Continuous Shooting

Hi all, I've been viewing the forum and looked enviously at all your lovely photos for a few months now while waiting impatiently to become a fully fledged Pentaxian. My first ever DSLR, a K-7, arrived on Tuesday 12th from the wonderful SRS (through the link on this site) it arrived on the following day the snowy Weds. I had to pick it up myself from ParcelForce in Newport (20 miles) as they couldn't get out because of the weather (which wasn't at all bad on the main roads). I couldn't wait another day without it having driven my family crazy talking about it for months.
I chose the Pentax
18-55 kit lens and as I have a limited budget I chose the Sigma 70-300 to go with it, a bit of macro, a bit of zoom. I have played and played with it to learn most of its functions and yesterday took the K-7 and the Sigma to a local nature reserve where I had my first attempt at panning birds in flight at 5+ frames/sec and was totally impressed by the performance of the continuous focusing giving sharply focused DNG pictures, 13 at a time (before the buffer slowed everything down). I also tried it with a dog running towards me with a big log in his mouth and also a child on his bike also coming towards me and both camera and lens coped admirably.

So, to cut a short story long, I had the camera in work today and was trying to demonstrate the continuous shooting to a colleague but had on the Pentax 18-55 and was shocked that it would not take more than 4 continuous shots before slowing down. I checked the settings and they were the same as previous. Also tonight I have tried at home first with the 18-55 and again it would only take 4 continuous shots so I put on the Sigma and took 13 continuous shots, back to the 18-55 4 continuous shots and more subsequent tests have produced the same results.

I am at a loss so I thought I would ask you guys to see if any of you had any ideas?
Steve

What brand of memory card are you using?

It seems that some budget ones struggle to keep up in continuous shooting. I've never had this problem but then again I don't tend to shoot more than three or four photos in quick succession.

Hi Steve - welcome to the forum.

I had the same first thought as DM, but I cannot see how that would explain why that would effect one lens but not another. Very odd.

Steve, both the problems with the standard lens seem to be with inside shots, was the flash firing ? could be the flash catching up, not the card ?
Dave

Thanks for the replies, I am using a sandisk ultra II 8GB and am literally swapping one lens for the other and performing the same test at the same place with the same settings and these are the results...I'm baffled.

I seem to recall a similar issue with the K7 elsewhere in this Forum. Something to do with the camera being set up to correct lens issues - CA, etc.

Could the camera be recognising the 18-55 and trying to correct lens abberations, but not recognising the 70-300?

Assuming the individual file sizes from each set of shots are comparable, what about the time between shots for each? Could indicate the K7 is 'thinking'/working harder?

As John says ... as default the camera has lens correction switched on.
The K-7 does not correct any other lens apart from Pentax hence no slowdown with Sigma.

You da man JohnX, I new you guys wouldn't let me down, spot on with lens correction, I turned both options off and bingo 13 continuous shots.
Thanks loads
Steve

Hi, also make sure your noise reduction is off

Now all I need is a K7 to go with what I know about it

I'm on the Island Gareth, BTW I did enjoy your fireworks photos from back in Nov.