I need some help, /p/. I don't have a full frame body, I never had. First I state the obvious (because this is what I understand so far), then I ask my question. When you put a full frame lens on an APS-C body, the lens will behave differently because of the sensor size: you have to calculate with a different focal length (lens's focal length x 1.6), and you will get also get a different DOF (eg. you loose the creaminess of the bokeh). The question: since the DOF is ALSO affected on an APS-C, does it mean, that your f-number had to be calculated differently? Does that automatically also mean, that if you shoot with the same lens with same f-number settings, you have to use a lower shutter speed on the APS-C to have the same ammount of light?
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Camera-Specific Properties: Equipment Make Canon Camera Model Canon EOS 5D Mark III Camera Software Adobe Photoshop 7.0 Photographer Jerod Foster Maximum Lens Aperture f/2.8 Image-Specific Properties: Image Orientation Top, Left-Hand Horizontal Resolution 96 dpi Vertical Resolution 96 dpi Image Created 2014:11:01 14:18:34 Exposure Time 1/30 sec F-Number f/11.0 Exposure Program Aperture Priority ISO Speed Rating 200 Lens Aperture f/11.0 Exposure Bias -1/3 EV Metering Mode Pattern Flash No Flash, Compulsory Focal Length 21.00 mm Color Space Information Uncalibrated Image Width 900 Image Height 600 Rendering Normal Exposure Mode Auto White Balance Manual Scene Capture Type Standard
Exposure values are constant. You're cropping into where the lens is sharpest. Only Canon's APS-C is 1.6. Everyone else is around 1.5x.
>>2867542
The amount of light coming through is the same. f/2.8 has the same exposure value on full frame and aps-c. The depth of field will also stay the same, so long as you don't move your feet. The field of view crops in.
The closer you are to something, the less depth of field you get from the same aperture, meaning the opposite is true. The further away you are, the wider the depth of field.
So if you shoot a 50mm on full frame, and then take that 50mm and put in on APS-C, to get the same framing, you have to step back, which means less depth of field at the same aperture, with the same framing.
There's math to figure it out, but who cares. It's about a stop difference, and that's really all you need to know.
It only really matters to bokeh whores who, for some reason, think that the smaller the depth of field you have, the better your photo will be (???)
>>2867548
the most useful answer I found on the net, thanks. unfortunately there's a (seemingly quite agressive) debate between the Northropes and other photographers about whether you have to multiply the f-number too on APS-C cameras or not.
>>2867552
He suggests multiplying the f number because he's a bokeh fag who judges the merit of photographs by their bokeh. Literally, he compares minutes differences in depth of field and suggests that it's a big deal. It only serves to confuse beginners. For now, ignore him, he's questionably useful and only to those who have their basics down pat
>the lens will behave differently because of the sensor size
No. The lens does not know or care what it is projecting an image onto, whether that is a useful image sensor area or whether it's being wasted and cropped out.
YOU will behave differently in taking your photos, because the field of view will be narrower. This will cause you to stand further back to get the same framing which you would have gotten had you been using a FF camera, and therefore because you are standing further back your DoF will be longer.
As for f/ number, no it does not change. The same intensity of light per area will fall onto the sensor no matter what size it is. Because the sensor is smaller, that will result in less total light captured which will give you less signal and therefore more noise in your photos. You can try multiplying the f/ number to get some effective f/ number for your sensor size but the people who advocate doing that are rabid gearfags and/or shills who make misleading statements to push you to buy more expensive cameras.
>>2867552
The best solution is always to go out and try it for yourself if you can. Obviously, not everyone has access to a full frame camera and an aps-c camera that will take the same lens, but really, the answer that comes out the other end is this:
The light gathering is the same in practice. The depth of field is about a stop different with the same framing.
>>2867557
>YOU will behave differently
that's what I meant, only came out stupidly
>>2867542
sony a7 used, less than $1000.
>>2867569
Slap on your face, fresh out of the oven for free
Depth of field definitely changes, you mega plebs, even if you don't move your feet.
>>2867581
It does. Imagine a 24 MP APS-C vs 24 MP 35mm. In the APS-C sensor, the pixels are smaller, so the circle of confusion is smaller, so you would get... smaller DOF in APS-C!! what?? yeah, but offset it with the different framing for the same lens and it ends up being larger.
NEGLIGIBLE!!!!
>>2867586
This is 100% correct
>>2867554
If you're talking about Northrop, he does it to calculate value for money.
A 25mm f/0.7 MFT lens should cost about the same as a 50mm f/1.4 FF lens.
The common claim that "it's a 50mm f/0.7 equivalent and therefore amazing" is what triggers his autism.
>>2867594
But it is, the f-stop value refers to the amount of light going through the lens.
The rest is just useless bokehwhoring.
>>2867557
>This will cause you to stand further back to get the same framing which you would have gotten had you been using a FF camera
This is the primary meme that gives away gearfags from people that actually use their cameras.
You do not "stand further back" with APS-C. You use different focal lengths.No one that picks of a 50mm 1.8 on crop is going to be using it like a 50mm 1.8 on full frame. They're going to be using it as a mid-tele. And the most likely choices of framing with a mid tele kind of inherently imply a decrease in perceived depth of field rather than an increase as gearfags insecurely perceive.
Why? Because a 50mm on FF is a normal field of view. It's usable for a great deal of different things. The usage scenario varies. The 50 on crop has been shoehorned, however, into the equivalent of one of the most single-purpose focal lengths there is; the mid tele. It's going to be used to shoot detail shots, generally at a close range, minimizing depth of field, or upper body/headshot portraits, once again minimizing depth of field with the typicalities of the framing.
For all of the talk so many of you so regularly have about the equivalence of light, water in buckets, and all of that bullshit, this one simple lapse of user-awareness betrays it all.
Crop users do not literally sit in the back of the photographic bus for equal framing.
>>2867595
>f-stop value refers to the amount of light going through the lens.
No it doesn't.
More light passes through a 200 f/2 than through a 50 f/2.
Which is clear to see just by looking at the front elements.
>>2867586
Smaller circle of confusion leads to more depth of field, not less.
>>2867614
not him, but smaller CoC = more considered out of focus = shallower DoF.
>>2867606
Yes it does, fucker. We have this same thread every weeks.
>f/2 for both lenses
>same fucking exposure time
>you can't explain that
>f-stop value refers to the amount of light going through the lens.
The t-stop is more accurate, since glass is a bit translucide.
>>2867620
You've got it backwards, buddy. Go play around with any depth of field calculator. Leave all variables alone and just play with the circle of confusion. You'll see right away that the depth of field gets large as you decrease circle of confusion.
It becomes pretty apparent why when you think about why, as well.
Came here to post this >>2867623
>>2867620
Think of the circle of confusion as the size of a "bokeh ball" created by an out of focus point of light. The bigger the ball, the narrower the depth of field had to have been to throw it "further out of focus".
>>2867614
>>2867620
exactly.
>>2867625
no it doesn't. check it out yourself (CoCs are at the end of the camera models list): http://www.dofmaster.com/dofjs.html
>It becomes pretty apparent why when you think about why, as well.
kek
>>2867705
Total nonsense. CoC is not a difficult concept to grasp to anyone who finished high school math and physics, no need to throw stupid wrong analogies.
Here's something that might make it simpler to grasp: There's only one infinitesimally shallow plane that is 100% in focus at any given time. If you had infinite resolution, you could tell exactly if something is not in that plane. Infinite resolution is just an infinitesimally small circle of confusion. Increase the circle of confusion, and you increase the depth of field, because you can no longer tell the difference in sharpness between that plane and other nearby planes.
>>2867719
>CoC is not a difficult concept to grasp to anyone who finished high school math and physics, no need to throw stupid wrong analogies.
Uh huh
The common values for CoC may not be applicable if reproduction or viewing conditions differ significantly from those assumed in determining those values. If the original image will be given greater enlargement, or viewed at a closer distance, then a smaller CoC will be required. All three factors above are accommodated with this formula:
CoC (mm) = viewing distance (cm) / desired final-image resolution (lp/mm) for a 25 cm viewing distance / enlargement / 25
For example, to support a final-image resolution equivalent to 5 lp/mm for a 25 cm viewing distance when the anticipated viewing distance is 50 cm and the anticipated enlargement is 8:
CoC = 50 / 5 / 8 / 25 = 0.05 mm
Since the final-image size is not usually known at the time of taking a photograph, it is common to assume a standard size such as 25 cm width, along with a conventional final-image CoC of 0.2 mm, which is 1/1250 of the image width. Conventions in terms of the diagonal measure are also commonly used. The DoF computed using these conventions will need to be adjusted if the original image is cropped before enlarging to the final image size, or if the size and viewing assumptions are altered.
Using the “Zeiss formula”, the circle of confusion is sometimes calculated as d/1730 where d is the diagonal measure of the original image (the camera format). For full-frame 35 mm format (24 mm × 36 mm, 43 mm diagonal) this comes out to be 0.025 mm. A more widely used CoC is d/1500, or 0.029 mm for full-frame 35 mm format, which corresponds to resolving 5 lines per millimeter on a print of 30 cm diagonal. Values of 0.030 mm and 0.033 mm are also common for full-frame 35 mm format. For practical purposes, d/1730, a final-image CoC of 0.2 mm, and d/1500 give very similar results.
>>2867724
>cont
Criteria relating CoC to the lens focal length have also been used. Kodak (1972), 5) recommended 2 minutes of arc (the Snellen criterion of 30 cycles/degree for normal vision) for critical viewing, giving CoC ≈ f /1720, where f is the lens focal length. For a 50 mm lens on full-frame 35 mm format, this gave CoC ≈ 0.0291 mm. This criterion evidently assumed that a final image would be viewed at “perspective-correct” distance (i.e., the angle of view would be the same as that of the original image):
Viewing distance = focal length of taking lens × enlargement
However, images seldom are viewed at the “correct” distance; the viewer usually doesn't know the focal length of the taking lens, and the “correct” distance may be uncomfortably short or long. Consequently, criteria based on lens focal length have generally given way to criteria (such as d/1500) related to the camera format.
If an image is viewed on a low-resolution display medium such as a computer monitor, the detectability of blur will be limited by the display medium rather than by human vision. For example, the optical blur will be more difficult to detect in an 8″×10″ image displayed on a computer monitor than in an 8″×10″ print of the same original image viewed at the same distance. If the image is to be viewed only on a low-resolution device, a larger CoC may be appropriate; however, if the image may also be viewed in a high-resolution medium such as a print, the criteria discussed above will govern.
Depth of field formulas derived from geometrical optics imply that any arbitrary DoF can be achieved by using a sufficiently small CoC. Because of diffraction, however, this isn't quite true. Using a smaller CoC requires increasing the lens f-number to achieve the same DOF, and if the lens is stopped down sufficiently far, the reduction in defocus blur is offset by the increased blur from diffraction. See the Depth of field article for a more detailed discussion.
>>2867724
>>2867725
Pro Tips: Literally not a single successful or productive photographer on the planet is thinking about any of this shit when they're taking photos or buying equipment. It's one of the most absolutely gear-faggotry centered concepts possible in photography, and it has very nearly no use to an end user trying to capture an image to share a location, event, idea, or emotion.
>>2867548
This.
OP this is the only decent explanation you need. Don't fall into pitholes with trolls and leave this place at once.
>>2867725
You spoke a lot but you said nothing worth to the APS-C vs Full-frame discussion. Of course viewing distance and print quality will change what is considered "acceptably sharp".
But I strictly compared two sensors, both with the same example 24 megapixels resolution, one full-frame and one APS-C. If you use the exact same lens focused at the exact same distance, print at the same size (with a printer that outresolves both sensors) and view the images from the same distance, WILL THE DOF CHANGE?
Yes! The depth of field of the APS-C will be larger because the circle of confusion is smaller.
How likely are you to ever have to use this information: 0%
>>2867784
correction: ****The depth of field of the APS-C will be smaller****
sorry, this much stupidity is making me stupid
>>2867548
You should make a youtube video explaining this.
>>2867784
I didn't speak at all. I merely copied the "Simple explanation of circle of confusion" from Wikipedia.
>>2867795
Whatever, it doesn't even have to do with what is being discussed. Did you actually read any of what you mindlessly copied?
>>2867902
It was, very obviously, a response to this statement:
>Total nonsense. CoC is not a difficult concept to grasp to anyone who finished high school math and physics
>>2867929
Why? Are you saying it's difficult? It's not, that article is just poorly written and over explained.
>cropcucks defending their shit cameras
my sides
>>2868632
why would anyone buy a crop camera for any other reason then financial?
>I love my 600d, I would never ever trade it for a hasselblad x1d
seriously if everyone could afford to put 3500$ into their camera setup would there be crop cameras?
eat cock
>>2868821
Reach for one? Size?
>>2868825
Never have I seen or been stopped in a photographic opportunity for having a "big" camera.
>>2868821
I have spent a total of about $6500 on my crop camera setup, and I'm very happy that I did so. Full frame adds bulk and provides me with no benefits.
>>2869090
reach as in not needing ridiculously big/expensive/niche telephotos because of the crop factor.
>>2869190
>reach
teleconverter.
>>2869190
Or getting more reach out of big expensive telephotos, too. When I was shooting auto racing professionally a few years ago, I carried a D3S and a D300s, which along with a 1.4TC gave me more reach options with my 500/4.
Teleconverters aren't always the best option when you need a lot of reach, by the way. Remember that AF sensors care about light transmission through the lens, but not about crop factor, so you'll get noticeably better performance with a 1.4x TC (making that 500/4 a 5.6) on a DX body than you would with a 2.0x TC (making that lens f/8) on an FF body.
When the sun starts to get low on the horizon it can also make a difference, as you might need the extra stop of S/S that you get with the bare lens on crop as opposed to a 1.4x on FF. (Though FF's better ISO performance kind of negates that.)
>>2868821
$3500 is pretty much exactly what I have in my current (Fuji) crop setup, actually.
My personal opinion is that from a sensor-only perspective, there's no reason for 90% of photogs to shoot FF over APS-C. Given a blank slate system where there are full-featured crop bodies and fleshed out lens systems designed for crop, it's totally viable as a serious photographer's system. The issue is that the best Canikon and Sony bodies and lenses are all FF, and so you can't really build a serious crop system without working FF glass that's not optimal for crop into it. Fuji is the only company that has a real crop system at the moment, and that's part of why I shoot them now, but I expect that to change in the future.
>>2869195
>teleconverter
Lol. Enjoy your slow lens, crap AF and reduces image quality.
1.5crop with 35mm 1.8 lens = fulframe with 50mm 2.7 lens
~same bokeh, same frame, same distance
>>2869890
The exposure value is f/1.8
Multiplying f-number for bokeh is retarded.
>>2869090
and everyday there have been photos of birds or objects in the distance which you didn't take or looked like shit because you have a FF camera.
The only time 35mm is truly superior is if someone can carry an infinite amount of weight, has an infinite amount of luggage space and an infinite amount of money.
And if that were true, 35mm would be shit, because 35mm isn't actually full frame, it's one arbitrary number. Medium format then blows 35mm away if there are no limits on lens weight, size and money.
And then a bigger format blows medium format away.
Eventually we get to someone comparing the hubble space telescope with a cell phone camera and saying "why would anyone ever own any other camera, MUH MEGAPICKLES ARE SO HIGH?!"
>>2870102
>it's retarded to do things correctly
DoF actually matters for people who aren't amateur snapshitters like you.
An accurate understanding of a lens has to take in account it's FoV, its exposure effects, its DoF effects and what it does to geometry.
Don't keep confusing your lazy ignorance and retardation for anything other than what it really is.
>>2870235
It's retarded because it's mathematically wrong, not because it's useless. Aperture is a ratio of the focal length. If you multiply the focal length the ratio changes even if you don't change the other factor.
>>2870233
Not relevant to anything I said :^) stay triggered. Full frame is by definition 35mm for DSLR :^) Stay cucked too
I have no trouble carrying an FX body, same situation as I was in with my DX body. Only now, less distortion on equivalent focal lengths, larger frame and better ISO performance, oh and much much longer battery life.
>>2867591
It's about 62% correct
