]

Leica doesn't give the data of the exact focal length - neither for the 28mm Summilux-M, nor for the Q-lens. Usually the actual focal length differs from the nominal one (look at the misterious digits besides infinity on longer M-lenses). E. g. the Summicron-M has 28.5 mm, so it shows a slightly narrower field of view than a "real" 28mm would do.

[bob24]

HI There

I did some comparisons with the 28 'lux, and the corrected images on the Q were very slightly wider.

So the field of view is 28mm AFTER correction

 

The lens is probably more like 25mm uncropped.

 

All the best

Jono

 

Thanks ... great of have clear feedback from someone with first hand experience.

[earleygallery]

Lots of confusion in this thread and two of our resident experts disagree on what is or isn't a 28mm lens! 

 

digitalfx Posted Yesterday, 20:09

its a 28mm lens, a 28mm lens is always a 28mm lens.

The amount of cropping is insignificant as demonstrated in your images.

BTW- its an ElectronicViewFinder..WYSWYG

 

This is obviously wrong. The lens (uncorrected) shows a much wider field of view than the final (corrected) image. As it is never intended that uncorrected images will be used I think it's safe to assume that it's a "28mm equivalent" lens.

 

WYSWYG - you're seeing the corrected image in the EVF or LCD, not the full image the lens produces.

[mjh]

Just to add some confusion (as if there wasn’t enough already): Strictly speaking the angle of view of a lens doesn’t depend on its focal length but on its distance from the sensor which can vary with the focus. The focal length is just a lower limit on that distance (for infinity focus).

[digitalfx]

Lots of confusion in this thread and two of our resident experts disagree on what is or isn't a 28mm lens! 

 

digitalfx Posted Yesterday, 20:09

its a 28mm lens, a 28mm lens is always a 28mm lens.

The amount of cropping is insignificant as demonstrated in your images.

BTW- its an ElectronicViewFinder..WYSWYG

 

This is obviously wrong. The lens (uncorrected) shows a much wider field of view than the final (corrected) image. As it is never intended that uncorrected images will be used I think it's safe to assume that it's a "28mm equivalent" lens.

 

WYSWYG - you're seeing the corrected image in the EVF or LCD, not the full image the lens produces.

 

 

Well I think you misunderstood what I said.

RE: a 28mm lens is a 28mm lens- I mean the properties of a 28mm lens are always the same

 

RE: WYSWYG= What you see is what you get. This means what you see in the EVF is what is recorded.

 

I stand by both statements.

As I also stated, put ten 28mm lenses from ten manufactures on ten cameras with same size sensor and the FOV will be slightly different manufacture to manufacture.

[digitalfx]

HI There

I did some comparisons with the 28 'lux, and the corrected images on the Q were very slightly wider.

So the field of view is 28mm AFTER correction

 

The lens is probably more like 25mm uncropped.

 

All the best

Jono

 

 

The difference is not this far apart. If you overlap the images in Photoshop the difference is only 5.5% on the edges and 1% in the center.

If you wanted to extract this to an angle of view difference its about equivalent to a 26.5mm-27mm lenses FOV. Which IMO is insignificant as the angle of view on any given lenses will vary this same amount manufacture to manufacture.

 

Regardless, in normal use you would never see this uncorrected image so it really doesn't matter. The user only sees the corrected image in the LCD and EVF and this is what is in the final DNG and JPEG file that you would process in LR

[jmahto]

I do not understand why we are worried about the image (outside crop) that we are never supposed to see.

 

Isn't it like worrying about the image falling outside the sensor? (Yeah, I know in the case of Q sensor is capturing more than what you get afterwards but you get my what I saying.)

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Hallo,

Look here: Leica Q

[earleygallery]

Well I think you misunderstood what I said.

RE: a 28mm lens is a 28mm lens- I mean the properties of a 28mm lens are always the same

 

RE: WYSWYG= What you see is what you get. This means what you see in the EVF is what is recorded.

 

I stand by both statements.

As I also stated, put ten 28mm lenses from ten manufactures on ten cameras with same size sensor and the FOV will be slightly different manufacture to manufacture.

 

Ah yes, the famous forum backtrack manoeuvre. 

 

As you can see from the first post, the Q lens in uncorrected form doesn't look like many other 28mm's on the market. It's because it's probably not a strictly 28mm lens until its been digitally fixed for the distortion and circular image (black corners). 

 

So clearly not all 28mm lenses aren't all 28mm lenses, and What You See many not be What You're Really Getting.