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10-20-2008, 12:22 PM   #1
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Pentax 1650 vs 1855 vs 50 1,7

My pentax 1650 odissey never ending!!!

1- ok in the beginning. optically good

2- broke the auofocus

3-com back broke the zoom

4-today it come back bu i have some doubt of it optically and at a certain poin it stopped focusing completely. so tomorrow i'll ask for a change.

NOW some test

1650 VS 1855 AT 18. TRIPOD MIRROR LOCUK-LIGHTROOM CONVERSION IN JPEG WITH BASE SHARPENING. ( THE crop from the 1855 looks not 18)


CENTER


CORNER 1



CORNER 2





1650 VS 50 at 50mm
The 50 is simply amazing

CENTER



CORNER



CORNER 2




1855vs 1650 vs 50 near focus at 50 mm
The 50 mm seems here in the other focus to be t least a 60. can somebody exlain me this?

CENTER



CORNER




CONCLUSION

what do u think of my 1650 optically?
am i exepecting too much?
why the 50 is a 60?

The 16-50 in these sample is better than my beginning sample. when the focus is lower than infinity is good and focus fast, but today a shot at infinity and it was simly terrible. blurry out focus, one corner sharp the other blurre. i'll post more sample of this.
I have seen this also with the 50-135 at 135. at this focal range it has a lot of problems focusing resulting in blurred photos.
i planned to buy the k20d and hope it focus more reliable. it's strange noting this because i have found the 50135 focusing good for surf shots or sport shits in daylight, but it has many problem at 135 with static object person.
pentax should work hard on thi for he next camera. I'll keep anyway the pentax for travel and studio shots, but for pjournalism nd editorial i think i'm gonna add a d3 or d300.


Last edited by jonny1986; 10-20-2008 at 12:37 PM.
10-20-2008, 03:27 PM   #2
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can help you decide if it is a god copy.. damn.. i jus bought a DA* 50-135 and i dont know myself if it is a PERFECT copy.... but i can tell you it impresses me and makes me proud of it.


I cant spend time worried about if i got THE copy... i was going the same route you did and decide just to take pics and keep it.


So i am not good judging these sample pics.. but i can tell you did a GREAT job reviewing your lenses.. and DAMN... that 50mm kick ASS!!!!!
10-20-2008, 03:39 PM   #3
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Keep in mind that the Pentax 50 1.7 variants are among the sharpest lenses Pentax ever produced - of course the 16-50 is not going to match up to a 50 1.7.
10-20-2008, 06:50 PM   #4
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Original Poster
the 50 mm is sharp as dead and i know the 1650 is not as sharp as it. but i hecked some sample of my copy before it was serviced from penax and they are far far far more sharp.
The lens now is wors than 18-55. This is not possible.

Some sample of my "old" 1650 before service.

16 mm f8



center crop




corner crop




corner crop




consider that this crop are completely unsharpened a all level, also in lighroom i don'tapply he base sharpen.

crop sharpened a bit, 0 image correction








i have seen also sample i took at 50 f56 and f8 and they are very very sharp, slighly worst than 50 1,7 but very very sharp.
the copy i have now is optically totally useless. it's sharper in a side of the photo than the other. they clearly disallined the elements fixing the zoom system.

10-20-2008, 09:48 PM   #5
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QuoteOriginally posted by jonny1986 Quote
why the 50 is a 60?
It is probably the other way around. The 16-50 is set at 50mm but focussed at close range and becoming eg 45mm, the 50/1.7 is still a 50mm.

The 16-50 is an internal focussing lens and at close range its focal length becomes shorter...

All (or most?) IF lenses have this, the 18-250 has it, but also my Tokina ATX400 fix focal has it.


Sorry about your 16-50 lens troubles.

Last edited by tomtor; 10-20-2008 at 10:07 PM.
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