Low light conditions: DSLR vs phone camera

[arbol]

Hello, I want to start being a youtuber. My setup is quite simple: an iphone 6 shooting video at 1080, with a tripod also holding a LED ring light, seamless grey paper on the background and a bulb illuminating the background, as well as a lavalier microphone connected to the 3.5mm jack of the iphone 6. I live in Europe.

I am quite pleased with the results of my face. However, the grey background paper is full of noise. I have tried to play around with the (very few) manual settings of the iphone 6, to no avail.

I was thinking initially to upgrade the iphone 6 to another, higher quality, smartphone. This would be the ideal scenario, since I would end up with a good smartphone for general purposes, plus a supposedly good shooting quality for my youtube videos. But I am wondering if I need a DSLR / mirrorless camera with a big sensor, or not, in order to avoid the noise I see in the background paper.

The point is that I will always shoot video under the same conditions, so I do not need a camera that will shoot well under all conditions. But I need that the camera does that specific task well. I am much less demanding on any other task.

I have been watching videos comparing several smartphones, as well as DSLRs, and there are apparently contradicting conclusions.

For example, DXOmark gives the Google Pixel 2 very high marks, suggesting the Pixel 2 could be a good "all-rounder" for me.

But then, some videos show the low light video performance of the Samsung S8 is better than the one of the Google Pixel 2, see around 4:30 in https://www.youtube.com/watch?v=320Vk-Pk2aU

Other comparisons, such as https://www.engadget.com/2017/12/21/2017-smartphone-camera-comparison-iphone-pixel-note-mate/ show the Huawei Mate 10 Pro (in "Noise in 4K") has almost no grain under very low light video shooting, unlike the Samsung Note 8 (which should be quite similar to the S8).

And in comparisons between DSLRs and smartphones, there is a big difference when shooting under low light indoor conditions (which are the relevant ones for me), with smartphones having much more grain than the DSLR (I guess due to sensor size). See around 4:55 in https://www.youtube.com/watch?v=hyJbIwWma3Y&feature=youtu.be&a= for a comparison between the iphone X and the Panasonic GH5.

So, my two questions are:

1) Is it true that no smartphone can shoot video under low light indoor conditions, in comparison to DSLRs? Especially, Samsung S8 and Huawei Mate 10 Pro (I believe the Google Pixel 2 and the iphone X have to be excluded, due to the video samples above).

2) If the answer to the first question is "Yes", then my second question is: is there a relatively well priced DSLR which shoots significantly better video in indoor low light conditions than any smartphone? Ideally, 4k, but 1080 would be OK too.

Thank you.

 

[bjornl]

If low light is your goal a phone is the wrong tool.

The larger the sensor, the better the image quality. The best all around low light video tool is the Sony a7s II. But any DSLR with a good lens will kick the snot out of the best phone-camera ever.

What is your budget?

 

[arbol]

Hello bjornl, thank you very much for your answer.

I am a physicist, and I guessed that what you say is true: the smaller the sensor, the less amount of light. There is no software that can avoid that.

But as said, I am not a video professional. I want to use video professionally, though. In a very specific framework: a talking head, with a ring light, two flat panel lights on my side, and a dark grey paper on the background (with a bulb on my back).

I tried shooting with my iphone 6, and the results were awful. There was a lot of noise. However, 1) I shooted with a non-optimal distribution of lights, so it could be that if I perform a better lighting, the quality could improve, and 2) iphone 6 does not allow to change ISO, exposure, shutter speed ... I believe that what happened is the phone increased dramatically ISO, and this created noise.

My doubt is whether a newer phone, with maybe a better sensor (tiny though) and manual regulations would be able to shoot with a decent quality ("decent" meaning that the watchers of the video do not focus on the quality of the video, but what the talking head is saying).

If I need to buy a Sony a7s II, let be it. I think it is worth it for my business. But for sure, if I could do it with a Samsung S9 or a Google Pixel 2, for sure it would be much better: less cost, more portable, only one device to learn ...

My doubt arises because I see there is "full frame" (I assume this is what it was called 35mm before), then APS, then micro four-thirds, and then the sensor of the smartphones.

If I understand correctly, the Sony a7s II is full frame. The Panasonic GH4, which is cheaper and many youtubers use, is micro four-thirds (smaller than full frame, but bigger than a smartphone sensor). It seems the sensor of the GH4 is good enough for even professional youtubers. So my question is: could it be that even a smaller sensor (such as the one of a smartphone) could do well?

This is a bit similar to buying a laptop: for sure, the more powerful, the better. But if you are able to optimize the laptop, and cheaper laptop can be faster in the real life than a powerful laptop which is not optimized.

I have a similar question: could a smartphone show a quality that is similar to the one of a Panasonic GH4 or a Sony a7s II? Of course, here I am assuming I "optimize", that is, I play around a lot with the optimal lighting, and I play around with the manual settings of the phone camera.

Or not? Or the image from a Sony a7s II will look more "cinematic" (sorry, I do not know if this word exists or not) than any shoot from a phone, irrespective of good lighting and manual settings?

Thank you.

 

[bjornl]

Short and simple: no

As a physicist I am sure you understand that photons can't be created where none existed. There is no way a smaller sensor can compare with a larger one. There will always be more light hitting the larger sensor. A state of the art sensor in a camera can not compare to a large sensor that is 10 years old.

ISO does not change light levels. It amplifies the signal coming from the sensor. Because the larger sensors have more data (light) to work with they produce less noise. My Nikon d700 from around 2009 is far less noisy than my Google Pixel XL. Your phone most certainly shot the ISO to the moon. This does increase noise it also dramatically reduces dynamic range.

The miniaturization of a laptop does not correlate to the miniaturization of a sensor. In a laptop the item being shrunk is not the data but the data processor and storage. The reduction in die size for the CPU allows for a short travel and higher frequencies resulting in more data being processed in a given time. But the data is not changed.

The GH4 is a great video camera / DSLR hybrid. With a fast lens (fast = small f-number which is a ratio indicating a larger aperture relative to the focal length). I use a GH3 for event videos. I rented a gh4 and a gh3 and bought a gh3 because I didn't want to deal with the processing time and storage of working with 4k video files. In addition to recording, I also live stream to several TVs and get the sound from a sound board. The Panasonic GH series is the best all around video DSLR hybrid. The gh5/5s are the newest but the gh3 continues to meet my needs and so I have no interest in upgrading.

If I were doing what you were doing, I might want to use my Nikon d750 instead of the panasonic though. You are talking about a relatively complex lighting scenario for most cameras. This like my d700 is a full frame (and yes, the sensor is the same size as a old 35mm film frame). An APS-C (DX) is roughly 1/2 the surface area of a FX camera. A m4/3 is roughly 1/2 the surface area of a APS-C and so on. (all approximations, google for actual mm^2)
Of the full frames, the Sony z7s II has the larger modern-tech pixels. It is not as good a camera, but it does a special job when the light level is low. The only challenge will be lens selection. With Sony you will have a very limited lens selection compared to a Nikon or Canon.

A smart phone can achieve "ok" but not "good" image quality with ideal lighting. A DSLR can achieve simply horrid image quality if you do a bad job with it. You can not buy image quality only image-quality potential.

I would guess a GH3 or GH4 would suffice. They can not match a Sony A7s II (or my Nikon d750). But they are much much better than a phone and for most are good enough. Also they are simple to operate.


The cinematic look you are referring to is probably shallow depth of field. The larger the sensor the shallower the DOF. The smaller the f-number (the larger the aperture) the shallower the DOF. The longer the lens the shallower the DOF. Then there is distance to subject vs distance to background (the closer the subject is relative to the background, the greater the back ground blur).

 

[arbol]

Thank you for your answer. I will think about it.

Just one question, when you say: "the closer the subject is relative to the background, the greater the back ground blur." Is it really like this? I mean, taken to the extreme, if the background is as close to the subject as say 1mm, one should think that the background and the subject "are the same", so there should be no blur.

Or am I thinking it wrong?

 

[bjornl]

DOF is exactly as I said.
Focus is a plane. This plane gets thinner as the sensor gets larger, as the aperture gets larger and the focal length gets longer. You can google DOF calculations and more detailed explanations to enhance your understanding of the subject. There are times when a 1mm distance will still be blurry.


This spider looks like it is on a porcelain platter. It is not. It is taken outdoors. The spider was microscopically small. To the naked eye it was a dot about the size you might make with a pencil. It was crawling on top of a rough hewn plank which was painted white. This plank was not not smooth nor completely uniform in color. See what the DOF did to the plank? In this case I obliterated the background on purpose by selecting the minimum DOF to get the spider in focus.

Here we have an eyeball of a snail. Not some huge snail but a tiny garden snail that could crawl around on a small coin. Before taking the photo I did not know it had an actual eyeball The eyeball is far smaller than a mm in depth. In this case I increased the DOF in order to get the entire eyeball in focus and to show some detail in the background to hint at what the eyeball belongs to.

In the photo of this little prankster I controlled the DOF to show where he was but blurred it enough so as to not distract from the main subject matter (the boy).