How do you view the Lens mm crop factor

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How do you view the Lens mm crop factor

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bmxdad

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soap said:
I hate to be the pedantic a**hole, but DX does not give you 1.5x zoom, it gives you 1.5x crop. A FX camera with the same pixel density as your DX camera would have the same resolution (pixels per degree) as your current setup. As the technology starts to mature (in so far as densities) I expect FX and DX sensors to plateau at around the same density, making this pedantic point all the more clear.

No where have I stated that DX gives 1.5 Zoom, but at the moment special in entry DSLR you get effective mm, right, what you see in your viewfinder. A 50mm lens on a DX will give you angle view of app 75mm if seen through a FX camera. If a customer walks in with a F80 and his 28-80mm lens and don't want a D700, what should I tell him that his 28-80mm lens is going to do on his new D90, should tell him that he would end up with app a (effective) 42-120mm lens, because if I do not get him to walk home with a 18-105mm zoom(or similar) he will back the next day telling me what is going on, I can hardly shoot any pictures inside now

Yes I know this argument will newer end or be won.

Why else would you purchase a new 35F1.8 DX lens, because it shoots the same way like a 50mm does on DX, yes DOF is different, but the angle and what is seen in the viewfinder is certainly very similar(and that is what's count the most

Pete

Posted 3 years ago #
NSXType-R

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Shouldn't the DOF be similar between the 35mm 1.8 and the 50mm 1.8? They're both the same apertures.

Posted 3 years ago #
bmxdad

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DOF is from a factor of focal mm and aperture

So an actual 50mm lens has the DOF on both DX and FX, at the same aperture and distance to subject

an actual 35mm lens same thing

But 35mm and 50mm lenses(or focal lenght) does not give you the same DOF at the same aperture and distance to subject, 35mm would have a larger DOF than 50mm at the same aperture and distance to subject

Pete

That is why a 85mm F1.4 can give such a amassing shallow DOF at F1.4

Posted 3 years ago #
soap

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bmxdad said:
No where have I stated that DX gives 1.5 Zoom,

I don't recall calling you out

bmxdad said:
but at the moment special in entry DSLR you get effective mm, right, what you see in your viewfinder. A 50mm lens on a DX will give you angle view of app 75mm if seen through a FX camera. If a customer walks in with a F80 and his 28-80mm lens and don't want a D700, what should I tell him that his 28-80mm lens is going to do on his new D90, should tell him that he would end up with app a (effective) 42-120mm lens, because if I do not get him to walk home with a 18-105mm zoom(or similar) he will back the next day telling me what is going on, I can hardly shoot any pictures inside now

While your discussion of FoV is technically correct, it is not the aspect of this conversation I was addressing.
Regardless of what the effective FoV is, wildlife shooters want pixels per degree. You want as many pixels on your subject as possible. You can do this with longer lenses, or you can do this with denser sensors. The _size_ of the sensor is irrelevant.

This argument _can_ be won (No, I haven't added up who is on what side) because facts are facts. DX is a cropped sensor format, not a magic zoom sensor format. Many people (rightfully) want the high-pixel-density sensors, but that is a whole other ballgame not technically tied to the crop formats.

For example:
A D3 has a higher pixel density than a D2H. Sure, on the D2H, that 600mm lens has a FoV equivalent to a 900mm lens on the D3, but the D3 is still putting more pixels on the subject bird than the D2H is with than 600mm lens. FX/DX isn't the indicator people make it out to be. The much more difficult to sell concept of density is.

Posted 3 years ago #
warprints

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I didn't know we we having an argument at all - when it comes to pure preferences (e.g. what should we call this lens - 35mm or 50mm), there is no right or wrong. If you want to name the lens by its focal length, then there is a correcdt answer. If you want to name it by the apparent focal length (FOV), there is a correct answer for that (based on what sensor size is being used).

Posted 3 years ago #
warprints

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Soap - Your argument has some merit, but does not give the whole picture (sorry about the pun). When I look through the viewfinder of an FX camera with a 600mm lens on it, I "see" a certain FOV. With the same lens on a DX camera, I "see" a mcuh closer view. Doing wildlife, I want that closer view -- for less weight and cost.

Posted 3 years ago #
soap

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A - FX viewfinders are physically larger, you're seeing more but the subject isn't _much_ smaller. (Varies depending on the models being compared)
B - magnifying eyepieces exist.

Posted 3 years ago #
warprints

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soap said:
A - FX viewfinders are physically larger, you're seeing more but the subject isn't _much_ smaller. (Varies depending on the models being compared)
B - magnifying eyepieces exist.

The viewfinder images on D700 and D300 are not going to give you the same size view with the same lens - unless there is some kind of optical illusion going on.
The point is to wag less stuff, not more, I don't want to use a magnifying eyepiece.

Going back to your point about pixels - again, the argument doesn't hold up with comparing the D300 to the D700. I could spend several thousand dollars more to get the added pixel denisty, but I'd rather not.

Posted 3 years ago #
Panamon_Creel

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bmxdad said:
DOF is from a factor of focal mm and aperture

So an actual 50mm lens has the DOF on both DX and FX, at the same aperture and distance to subject

an actual 35mm lens same thing

But 35mm and 50mm lenses(or focal lenght) does not give you the same DOF at the same aperture and distance to subject, 35mm would have a larger DOF than 50mm at the same aperture and distance to subject

Pete

That is why a 85mm F1.4 can give such a amassing shallow DOF at F1.4

If real life would be that easy :)
FX has a larger COC than a DX sensor which at a given Focal Length, Aperture & distance would give a larger DOF on FX.
In real life you mostly don't keep the same distance to the subject with different focal length and/or Sensor sizes instead you adjust the distance in order to frame your subject so the fixed distance/focal length DOF is not really that field relevant.
With a given Aperture, Magnification factor (lens) and sensor size/type the DOF will be about the same with differing focal length. DX / FX will put a little twist to it since you'll have to be closer with FX in order to get the same frame as DX. :)

Posted 3 years ago #
jonnyapple

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warprints said:
Going back to your point about pixels - again, the argument doesn't hold up with comparing the D300 to the D700. I could spend several thousand dollars more to get the added pixel denisty, but I'd rather not.

Soap is saying that if you buy the D700, you'd be paying extra for -lower- pixel density, which is why some wildlife photographers will choose the D300 over the D700. The only other Nikon choice for the same pixel density as the D300/D300s/D90/D5000 is the D3x.
Of course, physical pixel density doesn't tell the whole story, either. Some people say the D300 outresolves the canon 7D: http://nikonrumors.com/forum/topic.php?id=915

Posted 3 years ago #
adamz

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as for pixel density - indeed that's what matters, but AFAIK only d3x has a pixel density similar to d90/d300, and for the price difference You can get a really good glass

Posted 3 years ago #
warprints

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Adamz, yes, that was kinda my point. As Soap points out, I can get the same effective pixel density by using a high density FX camera, but I don't want to put out that kind of money right now. The D300 and D700 are what most people are deciding between when thinking about DX vs FX purchases.

Posted 3 years ago #

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How do you view the Lens mm crop factor

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