Lenni Vilen wrote:
First, I hate this DPR editor. The quote handling is impossible, thus this will be a bit messy entry, sorry.
The DOF, FOV and light collectng ability are similar in both cases. It is about the size of the aperture (not the f-number, but focal length divided by it) and the FOV.
You said:
DOF will be nearly equivalent, but sensor of NEX will get relatively more light than sensor of true "FF" camera when same lens and aperture used.
Both sensors will get the same amount of light (well, there is still a slight crop factor, so there is a slight difference). It is irrelevant what the density of the light is, assuming that is what you mean by "relatively". Surprisingly the size of the sensor itself is not relevant at all - it is only about the aperture (ie. entrance pupil, not the f-number) and the field of view. With this adapter the field of view will remain the same with the APS-C annd the FF and naturallly the aperture will too, thus the optical effect will be the same.
You wrote:
So you need higher shutter speed or lower ISO (with NEX+speed booster combo) if you want same kind of exposure.
ISO has nothing to do with what exposure is - exposure is the combination of the amount of light, shutter speed and aperture, nothing more, nothing less.
http://en.wikipedia.org/wiki/Exposure_(photography)
Also, this has
nothing to do what you said very clearly which is what I originallly commented:
you said:
maybe f/1 in terms of the amount of light, but not f/1 what comes to DOF
This is just false and you know it as...
in your next reply
you contradicted yourself by saying: DOF will be nearly equivalent
Normally when you use a FF lens on a crop camera, more than half of all the photons are lost. However, with this adapter no photons are lost but the image is formed using all the same photons on APS-C that would be used by a FF camera without the adapter. There is no difference. (Stricktly speaking there's a slight crop factor and minimal reflection losses, but they're not relevant to this discussion.)
Anyhow, regarding the ISO, even though is has nothing to do with this discussion, but just to make things clear: it is true that the ISO of the crop tends to be about half of what it tends to be on a FF if an automatic exposure mode is being used. However, the FF typically has about one stop advantage in "ISO quality" over the APS-C - a FF ISO 3200 has similar quality to APS-C ISO 1600, thus
the image quality will still be similar - why would it not when the very same photons are being captured!
I hope this helps.
Ari Aikomus wrote:
Lenni Vilen wrote:
Ari Aikomus wrote:
Joseph S Wisniewski wrote:
And will it be a full stop faster? Put an 85mm f1.4 on one of these, and you get a 60mm f1.0. A 50mm f1.4 becomes a 35mm f1.0. So, when you talk of the lenses that "you can buy", remember that there are things you can't buy, like Pentax mount f1.0 lenses.
...maybe f/1 in terms of the amount of light, but not f/1 what comes to DOF. It still produces same DOF than f/1.4 lens. However still pretty nice performance on APS sensor, I think :-D
No. There is no special f-number for DOF and amount of light. It is all just about one single f-ratio (for a fixed field of view). If the f-number goes down, both the amout of light collected will go up and the DOF will go down. There is nothing special about this converter - it is no different that a for purpouse built f/1 lens of similar specs would be.
No, I meant how same "FF" lens behaves on the "FF" camera, and how it behaves with the NEX+Metabones speed booster combo.
DOF will be nearly equivalent, but sensor of NEX will get relatively more light than sensor of true "FF" camera when same lens and aperture used.
So you need higher shutter speed or lower ISO (with NEX+speed booster combo) if you want same kind of exposure.
