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I looked up the CRI of tungsten and places just list it as 100.. and it's way cheaper than LED bulbs with lower CRI. Of course they're big and heavy and hot and chew power but for my purposes (the odd camera test at home) those limitations are fine. There's a table of CRI values in this: https://en.wikipedia.org/wiki/Color_rendering_index I laughed - Low Pressure Sodium has a CRI of -44. I didn't know the scale could go negative!! ???

Ignore @xzobinx and his evil temptations... lots of older lenses flare like crazy - check out the Super Takumar flare in the car headlight shot of this (it's B&W but you'll get a sense of it): My memory of the raw footage was that the flare was full of reds and greens, but who knows how it would flare with the sun as it's waaaaaay brighter than car headlights

Careful.. someone will read this and take it one step further and we'll end up with some 2-bit cinema camera company. We've had those before and they only leave broken promises and heartbreak in their wake!

Wow.. @BTM_Pix and @Cinegain - you guys are very punny! There were some camera systems made that used an m42 mount but had a shorter flange distance, so you buy the lenses as m42 lenses and they fit perfectly on your m42 adapter but can only focus about 1cm in front of the glass. Great if you need to get a splinter out of your finger or something, but not so useful for anything else!

.....and @leslie and I will eventually sort out our infinity focus issues and then there will be more lenses in the mix Great stuff!

The video is cached just fine, but displays badly when it's playing but not when it's paused. I tried Firefox and it didn't have this problem at all, but I'd rather use Chrome if I can. It's very odd.

I've been doing lens and camera tests, and want to do them in a stable lighting environment, so I know that means I need some artificial light, and that it needs to be high CRI. My challenge is that I have no real need for this lighting apart from doing these tests, so I want to spend as little as possible. I'm assuming that the best option is a large power halogen light? Something like this? https://www.bunnings.com.au/arlec-1000w-halogen-worklight-with-tripod_p7070522 And maybe just bounce one / both of them off the ceiling (which is painted white) to soften things a little? Thanks.

Hahaha.. thanks for that... umm.... useful... advice! I've got about the same likelihood of getting my wife to pull focus or to appear in the tests as to get my teenage kids to be involved in any way whatsoever, but oh well!

I'm very interested in this and would like to get to the bottom of what you're seeing. Is it that a wide angle has a shallower DoF? On smaller sensors shallow DoF on wide-angle lenses is very difficult to do, so that would make sense. Or is it to do with the falloff between what is in focus and what isn't in focus? I'm 100% sure that there's some kind of engineering or physics principle behind what we're talking about, the challenge is figuring out what it is

Thanks for the feedback, that makes sense.. I'm completely fine with this being a continuous challenge or even just discussion about Soviet Primes as I think they don't get the attention they deserve. I was thinking that the next 'challenge' might be just purely budget-limited but instead of $200 it be something like $50, or $100 for the entire kit of equipment so that everything would be taken into account, plus it would be great to see what people can do with very little funds. Anyway, it's all just some fun and hopefully we all learn something in the process. The Industar 50-2 m42 lens is USD$20 with free worldwide shipping and adapters are also readily available.. I even posted a link to the Industar in the thread. I would imagine that being part of a challenge would involve at least some degree of... well... challenge! And the people that don't have any Soviet lenses are exactly the people that I would like to have bought one, to widen their horizons a bit. If only the right camera for that app had been more like the right camera for me! Thanks for the recommendation though, I'll check out that app and see if the peaking helps at all.

Any idea where "the look" comes from? That's what we're trying to figure out.

I'll try to do some proper lens tests of all these if I can work out how to film myself with manual focus lens and actually get correct focus. Let's hope someone has some tips - I've asked in the GH5 thread.

See this video: I'm watching Amazon Prime Video (The Expanse) on my MBP in Chrome on my external Dell monitor. Any idea why this is happening? And more importantly, how I can fix it? Thanks....

Does anyone have any hints on nailing focus on manual lenses when filming yourself? For example, I want to film a bunch of tests of myself (like the lens tests always have a model in them) but when the lenses are wide open I can't work out how to check critical focus. I've tried the app, but found that it doesn't have enough resolution to tell what's in focus, I can't setup something at the same distance and pre-focus because if DoF is only a cm or two then I can't make sure my eyes are exactly that distance. The only couple of thoughts I've had is either to hook up the HDMI out to a huge TV that I can see well enough, or to buy a telescope so that I can see the flip screen well enough from where I'm sitting. Help?

And now some test shots I took earlier today with the Industar 50mm F3.5. Every shot is wide open at F3.5. This wasn't shot with a speed booster, so is 100mm equivalent. This lens is US$20 with free world-wide shipping. You probably can't beat that for value if you're on a budget!

OK.. My first film was with the Mir 37mm f2.8 - I think it might have been on a speed booster but can't quite recall: Second film was the Helios 58mm F2, also can't recall if it was on the speed booster or not: I shot the Helios at F4 where it has sharpened up significantly, but still has some subject isolation. I was hoping for "wow that's a great modern looking lens look how sharp it is what could it be" type reactions, but you know, everyone is off talking about 6K and completely missing the point of... well... everything Third film is uploading....

It's all good. Even if information is wrong (or incomplete) then it's worth talking about. There's a chance we might learn something, which is basically the only thing that is actually worth anything in the long run Super-shallow DoF is an interesting one, as the forums are full of conversations that go: "I've got to get that FF look... BOKEH!!!" "You're an idiot, real cinematographers rarely shoot wider than F2.8 - lots of cine lenses are only that fast, go get an education you moron" "Yeah, but....... BOKEH!!!!!" "I'm done with you... <block>" but in reading a lot about cine lenses for my cine lens deep-dive thread I found quite a lot of references of people using the Zeiss Super Speeds (T1.3) or Master Anamorphics (T1.9) wide open for one reason or another. Think about that - S35 sensors being used with 50mm or 85mm lenses at T1.3!! And people make snide remarks at me for wanting a Voigtlander f0.95 lens - that's only f2 equivalent. DOF falloff is a very interesting topic and I found references to that on my cine lens deep-dive. Apparently people like it when the falloff is more gradual. In terms of what is going on here, I'm at a loss to understand it. The way that a lens works is this: the light coming into the lens is projected onto the sensor for any (sensible) setting of focus on the lens there will be a place you can put something in the FOV of the lens that will be "in focus" on the sensor "in focus" has to do with the Circle of Confusion Circle of Confusion essentially says that any point in front of the lens will either be a perfect point of light on the sensor (ie, perfectly in focus) or it will be out of focus and in the shape of a circle (which is actually the shape of the aperture blades, but circle works well enough as an analogy). Therefore, in theory, the DoF of what is in focus is infinitely shallow. This isn't true in reality though, because pixel size matters. Let's imagine that we have a sensor with pixels that are 1um across (for ease of maths). If you get an object with an infinitely sharp edge and put that edge at the exact focal distance then the circle of confusion will be 0um across, and therefore will only hit one pixel, and in the final (RAW) file that point of light will be in-focus as it's only putting its light onto one pixel. Now let's imagine that we get that object and move it towards (or away) from the camera such that the circle of confusion is 10um across, that will be 10 pixels wide, and will probably hit 11 pixels. Obviously this is going to be seen as out-of-focus in the output files. The interesting part is where we position the object such that its circle of confusion is 0.3um across. It's technically out-of-focus, but 0.3um will probably only hit one pixel and so in the output file it will still be perfectly in focus. What this means is that we have a DoF greater than zero because the size of the pixels is a limitation. This means that the larger the pixels, the deeper the DoF for any given lens. Which is why the DoF calculators ask you for the sensor size and resolution. A 500MP MFT sensor will have a lot shallower a DoF than a 12MP S35 sensor, even with the same lens. The maths of this really doesn't care about what sensor you're using - for a given FOV and the same number of MP on the sensor the fall-off should be identical. The tricky part is where we position the object such that its circle of confusion is 0.99um across. It's technically out-of-focus, and if that 0.99um happens to like up perfectly with one pixel then it will still appear perfectly in-focus, but all probability suggests that it will fall across 2 or more pixels, making it a bit of-of-focus. This will also be true for the detail with 0.3um circles of confusion. What we're getting into here is maybe the gaps between the pixels (larger gaps will mean that more stuff looks in-focus) and maybe it's also the sharpness of the lens as in just the same way that the sensor has a maximum sharpness (it can't tell the difference between 0.001um circles and 0.01 or 0.1 circles) so do lenses. A lens with lower resolution will have a deeper DoF despite having the same FOV and aperture as another higher resolution lens. I guess this ponders the question, does a lower-resolution optical path or a higher resolution optical path have a gentler roll-off? A higher resolution optical path will have a shallower DoF and therefore have a deeper area that is almost in focus, and a lower-resolution optical path will have a deeper DoF and a shallower area where the transition occurs. Can anyone confirm this? It would require having two lenses with different resolutions that are the same focal length and can do the same aperture. @BTM_Pix has a bunch of lenses but might be too busy working on his 127 projects.. I'll have a look through my lens collection. Certainly if you have a larger sensor camera then the gaps between the pixels are likely to be smaller and the glass you're using is likely to be more modern and higher resolution, so both of those would mean a deeper area of things almost in focus, so the logic fits.

Indeed @leslie - being a bit more sceptical on who is posting is definitely an up-side. Plus I always look forward to @BTM_Pix somehow working in a can of processed ham into the thread. That mans creativity knows no bounds!

That’s what I was thinking too, that it’s basically false. I didn’t want to say so straight out because of two reasons, the first is that I don’t think I understand this stuff well enough to say things like that (and i’ve been wrong before!) and secondly that although I can’t find any tangible reason that a larger sensor should be better I have seen enough videos shot with larger sensors (FF and also larger) that had some kind of X-Factor that I just couldn’t place, so they always left me wondering if there was something to these urban legends.... It may well be colour science though, that’s entirely possible.

So, the competition is now officially meant to be closed, and judging to commence. My prize winners! Considering the low participation rate, everyone who posted anything is a winner and receives the I BEAT ALMOST EVERYONE SIMPLY BY ENTERING prize! and a special mention to @BTM_Pix who wins the I PUT EFFORT INTO EVERYTHING EXCEPT READING THE RULES prize! What’s next Anyone else that wants to award any prizes is now free to do so... the more creative the better. I’m willing to award a prize for best prize, so have at it. I’m curious to hear why more people didn’t enter... I suspect it might be the requirement to have close-ups of people, and I must admit that I had a third lens ready to shoot with and just didn’t find an opportunity to film anyone at such close quarters. So, all rules are now suspended except the Soviet Prime Lens rule, and let’s keep posting things shot with those lenses. I’m keen to see what anyone is filming (or has filmed) with Soviet Primes. I’ll definitely be filming and posting some stuff I’ve shot with the Soviet primes I have owned for some time and bought for this challenge.

I found that article to be very confusing. We all know that different crop factors can be compensated for in some ways (eg, FOV) but that other things don’t scale (eg exposure) so for example on MFT you put on a lens that’s 25mm T2.8 and get a certain exposure and a certain DoF, but when you put a 50mm onto a FF lens then you can set the lens to be T5.6 and get less exposure but the same DoF, or you can set it to T2.8 and get the same exposure but a shallower DoF. Tha article seems to be indicating that something changes when you use the larger sensor and then put on a lens to give the same FOV, but it doesn’t say what it is. It seemed to indicate that you can get closer and still see the same things on the edges of the frame, but that would mean a wider FOV, which is something you can do with any sensor size - just go wider and closer. Does anyone actually know what they’re talking about?

I didn't know Sirui is getting into lenses. That's pretty cool. More competition the better. I think my whole camera kit only has two firmwares - one for each camera body. Yet another reason for manual lenses

Well, I started a thread about 6K being overrated as there's not much difference between a 6K image and a 4K one, or a 4K crop from a 6K image and a 2.7K crop from a 4K image upscaled to 4K and I was told in no uncertain terms that the images were completely different and that we all need to film in 6K or we will starve because our films will never be watched by anyone. Never mind the films in cinemas shot on 2K cine cameras, apparently they don't count and you need 6K! I personally find this stuff all very amusing, how people get so upset

HAHAHAHA.... all these people going FF and re-buying all their lenses are already behind the curve! I've always said that if you're not shooting Medium or Large format then you might as well be using a 1/3" chip camera - you're not going to be getting those luscious immersive images! Sell all your FF lenses now - the format is dead! Get out while you still can!!

I haven't looked, but there might be a way to assign a shortcut key to the action. The keyboard shortcut engine in Resolve is pretty comprehensive, if you haven't already checked it out