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my first DSLR a T7 - ok to use a USM with bad focus motor?

ROMzombi
Contributor

I'm coming off S95 (lens error) S100 (lens error) S110 and an SX620hs. This is my first DSLR. I went to a camera shop today that is going out of business and found a 50mm 1.4 USM for free. I took some pictures with it using manual focus and it seems to be ok other than no autofocus. It it ok to use with a broken focus motor? I don't like the kit lens it came with as the focus is so slow going in and out before it settles on focus in a semi dark room. Sometimes it won't even let me take a picture. The powershot cameras didn't care, they would take a picture no matter what. I'm very new with DSLR so maybe I'm not doing something right or some setting is off.

20 REPLIES 20

jrhoffman75
Legend
Legend

You won't harm the camera by using the lens for manual focus if that is what you are asking.

John Hoffman
Conway, NH

1D X Mark III, Many lenses, Pixma PRO-100, Pixma TR8620a, LR Classic

ROMzombi
Contributor

There are step by step instructions on replacing the motor in this lens. It appears that this lens is prone to motor failure?  I'm wondering how hard it would be to do it myself. There are a lot of steps....

ebiggs1
Legend
Legend

Use it as is. DIY lens repair is not for the untrained. Just getting the right part may be a challenge. If the store gave it to you for free that should tell you something like it isn't worth repairing.

EB
EOS 1DX and 1D Mk IV and less lenses then before!

The store is going out of business. The owner wasn't even there - just some people hired to liquidate everything. The lens was from the leftover repairs that were abandoned, which was free.

"The lens was from the leftover repairs that were abandoned, which was free."

 

And that tells you nothing? 🤔

EB
EOS 1DX and 1D Mk IV and less lenses then before!

Anonymous
Not applicable

If you raise the flash on the camera, it will emit a burst of flashes to help the camera focus in low light.

When I was using the S powershot cameras, I would always use manual and never used the flash. I used a tripod to take pictures at night.

What @5DIV is referring to is called an AF Assist Beam. Your semi dark room is too dark and lacks contrast for AF to work correctly. A DSLR camera relies on contrast not how bright something is. For instance the camera won't lock focus on a clear blue sky because it lacks contrast. The built in flash can provide quick strobe bursts of light to assist the camera's AF system. You can set to built in flash not to fire. Then have the built in flash providing AF Assist when the camera needs it. Some of Canon's speedlites project a red grid to assist the camera's AF system too. This method is faster and doesn't have any buzzing noises. Associated with Intermittent Flash Firing that the built in flash uses or some speedlites utilize.

AF Assist Beam projected from a speedlite. Note depending on how many AF points your camera has. The speedlite will project different AF Assist patterns.AF Assist Beam projected from a speedlite. Note depending on how many AF points your camera has. The speedlite will project different AF Assist patterns.


-Demetrius

Current Gear: EOS 5D Mark IV, EF F/2.8 Trinity, EF 50mm F/1.8 STM, EF 85mm F/1.8 USM, 470EX-AI & 600EX II-RT

Retired Gear: EOS 40D


@deebatman316 wrote:

What @5DIV is referring to is called an AF Assist Beam. Your semi dark room is too dark and lacks contrast for AF to work correctly. A DSLR camera relies on contrast not how bright something is. For instance the camera won't lock focus on a clear blue sky because it lacks contrast. The built in flash can provide quick strobe bursts of light to assist the camera's AF system. You can set to built in flash not to fire. Then have the built in flash providing AF Assist when the camera needs it. Some of Canon's speedlites project a red grid to assist the camera's AF system too. This method is faster and doesn't have any buzzing noises. Associated with Intermittent Flash Firing that the built in flash uses or some speedlites utilize.

AF Assist Beam projected from a speedlite. Note depending on how many AF points your camera has. The speedlite will project different AF Assist patterns.AF Assist Beam projected from a speedlite. Note depending on how many AF points your camera has. The speedlite will project different AF Assist patterns.


Won't help the OP's situation because he stated that the AF motor is broken.

John Hoffman
Conway, NH

1D X Mark III, Many lenses, Pixma PRO-100, Pixma TR8620a, LR Classic
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