Long exposure noise on 5D MKII or II vs 7D

[A_S]

Hi all,

I am just wondering if people could post or give some experience of the long exposure noise on a 5d MkII or III and how they compare to the 7D. I'm thinking of upgrading because the type of stuff I take now its more landscapes often with my big stopper.

The issue i'm having with the 7D is that if I go above a minute exposure on anything above about ISO 200 the noise is cronic and frightening and renders the photos often unusable. It also doesn't give me much scope for ISO adjustment at dusk with a 10 stop filter, which I do need to avoid 4 minute plus exposures. I just feel really compromised by the noise produced by the camera and I'm wondering how the 5D compares and what additional scope that would give me.

For example what is the noise like above ISO 200 on a 1 minute exposure, 2 minute, 4 minute etc. What would be my maximum usable ISO baring in mind that I may want to lift the shadows a little to ensure I've got a nice rich sky.

 

[Bebop]

I have a 5DIII and the longest exposure I've tried is 30 seconds at ISO 2500 f/8 - example below - There's been no noise reduction on this, but I have tweaked black clipping, vibrance, contrast and the lens profile.
I've no idea how it might compare to a 7D and I expect there are people on here who have experience of both. I know the 5DIII is meant to be good at high ISO

I've never used any 10 (or less) stop filters, so please excuse my ignorance… but if you want to avoid an exposure of more than 4 minutes… would it not be possible to use a lower stop filter or even no filter? I do know someone who does take long exposure photos at dusk to get the blurry water effect with no filter.

edit: p.s. long exposure noise reduction on this shot was disabled.



Shooting star by BuzzleCup, on Flickr

 

[A_S]

Thanks, it does look very good for a 30s exposure at such a high ISO. lovely picture too - where was it shot?

To answer the question of using a less dense filter - Currently I have each available Lee ND filter (2 stops, 3 stops, 10 stops). Therefore I can have 2,3,5 or 10 stops by stacking filters.

A quick excersize in excel shows the following @ a base exposure of 4 minutes ISO 400 (ignoring the aperture for now)

As you can see - at ISO 400 I have a choice of 4 minutes at 10 stops, or 0.13 minutes at 5 stops. If I decrease the ISO to 100, I am still left with a max exposure of 0.5 mins (30 seconds) on the 5 stop option.

Therefore if I want to get a 1 minute exposure in order to get streaky/moving clouds or to make people disapear etc then I'm a bit stuck.

Ideally I'd love to be able to boost that ISO on the 10 stop filter to 800 or 1600 to get a 2 or 1 minute exposure but I can't because of the noise issue. Therefore I am limited to having to reduce the apature say from F11 to F16 or F22 but ideally I'd like to keep F11 and use the ISO to control the exposure length.

 

[Bebop]

Ah okay Andrew, thanks for explaining. I can see your dilemma. I guess the purchase of another ND filter might sort it too, but there must be an expert on here who could shed some light on it …. if you'll forgive the pun

My photo was taken on the Isle of Wight at Newtown. We do get some nice dark skies here, though in this particular photo the glow on the horizon is light pollution. The south side of the island is much darker

 

[jerry12953]

The 7d is not known for its ability to produce low-noise images. I can say with complete confidence that the 5d2 is much better and I suspect the 5d3 is even better than that.

Personally I think 10 stop filters are over-rated. Recently I waited until after the sun had gone down and I was getting exposures of about 2 seconds at 100ISO and f20. I think something in region of 3 less stops might have been handy but I got some nice flowing water images without a filter. I can't really see the need to use exposures in the region of minutes.

 

[markmullen]

If you want longer exposures than just ambient light, but the Big Stopper is too strong that is just the situation the Little Stopper is aimed at.

 

[Stu Blackpool]

I moved from the 7D for EXACTLY this reason mate and the difference is actually staggering. I went along to Buttermere one morning and we had a horrendous 70mph headwind and I was trying to get a reasonable sunrise set of that poxy dilapidated tree and I had to use IS0 3200+ to get the shutter speed right and the images were just awful. My mate was shooting ISO 10'000 with his 5D3 and they were absolutely fine. I bought one the very next week.

That being said, I never need to use high ISO for long exposures so don't have anything visual to confirm the above statement so take that as you will, but its certainly one of the best performing High ISO cameras money can buy.

 

[Stu Blackpool]

These may help though... ISO 10'000, handheld, no flash.

 

[Martyn D]

Expose 1/3 to 2/3 to the right with the 7d and you'll see quite a difference, darkening shadows has no noise effect but trying to lighten shadows on the 7d brings in a bit of a snowstorm.
Ok so you're not going to get good stuff at 10,000 ISO but then again you're trying to compare a camera in the 5D3 that's over double the price so anyone would expect it to perform better.