#1  
Old 10-10-2017, 10:17 PM
langman78 (Ben)
Registered User

langman78 is offline
 
Join Date: Sep 2013
Location: Melbourne, Australia
Posts: 66
Green laser pointer use with DSLR

Hi all.

A couple of yrs back I purchased a decent quality green laser pointer to mount on my (hopefully soon to be sold) 8se to take the place of the finder scope. Never got around to doing so I pondered on the thought of using with my 70d.
I posted a thread on cloudy nights sometime ago asking if it was safe flash through the view finder to make targeting easier when selecting object for widefield AP with my iOptron skytracker? Never really got a definitive answer. As couple of ppl suggest it was fine and a great tactic for the mentioned purpose but live view MUST be deactivated to be 100% safe. Others said bad idea don't do it know of others who damaged sensors etc.
Anyone here use the method or know it to be a safe/practical method?
Cheers for reading,
Ben
Reply With Quote
  #2  
Old 11-10-2017, 05:05 AM
fsr
Registered User

fsr is offline
 
Join Date: Nov 2015
Location: Hurlingham, Buenos Aires
Posts: 23
I have seen videos of camera sensors damaged by "disco" lasers when recording video. DSLRs when NOT taking pictures have a closed physical shutter over the image sensor, and a half-mirror on top of that. I've never tried, but i don't see how the light would reach the sensor at all in that conditions.
Reply With Quote
  #3  
Old 11-10-2017, 07:45 AM
RB's Avatar
RB (Andrew)
Moderator

RB is offline
 
Join Date: Aug 2005
Posts: 25,732
Ben please be aware of the dangers to your eye sight first.
I have experience with lasers and I can tell you that those pointers are dangerous.
Even so called 'low power' ones can actually be over spec which means they may claim 1mW or 5mW but could actually be much higher.
Anything above 5mW can cause instant eye damage, before your eye has time to blink or react.
Also if they're a 'cheap' Chinese green pointer, ie: 532nm then you need to make sure it has a built in IR filter since it's pumped with an IR source to produce 532nm.
Decent ones usually have IR filters but you can't be sure unless you check or test them.

A lot of cheep pointers don't have this filter so it leaves you exposed to dangerous levels of invisible IR.

Also, the only way to know for sure about the power level is to use a proper Laser Pointer Meter.
Brightness is no indicator of true power levels.
And as we all know various states have different max legal levels, between 1mW and 5mW, nothing over and for good reason.

This all adds up to the point I want to make.
If by chance you get any type of unfortunate reflection via the camera viewfinder or other surface, even for a brief moment, you could be damaging your eyes without knowing it.

If this happens, your camera sensor is the least of your worries.

Just wanted to share, hope it helps.
Safer to just mount the pointer on a bracket and take all precautions.

Another unrelated matter, those 532nm pointers don't take kindly to the cold and may fail until they're warmed up.

Not saying don't use it but be aware or the power levels, IR dangers and the legalities.
Make sure there's no aircraft in the sky, very important.
You don't want a knock on your door from the authorities.

RB
Reply With Quote
  #4  
Old 11-10-2017, 09:18 AM
sil's Avatar
sil (Steve)
Not even a speck of dust

sil is offline
 
Join Date: Jun 2012
Location: Canberra
Posts: 1,474
Just buy a "hot shoe red dot finder". Its the tool for the job, lasers for home astrophotography are not needed ever and people like yourself misunderstand the point of them at all in astronomy. Its just not the right tool.
Reply With Quote
  #5  
Old 14-10-2017, 09:05 PM
DarkKnight (Kev)
Registered User

DarkKnight is offline
 
Join Date: Jun 2015
Location: Morpeth NSW
Posts: 177
I've looked into this and found that the green pointer throws a beam, whereas the red one doesn't, and I think it would be really difficult to see a red dot on a star sixteen zillion miles away.

My intention is to mount it on my cameras hot shoe, align it, and use it to get me into the ballpark with finding what I intend to image, without looking through the viewfinder or using live-view. Be aware of not using it if aircraft are in the vicinity, gaol is not a good place to be from what I've heard.

As I'm sure you are aware, looking through a DSLR's viewfinder at a night sky can be pretty underwhelming, particularly trying to find that one speck of light.
Reply With Quote
  #6  
Old 14-10-2017, 09:30 PM
raymo
Registered User

raymo is offline
 
Join Date: Sep 2011
Location: margaret river, western australia
Posts: 6,070
I presume that you are aware that it is illegal to use any laser pointer
unless you are a member of an astronomical organisation. Big fines.
Stick a red dot finder on your hot shoe; would do the same job with no possibility of danger,
or the green beam showing up in someone else's photograph[if there is anyone nearby ].
raymo

Last edited by raymo; 14-10-2017 at 09:35 PM. Reason: more text
Reply With Quote
  #7  
Old 14-10-2017, 09:51 PM
DarkKnight (Kev)
Registered User

DarkKnight is offline
 
Join Date: Jun 2015
Location: Morpeth NSW
Posts: 177
Quote:
Originally Posted by raymo View Post
I presume that you are aware that it is illegal to use any laser pointer
unless you are a member of an astronomical organisation. Big fines.
Stick a red dot finder on your hot shoe; would do the same job with no possibility of danger,
or the green beam showing up in someone else's photograph[if there is anyone nearby ].
raymo
Yes raymo, I'm aware of the legal requirements re using a laser pointer. And I am a member of an astro society.

I have both, have tried them both outside, after dark, and I can see SFA with the red dot finder when pointed at the sky, whereas the green pointer throws a visible beam which is a useful assist in where to point your DSLR.
Reply With Quote
  #8  
Old 16-10-2017, 07:03 AM
sil's Avatar
sil (Steve)
Not even a speck of dust

sil is offline
 
Join Date: Jun 2012
Location: Canberra
Posts: 1,474
A red dot finder is NOT a laser it does NOT throw a beam ever. I dont think you understand the difference you're talking about. A laser advertises itself to everyone for miles around so expect police cars to show up, and I'll repeat a laser is the wrong tool for the job, its a red dot finder or telrad you need. Hard to imagine your astro society so poorly educates its members (plus being a member is NOT a licence to use lasers, so you are clearly also NOT aware of the legal requirements.
Reply With Quote
  #9  
Old 16-10-2017, 12:05 PM
DarkKnight (Kev)
Registered User

DarkKnight is offline
 
Join Date: Jun 2015
Location: Morpeth NSW
Posts: 177
Quote:
Originally Posted by sil View Post
A red dot finder is NOT a laser it does NOT throw a beam ever. I dont think you understand the difference you're talking about. A laser advertises itself to everyone for miles around so expect police cars to show up, and I'll repeat a laser is the wrong tool for the job, its a red dot finder or telrad you need. Hard to imagine your astro society so poorly educates its members (plus being a member is NOT a licence to use lasers, so you are clearly also NOT aware of the legal requirements.

EDIT: It seems Sil and myself are on two different wavelengths here with me talking about red lasers and Sil about red dot finders.

All lasers throw a beam, full stop, it's just that some colour wavelengths are more visible to the human eye, with green, followed by blue, being the most visible. To see the beam of a red laser you would need to be in a heavily dust polluted or smoke filled environment, not the best of settings for viewing the night sky.

For any laser beam to be visible it must have something to reflect off and in normal conditions there is enough reflecting particulate matter in the air to see a green beam, the one with the wavelength most perceptible to our eyes.

I assume that is why the military use red laser sights for target acquisition, because it doesn't throw a tell-tale warning beam but merely pinpoints the target itself.

That is great for finding a target that is only a hundred metres or so away but not so useful when the target is light years off in the distance.

I am well aware of the dangers that improper use of lasers can pose and when using one would take whatever steps necessary to mitigate the risk of danger, or inconvenience, to others.

As for the legal requirements for owning and using lasers I will post a quote from the NSW Police Departments website. I'm sure the requirements vary in other states.

Quote:
The following relates to the changes which are now law. These laws apply to all laser pointers, regardless of their power level.Q: Am I allowed to own a battery operated, hand held, laser pointer?
A: You are allowed to own such a laser pointer. However recent amendments to the Weapons Prohibition Act 1998 require a permit be issued (or the person be eligible for an exemption) where the laser pointer exceeds one milliwatt. Regardless of the milliwatts, no laser pointer can be carried or used in a public place without a reasonable excuse.
Q: What is a reasonable excuse?
A: A reasonable excuse will be determined on a case by case basis but examples of a person with a reasonable excuse could be an amateur astronomer, a teacher or a lecturer who uses the pointer for astronomy or teaching and has it in his or her possession at the relevant time for that purpose.
Q: What is the penalty?
A: The penalty for possession or use of a laser pointer in a public place without a reasonable excuse may be up to two years imprisonment or a fine of up to $5,500.
Q: Can the police search me if they are looking for a laser pointer?
A: Laser pointers are now classed as dangerous implements under the Law Enforcement (Powers and Responsibilities) Act. This gives police the power to request a person in a public place (but not a school) to submit to a frisk search if the police officer suspects on reasonable grounds that the person has a laser pointer on them.
A police officer also has the power to confiscate the item if the laser pointer is unlawfully in the person's possession.
Q: Are medical lasers, laser-based tools and other such devices covered by these laws?
A: The law relates to battery operated, hand held laser pointers.
'Laser pointer' means what it is commonly understood to mean - a device for pointing out an object.
Laser devices that are used for medical purposes are unlikely to fall within this definition. In any case, a surgeon would be able to point to their occupation as a reasonable excuse for possessing a laser pointer in a public place,
Similarly, if the device is powered by mains electric power, it is not battery operated and so is not covered by these laws.
Similarly, various laser measuring or levelling devices used in the building industry should not be affected as they are not 'pointers'. In addition, they are not held in the hand while being used and so are not 'hand held pointers'.
Q: Are any laser pointers prohibited?
A: Laser pointers with a power output of more than one milliwatt are now prohibited weapons. You must obtain a permit to possess or use a laser pointer that is in this category, unless you use the pointer for activities associated with astronomy and are a member of an approved astronomical association.
Q: How do I get a permit to use a laser pointer whose power is over one milliwatt?
A: You must make application to the NSW Police Firearms Registry (telephone: 1300 362 562), website www.police.nsw.gov.au/firearms. Permits are not granted automatically. You must have a genuine reason for the use of such a laser pointer.
Q: What is a genuine reason?
A: It is not possible to provide an exhaustive list of genuine reasons. Each application for a permit will be assessed on its merits. An example of a genuine reason would be if an applicant could demonstrate that a laser pointer greater than one milliwatt was required for business/employment purposes. Other reasons listed under Section 11 of the Weapons Prohibition Act 1998 include, recreational, sporting, film/television, theatrical and scientific purposes.
Q: Are there any exemptions to the need for a permit?
A: If you are using the pointer for activities associated with astronomy and are a member of an approved astronomical association you are not required to obtain a permit.
Q: What must I do if I currently have a laser pointer with a power level of more than one milliwatt?
A: If you want to keep the laser pointer and you are not a member of an approved astronomical organisation, you must obtain a permit from the Firearms Registry by 1 December 2008.
If you do not obtain a permit, then you should safely dispose of the laser pointer. Unauthorised possession/use of such a laser pointer is a criminal offence.
It is my belief that a green laser pointer, used thoughtfully and responsibly in an appropriate environment, should offer no risk to others.

And Sil, in the future please try get your facts right before you decide to waffle on about things you seem to know little about

Last edited by DarkKnight; 16-10-2017 at 01:01 PM.
Reply With Quote
  #10  
Old 16-10-2017, 12:33 PM
bojan's Avatar
bojan
amateur

bojan is offline
 
Join Date: Jul 2006
Location: Mt Waverley, VIC
Posts: 6,932
Quote:
Originally Posted by sil View Post
A red dot finder is NOT a laser it does NOT throw a beam ever. ...
This is very much correct... and sometimes on ebay RDF's are incorrectly advertised as "laser" devices.. .


Quote:
Originally Posted by sil View Post
...being a member is NOT a licence to use lasers
This is also correct, at least in VIC.

Green lasers are not welcome at gatherings, where someone may be imaging at that moment and the (even brief) laser firing at the wrong part of the sky could ruin the frame.

This is what you really need...

My 2 cents...

Last edited by bojan; 16-10-2017 at 12:56 PM.
Reply With Quote
  #11  
Old 16-10-2017, 01:06 PM
DarkKnight (Kev)
Registered User

DarkKnight is offline
 
Join Date: Jun 2015
Location: Morpeth NSW
Posts: 177
Quote:
Originally Posted by bojan View Post
This is very much correct... and sometimes on ebay RDF's are incorrectly advertised as "laser" devices.. .




This is also correct, at least in VIC.

Green lasers are not welcome at gatherings, where someone may be imaging at that moment and the (even brief) laser firing at the wrong part of the sky could ruin the frame.

This is what you really need...

My 2 cents...
Bojan, it would seem that Sil and myself were not referring to the same thing and got our wires crossed.

I'll have a look at red dot finders as an alternative to the green laser.

PS; What brand is the finder in your link.
Reply With Quote
  #12  
Old 16-10-2017, 02:13 PM
bojan's Avatar
bojan
amateur

bojan is offline
 
Join Date: Jul 2006
Location: Mt Waverley, VIC
Posts: 6,932
It could be one of those.
You will also need a shoe adapter... one of those?
Or this...
Reply With Quote
  #13  
Old 18-10-2017, 09:06 AM
sil's Avatar
sil (Steve)
Not even a speck of dust

sil is offline
 
Join Date: Jun 2012
Location: Canberra
Posts: 1,474
Quote:
Originally Posted by DarkKnight View Post
And Sil, in the future please try get your facts right before you decide to waffle on about things you seem to know little about

I couldn't agree more, Ken. ?This is Ben's thread, his question. I'm trying to give him precise facts without you muddying up the waters on this subject even further. Deal with it. Yes green lasers are more visible than red lasers to the naked eye. Its why sensors are bayered with two greens to one red and one blue for each pixel and it ALL comes back to the properties of our eyes.

Either way the right tool for BOTH of your going of your descriptions of what you want to do is a Red Dot Finder or Telrad (if you're going to whinge about not seeing a red dot on a star. Sound like you're arguing to justify you wanting to play with lasers which is an irresponsible attitude especially on a family friendly forum.

Lasers are handy for educators pointing out stars on location for a group of students, and observatories use them to create an artificial star by ionising the atmosphere to take calibration data for the adaptive optics system its NOT required for amateur astrophotography.

Feel free to start a new topic instead of hijacking and wasting others with irrelevance.
Reply With Quote
  #14  
Old 18-10-2017, 04:30 PM
SkyWatch (Dean)
Registered User

SkyWatch is offline
 
Join Date: Jan 2013
Location: Adelaide
Posts: 400
Just a comment about the use of laser pointers as a member of an Astronomical Society. It is my understanding that each State has different rules- so you need to check what is legal in your State; and if you are from another State but using a laser pointer (say at a Star Party), then you need to abide by the rules of the State you are in: not your home State.

Further, in SA at least, we (the ASSA) are required to hold a register of members who have laser pointers. This is updated regularly, and the members are issued with an identification card, including details of their pointer/s, that they may be required to show the Police. Just being a member of the ASSA is not enough, you must register your laser with the secretary. This is a condition that was included in the legislation when we negotiated directly with the SA Attorney General at the time (we even had him come to our observatory at Stockport and have a play with a laser pointer!). The alternative was that they could be banned outright in SA even for amateur astronomers.

So, bottom line: be very careful with their usage, and check the laws in your State.

All the best,

Dean
Reply With Quote
  #15  
Old 18-10-2017, 05:16 PM
doppler's Avatar
doppler (Rick)
Registered User

doppler is offline
 
Join Date: Nov 2012
Location: Mackay
Posts: 1,656
I did notice that NSW laws all refer to use/ possession in a public place, I guess that means it's ok at home? BTW, Lasers are only visible side on for a very short distance so the only ones coming to police attention are miss behaving by pointing them directly at something they shouldn't be. We use them at school astronomy nights and the group has to stand close and behind the beam or it is not very visible, so no one will know you have one unless you misbehave.

Last edited by doppler; 18-10-2017 at 05:28 PM.
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 09:38 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Advertisement
Bintel
Advertisement
Testar
Advertisement