Any suggestion as to what's going on here?

[Phill D]

Shot a sequence of a passing balloon using the 300mm and the MC20. First shots seemed OK but the quality seemed to go a bit off as the images progressed. All images were jpgs and I just cropped then a bit and tweaked them for contrast etc in Lightroom. Just copied the processing across all the shots and didn't do any sharpening. Unfortunately I can't remember what focus setting I was using as I wasn't expecting any issues with such a simple shot. I think it was SAF though with the small spot area.

First shot....OK looks pretty detailed,


Shot 10. I think this is still focussed but it's starting to look a bit fuzzy for want of a better description.


Shot 14. This was the first from a set of 5 shots that definitely missed focus. Focus returned after these.


Last shot shot 25 of the sequence, back in focus I think but very fuzzy edges.


All done from the jpgs to avoid any issues with viewing the orfs

I can cope with missing focus on some shots but anyone got any clues to why the images start looking so weird?

[pdk42]

If it was SAF, did you re-focus between each shot?

[pdk42]

It could also be atmospheric issues. There's lots of heat coming from a hot air balloon!

[pdk42]

But then again, there's weird artefacts in there too. Perhaps upload the ORFs via WeTransfer so we can take a detailed look?

[Miketoll]

My first thought is the smallest single point in S-AF??? That point is tiny and there are large areas of low contrast that you may have had your point on one of those.

My feeling is that the smallest focus point should only be used for very specific subjects and occasions, very like spot metering is best not to be used for general purpose shots but carefully used for specific conditions.

[Ian]

Could heat haze be messing with the focusing?

Ian

[DerekC]

I think it is the heat haze causing the affect, I had something similar last week whilst photographing aircraft.

[Scottwin]

Looks like heat haze to me.

[Phill D]

Interesting, I did wonder if the application of the burner was having an effect and the fabric was vibrating more than the shutter speed could freeze. It did seem worse when the burner was on. Hadn't thought of it also generating heat haze that's a good call. We get balloons over occasionally I'll do some more considered shots next time.

I'll also have a look at the orf files too for completeness.

I think it was SAF and probably I refocussed a couple of times. I definitely used the small focus point though so all good thoughts.

[pdk42]

I think heat haze is a reasonable explanation for all but shot number 3. That has nothing in focus - not even the basket which is probably away from heat haze effects. That looks like mis-focus.

[Phill D]

Yes that was definitely oof Paul. First of a sequence of 5 before it focussed again.

[Tordan58]

I am inclined to agree with the distortion caused by heat haze. What were the weather and atmospheric conditions? (in addition to sunny).

[Phill D]

Pretty warm and still Tord. Unusual for here this time of year.

[MJ224]

How are you processing the RAW's Phill? Not that has anything to do with the focusing.

I got similar results with overhead Kites last week. Focus was rubbish o some shots...(no camera now)

[Phill D]

Only jpgs Mark so far not processed much raw.

[blu-by-u]

Just thinking, could it be OM-Systems gave the Focus Analyser in the WS because they found a fault in the AF accuracy? So if we machinegun we just put it all into the WS and let the PC pick those sharp one and discard those OOF?

it's just a thought.

[Dave in Wales]

My conclusion after taking loads of overhead and sky stuff for BIF is that the AF is 'FLAKEY'....I was using C-AF.

I'm still not convinced it aint me.

Get the bird somewhere within the Dot Sight and hope for the best, the end of the 100-400 is waggling all over the place, IBIS useless.

No probs with S-AF normally, single shot.

Is it the C-AF

BIF doesn't represent a large percentage of my work, so I'm not overly bothered, but this is a disaster.

A lamp, a street away....camera steady for this one.

[blackfox]

its a hard one to define on a large target like the balloon that is moving albeit slowly you should in all honesty have used c.af as if using s.af and burst mode it would have to recompose between each shot .. so if s.af was used as you seem to think Phil its most likely user error ..... and again with Daves lamppost as its stationary s.af should be used as opposed to c.af ..... it does seem the OM1 is more sensitive to settings than previous models

[Phill D]

Thanks for all the comments guys. Really helpful. I tend to agree with largely user error on this one. But like Dave I'm not totally convinced the af is fully sorted yet. Jeff I think you have a good point too, the OM1 is probably more of an experts camera therefore easier to cock up by us amateurs.