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03-13-2010, 10:07 AM   #1
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Not Happy With My New Sigma APO 120-400mm

Hey all - appreciate some help with this. I got the new Sigma APO 120-400mm F4.5-5.6 DG OS HSM. I have been shoot birds in my back yard on a tripod (although a very cheap tripod) and i have been using the pentax remote. My problem is that every pictures that does turn out seems to be quite blurry when viewing it on my computer and hitting the zoom button a couple times. I guess i thought it would be nice to take some 400mm pictures - zoom and crop and have some nice photos. I haven't taken one picture yet with this thing that i would be happy zooming and cropping in with. I am not sure if it's me or what - i have absolutely NO experience with a lens this big. Again the pictures seem "Not Bad" until i hit the zoom a couple times on my camera or computer and then the subjects seems so out of focus????????/.............thx

https://www.pentaxforums.com/forums/members/audio-mann-albums-misc-picture2800-chick-small.jpg


Last edited by audio.mann; 03-13-2010 at 10:18 AM.
03-13-2010, 10:25 AM   #2
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Looks like your focus is on the tree stump that the bird is sitting on, not on the bird itself. If you're sure that you have focused correctly, there are some threads here how you can test for focusing problems. Next, if you have a K20D or K7, you can adjust this in one of the menus. Else debug mode (not sure if it's in every Pentax camera) or send camera and lens to Sigma.
03-13-2010, 10:39 AM   #3
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To be honest I think you may be expecting a bit much from the lens. I had the 135-400mm and it was fine for large items (boats, cars, animals, aircraft) but not so hot on anything with fine detail such as birds .. unless you were pretty close to start with (especially wide open).

The 50-500mm I replaced it with is in a different league
03-13-2010, 11:05 AM   #4
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QuoteOriginally posted by audio.mann Quote
Hey all - appreciate some help with this. I got the new Sigma APO 120-400mm F4.5-5.6 DG OS HSM. I have been shoot birds in my back yard on a tripod (although a very cheap tripod) and i have been using the pentax remote. My problem is that every pictures that does turn out seems to be quite blurry when viewing it on my computer and hitting the zoom button a couple times. I guess i thought it would be nice to take some 400mm pictures - zoom and crop and have some nice photos. I haven't taken one picture yet with this thing that i would be happy zooming and cropping in with. I am not sure if it's me or what - i have absolutely NO experience with a lens this big. Again the pictures seem "Not Bad" until i hit the zoom a couple times on my camera or computer and then the subjects seems so out of focus????????/.............thx

https://www.pentaxforums.com/forums/members/audio-mann-albums-misc-picture2800-chick-small.jpg
Honestly, just about any lens will try focusing on the stump. It's closer, and close to the center making it even more intriguing for the focus point.
I'd blame that more on the camera just not knowing what your focusing on rather than the lens. Manual focus should correct that problem.

While birding I never use the remote. The chances of the subject moving before you take the picture is just far too great.
I've rarely used a tripod, since if the bird takes off it's almost impossible to pan along and snap a shot.
It takes some serious practice to get right.

QuoteOriginally posted by Mike.P Quote
To be honest I think you may be expecting a bit much from the lens. I had the 135-400mm and it was fine for large items (boats, cars, animals, aircraft) but not so hot on anything with fine detail such as birds .. unless you were pretty close to start with (especially wide open).

The 50-500mm I replaced it with is in a different league
I have the 135-400, and it's been great to me. It does have some quirks, however I've gotten more money shots with both still and moving subjects than I could have imagined.

03-13-2010, 11:09 AM   #5
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Other Shots

While i do understand the focus thing on the STUMP and that makes sense to me -- however i have a bunch of shots of chicks eating out of my kids hands as well and in those shots the bird should be in focus.........but again once i zoom in a couple times on these shots - the birds are out of focus. I can't imagine using this massive heavy lens without a tripod and i've been told that for the most part almost ALL pictures taken with this lens should be with a tripod.......

thx for you help, i appreciate the feedback on this particular issue. i can send more pics if it would help someone.
03-13-2010, 11:29 AM   #6
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I've been told by some that I can't hand hold my 135-400, however I've never had a problem with it on nice days. The main thing is I usually used ISO400, giving me a little faster shutter speed.

I'd have to see the pic's to try figuring out the problem. With that lens you may even be just a little too close
However, if you do have a problem with it Gentec (Canada's Sigma distributor) should be able to correct it quickly. For the best results they really need the camera though.
However that might not be too bad... for you. They're located in Ontario, so there's a small chance that they're close to your house. If they are I don't imagine that they'd mind a quick phone call, and they may even say to come on by and get it fixed fast.
Here's their contact info.

I'm going out with the camera for a few hours, so please don't expect a response from me right away
03-13-2010, 11:30 AM   #7
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QuoteOriginally posted by audio.mann Quote

thx for you help, i appreciate the feedback on this particular issue. i can send more pics if it would help someone.
Stick some up full size, its a bit difficult to see your problem with such small pictures.
03-13-2010, 11:45 AM   #8
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There can be a number of factors with the setup and without more examples, it's guessing at this point. Along with what's already been posted:
1) on a tripod are you turning the SR off?
2) Is the tripod really steady enough to hold this amount of weight?
3) is the shutter speed high enough to freeze motion blur? That is different than camera shake. If the bird moves quickly the second the shutter fires, you may get a soft photo. 1/250 + is desired.
4) are you shooting at the extremes? Most zooms are not at their sharpest zoomed all the way in or at the widest. So shoot at 380mm or so and the results should be better.
5) Are you shooting wide open? Same as #4 wide open can be softer than stopped down 2-3 stops. So if the lens is at f5.6 when wide open, try shooting at F8 or f11 when possible. this is true for even the most expensive glass.
6) if you can't get the settings for #4 and #5, shoot at a higher ISO.
7) don't expect to crop more than 25% on a long telephoto lens unless it's the best lens in it's class. Telephoto lenses and especially zooms are lower resolution than short primes. Zooming in on the computer is going to show a loss of detail. If you need to crop more, get closer!

03-13-2010, 12:01 PM   #9
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Sterretje is exactly right, the AF focusing beam appears to be working off the stump in front. 100% crop would be better to diagnose.

Also, are you shooting wide open or 2 stops down, makes a difference in many lenses. i don't know the details of this one, photozone.de or similar might have more details on where this lens gets sharp.

Tripods: To make sure you have a good copy, tripods ensure the chances of letting the lens achieve its best performance. At least thats my experience. Are you using a 2 second delay to let the mirror vibrations die out? Also for test shooting, best to put the tripod feet on something solid like concrete or hard packed ground. grass is no good and wooden decks can vibrate as people or yourself move around.

I have this one special landscape photo i get with a tripod and the DA-300 but it came out fuzzy the first few times i took it. Unfortunately the location is a grassy hilly side. after getting some advice from this forum, i went back with the tripod and jammed the feet into the ground as hard as i could, and then hung my camera bag underneath the tripod, AND WOW, the image was as sharp as one could want.

Any picture is going to get fuzzy if you keep zooming on it on a computer monitor. Seems like most people use a 100% crop as the standard. Most software will tell you when you are at the 100% viewing display. Any crop from that is a 100% crop. Is it sharp at that or not - you need that specific information. I do a lot of photos inside a amateur play theatre where lighting conditions are not optimum. Many of my shots under these conditions are not sharp at 100%, but still are fine for display on 8x12 or web viewing conditions. But its nice to have that standard of 100% to know what you are producing relative to other folks with similar equipment. If the lens is not capable of producing a sharp image under optimum conditions, consider returning it if possible. Can't speak to the adequacy of the tripod. oh by the way, do not have the neck extended if doing test photos, any distance from the apex of the legs can introduce fuzziness into the images.

best wishes
03-13-2010, 12:08 PM   #10
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Thx Peter

Well Peter - you bring up some interesting thoughts for sure.

1) I have not been shutting of SR and i know that i should have ---- thx
2) Tripod is a $20.00 tripod that i found at a surplus place--- thx
3) Shutter speed was on track it seems 125, 250 and more.......thx
4) I was almost always at 400mm........i will try a bit less........thx
5) F-Stops where 4.5, 5 etc. .......i can try more open............thx
6) I think i was looking to really crop to bring the 400mm in really close.......thx

I think I could post more images but based on what you're saying - i need to clean some stuff up myself by the sounds of things. I am not able to post photos here that are very big anyways (1000 x 1000) roughly i think - i don't have much MB it seems.

Thanks for you expert advice - it helps and makes me feel better that it's like ME - (lol) not my lens.......back to the drawing board.
03-13-2010, 12:31 PM   #11
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QuoteOriginally posted by audio.mann Quote
I think I could post more images but based on what you're saying - i need to clean some stuff up myself by the sounds of things. I am not able to post photos here that are very big anyways (1000 x 1000) roughly i think - i don't have much MB it seems.
That's what crops are for
03-13-2010, 04:49 PM   #12
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I have same lens - no problems

I bought the same Sigma 120-400 some time ago, and although I haven't used it a lot, I did do some testing when I first got it to check that it was working OK. I had exactly the same problem with focusing that you report until I figured out that I needed to control the focus point myself. I shot it on a tripod and handheld at various focal lengths and find it to be acceptably sharp. It certainly seems to be an improvement over the older 135-400 version.

I concur with the other posters - you may need to get a bit more experience in handling it and making sure it really is focused where you want it to be.

Mike
03-13-2010, 06:19 PM   #13
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All great advice. Also keep in mind that birds are designed by evolution to hide from predators and thus screw up autofocus that relies on contrast detection. Try focus lock on something with a hard edge in the same plane of focus as the bird. Beaks are usually pretty good, ditto bird feeders.

Last edited by LouD; 03-13-2010 at 06:19 PM. Reason: sp
03-13-2010, 07:39 PM   #14
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Don't get discouraged. I think it would be fair to say most of us weren't happy with our first bird shots and our first long lens. While I don't have that particular lens, I think following the advice already given will give you some better results. I always try to stop down to f8 or more for birds and get as fast a shutter speed as I can. Make sure the focus is right on the bird. It's so easy for a long lens to focus on a branch of leaf in the foreground or background, especially with smaller birds. Keep at it.
03-14-2010, 06:08 AM   #15
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QuoteQuote:
However, if you do have a problem with it Gentec (Canada's Sigma distributor) should be able to correct it quickly. For the best results they really need the camera though.
However that might not be too bad... for you. They're located in Ontario, so there's a small chance that they're close to your house. If they are I don't imagine that they'd mind a quick phone call, and they may even say to come on by and get it fixed fast.
Here's their contact info.
This cannot be repeated too many times. Sigma fixes this stuff cheap/free in most cases. The result is a lens perfectly matched to your specific camera, rather than some generic calibration to your model. Less than half the units sent in avail themselves of this service, much to their detriment.
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