Laser aiming and focus in photomacrography

A forum to ask questions, post setups, and generally discuss anything having to do with photomacrography and photomicroscopy.

Moderators: rjlittlefield, ChrisR, Chris S., Pau

tevans9129
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Location: TN

Post by tevans9129 »

What a great idea, thanks for all the info. I am a beginner in this macro photography process and finding the subject through the viewfinder has been very frustrating for me, this should help immensely. Just came from my shop and everything is done just waiting for a battery holder. Thanks again, happy I found this forum. Ted

Chris S.
Site Admin
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Post by Chris S. »

Ted, welcome to the forum! :D

Thanks for letting me know the info was helpful. Makes me happy! (Thanks, too, to those who expressed kind words earlier in the thread. As the many contributors to this forum well understand, these are much-appreciated.)
tevans9129 wrote:Just came from my shop and everything is done just waiting for a battery holder.
You have more patience than I do. I'd surely be taping batteries and wire together right now. . . . :D enjoy your laser!

--Chris S.

tevans9129
Posts: 129
Joined: Thu Nov 30, 2017 8:03 am
Location: TN

Post by tevans9129 »

Chris S. wrote:Ted, welcome to the forum! :D

Thanks for letting me know the info was helpful. Makes me happy! (Thanks, too, to those who expressed kind words earlier in the thread. As the many contributors to this forum well understand, these are much-appreciated.)
tevans9129 wrote:Just came from my shop and everything is done just waiting for a battery holder.
You have more patience than I do. I'd surely be taping batteries and wire together right now. . . . :D enjoy your laser!

--Chris S.
Thanks for the welcome...I found this forum due to your bratcam article on another forum and so glad that I did. It is a great source for those of us that are ignorant of the macro part of photography.

Yawns
Posts: 400
Joined: Sun Dec 20, 2015 9:18 am
Location: Benavente, Portugal

Post by Yawns »

so glad this post is on again.. looked for this before but couldn't find it ...

I got some laser diodes.. 1€ each (France.. not China) .. to make a laser pointer for the camera...
- 5V
- 650 nm
- 5 mW

the thing is.. i'm using a 4,5 V battery ...the beam looks fine when I point to a wall, even a distant wall ... but the beam coming out through the objective is very dim ... I only can see it over the insect in the dark .. mmmm. something is escaping to me here......
YAWNS _ (Y)et (A)nother (W)onderful (N)ewbie (S)hooting

Chris S.
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Location: Ohio, USA

Post by Chris S. »

Nice bargain, Yawns!
Yawns wrote:. . . the beam looks fine when I point to a wall, even a distant wall ... but the beam coming out through the objective is very dim ... I only can see it over the insect in the dark .. mmmm. something is escaping to me here......
The beam will be darker after traveling through an objective that it would be simply shining on a wall. And the higher the magnification of the objective, the dimmer will be the beam. This said, I have no trouble using my laser (of the same output rating) even with my 100x/0.70 objective. For this, however, I do turn off the room lights.

--Chris S.

Chris S.
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Post by Chris S. »

tevans9129 has posted on his implementation of the sighting laser, "View finder laser for subject location". His post is well worth reading!

--Chris S.

razashaikh
Posts: 124
Joined: Tue Nov 14, 2017 11:40 pm
Location: India

Post by razashaikh »

Great Information, thank for sharing.

MacroLab3D
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Joined: Tue Jan 31, 2017 11:40 am
Location: Ukraine

Post by MacroLab3D »

What to do now, when mirror cameras are gone?
Maybe put it at the top of a tube lens and use as a gun aim? I will try.
Thank you for the idea.

Smokedaddy
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Location: Bigfork, Montana
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Post by Smokedaddy »

As always, excellent idea with clear instructions. Looks like it might be a fun 3D printing project too.

-JW:

Smokedaddy
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Post by Smokedaddy »

Well Chris asked me if I ever made one of these to post it, so here it is. I went a little different route and made mine battery operated. I have plenty of plugs in my wall socket as it is. :shock: This didn't require any tools whatsoever and seems to work fine to me, although I don't know what I'd use it for. I purchased the replacement Canon rubber eye-cup and twin AA battery box (with a switch) on eBay for about $5.00. Used the same machined block and laser that Chris suggested. I made a jig to center the machined block on the eye-cup so it would center properly and glued it on with contact cement. I've used contact cement many times on my 4x5 and 8x10 cameras bellows when replacing them. There is a very slight gap on each side (top and bottom seal fine) but it works as is. It would be very easy to mask the perimeter with (something) and tack hot glue it in place too.

Image

Image

Image

-JW:

Chris S.
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Post by Chris S. »

JW, looks great! Thanks for posting your implementation. I like your replacement eyecup and contact cement approach.

Batteries vs. wall power is probably a "to each his own" sort of choice. I started minimizing batteries in the studio because it used to seem like every time I was ready to shoot, I had to stop and change a battery in something. But these lasers shouldn't drain a battery pack all that fast.

--Chris S.

wvessjr
Posts: 1
Joined: Sun Jun 28, 2020 9:42 am
Location: Cherryville N.C.

Re: Laser aiming and focus in photomacrography

Post by wvessjr »

Will this damage a 5D mark ll
I have ordered the laser and a heat sink to try this.
Walter

Smokedaddy
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Joined: Sat Oct 07, 2006 10:16 am
Location: Bigfork, Montana
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Re: Laser aiming and focus in photomacrography

Post by Smokedaddy »

I wondered the same thing. Since I'm involved in Astronomy too this is the only information I was able to find.

https://www.cloudynights.com/topic/4611 ... nder-safe/

-JW:

aveslux
Posts: 83
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Re: Laser aiming and focus in photomacrography

Post by aveslux »

Lasers can damage your sensor so be careful when you use them.

Chris S.
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Re: Laser aiming and focus in photomacrography

Post by Chris S. »

I've taken far too long to reply--my apologies. Family health issues intervened.

In this implementation, there is no danger of the laser hurting the sensor. Let me explain.

In the configuration presented in this thread, the light from the laser never has a chance to reach the sensor in any damaging way. Take a look at the graphic below, in which a red line represents the light path in a DSLR in normal use--where the light comes from the subject, through the lens, bounces off a mirror, then enters the pentaprism and bounces off its inner surfaces until exiting through the viewfinder. In our case, simply reverse the arrows on the red line to show the lightpath of an eyepiece laser in a DSLR. Notice that the mirror protects the sensor before and after a shot is taken, thanks to the mirror's blocking position in front of the sensor. While not shown in the graphic, this mirror flips up out of the way while a picture is being taken. And in this flipped-up position, the mirror continues to protect the sensor from the laser, by blocking the light path from the eyepiece, just below the pentaprism.

DSLR light path.JPG

Hence, the viewfinder laser described in this thread is quite safe for DSLR sensors. Safety was a consideration to which I paid careful attention when designing/building this sighting laser. I gave safety an additional rethink before publishing the how-to on this laser assembly. My thinking then and now is that this implementation is quite safe. And empirically, having used my sighting laser for some years, I've found zero sensor damage. I often forget to turn off the laser or camera (both are on mains power) after shooting sessions, and have left both on for months. Even with the laser and camera both turned on for months at a time, I've seen no sensor damage at all.

--Chris S.

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