Strange problem with Olympus 9-18mm zoom

eengelmann said:

I'm often using the Olympus 9-18mm zoom ( https://www.dpreview.com/products/olympus/lenses/olympus_m_9-18_4-5p6 ) for taking pictures of the interior of churches and other historical buildings. Usually I shoot three pictures with a different exposure in order to fuse them and improve dynamic range and color.
The strange thing I have noticed is that sometimes the focal length varies slightly in one or two of the picture, as if the zoom gear had been a little bit rotated between the different shots, something I am sure I don't do!

Has someone else met the same problem? Ideas about the causes?

I would like to add that I have to change the exposure time manually, since the camera I use needs that you keep the sutter button pressed in order to carry out exposure bracketing automatically, something which doesn't work with long exposure times!

Click to expand...

Najinsky said:

eengelmann said:

I'm often using the Olympus 9-18mm zoom ( https://www.dpreview.com/products/olympus/lenses/olympus_m_9-18_4-5p6 ) for taking pictures of the interior of churches and other historical buildings. Usually I shoot three pictures with a different exposure in order to fuse them and improve dynamic range and color.
The strange thing I have noticed is that sometimes the focal length varies slightly in one or two of the picture, as if the zoom gear had been a little bit rotated between the different shots, something I am sure I don't do!

Has someone else met the same problem? Ideas about the causes?

I would like to add that I have to change the exposure time manually, since the camera I use needs that you keep the sutter button pressed in order to carry out exposure bracketing automatically, something which doesn't work with long exposure times!

Click to expand...

Click to expand...

eengelmann said:

Najinsky said:

eengelmann said:

I'm often using the Olympus 9-18mm zoom ( https://www.dpreview.com/products/olympus/lenses/olympus_m_9-18_4-5p6 ) for taking pictures of the interior of churches and other historical buildings. Usually I shoot three pictures with a different exposure in order to fuse them and improve dynamic range and color.
The strange thing I have noticed is that sometimes the focal length varies slightly in one or two of the picture, as if the zoom gear had been a little bit rotated between the different shots, something I am sure I don't do!

Has someone else met the same problem? Ideas about the causes?

I would like to add that I have to change the exposure time manually, since the camera I use needs that you keep the sutter button pressed in order to carry out exposure bracketing automatically, something which doesn't work with long exposure times!

Click to expand...

Click to expand...

Click to expand...

Spiridakis Michael said:

I have done 1000sts HDR bracketing usually 7 shots -3/0/+3 with mzu 9-18 with absolutely no problem. My workflow is M mode ISO locked, Focus LOCKED so as mentioned before you are facing just focus breathing - any way it would be useful to upload a bracketing with the problem you are telling us, and also you don't mention the camera that you use.

Click to expand...

eengelmann said:

Spiridakis Michael said:

I have done 1000sts HDR bracketing usually 7 shots -3/0/+3 with mzu 9-18 with absolutely no problem. My workflow is M mode ISO locked, Focus LOCKED so as mentioned before you are facing just focus breathing - any way it would be useful to upload a bracketing with the problem you are telling us, and also you don't mention the camera that you use.

Click to expand...

Click to expand...