French Maran Eggs - incubating - candling for dark eggs? blind myth?

[gallatea]

I have ~10 French Black Copper Marans - I'm new to incubating. Am having success with some other breeds that are a week a head of the Marans so at least I know I'm doing something right thus far. I have 2 hatch dates a week apart - and yes I know about all the temp/humidity changes for the last 3 days, will be separating batch 1 & 2 when the time comes so will have 2 separate environments for incubating vs. hatch/drying.

Anyway, things are going well, but I cannot see a thing when candling these eggs. I have no issues with my white eggs obviously.

I do have a slide projector (the ultra bright light I heard is good for dark eggs). I have some professional chicken books and read everything I can find on incubating eggs. I've heard some tales that candling can make your chickens blind (ok, like every hour, or twice in incubation of 21 days is never explained - or with what? A blow torch or a tiny mini flashlight).

I'm wondering *not* if this is true (for that is a matter of opinion), but if anyone has actually experienced or seen it happen? My flashlight is not going to do the trick for candling these dark brown eggs, but before I use my projector I want to make sure it's safe. My professional books says it's safe but doesn't mention brighter light sources like a projector. I plan to candle on day 10 coming up. I guess in one way the dark eggs are good as I leave them alone and don't want to candle as much.

As a newbie I'm loving seeing the babies in action. It's so nerve wracking worrying about being a half degree off or something and worrying about deformities etc...

Thanks in advance!

 

[FireTigeris]

I don't think the developing eye exposed to light from- anything - is going to cause blindness- I have never seen this in my hatched chicks.

 

[they'reHISchickens]

I tried the slide projector and my problem was reducing the lighted area small enough to focus through the egg.
I am having good luck with an LED maglight ( large) that I made a cover for with only about an inch opening. Even my hand over the lens didn't block enough light.
For the marans, I needed complete darkness and no larger than 1 inch lighted hole with no light leakage. THEN, I could see the air space and shadows.
Even this didn't work for blue eggs. Those rascals are impossible to see anything but shadows and air space all the way at lockdown.

 

[youngbiddy]

All I can see with my Maran's eggs is an ever-growing dark patch. That means they're alive and growing, which is pretty much all I need to know! I can't tell you how relieved I was to see a noticeable size difference when I candled at day 7 and then 10. This is my first hatch so I'm pretty neurotic. Are nightmares and a deep-seated fear/certainty that I'm going to kill them all normal for a first-timer?

I'm not sure my nerves can take this on a regular basis. I'm going to go gray early if this keeps up.