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Old Dec 30, 2007, 3:26 PM   #31
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lomitamike wrote:
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Frank; I do not uderstand the mechanics of the AF system but, I do know that thereare 3 screwson the bottoma 5D that if I'm not mistaken adjust the position/angle of the sensor. When screws are properly adjustedthey cause the camera to focus on target.

I'm wondering if the focus test that lsifsconducted with the books spaced evenly apart would have been more favorable if the books had been different colors (high contrast).

I've had my camera/lenses have difficulty getting to AF under low light / low contrast conditions.
Hi Mike,

Your understanding of the AF adjustment screws agrees with articles that I've read on the subject. If I understand it correctly this adjustment applies to all lenses mounted on that body. I'm a little puzzled how an individual lens can be bad - maybe if it was way out of alignment?

Perhaps you are on to something with the low contrast target. I've tried the test chart from herea few times that I've doubted my camera. With this chart the camera/lens passes every time.

--Frank


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Old Dec 30, 2007, 7:33 PM   #32
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With this chart the camera/lens passes every time.

--Frank


Great chart to test your stuff. I downloaded the chart and tested all my primes and my 28-75. Everything tested good.

The 100 f/2 took some time to get everything lined up correctly. The distance from the camera to the chart is just far enough where you have to leave the veiwfinder move the chart then look through the viewfinder again to make sure the chart is lined up. I got a few bad results until I made sure thatthe horizontal plane was level. That was a little scary until I realized what I was doing wrong.

Hopefully lsifswill read this and test all lenses with this chart.

Here's what it looks like.


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Old Dec 31, 2007, 11:41 AM   #33
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I was actually using this focus test sheet before using the books method, but the results were depend on the angle of the camera,for some lenses that have very long minium focus distance, the texts and numbers on the sheet are very small and hard to see. I like to use the books method better.

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Old Jan 18, 2008, 10:07 PM   #34
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I have the 50mm 1.7 (RS), I have to stop down to 2.8 to get sharp pictures, I want to get the brand new 50mm 1.4 from B&H ($324) because it's lot sharper at wide open and very sharp at 2, I also see the used 85mm 1.4 on ebay ($800): http://cgi.ebay.com/Minolta-AF-85mm-...QQcmdZViewItem

I want a really good portraid lens that has excellent sharpness and bokeh, can't make final decision, need advice. Thanks

Interesting... I have the 1.7 and it is pretty sharp. In fact I have two of them. I bought a second one on EBAY for a BIN of about less than 20 dollars. At that price I couldn't resist. I didn't pay much for the first one either because it was packaged with a Maxxum 7000.

In all fairness, Ihave never compared it to the 1.4 and I probably never will because I'm not willing to spend 300 dollars when I'm happy with the 1.7 . At least not until someone shows me that it does that much better of a job. I wouldn't mind the extra light capabilties but I can't have everything and my lens lust days are over for now.

I'm not knocking anyone's desire for it or that it really isn't worth every penny. That's not to say that the 1.4 isn't worth it... just not to me. Besides, because of the crop factor, I prefer to workwider primes or low power zooms. Just wish I could squeeze more light out of them.
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Old Jan 19, 2008, 2:06 PM   #35
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meanstreak wrote:
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lsifs wrote:
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In all fairness, Ihave never compared it to the 1.4 and I probably never will because I'm not willing to spend 300 dollars when I'm happy with the 1.7 . At least not until someone shows me that it does that much better of a job. I wouldn't mind the extra light capabilties but I can't have everything and my lens lust days are over for now.
I agree with you that the difference is not alot but the f1.4 does test a little better.

For me I am considering it for two reasons. 1. I like the 55 mm filter diameter and 2. I like the hood. I would bet that the flare is somewhat better but those are not that big of differences. Also if you could get around $100 or so for your 1.7 that would be a $100 of the cost.
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Old Jan 21, 2008, 8:37 PM   #36
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lomitamike wrote:
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meanstreak wrote:
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lsifs wrote:
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In all fairness, Ihave never compared it to the 1.4 and I probably never will because I'm not willing to spend 300 dollars when I'm happy with the 1.7 . At least not until someone shows me that it does that much better of a job. I wouldn't mind the extra light capabilties but I can't have everything and my lens lust days are over for now.
I agree with you that the difference is not alot but the f1.4 does test a little better.

For me I am considering it for two reasons. 1. I like the 55 mm filter diameter and 2. I like the hood. I would bet that the flare is somewhat better but those are not that big of differences. Also if you could get around $100 or so for your 1.7 that would be a $100 of the cost.
I haven't done a lot of research on the the 1.4 but there appears to be an older49mm version also. They appear to sell on EBAY forcloser to 200.00. At least that is what I have noticed for the used 49mm version.
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