andy_coach

<p>I recently pulled out my 70-200 Sigma to shoot some kid sports and noticed these odd-looking bubbles under the front element. Not sure what they are but they do not appear to be fungus, as far as I can tell. Picture quality did not seem affected, except when shooting into the sun. <br /> <br /><br>

<img src="http://lejek.smugmug.com/Other/Sigma-70-200-Bubbles/P1190780/1228551669_xABAY-L.jpg" alt="" /> <img src="http://lejek.smugmug.com/Other/Sigma-70-200-Bubbles/P1190779/1228551652_UAz5z-L.jpg" alt="" /> <img src="http://lejek.smugmug.com/Other/Sigma-70-200-Bubbles/P1190782/1228551614_Gdi7F-L.jpg" alt="" /> <br /> <br /><br>

Wondering if anyone has seen this before?</p>

<p>Nice view from your spaceship :)<br>

Btw, how do you like the handling of this lens?</p>

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<p> andy, how do you like the lens? how is the auto focus speed? i regret selling my fa35f/2.0</p>

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<p>Well, I am not sure how I feel about this lens. It's quite homely looking and does not inspire instant love. It looks very "plasticky" and feels fragile although I am sure that's just my perception. But the lens is incredibly light. I did a quick comparison of it's IQ (on the K-5) to the Nikon 35/1.8 (on D90) in poor light and they seem very close to my eye, at F/2.4 and 2.5, respectively, although the 35/1.8 seems a bit sharper but that might be due to camera settings. I am now anxiously awaiting the arrival of a square hood, anything to make it look like a real lens :)</p>

<p>Well, here is the answer: they had planed to offer TCs for this (HSM) lens but somehow that never materialized. They of course have no plans to make them now. The support person could not recommend any 3rd party TCs for this lens. Total bummer.</p>

<p>Thanks a bunch everyone for your responses.<br>

While I realize that IQ is affected with a TC, the 70-200/2.8 + 2xTC combo seems like an acceptable compromise for the many outdoor sports events that I attend because of my daughter. Of course, I'd still bring the 400mm prime to the more important games.<br>

I just fired off an email to Sigma tech support about the 2x TC for this lens, will post any response I receive.</p>

 

<p>Doug, you may be right.. I am tempted to try the Vivitar VIV-2x4-P that B&H is selling for under $100, the three reviews there are quite positive.</p>

<p>According to the official Sigma <a href="http://www.sigmaphoto.com/sigma-lens-teleconverter-compatability-chart"> chart </a>, there is not a Pentax-compatible Sigma TC for this lens. I sometimes use a Kenko 1.5 with it and it seems to work ok but wonder if anyone has tried a 2x TC with this lens and whether AF worked. My goal is to replace my 400/5.6 with just the 70-200/2.8 and a 2x TC.</p>

<p>Javier, I am still waiting for the mail but will gladly report on my impressions when it gets here. I sure hope it's as good as some have been reporting (e.g. on dpreview).</p>

<p>The 2nd pic (Straw Flower) made me think of things trapped in amber, great shot.</p>

<p>Oops, never mind, I just found after-market copies of both hoods on ebay, I think they ship from Hong Kong and/or India.</p>

<p>Having missed the 35/2.0 while it was still available, I bought today the Pentax 35/2.4 lens, only to realize that it does not come bundled with a hood. Pentax Imaging web site lists PH-SA49 and RH-RC49 as optional hoods for this lens but their web store does not know about them. Neither does BH Photo nor Adorama. Would anyone happen to know where either hood can be purchased? Or has anyone perhaps tried another hood on this lens?</p>

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<p>They always do Canon & Nikon first.</p>

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<p>I wouldn't mind waiting a bit for the 18-270mm in K-mount but wouldn't they have at least announced it by now?</p>

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<p>You could also get Judge Joe Brown on your side. ;-)</p>

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<p>Oy, tough crowd here.. :)</p>

<p>Yeah, parting with this lens was plain dumb. Been reading reviews on the shorter Tamron and the same-range Sigma, people seem to agree that the 18-250 Tamron has the best IQ of the bunch. I so want my Tamron back...</p>

<p>I made a mistake of lending my Tamron 18-250mm to my sister and she refuses to give it back. Looked at Amazon and the usual photo stores, not a copy to be had (Tamron or Pentax version). Have these been discontinued? I see a Sigma 18-200 available on Amazon but is that any good? I really miss having this focal range for my everyday carry-around kit.</p>

<p>Mine seems to work OK in low light, w/out the AF assist beam. Mostly with 50/1.4 and 18-50/2.8.</p>

<p>My K-5 is here and sans spots (S/N 39546xx). Just to be sure I plan to test it tomorrow some more, for now I used the method described here:<br>

<a>http://www.mm-log.com/blog/2010-12-08/check-pentax-k5-sensor-stain-or-dust-with-photivo</a><br>

Did some quick test shots with the very light kit lens, also tried the 18-50mm F2.8 Sigma Macro (it looks quite sexy on the K-5), and a 400mm Sigma, the camera acquired focus quickly, as a matter of fact the 400m Sigma focused unbelievably fast, all in pretty poor light. And the shutter really is super quiet.<br>

I like this camera very much already.</p>

 

<p>I appreciated Lindy's post as an informative summary of what I can do if I receive one of those stained sensors. Of course, we should also consider the possibility that those defective units may become collectors items at some point :)</p>

<p>I saw the price drop and couldn't resist, the K-5 with kit lens will be here today, I can't wait. Crossing my fingers the sensor is clean. Time to dust off my K-mount lenses :)</p>

 

<blockquote>Shoot a blue sky or white wall at f/22 and if you get spots blow it out. If you still get spots it might be under the filter.</blockquote>

<p>I just called Abe's of Maine, asked if they had K-5 in stock (they did), then asked if they'd heard of the sensor streaking issue (they had not), then asked if they would do a quick visual test to confirm streaking was not present (they would not). So I guess I will have to wait until there is a new batch that's confirmed to not have this issue.</p>

<p>Lindy, thank you for the reply and pointers. This sensor stain issue appears pretty nasty and of epic proportions, based on that poll. It's really too bad, the K-5 was going to free me from using two systems, now it's back to waiting :(</p>

<p>These scary stories make want to reconsider getting the K-5 as my Christmas present to myself. But it is quite possible I will fail in my resolve and order one anyway.. How would you recommend I test it for faults upon arrival?</p>

<p>Peter, I would love to hear how you like shooting sports with a 70-200/2.8, I tried that for a couple of years with the K10D and then with the K20D but found it quite difficult to get as many keepers as I hoped for (kids soccer and baseball, 2-3rd grades).</p>

<p>My daughter with her first DSLR<br>

<img src="http://lejek.smugmug.com/photos/1033137059_fwqvQ-XL.jpg" alt="" width="511" height="768" /></p>

<p>@Chuk - it sounds like I should try more than one screen; I have the SI-20, SE-20, SD-21, SA-21, and SG-20 coming in the mail, it will be interesting to see how they perform. I've fiddled with the diopter on the LX and it's as good as I can get it; I am just hungry for a new screen after playing with that FE...<br /><br />@Les - thanks for the tip about the Varimagni Finder, I must admit I've never seen one, it seems they are quite affordable on ebay, would be fun to try one!<br /><br /><br /></p>