William Optics Red Dot Finder too bright

[marcosscriven]

Hi

I somehow managed with my WO 72mm apo just by roughly lining up, and using a 25mm EP to centre, before moving to higher power.

I got an RDF yesterday, and tried it out last night (having lined it up during the day). For Jupiter, it was fantastic - I lined up the planet in the middle of the reticule, and there was Jupiter right in the middle of my 4mm EP.

Next stop was Orion's Nebula. Trouble was, although I could just see in with the naked eye (with the double whammy of a bright moon and city light pollution), the reticule was too bright, even on its lowest of 7 settings.

Does anyone have this RDF? Is there an easy way to reduce the brightness further than the manual setting? Ideas include a lower voltage battery, or some kind of flat resistor to go in serial with the battery.

[foundaplanet]

I use one on my 70mm frac and I know what you mean by the settings being bright, although I can't say the lowest one is too bright for me.

Did you try all 4 reticle settings as well?

[marcosscriven]

I use one on my 70mm frac and I know what you mean by the settings being bright, although I can't say the lowest one is too bright for me.

Did you try all 4 reticle settings as well?

Mine only seem to have three - a circle, a dot, and a crosshair

[biz]

Hi

I somehow managed with my WO 72mm apo just by roughly lining up, and using a 25mm EP to centre, before moving to higher power.

I got an RDF yesterday, and tried it out last night (having lined it up during the day). For Jupiter, it was fantastic - I lined up the planet in the middle of the reticule, and there was Jupiter right in the middle of my 4mm EP.

Next stop was Orion's Nebula. Trouble was, although I could just see in with the naked eye (with the double whammy of a bright moon and city light pollution), the reticule was too bright, even on its lowest of 7 settings.

Does anyone have this RDF? Is there an easy way to reduce the brightness further than the manual setting? Ideas include a lower voltage battery, or some kind of flat resistor to go in serial with the battery.

Hi. I encountered the same problem so I insertered washer in place of the 20mm 3volt battery and then inserted a stock 11mm 1.5volt battery in the centre hole of the washer. It works just fine , My common use is now on the 3 and 4 switch settings. You may have to experiment with washers and a file to get this to work, for example the smaller battery has to make contact with the sides of the washer centre hole to complete electrical contact but I have done all 4 of my RDF units and all are workers.

You could also fit a small piece of camera film negative over the small glass where the LED shines thru (not the main screen) as another fix... Just a note these RDF finders are actually built for rifle shooting so obviously will be too bright for astronomy use but they can be modded so give it a try.

cheers.

Graham.

[marcosscriven]

Hi. I encountered the same problem so I insertered washer in place of the 20mm 3volt battery and then inserted a stock 11mm 1.5volt battery in the centre hole of the washer. It works just fine , My common use is now on the 3 and 4 switch settings. You may have to experiment with washers and a file to get this to work, for example the smaller battery has to make contact with the sides of the washer centre hole to complete electrical contact but I have done all 4 of my RDF units and all are workers.

You could also fit a small piece of camera film negative over the small glass where the LED shines thru (not the main screen) as another fix... Just a note these RDF finders are actually built for rifle shooting so obviously will be too bright for astronomy use but they can be modded so give it a try.

cheers.

Graham.

Thanks for the tip - I'll try a smaller battery with a washer

[Nibor]

Hi. I encountered the same problem so I insertered washer in place of the 20mm 3volt battery and then inserted a stock 11mm 1.5volt battery in the centre hole of the washer. It works just fine , My common use is now on the 3 and 4 switch settings. You may have to experiment with washers and a file to get this to work, for example the smaller battery has to make contact with the sides of the washer centre hole to complete electrical contact but I have done all 4 of my RDF units and all are workers.

You could also fit a small piece of camera film negative over the small glass where the LED shines thru (not the main screen) as another fix... Just a note these RDF finders are actually built for rifle shooting so obviously will be too bright for astronomy use but they can be modded so give it a try.

cheers.

Graham.

I used 35mm negative film (overexposed areas) and built up the required number of layers - they were cut to "spring" into place and they work a treat!! - the washer trick is also a neat idea!!