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iron
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PostMon Feb 06, 2017 5:04 pm 
does anyone have one they'd be willing to lend me for a week? i'm in kenmore (near bothell). thanks!

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Jim Dockery
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PostThu Feb 09, 2017 8:56 am 
Don't know how many people realize how important such a tool is for critical focus on SLRs, esp. with latest and greatest high res. This is another argument for going mirrorless, since they focus off the sensor itself, there is no need for calibrating lenses.

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mike
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PostThu Feb 09, 2017 10:47 am 
I know that people DIY using a ruler. Don't know how accurate it is though. Never needed it. duckduckgo shows lots of hits. here's one showing the basic idea

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joker
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PostThu Feb 09, 2017 2:15 pm 
Jim Dockery wrote:
Don't know how many people realize how important such a tool is for critical focus on SLRs, esp. with latest and greatest high res. This is another argument for going mirrorless, since they focus off the sensor itself, there is no need for calibrating lenses.
Indeed. As I shared with Iron in a PM (while offering a loaner), I just calibrated my lenses and found that the ones I use most needed from zero to little adjustment, but a few of my lenses needed quite a bit (i.e. a setting of plus or minus fifteen on a scale that goes to plus/minus twenty). Re: the mirror/mirrorless aside, I talked with a couple of accomplished landscape photographers in October who had tried mirrorless and felt it was "not really there yet." Their primary complaint was how prone they are to picking up dust on the sensor as compared to DSLR cameras. I must say that I still love an optical viewfinder too...

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joker
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PostThu Feb 09, 2017 2:19 pm 
mike wrote:
I know that people DIY using a ruler. Don't know how accurate it is though. Never needed it.duckduckgo shows lots of hits. here's one showing the basic idea
After skimming that page, I'm kind of content with the $ I paid for a LensAlign kit. It incorporates a pretty simple an nifty approach to getting proper alignment of camera with the target. I think the time I saved in using a well-designed turnkey kit was well worth the money (of course everyone has a different equation in that regard).

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mike
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PostThu Feb 09, 2017 2:42 pm 
joker wrote:
how prone they are to picking up dust on the sensor as compared to DSLR cameras.
Don't understand this. My cameras do an auto sensor clean at every start up. Never ever had to clean. My canon friends were always having to do it...and I'm liking the EVF just fine after claiming I never would.

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mike
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PostThu Feb 09, 2017 2:45 pm 
joker wrote:
I'm kind of content with the $ I paid for a LensAlign kit.
Yeah, the DIY route isn't my choice either. Just putting it out there.

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PostThu Feb 09, 2017 2:52 pm 
mike wrote:
joker wrote:
how prone they are to picking up dust on the sensor as compared to DSLR cameras.
Don't understand this. My cameras do an auto sensor clean at every start up. Never ever had to clean. My canon friends were always having to do it...and I'm liking the EVF just fine after claiming I never would.
I'm merely relating the experience of two very experienced dslr users when comparing to Sony, with respect to dust. Both these guys shot a lot in the rather dusty desert southwest. I have sometimes/rarely had to clean when the camera sensor clean was insufficient. As for evf, I use one on my digital compact and while it's better than just having a rear screen, I still prefer the optical viewfinder on my dslr. It would not, however, be the thing that stopped me from going mirrorless...

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mike
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PostThu Feb 09, 2017 3:27 pm 
joker wrote:
dslr users when comparing to Sony, with respect to dust.
That explains it. never had a problem with the Olys since forever. The auto sensor clean and in-body IS were two things that attracted me to Olympus.

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Jim Dockery
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PostThu Feb 09, 2017 6:37 pm 
I'm fine with the evf on my Sonys, but they are more prone to dust than my old Canon SLRs. I clean mine every couple days in the desert when car camping, and always after backpacking for a couple days if I've been changing lenses.

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Gray
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PostWed Feb 22, 2017 2:27 pm 
joker wrote:
As I shared with Iron in a PM (while offering a loaner), I just calibrated my lenses and found that the ones I use most needed from zero to little adjustment, but a few of my lenses needed quite a bit (i.e. a setting of plus or minus fifteen on a scale that goes to plus/minus twenty).
What tool/software do you use for calibration? --Gray

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joker
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PostWed Feb 22, 2017 5:39 pm 
I used the LensAlign tool with the FocusTune software (could have tried to do it by eye but the SW helped speed up the process and saved a lot of strain I think). These tools were recommended to me by John Shaw, who also mentions LensAlign in his good book on landscape/outdoor photography technique. I appreciated the affordance that LensAlign has for ensuring that the sensor plane and focus target are fairly close to parallel.

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Gray
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PostWed Feb 22, 2017 5:48 pm 
Thanks for the reply. I'd seen that one in various photography magazines (in the back). Hmmm, looks like the "Mk2" version is available from Amazon for ~85$. I might have to splurge. We've got several kinda not great lenses, and I wonder if part of the reason they are so soft (in addition to just being cheap lenses) is that they need to be properly calibrated. --Gray

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PostThu Feb 23, 2017 12:35 am 
Calibration helps if the autofocus is putting the focus point in the wrong plane - either in front of or in back of the intended focal plane. So if a photo has things in it at a range of depths from the camera, you'd likely end up with something in focus, even if not what you intended. E.g. if you were doing a portrait and put the autofocus point over an eye, but the eye was fuzzy and either the ear or nose were sharp, for instance, that would be a sign that calibration is likely needed.

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domaz
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PostFri Feb 24, 2017 11:39 am 
The most straightforward way to test if a lens is in critical focus is to use a ground glass and a focusing loupe. Obviously with a digital SLR there is no way to do this since you can't access the film plane. However, you could check focus by using a film version of your SLR if there is one. Canon EOS film bodies go for peanuts. Basically mount the lens, put a piece of ground glass along the film plane and check focus using a loupe. A piece of frosted tape also works in a pinch if you don't have a piece of ground glass.

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