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03-04-2013, 01:05 PM   #16
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Best lens for autocross

I don't have access to the EXIF and I am not sure how to get it yet. Suggestions? I am still new to this! I'll look into the threads on lens focus. The larger of 97 with the least motion is the Kodak. It is a fixed zoom. There is no hood on either just a UV on the Pentax.

03-04-2013, 02:00 PM   #17
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QuoteOriginally posted by Jane Quote
I don't have access to the EXIF and I am not sure how to get it yet. Suggestions? I am still new to this! I'll look into the threads on lens focus. The larger of 97 with the least motion is the Kodak. It is a fixed zoom. There is no hood on either just a UV on the Pentax.
No worries! By this spring you will be all set.
Well, I don't want to start a filter thread, but my suggestion is that you take that filter off and get a hood on the lens.

If you use windows you can right click on the photo and go to 'properties'. About half way down will be all of the data on the photo. Copy and paste that here.
03-04-2013, 05:28 PM   #18
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Im may be repeating someone cause im lazy and didnt read the other posts but i would try and stay around 200mm. The longer the focal length the harder its going to be to keep the camera from shaking and finding your subject gets harder the higher you go. You're losing a lot of quality using a zoom lens at it max. I have a pentax 55-300 and a Sigma 105mm. I can take a photo at 300mm with the pentax and a then the same photo at 105mm on the sigma. I can crop the 105's photo until its the same as the 300mm and the 105 image will still be sharper. I would recomend a 200 F2.8 but they arent cheap so a DAL 55-300 may be a good fit since its going to have better IQ than the 50-200 and they can be had for around $200. Also i think your shutter speed is too slow, try and go down to a F5.6 or up the ISO and keep the shutter faster then the focal length (like 1/250s for 200mm). The 55-300 can hold f4 to about 107mm and the f4.5 to about 190mm so if you use it at 190mm you can shot that much faster and still have good IQ
03-04-2013, 05:41 PM   #19
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I use a Pentax-A 70-210 F4 for my motorsport shots.
I've always found it to be fine, granted I've tended to be using around the 100-150mm range (close to the track, or in the photo bunkers)

I'd recommend using shutter priority, start off at about 1/180 and then work out if you'd like to use a higher or lower shutter speed for the effect you want (I find 1/180 fine for panning on a racetrack, but Autocross is a lot slower, so it wouldn't work as well)

Next step I'd say is a lens hood, it looks like the area is very bright, a hood will be a big help.

if you want to be a little more stable a monopod is great for motorsport, you can pan and move while still having some up/down stability.




And personally, I'd just turn off Autofocus altogether, I find that by the time the AF has stuffed about and focused I've missed everything.
I tend to pre-focus, you know roughly where the car is going to be, so focus on the ground at the point and hold it, then simply follow the car and snap the shutter as it reaches that point.
This last point can be done with AF or MF, I just find MF to be much faster and more accurate.

03-04-2013, 11:23 PM   #20
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QuoteOriginally posted by Jane Quote
I don't have access to the EXIF and I am not sure how to get it yet. Suggestions? I am still new to this! I'll look into the threads on lens focus. The larger of 97 with the least motion is the Kodak. It is a fixed zoom. There is no hood on either just a UV on the Pentax.
If the larger of the #97 car is taken with the Kodak, and the last picture with the smaller #97 is the Pentax, then I would agree that there is something wrong with the Pentax setup. The contrast and detail is quite poor. Looking forward to seeing the EXIF data associated with the shots, we should be able to figure out what is going on.
03-05-2013, 02:32 PM   #21
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Best lens for autocross

I have attached screen captures of the data for the two camera's shots. I had set one of my user modes for spot metering to experiment. I think I have gone back to center weighted metering.
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03-06-2013, 06:56 PM   #22
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A question:

What focus mode are you using for the panning shots, AF-S or C(ontinuous)? It should reacquire focus during a burst, but it may not be fast enough or accurate enough, so it just misses. Continuous should in theory predict where the car is going and appropriately adjust focus.

If you want to test if the autofocus is missing or miscalibrated, try focusing on a stationary object using AF-S. If you have good eyesight, you may be able to see if the object is out of focus in the viewfinder. If you can't see if it is in focus or not, put the camera in live view and check focus using the screen. The best time to try something like this is when the light is good so the details can be seen more easily. If you still can't see any difference, take a couple of test shots and check them on your computer.
03-07-2013, 04:41 AM   #23
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QuoteOriginally posted by Jane Quote
best lens for Autocross
I guess really it's all about your access, how close you can get to the subject that really will help determine choice.

The other thought I have, is get a fastest lens you can afford at that focal length, I know I would be using manual focus too.

03-07-2013, 10:04 AM   #24
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Yes, I don't see anything wrong with your settings, so I think one of three things is happening: 1. There is some motion blur in your shot as it is a lower shutter speed. 2. The 50-200 is extremely soft at 200mm 3. You have a focusing issue with your lens.
03-07-2013, 11:18 AM   #25
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Jane, I've shot some autocross and unless I had the camera on a tripod and was panning with the car to create motion blur in the background I never thought any of my "broadside" shots looked good. I've shot autocross with everything from wide angle lenses to 300mm telephoto lenses.

My tip for autocross (again, if you aren't doing a tripod-mounted panning shot) is to position yourself so you have a good shot of the front of the car near the apex of a turn ... you get the least amount of movement combined with the most aggressive positioning of the car:
03-07-2013, 12:41 PM   #26
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Hi Jane. I stumbled upon your thread and thought that I might provide some comments, for whatever they're worth. When I look at your two photos of the same car taken with Kodak and then Pentax, I noticed that there seems to be more lateral speed blur in the Pentax shot - see the cone to the right. At first I thought that might have been due to you panning the camera more quickly. However, the EXIF data shows that the shutter speed was slower for the Pentax (1/125 vs. 1/200). That may not be much of a difference, but it may have contributed to the lack of sharpness.

In fact, I would not blame the lens/camera combination unless you do controlled tests with both while motionless. If at that point, the Pentax seems to fall down, you may have one with focus inaccuracy that can be compensated in camera as someone previously mentioned. Also, cameras with larger sensor sizes (Pentax compared to the Kodak) will have less depth of field for a given effective focal length and f-stop combination. That might result in missing sharpest focus, even in continuous autofocus mode.

Having taken lots of photos at autocrosses and at road race circuits, I would suggest taking shots where the cars are not going exactly perpendicular to your straight ahead line of sight. Try to set things up so that the car fills from half to 90% of the frame. Prefocus on the spot where a car enters this shooting zone (half frame). The autofocus should find it easier to start and stay in focus that way. Try not to use any zoom at maximum or minimum focal lengths, as they are typically softer there than just off max or min. I would also use the lens shade religiously.

Good luck with you renewed hobby - keep trying different things until you find out what techniques work best for you.
03-07-2013, 03:05 PM   #27
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Best lens for autocross

Thank you all for your advice and suggestions. I am taking notes on all of this and will be doing some lens tests this weekend or early next week. I do have the camera settings set for continuous focus but noticed this week that the setting on the side of the camera was still was set on AFS and have that now corrected to C. I don't know how much of an affect that might have made. If I find the lens need correction I'll try the adjustment in the camera settings. If I find a sweet spot I'll try to work with that. I have a tripod but stopped using it for panning due to awkwardness that I need to deal with. I have turned off the shake reduction, will try shooting near 1/200 for now. I'll try to position myself for multiple possibilities in a close area so the AF doesn't have to work so hard and get a better handle on the tripod or remove the handle since I find it is a hindrance. My husband suggested using the tripod folded to mimic the mono-pod. I am looking into the DA 55-300 and If I can come up with the money, the DA 18-135 WR. Up until resent years I have kept to manual everything but my eyes have aged a bit and I figured it was time to get used to AF. I used to use a 135mm, 300mm and an 85-205mm zoom. I am not sure how I handled the weight of them especially the 300. It does have a tripod mount and I remember using it a few times that way but I always hand held the zoom. Today the cost of them, in digital form, alone would brake my back LOL! And I haven't tried attaching the old K mount zoom. The rest are screw mount and I have an adapter for the K mount. I don't find the K30 setup heavy but the Kodak was light as a feather so I need to consider that. I will post my lens test findings and how next weekend goes. My gut feeling is that I got a lousy lens to add to the many other new variables that I have to learn to deal with. You all have helped me come up with a plan to sort it all out. Oh and as for the sensor dust, going back to the first set of photo's with this lens, I can't see it. It appears to have appeared after the first days use of the camera. I read somewhere in my Google searches that manufacturing dust inside a new camera is not unheard of. Regardless, I have a plan for that also. Jane
03-07-2013, 06:10 PM   #28
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Jane, having the focus set to continuous might be the major issue. Keep us updated on your progress and keep posting pics. There are comparatively few motorsports shooters here. We need more of us. . Also, check into a monopod. I know after a couple hours of shooting my panning takes a dip in the middle of the swing. That makes for blurry pics.
03-08-2013, 07:09 AM   #29
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Your also trying to focus on a solid color such as the side of the car where its hard for the camera to autofocus. You may want to try and focus closer to where the number is printed or on a door seam,etc...
03-08-2013, 05:05 PM   #30
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Next time you are out at the course, take a few moments to shoot some photos in the paddock with both cameras, that should rule out any motion related issues. Also, take some comparative shots with the 50-200 at other focal lengths like 150mm, that will help rule out any problems at the extreme end of the zoom range. This will help you (and us, if you care to post them in a follow up) to figure out if there is some other problem.

I've heard the 50-200 is not very sharp, but that image is really bad. I can see why you are disappointed, and really want to be able to help isolate the problem further.

I think there is a way to upload the EXIF data on your next post. You can also download a free program called exiftool from the Internet -- you'd be surprised at how much extra data your camera stores along with the photo.
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