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02-25-2010, 01:48 AM   #1
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Is my A*300mm F2.8 Sharp Enough?

I have just done a few test shots through the lense and posted some 100% crops in the 300+ club thread and am looking for opinions. Please see below for the crops and photography conditions.

Newpaper shot at approx 4m, center crop from 3872x2592 to 550x650, and at 45degrees, with flash.

With and w/o B+W F-pro UV 49mm used as a dropin for A*300mm/2.8, tripod mounted, 1/180 with flash.

Any observations, comments, suggestions?

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02-25-2010, 02:04 AM   #2
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For me the more crictical test is that when I use the lens, does it give me good images, good enough that I'm pleased with them and more importantly that I will get paid.

What do the images look like when you use the camera normally at sports or birds or whatever you bought this lens for. Is there a problem with them, hence the newspaper tests. Perhaps you could post a couple here, so we can see.

It's very easy to get wrapped around the axle with the testing of lenses and then it doesn't take very long and becomes very easy to convince yourself that you have got a duff example of one.
02-25-2010, 02:13 AM   #3
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QuoteQuote:
It's very easy to get wrapped around the axle with the testing of lenses and then it doesn't take very long and becomes very easy to convince yourself that you have got a duff example of one.
So true! And same goes for AF calibration, clearing dust off the sensor, etc etc!

As for the photos - they seem pretty sharp, but the contrast is kinda low. It's easy to fix, though.

Oh, and what's the point in putting a clear filter in the rear of the lens?

Last edited by pbo; 02-25-2010 at 02:18 AM.
02-25-2010, 02:28 AM   #4
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QuoteOriginally posted by pbo Quote
So true! And same goes for AF calibration, clearing dust off the sensor, etc etc!

As for the photos - they seem pretty sharp, but the contrast is kinda low. It's easy to fix, though.

Oh, and what's the point in putting a clear filter in the rear of the lens?
Thanks for the comments.

The clear filter idea is based on the 300+ thread where we have seen that some lenses seem to become a little better with the right rear filter.

Right now I am deciding whether to keep or sell the lense, thats all.

02-25-2010, 02:53 AM   #5
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QuoteQuote:
Right now I am deciding whether to keep or sell the lense, thats all.
Well, you can't decide that on newspaper can you?
Take it out and shoot something, see if you like it (if that's even possible with that hunk of glass...)
02-25-2010, 03:17 AM   #6
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Given the fully open aperture, I find the examples really sharp enough. Contrast is so much dependent on shooting situation, that I would not overly interpret the newspaper results, which show a not really high contrast. But even that level is easily manageable at the post-processing stage. All in all, I would use the lens myself.

Ben
02-25-2010, 04:35 AM   #7
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thank you for your comments
02-25-2010, 05:10 AM   #8
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I've shot another 3 for A*300/2.8
@2.8
with and w/o the B+W F-Pro UV

Directional but harsh lighting, at 1/500, camera and lense supported on the floor, straight from raw through CS2, and cropped from 3872x2592 to 425x350.

First is with the filter and the 2nd without, note the higher contrast.... I'd say my silly k10d is the limiting factor... I think?? A full photo is shown to show crop area.

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02-25-2010, 05:56 AM   #9
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I dont think I would be over impressesd with the sharpness of those pictures if I'm honest which is why I don't shoot focus charts.

Picture taken with my A* 300mm f2.8 (hand held) K10D



With 2x-L TC



A 100% crop with the 2x-L TC attached (600mm again hand held).

02-25-2010, 06:19 AM   #10
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Is that straight from camera Mike? What are the dimensions of the 100% crop?
02-25-2010, 06:22 AM   #11
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fyi, very narrow depth of field in my shots.

What aperture were you shooting at??
02-25-2010, 06:24 AM   #12
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QuoteOriginally posted by cps_goodbuy Quote
Is that straight from camera Mike? What are the dimensions of the 100% crop?
Little bit of processing, not much though.

As for the original dimensions I have no idea as it has been resized for Flickr and I lost the original raw file (along with thousands of others) when my external hard drive corrupted
02-25-2010, 08:32 AM   #13
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QuoteOriginally posted by cps_goodbuy Quote
I've shot another 3 for A*300/2.8
@2.8
with and w/o the B+W F-Pro UV


If you stop it to f3.5 and the contrast is much better as well as slightly sharper then it looks like my A*400/2.8 which thanks to help in the 300mm club is now sharper than ever imagined. I can't see worrying about the drop in IQ when wide open if one stop buys you what you want. Lets see a 3.5 or 5.6.

In your first shots it appears that the rear filter does sharpen it up a bit.
02-25-2010, 09:52 AM   #14
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QuoteOriginally posted by pbo Quote
Well, you can't decide that on newspaper can you?
Take it out and shoot something, see if you like it (if that's even possible with that hunk of glass...)

That is true, If the subject taken is some other object instead of newspaper, it will be much easier to gauge the quality of the lens thru the image shown.

If TS could try taking a cat or other animals at some not tooo far away distance, at different apertures, f 2.8(wide open- see how the subject isolated from the background, f5.6 or f8 to campare the sharpness, using a tripod, the image wuld show the quality of the lens. You may want to try with filter and anothe set without filter.

The picture Mike posted, is beautifl especially the image of dog.

marcus
02-25-2010, 11:44 AM   #15
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QuoteOriginally posted by marcusyoung Quote
...some other object instead of newspaper, it will be much easier to gauge the quality of the lens thru the image shown.

If TS could try taking a cat or other animals at some not tooo far away distance, at different apertu...
*chases girlfriends cat around the house*

Edit: lovely dog image
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