100 ISO or 400 ISO in sunny days - video?
Hi, with my GH5 I made some tests in sunny days with 100 ISO and I noticed a better video quality with more details. But I don't know what could it happen when I wil have to use the camera for more important jobs. What is your opinion? What problem could I get shooting in 100 ISO in sunny days? Thanks
|
Re: 100 ASA or 400 ASA in sunny days - video?
Not exactly sure what you are asking...
|
Re: 100 ASA or 400 ASA in sunny days - video?
Quote:
|
Re: 100 ASA or 400 ASA in sunny days - video?
Quote:
with my GH5 I made some tests in sunny days with 100 ISO and I noticed a better video quality with more details. But I don't know what could it happen when I wil have to use the camera for more important jobs. What is your opinion? What problem could I get shooting in 100 ISO in sunny days? Thanks |
Re: 100 ASA or 400 ASA in sunny days - video?
If you can find out the "native" ISO of your sensor, it is better to shoot at that when possible, it is its as-near-to-perfect as possible setting. 100 ISO should be less noisy than 400 ISO, but it depends on how 100 is achieved by the camera.
|
Re: 100 ASA or 400 ASA in sunny days - video?
Quote:
|
Re: 100 ASA or 400 ASA in sunny days - video?
Why is it better?
|
Re: 100 ASA or 400 ASA in sunny days - video?
It is better for a better video quality. I made same test 100 ISO vs 400 ISO. The quality is better about definition.
|
Re: 100 ASA or 400 ASA in sunny days - video?
Are you sure all camera settings, except iso, where exactly the same when you did test 200 vs 400iso? 200 vs 400iso should not have any effect on the detail you see in your image, difference in f-stop can, like when you would shoot at f0,95 vs f4 on a voigtlander lens f0,95 would look a lot softer then f4, also the further you close down the iris diffraction can occur also making the image softer.
|
Re: 100 ASA or 400 ASA in sunny days - video?
Quote:
Shooting in 100 ASA I had to notice a softer image for the larger aperture but I noticed a prettier picture about definition. |
Re: 100 ASA or 400 ASA in sunny days - video?
My guess is that a changed f-stop caused some diffraction leading to a softer image, that is what you can get if you let the camera handle exposure. Where you using a nd-filter?
Was the camera in manual or autofocus? |
Re: 100 ASA or 400 ASA in sunny days - video?
Quote:
|
Re: 100 ASA or 400 ASA in sunny days - video?
Did I wrote badly? I mean: if I use 100 ISO with S profile I have to get a software image because GH5 uses a larger aperture, instead I got it a better image with better definitions.
|
Re: 100 ASA or 400 ASA in sunny days - video?
Quote:
And you were talking about ISO 200, not 100. 400 is the native ISO of the camera, below that is what used to be known as "negative gain". 400 ISO will give you the maximum quality of the sensor, but will have nothing to do with resolved detail. That will be in your lens. I assume what you're doing is stopping it down significantly. You should be at f/4 ideally. All the time. With any lens. On the m43 system. I would never stop down below f/8. If you need to to expose properly, you need to invest in Neutral Density filters. |
Re: 100 ASA or 400 ASA in sunny days - video?
With S profile I mean in semi-automatic mode. Hovewer I will verify better if I get f/8. I made many clips with 200 ISO and 400 ISO. 200 ISO clips are very better.
|
Re: 100 ASA or 400 ASA in sunny days - video?
Quote:
|
Re: 100 ASA or 400 ASA in sunny days - video?
Friends, I've done a lot of tests, shooting in many ways and I've just come home to evaluate them with a good big monitor. Here are my mental results. Maybe they will be wrong but I say this: I haven't used any filter and the best results in absolute I had them in manual choosing 100 ASA and an aperture between f5.6 and f11 (f11 is the maximum limit to get good images). In my opinion is better open more the diaphragm maybe speeding the shutter (1/320) that close the diaphragm (f16) with a slower shutter speed maybe at 1/100. I've been in the countryside, the day was good with sun and clouds. I filmed landscapes in 4K with lots of green and yellow ripe wheat. What surprised me was the fact that with F5.6, 1/100, with 100 ASA I needed an ND filter. But can it be? It seems a bit 'strange because I was not at the beach and the day was not very sunny.
I will go to Africa but I always brought the videocamera with me. The GH5 is a completely new thing that makes me anxious. We hope well. I don't go to visit the african cities, they don't interest me. I'm interested in people. A consideration I have to do: in this forum I learned a lot, especially the fact of trying on the field the advice all you have given me. PS: 1) Could someone suggest a good variable ND filter? 2) If someone use a GH5 with lens hood, can you tell me if it is hard to turn the filter? I'm worried the lens hood could bother a lot because I have to make fast shooting. Thanks |
Re: 100 ASA or 400 ASA in sunny days - video?
Not sure if you are up on the latest, but the term ASA is not really used any more. It was replaced by "ISO". Even still, the more accurate term for image sensors would be "gain" as that is actually what is really being applied to the signal off the sensor.
Sensors only have ONE "sensitivity" to light. That sensitivty is adjusted to "0db" by the manufacturer. You can then apply your own user adjustable gain after that. "Dual gain" cameras simply re-map the same pixel well output to a higher "0db" brightness rating. It's just different "pre-gain" at the collection level. It doesn't change what the sensor actually "saw" in any way whatsoever. A 50% full pixel well will always be 50% full no matter how high you gain up your camera. 100 ISO, 800ISO, 1 million ISO....and your pixel well is still exposed to only 50% full. "ISO" is not even "exposure" at all in the image sensor world. Only shutter speed and iris affect the image sensors true exposure. Unlike film, ISO/gain has no affect on a sensors exposure in any way at all. Just thought I would throw this out there as its common to talk about ISO and treat sensors as though they are like film...but nothing could be further from the truth. |
Re: 100 ASA or 400 ASA in sunny days - video?
I don't think this is the answer Adriano was waiting for, even if it was very informative for those who are into these kind of technicalities.
Adriano; when you shoot outside with a low shutterspeed like 1/100 you often will need to apply a nd filter to keep your f-stop at 5.6, even without direct sunlight the incoming light on a cloudy day can be bright enough that you need to apply a extra ND in such a case. When you use a lenshood you will not be able to turn your variable nd filter anymore without seeing your hand reaching for the filter. You need to leave the lenshood off if you plan on turning the ring while you are recording. I have used some variable nd filters in the past and found that the cheaper filters gave colorshifts, the expensive ones didn't, I think you can compare this with cheap vs expensive lenses, the more expensive the lenses remain sharper across the frame when wide open, they show less chromatic abberation etc, same for filters you put in front of your lens, it's best not to put some cheap filter in front of a expensive lens. |
Re: 100 ASA or 400 ASA in sunny days - video?
Cliff, thanks for your availabity. I always used videocameras and it is new to me to use camera to make videos. Afrer reading your interesting writings a concept isn't clear to me and I'd like to understand better. I give you an example. If my GH5 has 400 native ISO, if I will use 100 ISO in a very sunny days, what will it happen? The image that I will get will be a little degraded?
|
Re: 100 ASA or 400 ASA in sunny days - video?
Quote:
|
Re: 100 ASA or 400 ASA in sunny days - video?
Quote:
All camera companies have to read their image sensor and collect a raw linear output. This raw data has no real gain inside of it. But then they need to amplify it and apply some type of gamma respose to it and assemble that into an actual "image". They try to find the nominal "pre-amp" that gives that sensor the best signal to noise ratio.....after they are done with pre-amp settingd, they then call this "0db". You and I then take it from there and we add all the gain we want above 0db. This "0db" will then be tested in a lab and they try to match up what the estimated ISO would equal to with light meters. However,...this is not etched in stone. If that company "changes" the pre-amp values on the sensor readout and apply a "different" gamma curve...they now have a NEW "0db" brightness. They have to test this new "0db" and match it up with new ISO lab readings. On your GH5....just for a minute, forget "ISO" and only watch gain settings. You always want "0db" no matter what gamma you are using. VLog, CineD or Natural can all give different minimum ISO values but you can always use "0db" as your reference. While at 0db, that is the NOMINAL gain amount....for THAT actual gamma curve you are using. Remember....0db is a SET gain amount that was determined by the camera engineers with their "PRE-Amp" gain that you dont have access to. They could make "0db" equal 100ISO...or 800ISO. They could make 0db equal 25,000ISO. (Would look horrible but they could do it) Panasonic chose to make "0db" equal arround 400ISO for VLog-L because they needed that much pre-amp to get the most out of that sensor...and make the best "0db" that they could. (The end result was about 400 ISO after they tested it) Gamma curves with less dynamic range require less pre-amp and their "0db" will equal a different ISO light meter reading. But again,..."0db" should always be the best signal to noise ratio and highest dynamic range for THAT particular gamma curve you are using. This is why ISO confuses so many people today. I tell people that ISO has nothing to do with actual image sensor exposure and that raw files dont even have any camera ISO in them, only ISO metadata and many people cant understand it. It blows their mind. I hope is explained this in an easy to understand way! |
Re: 100 ASA or 400 ASA in sunny days - video?
400 iso on the gh5 should give you the cleanest image with the most dynamic range but I doubt if you are able to see a difference from a normal viewing distance to a screen if you shoot at a lower iso.
|
Re: 100 ASA or 400 ASA in sunny days - video?
Adriano, what gamma curve are you using? This determines its "native ISO".
|
Re: 100 ASA or 400 ASA in sunny days - video?
Quote:
|
Re: 100 ASA or 400 ASA in sunny days - video?
Gamma type is your choice. There is no right or wrong. If color grading is not your thing than standard or natural is fine. Im only saying your cleanest image will be 0db on every gamma setting and adding any more gain wont give you any more dynamic range anyway. Standard gammas dont use the entire sensor dynamic range. It already throws away allot so you dont get anything more by adding any more gain.....you just get more noise for nothing in return.
|
Re: 100 ASA or 400 ASA in sunny days - video?
Suggest me please. For me it is the first time I will take a 4K documentary in Africa wirh a camera. I always used videocameras. Would you shot 25p or 50p? Now I don't have free time to study v-log, etc. etc. I have to settle for what my GH5 offers me. Which style would you choose instead of "Standard"? How would you set the GH5 please?
Thanks |
Re: 100 ASA or 400 ASA in sunny days - video?
First thing...take your camera to your back yard or local park and do test shots! Get to know your camera ASAP.
I cannot tell you 25 or 50p. Nobody can, this is completely your preference. Im in the US and if I didnt know my GH5 or what VLog was, I would shoot 4k in 29.97p in natural gamma. I dont like 24p that much and I hate 60p. 30p is the perfect middle ground for me and using 30psf (progressive segmented frame) this will give a progressive look over traditional 60i monitors or even 60i broadcast. Anyway.....shoot right now and test the different profiles and figure out what "you" like. What is your delivery goal? Are you editing this? Are you delivering it to somebody else? If so, get THEM to tell you what they require. You need an end goal. Once you know it, you can shoot acordingly. |
Re: 100 ASA or 400 ASA in sunny days - video?
Cliff, I did a lot of tests and for that reason I asked if you had a GH5 how you would set it. Sure I will do my choise but I'd like to know another thought. I have Pal system, do you think me too I could shot 30p? Or is it better 25p for me? If I have to be sincere I like more 25p than 50p. I see a better image quality but I shoot indigenous people they sometimes walk and then run, I need often to walk with fast step behind them with the camera in hand. I'm afraid 25p could create some problems, maybe 50p is better for me.
I don't have to deliver my documentaries. They are for me only. I only do video projections and I like to get a good quality of image. I always make editing of my videos with Edius 9. |
Re: 100 ASA or 400 ASA in sunny days - video?
25P or 30P will give you problems if you walk fast or run with it in your hand. As you know I am not a fan of slow frame rates preferring the smooth motion. You have to decide yourself, nobody can do that for you only offer their opinion. My opinion, shoot UHD50P, shutter 1/50 ( so you get the motion blur of 25P ) make sure the lens image stabilizer is on so that you have both lens and IBIS active all the time. Before you go shoot some Cine-D or Like 709 and see how they work for your editing. You will have to learn how to set iris, gain and ND as you want. It will not be as easy as your AX100 with auto ND etc
|
Re: 100 ASA or 400 ASA in sunny days - video?
Quote:
Adriano, both Ron and I have a GH5 and edit in Edius so we can give you some tips based on our own experience but they will be very different as Ron mainly shoots indoor with stagelights and I shoot in all kinds of lightconditions at weddings. As for Cliff's tips, I know he means well but I find he often overcomplicates things when simple questions are asked, it's like asking how to start up a computer and someone trying to explain using binary numbers, ASCII chart maps and how that effects the start up process of your pc while all there need to be done is just push a button :) If I was in your place having to shoot in the conditions you have mentioned earlier I would shoot with a Natural profile with contrast -2, sharpness-2, NR-2 and saturation-2 Those are my prefered settings when I shoot weddings, I dial down contrast and saturation a bit because with all set at 0 I find the gh5 a bit too contrasty and saturated, sharpness I dial down because I find it helps a bit with very fine detail like leafes in trees or hedges that sometimes cause a flicker on some tv's, dialing down sharpness helps with that, I know many users that dial down sharpness to -5 when they use native Panasonic or Olympus lenses because they find the image is otherwise oversharpened, making it less sharp gives the image a bit more "organic" look or some also say it looks more "cinematic" in that way. The Noise reduction I dial down a bit as well because at higher iso the image gets softer with a too agressive NR setting. I also would get a variable ND filter as that will help controll your shutter. You only cannot use a lenshood in that case. Use something like a xume magnetic filter adapter as in that case you can quickly remove or put on the filter meaning no need to srew on or off but just pull off or put on and it will stay in position with a magnetic ring. I would shoot in 4K50p 420/8bit at 150mbps or you could test 1920x1080 50P 4:2:2 10bit/all-I 200mbs as the gh5 shoots very good HD. I have not tested it but the HD mode could be much easier to edit and faster to export. As for stabilization, never use e-stabilization and use IS lock only when you want to have extra stability on static handheld shots as that makes a big difference. Don't use "is lock" on moving shots though. For whitebalance, auto whitebalance is pretty good but best is to learn to dial in a kelvin value so your color stays consistent, what kelvin value you need to use is something you can mainly learn by just doing and looking at the lcd screen and seeing the result on a colorcalibrated screen. Just do some test like has been suggested here and shoot as much as you can, with very little preparation time you cannot expect a golden advice that will assure you come back with perfect footage, you will have to learn from your own mistakes. |
Re: 100 ASA or 400 ASA in sunny days - video?
Noa, step by step I'm knowing my GH5 more and more but I need to as 2-3 questions:
1) If you use Natural profile with contrast -2, sharpness-2, NR-2 and saturation-2 then when you edit those clips with Edius what do you do precisely? Do you encrease chromatism or contrast or what? 2) I have a good fixed Hoya ND filter. Some days ago I make a lot of tests and I was disappointed by the filter. The images were less defined and with more red color. Yet a fixed ND filter is always of higher quality than an ND variabiler filter. I can't think to use a ND variable filter. In those tests I liked more to play with iris, shutter and ASA at the cost of not applying the ND filter. Maybe I got better results without ND filter. 3) In this time I have always used the WB Preset. Do you think Automatic WB is better than the WB Preset? If you shoot where there is red earth as in Africa, with Automatic WB you will get bad images as if WB become drunk. I did it sometimes with my videocamera and I get red images. |
Re: 100 ASA or 400 ASA in sunny days - video?
To add a little to Noa's shutter input. Film and video are a series of still images. To make them look like motion they need to have a refresh( flicker rate) greater than 48 refreshes a second. For film this is accomplished with a 2 blade shutter on the film projector projecting at 24fps. In PAL the refresh is 50hz for NTSC 60hz. So a video shot at 25P will have each frame repeated twice. If you shoot at 50fps there will be a unique frame displayed every second. The intent of the shutter speed rule was to make sure that the max shutter did not exceed twice the frame rate since that would make any motion in the frame "freeze " and thus the playback at this minimum flicker rate would stutter. Better to create some blur in the image by lowering the shutter speed. This rule is at twice the frame rate. However once the flicker rate exceeds 50 the effect becomes less. It is still there of course and shooting with shutter faster than 1/100 at 50P will still give the potential for stuttering. But a slower shutter will only apply more blur to the image. Going all the way down to 1/50 and the blur is the same as shooting at 25P. There are now twice as many frames so the resulting motion is also smoother. My reason for saying 1/50 is that if in editing you want to look like 25P all you have to do is start a 25P project and place the 50P file on the timeline and EDIUS will remove every other frame and give you a 25P motion with the correct motion blur of 1/50 shutter. If you shoot with 1/100 shutter it will allow you to take nice still from the video but you will have stuttering if you try to create a 25P file because the shutter speed is too fast.
EDIT: At 50P I should have said a unique frame every screen refresh NOT every second !!! I would take Noa's advice for shooting outdoors as that is what he does all the time. I am indoors all the time so have the exact opposite from you and Noa. Getting enough light is the task for me !!!! |
Re: 100 ASA or 400 ASA in sunny days - video?
Quote:
There is no right or wrong when choosing settings because when you ask 10 people how they set their camera you will get 10 different answers as it's all personal preference. Quote:
Quote:
|
Re: 100 ASA or 400 ASA in sunny days - video?
Quote:
So, nothing to add of value to the topic, but a comment if you were to consider Noa's suggestion to add a monitor. From my experience shooting with a Canon HDV and Atomos Samurai Blade, when I went 4/3 with the GH4, it was almost immediate that I realized the advantage and added an Atomos 7" Ninja Flame monitor/recorder. When I pickup a GH5, it will also include an Atomos Ninja Inferno 4K/60p monitor/recorder. It's a bit of expensive kit to add considering it will also require a cage, drives, batteries, etc, but once you experience the Ninja+GH(x) combination it is difficult to go without it, at least for me. Just wanted to add this to Noa's excellent suggestion. Here is a link to a demo video https://www.atomos.com/ninja-inferno |
Re: 100 ASA or 400 ASA in sunny days - video?
I have a curiosity that grips me and I would like a precise answer from those who did the test. As I said, I would like to buy a very good variable ND filter (I already have a fixed one) and I have heard that maybe B & W BW1075251 is the best among variable ND filters. It costs around 200 euros. Since I value the quality of the image, I would like to know how much this filter can degrade the image more than a good fixed ND filter.
|
All times are GMT -6. The time now is 08:26 AM. |
DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network