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02-03-2011, 07:23 PM   #151
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QuoteOriginally posted by areidjr Quote
OK, I wasn't sure as you didn't quote anything to put your post in context

Yes, that's the case. However, the shift was enough that even at f/5.6 the FF was noticeable in actual real life shooting (portraits under studio lighting). In fact, that's the only reason I started looking to the forums to see if this was a known issue. If the focus behaved as my K100DS does I never would have looked any deeper and would have been tickled pink over my new toy.
The reason I asked the question the way I did, the issue, as I first understood it was this. A fast lens, meaning faster than f2.8 (which is where the AF system is calibrated so I'm told), in low level tungsten lighting would give a FF error. These same lenses, in 'normal' lighting, would Not display this issue. It doesn't matter what the lens is set at for the photo, the cameras focus with the lens wide open.



02-03-2011, 07:26 PM   #152
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QuoteOriginally posted by creampuff Quote
All this while when people mention they got FF with their K-5 cameras, there is little or no mention of the lens used when they test. The natural assumption is that the camera is the problem when it could just as well be the lens that could require focus calibration.

.
What you are missing is that the FF problem occours in low light levels. Below EV4 for example.

So calibrating the AF for a particular lens in 'normal light' makes no difference to the FF in low light problem.

You want mention of specific lenses... OK, no problem ..... I have calibrated my K-5 with my following main use lenses ..

Pentax DA* 50-135mm
Pentax DA 10-17mm
Pentax DA 14mm
Pentax FA 50/1.4
Sigma 17-70mm
Sigma 30mm/1.4
Sigma 135-400mm

Once calibrated they all focus perfectly with the K-5 in regular light

but in low light ( <Ev4) ALL OF THEM exhibit the Front Focus problem.

The camera IS the problem. You should know better, i've seen you in these threads for long enough
02-03-2011, 07:44 PM   #153
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QuoteOriginally posted by Smeggypants Quote
What you are missing is that the FF problem occours in low light levels. Below EV4 for example.

So calibrating the AF for a particular lens in 'normal light' makes no difference to the FF in low light problem.

You want mention of specific lenses... OK, no problem ..... I have calibrated my K-5 with my following main use lenses ..

Pentax DA* 50-135mm
Pentax DA 10-17mm
Pentax DA 14mm
Pentax FA 50/1.4
Sigma 17-70mm
Sigma 30mm/1.4
Sigma 135-400mm

Once calibrated they all focus perfectly with the K-5 in regular light

but in low light ( <Ev4) ALL OF THEM exhibit the Front Focus problem.

The camera IS the problem. You should know better, i've seen you in these threads for long enough
You can add a DA 40mm to that list as well.

Last edited by Zugzwang; 02-03-2011 at 09:04 PM.
02-03-2011, 10:47 PM   #154
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QuoteOriginally posted by MrPetkus Quote
Thanks. I checked out the DPR forum - it was "Mike" who sent it in for service, I think. His claim was that FF was a little better but not 100%. If that's the case then the servicing was a failure.

I imagine if the problem was isolated to software - then when the camera was returned from servicing a new firmware could be detected in EXIF. Unless Pentax decided to spoof the user by renaming the version. One would hope that wasn't and never will be the case. If there was no firmware change a hardware fix is implied. Perhaps I should join that forum and ask. I was hoping someone here would've actually sent their camera in for servicing.

I'm glad your FF problem is minor. For me, studio work (bread-n-butter) is never a problem. It's when I have to shoot a concert, dance class, family fun, etc., that the FF issue rears its head. When I was at the Museum of Natural History yesterday with my family I used the DA 15/4 exclusively and relied on Live View to get the great focus I needed. Which is fine because the dioramas aren't running around. It was a good day.

My DA* 50-135/2.8 doesn't exhibit FF which supports reports from the Spaniard that SDM lenses are unaffected. However, my Tamron 28-75/2.8, magnificent and tack-sharp on the K7, is pissy like an unruly child in low light. At any rate, I picked up a used K20 as a backup camera so at least I'll have something to use when sending out the K5.

Cheers,
so the modelling lights give enough light to get you above the FF problem ?
I only ask as Im in the process of buying a set for home.. I've decided on studio flashes rather than a Hot shoe set up for this reason...am I on the right track?

Ive a sigma 17-50 that exhibits FF at EV4 and lower....Ive not tested my sigma 70-200 HSM...but i will tonite if nothings on the telly


my contribution to a FF test done by Jolepp

https://www.pentaxforums.com/forums/pentax-k-5-forum/129738-k-5-user-auto-foc...results-4.html


Last edited by Tommot1965; 02-03-2011 at 11:00 PM.
02-04-2011, 06:05 AM   #155
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QuoteOriginally posted by Tommot1965 Quote
I only ask as Im in the process of buying a set for home.. I've decided on studio flashes rather than a Hot shoe set up for this reason...am I on the right track?

[/url]
I think you're on the right track. I used hot shoe flashes and remote receivers for a while, but was never 100% satisfied. They take too long to recharge and if you don't wait long enough the flash output can be inconsistent. For those reasons I bought a couple Alien Bees AB400s. They use 150W halogen modeling lamps and in my setup I get about 5-6 EV (as measured by my Sekonic light meter) falling on the subject. That has been plenty in the past, at least for my K100DS.

The other thing about the AB400s is that they can flash at full power 2 times per second and the modeling lights can follow the slash output intensity. With a K-5 set on continuous low, the strobes will easily keep up.

Of course, there are a lot of studio flashes to choose from, depending on how much money you want to invest.

Just my $0.02
02-04-2011, 06:25 AM   #156
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QuoteOriginally posted by creampuff Quote
All this while when people mention they got FF with their K-5 cameras, there is little or no mention of the lens used when they test. The natural assumption is that the camera is the problem when it could just as well be the lens that could require focus calibration.
...
An important point. The issue at hand is about a focus shift (FF) in low/artificial/tungsten light: if the FF is present in all conditions then it is another, well established problem that can be dealt with (AF micro ajustment and/or shop calibration), with the K-5 focus shift issue there is no known cure yet.

Would you BTW happent to have an idea what is done to the lenses that take a trip to service and come back without their former FF (BF) problem? I mean, this lens specific BF/FF is a bit of a mystery to me as one would expect AF as such to compensate for anything but focus / image sensor misalignment. Knowing the fix would probably be close if not equal to knowing the root cause.
02-04-2011, 06:46 AM   #157
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reg issues here is my case:
Iv sent k5 for repair for the first time when i discovered bounced flash overexposure it was two months ago camera has been returned to me with new firmware 1.01 flash problem was still there.... later on iv discovered some spots and af tungsteen ff - so iv sant it back on middle of january - today i did get the answers from pentax service uk dept: my camera will be replaced for a new one with new firmware implemented in time unknown, there is hundreds of cameras waiting to be replaced, hundreds of waiting customers... New butch of cameras is supposed to be free from known issues like stains, af or flash problems. When thay arrive it is unknown......
02-04-2011, 08:35 AM   #158
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That sucks. Now I understand why folks are just coping and finding workarounds for their problems. I can envision some bad sentiment brewing as frustrated K5 owners, who payed a premium as an early adopter, witness a drop in market price while their camera is tied up in service captivity.

Bleh...

QuoteOriginally posted by filorp Quote
reg issues here is my case:
Iv sent k5 for repair for the first time when i discovered bounced flash overexposure it was two months ago camera has been returned to me with new firmware 1.01 flash problem was still there.... later on iv discovered some spots and af tungsteen ff - so iv sant it back on middle of january - today i did get the answers from pentax service uk dept: my camera will be replaced for a new one with new firmware implemented in time unknown, there is hundreds of cameras waiting to be replaced, hundreds of waiting customers... New butch of cameras is supposed to be free from known issues like stains, af or flash problems. When thay arrive it is unknown......


02-04-2011, 08:39 AM   #159
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QuoteOriginally posted by filorp Quote
reg issues here is my case:
Iv sent k5 for repair for the first time when i discovered bounced flash overexposure it was two months ago camera has been returned to me with new firmware 1.01 flash problem was still there.... later on iv discovered some spots and af tungsteen ff - so iv sant it back on middle of january - today i did get the answers from pentax service uk dept: my camera will be replaced for a new one with new firmware implemented in time unknown, there is hundreds of cameras waiting to be replaced, hundreds of waiting customers... New butch of cameras is supposed to be free from known issues like stains, af or flash problems. When thay arrive it is unknown......
I don't know if it was just the pictures I took or not but the very latest v1.02 seemed to fix the flash exposure. At least it was consistent enough to be able to compensate for any over exposures. It appeared to me that regardless of what I did, it was much better. Don't know if it actually 'cures' the Bounce flash over exposure though. There was noticeable difference between 1.02.007 and 1.02.010 in terms of flash exposure. My camera is in Arizona now so I cannot test it any further at this time.

02-04-2011, 08:47 AM   #160
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Yes - with the added bonus of seeing how the light will fall without constantly blinding your subject. I still use strobes when portability is required but I need to ensure that the ambient is cranked up.

However, I wouldn't necessarily endorse purchasing studio lights just to circumvent the K5 FF issue. You can still get sharp focus in low light when using SDM lenses or Live View.


QuoteOriginally posted by Tommot1965 Quote
so the modelling lights give enough light to get you above the FF problem ?
I only ask as Im in the process of buying a set for home.. I've decided on studio flashes rather than a Hot shoe set up for this reason...am I on the right track?

Ive a sigma 17-50 that exhibits FF at EV4 and lower....Ive not tested my sigma 70-200 HSM...but i will tonite if nothings on the telly


my contribution to a FF test done by Jolepp

https://www.pentaxforums.com/forums/pentax-k-5-forum/129738-k-5-user-auto-foc...results-4.html
02-04-2011, 10:40 AM   #161
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Pentax Hiring!

Be a part of the solution
Quality Control Manager Job in Mumbai ,Ahmedabad ,Pune - Pentax Engg. Pvt. Ltd. Job
Sorry I had to...
02-04-2011, 10:48 AM   #162
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Thanks for the "Heads Up"....Otis responded and interviews on Monday.

If there are any loose nuts, you can count on Otis to clean them up fast.
[IMG] [/IMG]

Best Regards!
02-04-2011, 11:24 AM   #163
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QuoteOriginally posted by MrPetkus Quote
Pentax Hiring! Be a part of the solution Quality Control Manager Job in Mumbai ,Ahmedabad ,Pune - Pentax Engg. Pvt. Ltd. Job Sorry I had to...
Not the same company

Pentax Engineering Pvt.Ltd.
02-04-2011, 11:26 AM   #164
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QuoteOriginally posted by Rupert Quote
Thanks for the "Heads Up"....Otis responded and interviews on Monday.

If there are any loose nuts, you can count on Otis to clean them up fast.
[/url] [/IMG]

Best Regards!
Awesome shot! You think Otis would like to meet Gustavia (Canadian Blonde)?
K7 (I know, it's a K5 thread, couldn't help it...) DA*200, ISO1000, F3.2, 1/400s

Gene
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02-04-2011, 01:25 PM   #165
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We're turning this into a Squirrel thread? I'll play..



Checking his heartbeat after a close encounter with The Hound.

K5, FA*85 f1:1.4

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