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09-20-2014, 07:15 AM   #16
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Having to calibrate a lens is a common occurrence. I purchased a new Sigma 8-16 about two years ago that was off. I wound up entering the maximum amount of correction (10 units), which made it better, but it was still off. CRIS here in the US is also a Sigma warranty shop, so I dropped it off - and they asked for the camera body to be left also (K5). Two days later they calibrated the lens (it was off by 45+ units) and had it setup perfectly with the body.

The other thing I was going to say, is that the K5 can hold up to 20 separate (Pentax) lens corrections, but only 1 for a non Pentax lens. So, if you have 2 Sigma lenses, both of them get the same correction. When you have time, I would send the lens in to your local Sigma service for correction.

I too know frustration. I have decided to go AF for my longer lenses.



09-20-2014, 07:16 AM   #17
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QuoteOriginally posted by Rupert Quote
Relax! Just a little time in a cool comfortable spot to adjust the back focus and you will be all set to shoot animals to your hearts content! Animals love a Pentax camera, take it from Otis, and we all know Otis is never wrong!
Hopefully you will make it your life's ambition to shoot handsome squirrels?


Regards!
Oo The animal looks like a squirrel/snake hybrid !
09-20-2014, 08:15 AM   #18
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Until you get the focus issue resolved, I recommend that you stop shooting wide open ( at f/2.8 ) and stop down a little bit. Try f/4, f/4.5 or even a little higher. At f/2.8, the depth of field is very narrow. That means only an inch or two will be in sharp focus at the ranges you are shooting. If your camera and lens are spot on, that gives perfect results but if it is off only a little you get the softness you are seeing. At f/5.6, you would have a foot or so which might be too much, causing the background to be sharp. At f/4 you should have enough depth of focus to get sharper subject focus while still throwing the background out.

The above is a temporary solution until you figure out exactly where the focus point actually is and adjust it.

Another thing to check is that your camera is actually set to focus on a single point. The way it is all over the frame in your examples makes it sound like you might be set up for area focus rather than a single center spot.
09-20-2014, 08:18 AM   #19
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Not sure which version of the Sigma 70-200 you are using but the previous version HSM II was a tad soft at f2.8.
The newer OS version is a little better but I find these lenses really start to shine at F4.
Once you fix the back focus set the aperture to F4 and I think you will be happy.

Personally I think you may be stressing yourself out by trying too many new things all at once:
New lens, unfamiliar focus technique, first time using manual ...

Here's what I would do:
Correct any back focus issue
Use TAv mode with F4 and 1/500-1/1000 depending on the available light and let the camera worry about the exposure by letting the ISO float.
Use the focus method you are used to- if that is shutter half press so be it, don't complicate things trying to learn back button during this class, wait till a time you have to practice.
This expensive class should be an enjoyable experience, make it easy on yourself so you can enjoy and learn.

09-20-2014, 08:29 AM   #20
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When you say you're sure that you focus between the eys, is it because you manually select the center AF point ? Or have you let the camera choose the AF point ? Sometime, when left to make the decision, the camera doesn't always select the right AF point...

As other mentioned, a 2.8 aperture at 120mm gives a relatively narrow DOF. This will amplify any issues in focusing and will only give good results if the focus is perfectly spot on with a well calibrated lens on a still target (and a still photographer!). Even then, with a moving subject like a dog, there will probably be more missed than good shots. A few inches of movement from you or the dog will result in an out of focus head. The suggestion of a F4 or smaller aperture makes lot of sense...

You should check your lens calibration. It's not a very difficult thing to do and only takes a few minutes.

So, overall, it's a combination of many details...

Last edited by CarlJF; 09-20-2014 at 08:58 AM.
09-20-2014, 08:50 AM   #21
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QuoteOriginally posted by allie181 Quote
I am at a very expensive 3 day animal photography course and the results I am getting are terrible.
Here is an example - ISO 400, 120mm, f2.8, 1/250
Any suggestions?
I wonder if those settings are the best recommended at very expensive course? No sarcasm here. Is it appropriate setting in OP's situation?
I would close down to at least 3.5, or 5.6 because of 120mm.

Is not wise before correcting anything to run test on tripod first?
09-20-2014, 09:19 AM   #22
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QuoteOriginally posted by crewl1 Quote
Personally I think you may be stressing yourself out by trying too many new things all at once:
New lens, unfamiliar focus technique, first time using manual ...
Using manual metering may be part of the exercise. Most photography course start off teaching the basics of exposure with manual metering.

@allie181: It is frustrating but once you get the focus calibrated you should get better results. And remember you typically learn more from your mistakes than your successes and it feels oh so good when you get it right.
09-20-2014, 09:55 AM   #23
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I have been using SLR's since the late 60's. Almost all of my lenses were manual focus until recently. I now have 3 auto focus lenses. Last year I took a trips out west to visit family and on the way home spent a day at Yellowstone. Being lazy I was using focus confirmation and the results were about the worst manually focused shot I have ever taken. And these with known good lenses. I was using a K5 and a K5-IIs. I looked in the mirror and saw the problem. It was me. The cameras were pretty new to me and I was just plain lazy in learning them.

This spring I started playing with my cameras and the 25 or so lenses I have accumulated over the last 4 decades or so. It was amazing how much I learned from just sitting in a chair and snapping shots across the room and evaluating each one as I did. My new neighbors across the street were kind enough to install a bright white picket fence which sits in front of a heavily shaded side yard giving me a great resolution target. I can sit in my garage and do all check out all sorts of things.

The results have been very good. I weeded out lenses that are just not up to the task anymore and found some gems in unexpected places. For example the 50mm f2 Ricoh Rikenon P lens that originally came on one of my two Ricoh XRM cameras is awesomely sharp. And it's size almost makes it a pancake lens. The technical aspects of my photography has improved greatly. Focus is back and I have learned how to use my equipment properly.

I was back at Yellowstone again last month and I am happy to say it was a lot more fun when I had confidence in my ability to use the cameras. On my manual focus lenses I trust my eye over the focus confirmation. Luckily I also had two of my little grandkids visit for 17 days this summer and their activites were a great test for the two new auto focus lenses in tracking action.

09-20-2014, 04:07 PM   #24
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I use the focus chart that's on page 18 of this PDF file: http://www.dphotojournal.com/focus-test-chart.pdf

While the documentation is written for the D70, the chart works for any camera. Came in handy when a Sigma 18-200 I had was back focusing.
09-20-2014, 05:59 PM - 1 Like   #25
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Do remember to adjust your focus in natural light. The focus performance in artificial light is different. I have a K-30 and the Tamron 70-200, I did the focus adjustment, and I get superb pet portraits. Here're some at full speed play time.






And a more sedate shot:
09-21-2014, 06:51 AM   #26
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QuoteOriginally posted by sadatoni Quote
I use the focus chart that's on page 18 of this PDF file: http://www.dphotojournal.com/focus-test-chart.pdf

While the documentation is written for the D70, the chart works for any camera. Came in handy when a Sigma 18-200 I had was back focusing.
This is an excellent document that everyone should read at least once. It explains very well how the AF system works. It really helps understand why and when it may failed, and what can be done to circumvent its inherent limitation.
09-21-2014, 07:50 AM   #27
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QuoteOriginally posted by CarlJF Quote
This is an excellent document that everyone should read at least once. It explains very well how the AF system works. It really helps understand why and when it may failed, and what can be done to circumvent its inherent limitation.
+1
This entire thread is a "must read" for all of us that wish to get the best images possible!
09-21-2014, 09:10 AM   #28
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Focus is off, my K5 sucked as well. Don't just blame the lenses... It took me days to adjust focus and it still did not work, so please excuse my language. K5 II/s solved this problem I think.
K3 is much more consistend, especially in low light.

Last edited by zapp; 09-21-2014 at 09:27 AM.
09-21-2014, 09:46 AM   #29
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Another easy way to test the AF is the "battery test" described on this webpage. It may not be as detailed as the one in the other link given above, but it's enough to check your AF. If everything looks fine, it's probably that either your len AF correctly or that any BF or FF isn't important enough that you should care.
09-21-2014, 09:48 AM   #30
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agreed, from the photo posted, it is classic back focus problem with the Sigma. Let us know if the in-camera focus adjustment worked.
Thank goodness you aren't shooting Canon, or you would not be able to correct for a deviant lens.
keep at it and be sure to share some doggie pics when you get it dialed in.
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