focus shift while zooming

[cressi]

is it just me or does the focus go of slightly while zooming i have the zeiss diascope 85.

cressi.

[IanF]

Nope it does shift.

Same happens with my scope even when I focus at a high magnification and zoom back, I usually have to sharpen focus.

[Keith Reeder]

From what I understand/have read on here, it's common to most zooms...

[AndyC]

The focus on my Kowa 20-60 goes completely when using the zoom. If I'm careful I can use the zoom and focus to keep the image sharp.

AndyC

[cressi]

thanks for the reply lads i have the zeiss quick camera adapter and on sunday while taking shots of a green woodpecker i set the focus on its lowest setting pin sharp then swung the adapter into position and zoomed to about 40x to 50x it looked ok in the lcd screen but when i got home and looked at the shots on my laptop they were all slightly out of focus dissapointig to say the least so i suppose i will focus on the scope at whatever zoom setting i want then swing in the camera or if anybody has a better idea i would much appreciate any feedback.

cressi.

[Keith Reeder]

For digiscoping I have my Canon A95 focus set on "Infinity" and do all the focussing with the scope, monitored via the camera LCD - I know that others on here do the same thing, and it works very well.