# DOF



## chrysoberyl (Feb 10, 2016)

Is there a resource where one can calculate DOF for specific lenses at varying f/stops for FF and APS-C? In reviewing the Cambridge in Colours tutorials, one DOF calculator shows that APS-C provides better DOF (for the same framing), while the macro DOF calculator indicates that FF has deeper DOF. Thanks!


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## dcm (Feb 10, 2016)

got a smartphone? There are several available. I use TrueDOF-Pro.


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## neuroanatomist (Feb 10, 2016)

I use Photo Aide. 

The CIC calculators are correct - APS-C gives deeper DoF for the same framing (because you're further away) but APS-C gives slightly shallower DoF at the same distance (which is the case with a macro lens at 1:1).


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## chrysoberyl (Feb 10, 2016)

dcm: Thanks, but TrueDOF-Pro does not appear to take into consideration magnification.

Neuro: Thanks! Photo Aide appears to be what I want. So for macro, there is little difference for inanimate subjects. But for wildflowers, APS-C would be better - at least for DOF.


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## neuroanatomist (Feb 10, 2016)

chrysoberyl said:


> It all depends on the flower and the sensors. The other factor is diffraction - larger pixels (usually but not always in the FF) mean you can stop down further before diffraction starts costing you sharpness, and if using ambient light the ISO noise when you stop down for similar DoF on FF will be about the same. Practically speaking, there's not much advantage either way...I generally use FF for macro/close-up.


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## Mt Spokane Photography (Feb 10, 2016)

The reduced DOF for large sensors is a source of disappointment for many who decide to upgrade their Camera phone or P&S to a DSLR. I've heard so many over the years complain that their new DSLR is not a sharp as their old phone, so they are going back.

There is nothing wrong with preferring more DOF, but its a shame that so many newly purchased DSLR's are just tossed into a closet because the buyer did not understand DOF. I've bought a number of those DSLR's over the years with just a few shots on them.

As for Macro, I like APS-C because you get more working distance for the same framing, or at the same distance (Compared to FF), you get a enlarged subject. Lighting is the big gotcha, as Neuro points out.


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## dcm (Feb 10, 2016)

chrysoberyl said:


> dcm: Thanks, but TrueDOF-Pro does not appear to take into consideration magnification.
> 
> Neuro: Thanks! Photo Aide appears to be what I want. So for macro, there is little difference for inanimate subjects. But for wildflowers, APS-C would be better - at least for DOF.



If by magnification you mean crop factor, it's on a second screen which allows you to configure by sensor width, print width, or print resolution. It's easy to switch between different sensor sizes.


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## Valvebounce (Feb 11, 2016)

Hi Folks. 
I have another two apps that I have on my iPad in addition to True DOF, they are Digital DOF and Deep Focus. Deep focus is a much more graphic representation where the other two are much more numeric orientated, it also has a flash calculator, how much use this is I'm not sure! 
All of these apps have the ability to select the crop ratio, either on the main screen or in a settings screen. Digital DOF also has a dual calculator in the paid version so you can do side by side comparisons between crop and FF sensors. 

Cheers, Graham.


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## chrysoberyl (Feb 11, 2016)

dcm said:


> If by magnification you mean crop factor, it's on a second screen which allows you to configure by sensor width, print width, or print resolution. It's easy to switch between different sensor sizes.



Hi dcm. By magnification, I meant lens magnification. Thanks.


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## chrysoberyl (Feb 11, 2016)

neuroanatomist said:


> It all depends on the flower and the sensors. The other factor is diffraction - larger pixels (usually but not always in the FF) mean you can stop down further before diffraction starts costing you sharpness, and if using ambient light the ISO noise when you stop down for similar DoF on FF will be about the same. Practically speaking, there's not much advantage either way...I generally use FF for macro/close-up.



Right, I am aware of the diffraction factor; I partly chose my 6D because the high diffraction limited aperture; and I do like some DOF for macro shots, and definitely for wildflower shots. I almost always use one or more flashes, off-camera.

I am considering a 7D II to use with my Sigma 180mm macro for those subjects one can't or won't (venomous snakes) get close to. The equivalent of a 288mm macro is appealing!


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## Valvebounce (Feb 11, 2016)

Hi chrysoberyl. 
Each of the programs has a place for selecting the focal length. 
As far as I know the magnification of a lens i.e. 5x zoom is just a mathematical ratio, a 25-100mm zoom would be a 4x zoom and so would a 150-600mm. So if you are trying to work from a camera that has a 60x zoom (like the Panasonic Lumix DMC-FZ70 16.1MP with a 60x optical zoom.) you need to know one end of the focal length, preferably the wide end which is quoted as a 20mm equivalent, 60x 20mm gives a 1200mm equivalent. 
Standing ready to be corrected! ;D
Hopefully this is the answer to the question you were asking. 

Cheers, Graham. 



chrysoberyl said:


> dcm said:
> 
> 
> > If by magnification you mean crop factor, it's on a second screen which allows you to configure by sensor width, print width, or print resolution. It's easy to switch between different sensor sizes.
> ...


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## neuroanatomist (Feb 11, 2016)

Valvebounce said:


> Hi chrysoberyl.
> Each of the programs has a place for selecting the focal length.
> As far as I know the magnification of a lens i.e. 5x zoom is just a mathematical ratio, a 25-100mm zoom would be a 4x zoom and so would a 150-600mm. So if you are trying to work from a camera that has a 60x zoom (like the Panasonic Lumix DMC-FZ70 16.1MP with a 60x optical zoom.) you need to know one end of the focal length, preferably the wide end which is quoted as a 20mm equivalent, 60x 20mm gives a 1200mm equivalent.
> Standing ready to be corrected! ;D
> Hopefully this is the answer to the question you were asking.



Graham, he's referring to actual magnification not the 'zoom factor'. 1x means the subject is 1:1 on the sensor, e.g. a 7mm grain of rice covers a patch of sensor that's 7mm long. 5x (such as with the MP-E 65mm 1-5x lens) would mean that grain would cover 35mm on the sensor (would nearly fill the 'width' of a FF image sensor). 

The standard DoF equations used by most calculators are based on assumptions that don't hold at close to or greater than 1x magnification.


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## chrysoberyl (Feb 11, 2016)

I have the answer I needed; for macro, there is a crossover point where both sensors sizes have the same DOF. And as usual, I received useful education.

Thanks to all!


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## Valvebounce (Feb 12, 2016)

Hi Neuro. 
Thank you for clarifying that, I guess that shows I've not understood the macro terminology, I have not done a lot of macro. It is interesting to know that the DOF calculators don't work for macro. Learn a little every day. 
At least it seems that the question has been successfully answered. 

Cheers, Graham. 



neuroanatomist said:


> Graham, he's referring to actual magnification not the 'zoom factor'. 1x means the subject is 1:1 on the sensor, e.g. a 7mm grain of rice covers a patch of sensor that's 7mm long. 5x (such as with the MP-E 65mm 1-5x lens) would mean that grain would cover 35mm on the sensor (would nearly fill the 'width' of a FF image sensor).
> 
> The standard DoF equations used by most calculators are based on assumptions that don't hold at close to or greater than 1x magnification.


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## tolusina (Feb 12, 2016)

Have you tried the Stop Down Preview/DOF Preview button and simply view the results of aperture changes for any scene instantly?

Works the old fashioned way through the viewfinder. 
Works in live view, best with exposure simulation activated.


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## slclick (Feb 12, 2016)

neuroanatomist said:


> chrysoberyl said:
> 
> 
> > It all depends on the flower and the sensors. The other factor is diffraction - larger pixels (usually but not always in the FF) mean you can stop down further before diffraction starts costing you sharpness, and if using ambient light the ISO noise when you stop down for similar DoF on FF will be about the same. Practically speaking, there's not much advantage either way...I generally use FF for macro/close-up.
> ...


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