Studying the 8-16mm lens on the SD Quttro H

Started 2 months ago | Discussions thread
jande9
jande9 Senior Member • Posts: 1,339
Re: But ...
1

xpatUSA wrote:

jande9 wrote:

xpatUSA wrote:

jande9 wrote:

xpatUSA wrote:

xpatUSA wrote:

jande9 wrote:

If the DP2M, when you turn on the camera in autofocus mode, it comes up at actual infinity focus. You then switch to manual to hold that focus. The infinity mark on the screen is nowhere close so you can't use that.

If you shoot stars you have to focus at infinity. Nothing else will do.

Jan

Thanks for the tip, Jan. I tried it on the DP2, it did the same. Also, powering up in manual, it showed indicator infinity initially but went quickly to 7ft. Since I mostly shoot in manual everything and since I've been reading about the Merklinger focusing method lately, I find that quite useful interesting...

... I went out on the street with the DP2 at default manual focus. I pointed it at the end of the street (about 1000ft) and shot at f/14, f/7.1 and f/3.5. Only got some sort of focus at f/14 - the other two were totally blurred out.

So maybe my DP2 is different ?!

So in the DP2, when you power up in autofocus mode, it doesn't go to true infinity focus?

I believe that was the case. Photographic lore says that if I shoot at "true infinity" focus, everything should be in "acceptable focus" from there back to the hyper-focal distance. In my case, even the distant details were heavily blurred at f/3.5 - which tells me that the DP2's "true infinity" was nowhere close to "true".

I went back out there later and auto-focused on the distance at f/8 and got a good shot with good DOF as promised by Merklinger. I also manually focused on the same distance as best I could in bright sunlight (one 'click' back from the stop) and got another good shot.

So, I deduce that 7ft on my DP2 is not ""true infinity" or even as good as ...

I am away from home so I can't check my DP1.

I am confused. Your first post said that when you powered up in auto it went to infinity,

I said it did the same as your DP2M, Jan. In Auto, It powered up in what you called "true infinity". I did NOT say "it went to infinity". When I switched to manual after powering up in Auto Focus mode, it was at 7ft.

So, your "true infinitity" on mine was indicated as 7ft.

but when you powered up in manual it went to 7 feet.

No. I said that it went to the LCD infinity symbol and then quickly to 7ft.

Have you powered up in auto and then switched to manual, obviously camera not in continuous autofocus or anything like that?

Yes, just like you said. Switching to manual revealed it set to 7ft.

At an indicated 7ft, my DP2 focus distance is less than your "true infinity". What indicated distance (on the LCD) does your DP2M go to?

Perhaps we should not use the word "infinity" by itself without qualification?

OK. Your "Also, powering up in manual," threw me. I don't have my DP2M with me this trip I'm embarrased to say so I can't check what the indicated distance was, but from memory it was just short of the infinity indicator. I was shooting aurora's and the focus was perfect. If I turned the focus all the way to the infinity mark, the stars were soft. It was well below zero so that little trick saved me a lot of fiddling.

By the way, Kendall originally told me about it.

Jan

 jande9's gear list:jande9's gear list
Sigma DP1s Sigma DP2 Merrill Sony Alpha NEX-7 Sony E 18-200mm F3.5-6.3 OSS
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