SleepyWill

​It's almost as if sensor size is irrelevant and skill (and skill at equipment choice) is everything! But sure, hit the conspiracy theories instead. Is there anyone on this board you trust to perform the test? Or will you only trust them after the test, if their shots are easy for you to tell apart.

OK, here we are then. 4 cameras, 4 different sensor sizes, 8 of the blandest lenses in my collection (read: most uniform). One camera is full frame, one is crop, one is 4/3's and a lot of kudos if someone identifies the other, with sound reasoning. My method was to use the full frame camera first, to take a shot. Then I examined it and set up all the other cameras to attempt to get them to replicate that look precisely. I used every trick in, on and around the camera that I know, with the exception of additional lighting, reflectors etc. Once I was happy with my setup for each, I took all four shots (including the ff again). Camera profiles were the most basic straight forward, consumer friendly ones, the reason being, so that the only post processing done was in photoshop where I combined the 4 shots into a single picture. No work was done on the pictures beyond pasting them into a square and putting a letter on them. The question is, of course, can you tell which sensor size took which image, failing that can you identify only the full frame?

​Another deflection, I was thinking you could just link to one of these countless other threads, or instead of coming up with proof, just state your theory, e.g. "I believe the size of the sensor increases the area of the sensor at a different rate to the propagation of, say f2's worth of light being spread over a different area. This means that it is impossible to have as shallow dof at any given ambient light on a crop frame sensor and have them expose the same, thus the full frame look is about proper exposure with natural light" See, easy. You could even, if we were using my example, simply say "FF exposes better", without having to dive into those awkward technical details.

​Yes, by recommending full frame, the budget option, as I explained in my second comment in this thread. You do realise it took you just as long to write that you're not going to tell us as it would have taken to just tell us. Is there a reason you won't?

​In english, we use the word repeat when we are saying something a second time. You haven't ever told us what the difference that you see is. You've said: While being sarcastic,and: while talking about doing the practical test with a different lens, and: After talking about a link to wikipedia being proof enough, which then you then later explained the maths in that article to be " wrong and only is semi accurate", next: Which was as helpful as a chocolate teabag. So no, you haven't ever told us what you think the difference is. You've told us now that it definitely isn't field of view or depth of field as you agree they can be replicated interestingly enough using primary school maths to work out how to select the correct lens for the equivalence. If it's a fact, as you say it is, state the factual differences, in a clear, precise way, without calling people colourblind or retards or any "sarcasm" [sic]. Maybe someone with an A7s and speedbooster would prepare a blind test for us, to see if we learn from your mighty intellect that shines through in every word you write. Perhaps you would lower yourself to take part in such a silly, easy little quiz, just to cement your superiority over us minions, begging at your feet for scraps of knowledge.

​You didn't answer my first question. It was the on topic and important one

​So, am I to understand that you believe that one can't adjust the aperture on a camera lens to change the depth of field, such that it matches the depth of field that a different sized sensor would have for an equivalent fov? See image: Am I also to understand that you have changed your mind since december? And that you changed your mind regarding medium and large format cameras between 12:31 on sunday: and 7:21 on sunday:

​Show me then, come on, put up or shut up, demonstrate to me a single specific example where either 1) Change in aperture does not change the DOF with all other setting remaining the same 2) Change in sensor size does not change DOF with the focal length adjusted to give a fov equivalence but all other settings remaining the same Because that is what you are arguing right now. Unfortunately, that specific principal of maths, that is taught in primary schools, is the basis for algebra, being that if you can equate thing a with thing b and thing a with thing c, you can equate thing b with thing c. It doesn't matter how deep into optical physics you delve, the most basic principle of algebra, the bedrock for all of modern mathematics remains true.

​I didn't actually do any math, don't know if you noticed, I just quoted formulas drawn directly from wikipedia, the reference you supplied us with earlier. So if your own evidence is "semi accurate" and the variances are not "lineal" [sic], it is actually irrelevant. All that matters is that there is a relationship between aperture size and dof as well as a relationship between sensor size and dof. Which you acknowledge there is. So you use one to adjust for the change in the other, because by understanding that there is these two relationships, you understand that there is a relationship between aperture size and sensor size for any given dof. This is primary school math. If you understand that there is a relationship between aperture size and sensor size, then you can achieve the same depth of field on a different sensor size by changing the aperture. Simples.

​Does it though? Do this thought experiment with me. Go into your darkroom, rig up some clamp stands and clamp a lens into one. Peek it through your curtains, then set up a piece of white paper inside, the proper distance from the lens, so the lens is projecting it's image circle onto the piece of paper. Notice it's depth of field characteristics. With me so far? Good. Now change the piece of paper for a differently sized piece of paper. Notice how drastically the depth of field of your lens has not changed. So now that we have established beyond any doubt that the size of the sensor does not change the optical characteristics of a lens, what we are left talking about is this: If we change the lens to a different lens, will it have the same depth of field . This is trickier to think about (Please note jcs has already shown you the following absolutely working in practice) So let's think about two lenses on your rig now, both projecting images next to each other onto two pieces of paper. They are two identical copies of the same zoom lens. These perfect specimens of theoretical lenses do not exhibit any variance in their pincushion or balloon distortion through their range, just for now. You set one lens to focal length fa and aperture aa. You set the other lens to focal length fb and aperture ab. The images projected are different, right? We know for certain that aperture affects depth of field in a linear predictable way, so it makes sense that we can equate the ratio of depth of fields. As it turns out, depth of field is inversely proportionate to the diameter of the lens opening. Which leads us to the following equation, for our two perfect lenses: DOFa/DOFb = db/da where d is diameter and DOF is Depth of Field. So for any given depth of field, at any aperture, we can match that depth of field with the other lens. Will they be projecting the same image, no, one is magnified. What is that ratio of magnification? Well, again it turns out that changing the angle of view changes the depth of field in a linear predictable way and again, this shows a direct proportional relationship, which is: DOFa/DOFb = la/lb We have an equivalence: db/da = la/lb So for any given depth of field, there turns out to be a linear predictable relationship between the angle of view (which is of course a function of sensor size and magnification) and the diameter, such that you can, with simple maths show the difference in angle of view. So what does this establish, that given a perfect lens, you can match the depth of field on any different sensor size by merely adjusting both aperture and zoom. As jcs already showed you yesterday. No-one disputes that different lenses have optical differences, but that is not what this thread is about, it's about sensor size. You have just been proven correct, that format size (angle of view) does indeed change the depth of field, but because it is a linear, predictable change, and because aperture also changes depth of field with a linear, predictable change, then given any fixed depth of field on two fixed sensor sizes with known focal lengths, perfectly matched to fix an angle of view, you can work out the aperture to set your lens at to give that depth of view on any sized sensor. So please stop with the personal attacks, it is making you look really really bad. If I, jcs et al are wrong, then you can attack our arguments with logic and wisdom, rather than calling into question our motives and calling us names.

​Funny, I heard the precise opposite argument over a coffee time discussion of this thread. My collegue whom I have a great deal of respect for was raving about how, for the same lens, FF picks up all the interesting, more distorted, less perfect and precise edges of the image circle, and there lies a unique aesthetic.

​Possibly because they don't want youtube being filled with footage that doesn't show off their camera in talented hands.

I strongly disagree. The effort required to keep a 100 year old camera working "as new" if applied to a 10 year old digital camera, and instead of mechanical, metalworking skills you have electronic engineering skills, will keep it running perfectly. I took my son out today to play with my 12 year old dsc f828, it was working as well as the day I first bought it, with a replacement battery.

I wasn't saying it was unusable, quite the opposite, but I was pointing out the drastic limitation of a shallow depth of field, thus the naievity of justifying larger sensor sizes by that alone. Unless you are a focusing savant, and they do exist, your subject will be rather stationary in the frame, especially if it is a human face and unless you like the effect of part of peoples faces/the thing that is the subject of your shot being out of focus, which personally gives me a headache, then you are going to be shooting small (depth wise) flat or very far away objects. Yes a human face side on at the end of a 200mm length filling less than a quarter of the screen is small. That's not a criticism. Your scene was gorgeous. But try watching something that makes you desperate to pick up your camera, the thing you turn to for inspiration. You will find a variety of shots, 95% of which are equally as easy to achieve on any sensor size, from iphone through to 70mm +, and you may find those other 5% of shots are in fact easier to achieve on a smaller sensor, depending on the style of the artist. FYI, my vote is for full frame, but the reason is perhaps surprising. It is the budget option. I know, I know, full frame cameras are very expensive when compared to crop frame cameras, but this is a genius of marketing over the consumers willingness to understand the product. If I want to achieve a specific look, it is almost certainly cheaper to achieve that look on a full frame sensor than a crop frame, because lens manufacturers lie when it comes to f numbers. They give the rating for the light gathered by a full frame camera, even on lenses designed only for crop frames. And because the consumer is either unwilling to do the simple maths - full open light gathered = diameter of lens opening/focal length or is willing to believe that their favourite lens manufacturer can somehow bend light into the front of their lens with magic. Thus that $1000 beautiful quality lens is not and f2.0 wide open, it's more like f4. Go look up the price for that lens that can cover a full frame, with the correct f number and see just how many hundreds of $ you can save to get a similar lens. Then work out how many lenses you need to buy before it would have been cheaper to go full frame from the beginning. With products like the A7s, it's getting close to 1 lens. The real kicker is that if you leave the crop frame system to go full frame, your lovely, overpriced lenses won't cover the sensor. So you have to hand over more $ to the scum who lied in the marketing material in the first place. It's important to note, not every company does this all the time, but every company has done this at one time or another. Of course, in the real world, you aspire to have a variety of cameras with a variety of sensor sizes and technologies. Then, no matter the look you are after, you can choose the tool that will achieve it the easiest. Because that's all sensor size is, a tool. I find internet discussions on the merits of claw hammers vs wooden mallets far more relevant and interesting, which is why my contribution to the debate is often tongue in cheek.

​Which is why so many full frame enthusiasts shoot very small, stationary objects?

I want to buy some lenses, PM'd you

​Er, yeah, did you get mine from before christmas?

​What shonky productions have you worked on where the youngest, or any inexperienced person was allowed to play with cameras or computers unsupervised? And you are aware that files can be recovered simply and easily since about 1995, unless the same morons who let the teaboy play quake on the production computers also let him take a used card and put it back into a camera and start recording with it. If your production has the budget to shoot film, then your production has the money to not have the most inexperienced wally on set touching things with delete buttons and the budget to have undelete software, raid harddrives and a full days worth of cards, with a box to put the used cards in that's locked.

I've seen some less great footage when you have a lot of the screen in focus - but then I'm stuck away from my computer right now and can only view this over public wifi on a surface pro 2, not the finest way to watch youtube! Any chance we could confirm or debunk this? This is what I saw: https://www.youtube.com/watch?v=WdoUTiG8XOM, look at the trees at 0:16ish (I'm on a ward, I can't turn up the volume either so maybe the guy explains this?). I'm guessing the new codec uses out of focus areas to heavily compress, maybe?

Well, I wasn't bothering you for "making pans traditionally" (Whoosh) until you bothered me by insinuating that I was lying about using them creatively and was in fact covering up for a lack of skill. And, by the way, shooting for a proper pan in post is really difficult, way more difficult than a "traditional pan" because you can't see what you are doing. In a really complicated move, the type where you maybe have to "traditionally pan", slide and especially crane your shot at the same time, keep appropriate focus, move lights and shims etc you may as well try to get the shot with a blindfold. It has to be planned so carefully and compared to a simple traditional pan is really difficult to nail, at least to any kind of quality, something you won't find out until after you've done a rough edit - which can take 15-20 minutes if you are fully hooked up on location, otherwise, you're coming back tomorrow to get it right! But yeah, I won't bother you any more about it!

Ahh, here we have the perfect example of a "technician" who doesn't understand how fundamentally different a pan is to a "pan in post", doesn't understand how different they can be made to feel, doesn't comprehend the mechanics of the moves, how differently spaced objects move differently and is happy to throw sarcasm, degrading the work of someone whose work he is neither familiar with or knows who he is. Please, tell me about how uncreative my work is, when you don't know what work I do nor where you have seen it before, and I'll tell you all about, in excruciating detail, why sometimes, I choose in preproduction a "pan in post" because a regular pan just doesn't match my vision. Then you can learn something new and apply that to your "by the numbers" music videos - see I can make a strawman too!

Oh, well, if YOU tried it!!! Obviously you are the arbiter of creativity, and all artists must run their techniques past you first! Tell me, I'm painting an oil for my sisters Christmas present, will you allow me to use the Bistre technique, or must I stick to Venetian?

Oh great, so it puts strain on the processor in the camera having to do the intensive calculations in real time, increasing the heat generated, decreasing the cameras ability to set it's processor to tasks that can't be performed better in post (Like speeding up the reading of the sensor and thus reducing rolling shutter). I think I'd let my 5960x do it, to be honest, with my choice of algorithm.

Hmm, you seem to not understand that adding a "camera move" of 1080p over a 4k source is not something you can replicate by moving your camera. Think about when you move the camera, unless you have it mounted on a gimbal directly over the centre of focus of your lens, when you slide, tilt or pan your camera, things move across the screen at a different rate depending on their distance from the centre of focus. Adding a "pan in post" is not the same as panning the camera, it creates a different visual sequence, a different feel to the film and a different aesthetic that cannot be replicated in camera, unless you set up another camera broadcasting live onto a screen which you then shoot with a second camera... that screen would need to be 4k at least though... I'm sure you're about to tell me that the differences in a pan in post and a real life pan are theoretical but negligible, which is what a lot of people used to say about the differences between a dolly and a zoom shot, until talented cinematographers used each of them to great effect.

I think it takes far more talent to make 4k look good. That's why I still work in 1080p :p