Lumix G9 is burst rate ISO dependent

I had noticed when shooting at high ISOs (1600 and above) with the Lumix G9, the burst rate seems be slower. To prove this I shot continuously at a running digital stop watch, and then calculated the burst rate based on the number of shots taken and the time eclipsed which I can read from the last and the first shot. I consistently got ~12 fps at ISO 200 and ~10 FPS at ISO 1600. I used H burst mode, mechanical shutter and AFS. Is this to be expected? Do DSLRs such as Nikon behave the same?

2 FPS drop is really not a big deal for me, but when I used AFC at low light conditions, the frame rate would drop even more, sometimes to 3-4 FPS depending on the lighting. Again I think this is to be expected. Will a DSLR do better in such situations?

That could perhaps be due to focus priority, what does it say if you have a look into the menus?

Focus for AFS and Balnaced for AFC

I would guess you can get the full speed back if you switch to shutter for AFC

Ahpeng said:

Focus for AFS and Balnaced for AFC

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Might want to retest @ balanced and release, just to check.

On AFS, the only focus should be first shot should be focused. If length to achieve focus is a difference, you may want to consider longer bursts to see if it approaches 12.

Also, just to confirm, I assume you do not have AFF set?

john

Ahpeng said:

I had noticed when shooting at high ISOs (1600 and above) with the Lumix G9, the burst rate seems be slower.

Click to expand...

Burst rates can be limited by the lens if it has to open and close the aperture between shots. At higher ISOs you were likely using smaller (and hense slower) apertures. I'd expect burst rates to remain the same at high and low ISOs if you shoot wide open.

I did around 50 burst shots in Raw only. This is pretty much the most I can do before it reaches the buffer limit, where the burst rate will slow down significantly.

I tried with AFS using release focus priority setting, and it made little difference. I still consistently saw about 10FPS at ISO1600 and 12 at ISO 200. I always half pressured the shutter before testing so the time it took to focus the first shot should not matter. I also tried manual focus and it showed the same phenomenon. It seems at high ISO the burst rate is indeed slower. Really not a big deal. I am just curious.

As for AFC, I found the burst rate really depends heavily on the lighting and the subjects. For easy to focus subjects I can get much faster burst rate. This is really as expected. Hard to prove if AFC burst rate is also ISO dependent, as slight change of shoot conditions affect the burst rate a lot so it is hard to to compare results from different ISO settings

Danielvr said:

Danielvr said:

I had noticed when shooting at high ISOs (1600 and above) with the Lumix G9, the burst rate seems be slower.

Click to expand...

Burst rates can be limited by the lens if it has to open and close the aperture between shots. At higher ISOs you were likely using smaller (and hense slower) apertures. I'd expect burst rates to remain the same at high and low ISOs if you shoot wide open.

Click to expand...

Good thought....and may be it.

however, why would it need to open aperture if it is not focusing for each shot?

I was using Oly 40-150mm Pro wide open at f2.8 for all the tests. Maybe it would behave differently on a Pany lens. I may tried it tomorrow