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Manual focus & Infinity setting


Andy H

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THIS IS A COPY OF AN EMAIL I HAVE SENT TO FUJI.  IF ANY OF YOU HAVE ANY IDEAS, I'D LOVE TO HEAR THEM!

 

I purchased a new XT10 (s/n 67L03084) along with 2 kit lenses in November of this year.  The 16-50 lens s/n is 62H09098.  The s/n of the 50-230 lens is 62H00965.

 

I have also booked a holiday to the Arctic Circle with the sole intention of shooting the Northern Lights.

 

Last night was clear so I took the camera out to try some star pics to see how it performed.  I know that autofocus is unlikely to work under such conditions, so I set the camera to manual focus and set it at the extreme end of its scale, i.e. infinity. The resultant pictures were all blurred.  I then experimented and found that infinity is in focus when the camera suggests there’s still some way to go.  I have repeated this experiment during daylight and it seems the 16-50 kit lens doesn’t focus on infinity when it’s set to infinity.

 

When I am photographing the Northern Lights, the temperature will be in the region of minus 20 degrees and it is extremely unlikely that I will be able to set the focus in such conditions using trial and error (actually, having spent a fair amount of money on said camera, why should I have to use trial and error?).  Furthermore, if it’s just stars, there will be insufficient light for me to manually focus anyway, so I could be out in the freezing cold  taking blurred pictures and I’ll only find that out when I upload them to a computer once inside the hotel.

 

So, my questions are:

1.      Am I doing something wrong?

2.      If not, what is the next step? I need the camera to take pictures of the Northern Lights and it looks like it may not be up to the job.

 

Attached are four files; 2 taken with the focus set on infinity (both blurred) and the other 2 with me manually focussing and ignoring infinity.

 

 

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Infinity is very rarely, if at all, ever at the end of a lens' rotation (any lens, any manufacturer, ever) This is due to temperature. If it were at the end for a warm temperature it wouldn't be at the end for a cold one. "Things" expand and contract due to temperature; it's the way of the world. Infinity will be towards the end, turn to the end and bring it back slightly. Many lenses don't even have a hard stop and continue to rotate.

 

There are many posts/helps on the internet showing how to focus at infinity. A simple technique is to focus on a distant object, it's effectively at infinity.

 

Thank yourself lucky you're not using film; then it's a real bummer.

 

I'd advise against SHOUTING in a post; you'll upset some. I DON'T MIND. Also against quoting your serial numbers.

Edited by MirrorMirror
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Infinity is very rarely, if at all, ever at the end of a lens' rotation (any lens, any manufacturer, ever) This is due to temperature. If it were at the end for a warm temperature it wouldn't be at the end for a cold one. "Things" expand and contract due to temperature; it's the way of the world. Infinity will be towards the end, turn to the end and bring it back slightly. Many lenses don't even have a hard stop and continue to rotate.

 

There are many posts/helps on the internet showing how to focus at infinity. A simple technique is to focus on a distant object, it's effectively at infinity.

 

Thank yourself lucky you're not using film; then it's a real bummer.

 

I'd advise against SHOUTING in a post; you'll upset some. I DON'T MIND. Also against quoting your serial numbers.

Many thanks for your reply, both speedy and informative - I'll now go and research some web articles.  

Not sure what you mean about "shouting" - maybe it was my use of uppercase at the start of the post?  If so, this was merely to separate and distinguish between the introduction to my query and the body of text that was sent to Fuji.

I feel OK about quoting my serial numbers - essentially everything was a copy&paste from an email.

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Glad to have helped. Yes, capitals signify SHOUTING in writing. It doesn't bother me but some see it as rude, or RUDE!

 

I prefer not to put anything personal on the internet, you never know how it can be used. I've already registered your lenses with Fuji and requested a refund!! :)

 

A colon and right bracket denotes a smiley face, or jest, and will appear here as a yellow face with smile.

Edited by MirrorMirror
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  • 1 year later...

Many thanks for your reply, both speedy and informative - I'll now go and research some web articles.  

Not sure what you mean about "shouting" - maybe it was my use of uppercase at the start of the post?  If so, this was merely to separate and distinguish between the introduction to my query and the body of text that was sent to Fuji.

I feel OK about quoting my serial numbers - essentially everything was a copy&paste from an email.

 

Hi,

 

Did you figure it out after all? I was wondering about infinity focus when capturing stars. I seem to have a hard time manually focusing on the stars afar, even in manual (with 10x digital zoom). I have my assist set to peak in red, but I`m never sur if I need to highlight the outter edge or smack in the middle.

 

Cheers!

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