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DSLR eyepiece cap?

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#1 Michael Covington

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Posted 19 April 2019 - 11:38 PM

Has anyone experimented to find out if the eyepiece cap should be on the DSLR when taking dark frames or, for that matter, light frames?

 

Its purpose is to keep stray light out of the exposure meter when the camera is not held up to someone's eye.  

 

I strongly suspect no stray light would get on the sensor without it, because the mirror (flipped up) is in the way.

But I'm not sure.

 

I know that another problem with taking darks in a light environment is that lens caps may not be quite opaque, especially in the deep red and infrared.

 

For a long time, my practice has been to put the eyepiece cap (as well as lens cap) on when taking darks if I am going to have any lights on, even intermittently.  But has anyone experimented?

 



#2 Samir Kharusi

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Posted 20 April 2019 - 02:49 AM

Most modern DSLRs do not have 100% reflecting mirrors. They need to pass through some light to sensors behind the mirrors, e.g. for exposure measurement, so, yes, you do need the viewfinder covers when shooting long subs (or darks). Also as noted some lens covers are not opaque to IR and you cannot trust all lens covers when shooting darks in full-spectrum modded cameras. Nice thing is, easy to check. Just shoot a 5-minute dark with/without whatever you have doubts about, in room light and in a dark drawer. Instant answers. Actually the viewfinder cover is the one I forgot most often. Very annoying! Because you feel safe having your laptop or whatever near the ground with the camera pointing at zenith with a deep lens hood. Until you try to source the mysterious extra light pollution on random frames the next day...


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#3 Michael Covington

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Posted 20 April 2019 - 11:29 AM

Thanks, Samir.  That's exactly it -- the mirror is not opaque.  And, thanks to laptops, we have a lot more light sources behind the camera than we used to.

 

Handy hint: If you are having trouble with the rubber Canon eyepiece cover, get hold of a Nikon DW-5 eyepiece cover, which is slightly too big, and line it with black vinyl tape.



#4 whwang

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Posted 20 April 2019 - 12:54 PM

Both my Canon 5D2 and Nikon D800 have leakage if the eyepieces are not covered. Even when covered, there will still be leakage if the environment is too bright.

#5 Cdnpilot

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Posted 20 April 2019 - 01:09 PM

I use gaffer tape over my D5300.



#6 Alex McConahay

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Posted 20 April 2019 - 03:48 PM

Check the strap that came with the camera in the first place......My Canons all shipped with a cover attached to the strap. It is a bitty piece of rubber, and you may not have noticed it. 

 

But, whatever you do, YES, USE SOMETHING to cover that hole or you could get light in there. And if you can, take darks in an otherwise dark environment. 

 

Alex


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#7 otoien

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Posted 20 April 2019 - 06:02 PM

One of the many small things I like with my D500 is the built in eyepiece shutter that is activated with a lever. The eyepiece shutter is bright on the outside  so it is easy to see if it closed in low light from some distance unless I have my DR-3 right angle finder attached.

 

On my D7100 I usually had the DR-3 right angle finder attached and used an old off-brand rear lens cap as cover that would fit on the eye cup of the DR-3.

 

Sometimes light can even leak though the clear distance window of a lens or even the mount. If I do darks in daylight I use to keep the camera in a black plastic bag or dark day pack.


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#8 Michael Covington

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Posted 20 April 2019 - 08:12 PM

Check the strap that came with the camera in the first place......My Canons all shipped with a cover attached to the strap. It is a bitty piece of rubber, and you may not have noticed it. 

 

But, whatever you do, YES, USE SOMETHING to cover that hole or you could get light in there. And if you can, take darks in an otherwise dark environment. 

 

Alex

Yes, I'm familiar with the cap supplied by Canon on the strap.  As noted above, I've also found a way to make a Nikon rigid plastic cap fit a Canon.




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