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When taking pictures of the full moon , useing a 300mm lens with a3x converter i could not get a good focus at infinity /

Im useing an albinar adg 75~300mm lens with a rokunar tele-converter 3x

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What is the question?

I'm going to assume that you're getting a featureless white blob for the moon, and you want to know how to fix it.

Switch to manual exposure mode. The camera's meter is trying to make the entire scene a midrange. Since the scene is dominated by a black sky, it will overexpose in an attempt to make the sky come out gray, resulting in the full moon washing out completely.

Think about what you're photographing. It's a big rock under a midday sun, isn't it? The proper exposure for that is the "Sunny-Sixteen-Rule." That simply means that the proper exposure is f/16 at a shutter speed of 1/ISO. So, for ISO 200, use an exposure of f/16 at 1/200 seconds, or an equivalent (such as f/11 at 1/400 seconds, etc.)

If you're using a digital camera, you can check the exposure and the histogram immediately and adjust if necessary. If you're shooting film, bracket a couple of stops in each direction.

Posted on Jan 20, 2010

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At 300mm focal length at a distance of 200 yards away what F stop will give me edge to edge sharpness in my photos?


The edge-to-edge sharpness of your lens is a function of the optical design much more than f-stop. What I would be more concerned with is depth of field. The important consideration is what the closest and farthest point you want to be in focus. Here are some figures that might help. For a 300mm lens focused at 200 yards (600 feet), mathematical calculations yield the following (0.03 mm circle of confusion in all cases):

f/22
Near limit = 256' 3", far limit = infinity, total depth = infinity, hyperfocal distance = 447' 5"
F/16
Near limit = 303' 9", far limit = 24,350' 8", total depth = 24,046' 11", hyperfocal distance = 615' 2"
f/11
Near limit = 359' 2", far limit = 1,821' 3", total depth = 1,462' 1", hyperfocal distance = 894' 9"
f/8
Near limit = 403' 4", far limit = 1,172' 2", total depth = 767' 10", hyperfocal distance = 1,230' 4"
f/5.6
Near limit = 447' 4", far limit = 910' 12", total depth = 463' 8", hyperfocal distance = 1,757' 7"

Jan 22, 2015 | Nikon D3200 24.2 MP CMOS Digital SLR with...

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How to mount a tair 300 on a nikon DSLR camera???


Sorry, you can't. The Tair 300mm uses the M42 mount, while Nikon SLRs (film and digital) use the Nikon F mount. Due to the deeper flange distance of the Nikon mount, M42 lenses cannot be adapted to Nikon cameras without losing infinity focus.

Nov 27, 2012 | Camera Lenses

1 Answer

Why wont my Nikon af nikkor 70-300mm G lens autofocus its self with my D5000 camera


The D5000 does not have a focus motor in the body, relying on the lens to have one. The old 70-300mm G lens does not have a focus motor, relying on the camera to have one. Thus, this combination will not autofocus.
The newer 70-300mm AF-S G lens, as well as the even newer 70-300mm VR AF-S lens, do have the autofocus motor and thus will autofocus on the D5000.

Dec 26, 2011 | Nikon AF 70-300mm f/4-5.6 G Nikkor Lens

1 Answer

I can't get the lens to focus at all on any close up setting manual or auto. I have been trying to take pictures of flowers and insects with it set to close up and I have tried also with it on manual...


The 70-300mm lens won't focus closer than about 5 feet (1.5 meters). If you need to get closer, there are several alternatives. Here are some in descending order of cost (and picture quality).

A special "macro" or "micro" lens. Some lenses are designed to focus closer than others.

Extension tubes. These are tubes that fit between the lens and the camera body. By putting more distance between the camera and the lens, the focus point moves closer to the camera.

Close-up lenses. These are like filters in that they screw onto the front of the lens, but act like a magnifying glass.

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2 Answers

Where can i buy a Sigma 70-300mm f/4-5.6 DL Macro AF Lens mount adapter for a canonEOS 500D


You can't, not as far as I know.

Getting functionally useful adaptors from any other brand to Canon EOS is difficult as the register distance from the sensor to the lens is the deepest of all current lens mounts. Adaptors therefore require expensive optical correction in order to preserve infinity focus ability and given that the adapted lens will still be substantially crippled most owners aren't prepared to pay for such an adaptor. In any case, the additional optical elements will reduce optical quality.

Due to similar electronics, it is possible to physically convert a Sigma mount lens to EOS by fitting an EOS lens bayonet but it's a skilled job requiring fabrication skills and even then there's no guarantee that the lens will communicate correctly with all EOS bodies. In practice, due to the scarcity of Sigma mount lenses the conversion is usually the other way around.

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1 Answer

Quantaray 70-300


Sounds like the aperture inside the lens is broken. You shuld send it in for service.

Aug 07, 2009 | Quantaray AF 70-300mm f/4.0-5.6 High Speed...

1 Answer

How do you go from zoom to macro?


From my experience, many zoom lenses that have a macro feature simply kicks into macro mode when the lens is in fully zoomed position. Remember, macro is used to take pictures of something (usually like a flower, insect, etc.) and to magnify it several or many times larger than it really it is. And as a result the subject is huge and sharply focused with a very blurry background. Another thing to keep in mind is that there is usually a focusing limit for the lens in terms of how close one can focus a subject in MACRO zoom mode. In other words, you (the lens) may have to be at least a foot or more away from the subject in order to automatically focus sharply. On this note, if you have manual focusing capability, you should be able to take pictures in macro zoom mode from even shorter distance from the subject, resulting in more larger than life pictures!

Good luck!

I Can Fix it

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1 Answer

Sigma 28-300 3.5-6.3 won't focus


Did it ever work on this camera?
I have seen some Sigma lenses that are auto focus on canon film cameras but then when put on the digital they dont work right. If you have used it on this camera then make sure the lens is clean.sometimes dirt on the front wil make it try focusing on the dirt. Next try focusing in manual focus to make sure the focus is working. Then take the lens off and then put it back on and make sure it clicks into place.

Let me know if none of those things work. also make sure to try focus on something close and somthing far away.

let me know how it works,
Caleb

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2 Answers

Quantary Tech-10 75-300mm use with Canon Rebel XTi


Hi all
On most lenses the way to test if your old lens works on a cannon digital to set the camera to AV then set the iris to the small setting ie F16/F22 then use the stopdown button.
Things that might happen
1 The lens will close down OK
2 The error 99 will show,will need are rechip if avaliable
3 Nothing happens, will need a rechip

Q.Why will it work inside but not outside.
A. Inside the camera needs light so the iris is full open, outside the lens needs to close down and if not compatible it is unable to close down. will need a rechip

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Unsure of how to use the extra functionality


That is the focusing ring. I'm guessing your camera is set to focus automatically (Little switch on the side of the lens should have settings for either AF or MF, or something similar.)

If its on AF, you don't need to adjust the focus ring.
However, if you have problems with the AF (sometimes it has trouble, especially in low light) you can switch it to MF, and focus manually by changing the ring.

As a general guideline, the more you twist to towards macro, it focuses closer and closer, and infinity futher away (if you're taking a shot of the moon, you want it on infinity)

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