please excuse my million questions on my new camera but what is the relationship between ISO and gain? It looks like I can go to 3200 ISO and have plenty of light but what is that doing to the image? is it like 36 db gain?

Base ISO is 200und = 0db

Add 6db = double ISO value:
6db = 400ISO
12db = 800ISO
18db = 1600ISO
24db = 3200ISO

I try to avoid values higher than 1600ISO/18db.
But the amount of digital grain also depends on your picture profile.
The higher the shadows are lifted, the more grain you'll see.

So either I add gain or ISO it really doesnt matter? ISO is equal to gain for the most part?

It's equal.

Just different readings.

Choose ISO if your familiar with and let the db readings alone...

Wow so it would seem that even with a fast lens this camera really sucks light. I am shooting in a very well flousencent bulb lit room and if I have it on 160 iso I dont have near enough light even if I get a faster lens it wouldnt be enough. On "The bright side:)" I shot last night at 1600 iso (I think) and looked at the footage and I couldnt really see much grain. So maybe there will be a lot of gained up shooting in my future.

Base ISO is actually 160 on this camera not 200 so 6db will be 320ISO and 12db 640ISO etc etc.

I limit my cam at 21db for weddings which is around 3200 but the gain at 24db is still OK to use. Randy? try an F2.8 lens or faster in low light. BIG difference ... My Tokina 11-16 wide zoom at constant F2.8 is magic!!!

Chris

Where can I get it? B&H doesnt seem to have it. Do I need a adapter?

What about this?
Canon EF 70-200mm f/2.8L USM Telephoto Zoom Lens2569A004 B&H

Where can I get it? B&H doesnt seem to have it. Do I need a adapter?


where can u find what? did you tried amazon?

I'm using Novoflex adapters on both cameras (eBay Germany) They are expensive but shucks they are really like the original part and well worth the extra!!

I have Nikon D90's too so mine are for all my Nikon lenses.

Chris

What about this?
Canon EF 70-200mm f/2.8L USM Telephoto Zoom Lens2569A004 B&H (http://www.bhphotovideo.com/c/product/91680-USA/Canon_2569A004_70_200mm_f_2_8L_USM_Autofocus.html)

oh i see we're talkin about faster lenses. try the sigma 18-35mm f1.8, that will definitely be fast. just needs an adapter ;-)

the gain at 24db is still OK to use.

That would be 5000 iso I think, no? But have to say it looks bad in terms of noise at that iso, if you are desperate to get a shot then I"d say yes and use neatvideo, but otherwise better stay clear from it.

So either I add gain or ISO it really doesnt matter? ISO is equal to gain for the most part?

It doesn't matter, also not what value in iso equals a gain value, you can use whatever you like and judge your footage afterwards to see what the max iso or gain is you can use before it turns ugly.

Hi Noa

Yes, I agree..that's why I limit gain to 21db tops!! (or 3200 ISO) 24db is noisy even if you are using a light fill so both my cams limit at 21db so the dark areas are noise free ... 24 db (5000 ISO) will give you an image if you are desperate but yes, it will need cleaning up considerably. What a lot of people don't realise it that in auto iris, the camera looks at the complete image area so if you have a small subject close up and a huge dark background then it will lift gain or iso EVEN if you are using a fill light on the subject. On my Panny's Randy, I actually used to clamp gain right down to 12db and use a fill light so the big sensor on the 50 does a lot better!

Chris

my camera iso starting from 160 after reset now starting from 200 to 6400 why?


solved...starting from 160 with no profile

Hi Serggio

Different profiles have different ISO's ...It's actually less confusing to switch to gain rather than ISO that way regardless of the base ISO the camera will keep adding gain in 3db increments ...that will give you an idea of what iris to use and reduce shutter when using a manual lens and when it hits 21db (or 24 db if you are brave and don't mind a few noise speckles) you know it's time to either add a bit of light or use a faster lens.

Chris

This is an awesome thread to read through... I didn't know the difference between Gain and ISO. Now I have a little bit better understanding than I once did. Also knowing that different PP's have different range of ISO is key.

21d is my limit (you hardly see any noise) but lately this hasn't been enough even with my sigma 1.8.... plus people turn away when I shine my 150LED light on them (even though its set at a low level)... : / This is not to say that the nexea50 has crappy low light performance when you compare it to other cameras.

I am probably just going to start using around 24d to 27d from now on as my limit.

The next think I need to find out is which video settings is more acceptable/least bad.

Video shot at 21d but brightness increased in post

or

Video shot at 24-27d

Unless you are shooting a black cat at midnight F1.8 should give you an acceptable image at 21db even without any lighting. I very seldom use lights at wedding receptions! Maybe just for the first dance otherwise ambient is more than enough.

Are you sure that you are not trying to turn night into day and spoiling the ambience?? I use all my manual lenses with the camera in auto so the cam does my exposure for me. Now based on that the camera "sees" a lot of darkness so it tends to push the gain up to try and expose correctly and normally what happens is faces are overexposed! You want the peoples faces nicely exposed so I never go higher than 21db so the background retains the overall ambience and people are not blown out. You really shouldn't need a 150LED light to blind them with ...I use a 6 PowerLED light only when I have to and more often than not it's turned right down to minimum.

24db is already a tad noisy but anything past that I wouldn't say is acceptable for professional video at all! so I have never gone to 27 or 30db!!

The secret with low light footage is to have your subject nice and close and well lit and let the background go dark as it should be ....If you have gain limited to 21db and zebras at 90% and have to use light then make sure that people's faces have no zebras on them at all.

Are you using PP3 profile BTW?? That gives you an automatic gain increase of 4.5db without any noise.

Chris

I use whatever gain (or in my case iso) it takes to get the shot, I shoot a lot at 3200 iso at very dark receptions and when needed I shoot at the max iso, 6400 iso on my gh3/gh4, on my rx10 I even use 8000 iso when needed (which is about the same in performance as 6400 on my panny's.

Eventhough the camera's are noisy at those iso levels, they still look a lot cleaner then 3200 iso on the canon 550d I started shooting with, that one you couldn't use past 1600 iso. For weddings I don't have any issue shooting at those iso levels, if needed I use neatvideo. Normally the only time I sometimes need to resort to these max iso's is during the first dance, a touch of neatvideo and lifting the image further in post can do wonders.

Candle light dinners have not been a problem for me, even not with my nex-ea50 and a fast f1.4 lens, the lights from the candle are enough to light the faces of the people that are sitting close and I use a preset that is quite flat so shadows are not that crushed, makes a big difference when shooting very lowlight scenes.

The only problems is when they kill the light almost completely during a first dance.

For next year I"m going to get a light stand that can go 3 metres high and put a strong video light on it and place on the side of the dancefloor just before the first dance starts, only if the kill all the light I will light my torch and bounce the light from the ceiling or point it downwards so it doesn't blind that much. Not going to spend 3K plus for a sony a7s and lens just for those 3 minutes during a entire wedding day :)

My feelings exactly Noa

I cannot see any justification for a Sony A7S at all as the only time I need to have a video light is when the idiots turn all the lights off ... the guests cannot see a thing so the bride has to accept that. My wedding at the end of last month caught be out though!! I was doing the first dance with the lights slightly dimmed and had decent exposure but half way through some idiot decided they should dance in the total dark ..that's what happened so that's what the bride will get.

Seriously I have never had a reception issue since I had the Sigma 18-35 F1.8 apart from the first dance where they over-dim the lights!

Chris

Must be the UK that has a penchant for 'mood' lighting then as I find most evening receptions push my EA50 up to 24db gain (that's where I limit it) and that's with my Tamron 24-70mm f2.8 (which goes down to f2.0 with the speedbooster) the A7s has been a godsend for me. The first dance however, like you guys, seems to nowadays take place in pretty much pitch black!

There would be many situations during a first dance where even a a7s wouldn't cope in my case, sometimes they kill all the light leaving only candlelight on the tables but there is always some lights coming from the DJ's side, sometimes strong light, sometimes just a weak fill light to create some mood.

I use the steadicam to very slowly circle the couple and do the first dance in one continuous shot..When I face the dj I have his lights pointing towards me with no light coming from my back so the couple would only appear as a silhouette against those lights with no detail in them. If I would have a camera like the a7s and expose so I can see the couple the lights from the dj would overexpose, not much of an issue but will become one once I circle further until I have the lights of the dj in my back and facing the couple , they will become totally overexposed with no way to correct on a steadicam without noticing.

So in my situation a a7s would be useless as well and adding my own lights on the dark side would be a better solution as I would create a more balanced lightsource which would allow no exposure changes.

Hi Noa - I've only tried that type of shot once and after 30 seconds or so the DJ got the rest of the wedding party to join them and I was pushed pretty much out the way - I had to dump the Merlin pronto and film the rest as I normally would - more and more I'm lucky to get a minute at best before everyone else joins in. I also have issues with the couple 'dancing' right on the edge of the dancefloor so a roundy shot with the Merlin would be impossible anyway - I just play it safe these days - sorry that was a little off topic :/

I think the topic starter question has been answered and we are still talking about gain or iso :)

Another example when they take in the cake, then also kill all light but I never can go higher then 1600iso as the sparkles on the cake would overexpose the faces of the couple when they cut the cake.

Otoh, I'd love to have a a7s with a fast prime just for my creative shots :)

Once we get into the 'dark' part of the reception, I keep a 132 led dimmable light handy on my double tripod mount, so that if someone decides to lower the lights I can always resort to my own light as a fill, rather than trying to increase the gain too much.

Roger

The wedding we shot yesterday was a budget affair in a sports hall and one could either have all the lights on or none on! Luckily for me they decided to have them all on!

I not only left my speeches lighting kit in the car but also my on camera light. Ok, it doesn't create an event mood but shucks, shooting was a breeze!!

I still zap my on camera light on the B-Cam for the first dance in case I need it as some event co-ordinators don't know the difference between "dimmed" and "dark"

Then again the wedding I'm doing on the 8th of next month has fancy light controllers and a professional theatre spot focussed on the speeches lectern. Easy peasy for that venue!! I could of course still have to use the on=cam light for the first dance!

Chris