Need help debugging dark spots on my negatives

[rob.nyc1]

Hey guys!

I started developing my own film at home about 6 months ago. The results are generally great, but I keep producing these tiny dark spots / dots on my negatives:

They're not on all negatives in a given batch, only some photos have them.

I'm using D-76, then all Kodak chemistry for the rest of the process (stopper, fixer, hypoclearing, and photoflo).

These dots are appearing across different batches of chemicals, so there's something in the process that's consistently introducing them.

Any thoughts?

Thank you

 

[Beemermark]

Dust most likely.

 

[Chriscrawfordphoto]

They're air bubbles stuck on the film during the developing. They block the developer from working on the spots where the bubbles are, leaving a dark circle.


When you agitate, you must bang the developing tank on the palm of your hand after each tank inversion to dislodge them.

 

[KenR]

Water spots?

Water spots?

They look too round and too regular for dust spots which on my negs are rather irregular in shape. Water spots seem more likely IMHO. Too low are concentration of Photoflo? Are the spots in the same places on the negs or the scans - this could be something on the scanner glass or even the condenser glass if using an enlarger.

 

[rob.nyc1]

Thank you everybody!

These spots are on the negatives themselves - I see them both when I scan and when I print in the darkroom.

I agree they look too round and regular to be dust. Each dark circle also has a lighter ring around it. Very consistent pattern.

Air bubbles seem like an interesting theory. I'll be sure to slap the bottom of the tank or tap it on the counter between inversions, and see if that helps.

 

[Highway 61]

They're air bubbles stuck on the film during the developing. They block the developer from working on the spots where the bubbles are, leaving a dark circle.

When you agitate, you must bang the developing tank on the palm of your hand after each tank inversion to dislodge them.

Air bubbles for sure.

Banging the bottom of the tank after each agitation-inversion period is mandatory.

This is where steel made tanks rule over plastic tanks : with a steel tank you can frankly bang the tank bottom on the table with no fear of breaking it.

 

[retinax]

If you use a Paterson tank, use the twirl stick for (at least the) initial agitation. It's excellent at getting bubbles out, as you can observe if you try it during washing.

 

[giganova]

They're air bubbles stuck on the film during the developing.

This.

After you agitate the tank, bang the tank against your kitchen counter or palm of your hand twice to dislodge them.

 

[giganova]

This is where steel made tanks rule over plastic tanks : with a steel tank you can frankly bang the tank bottom on the table with no fear of breaking it.

The JOBO plastic tanks are just as sturdy as metal ones, won't break and won't bend. No advantage of metal over plastic.

 

[rlouzan]

Fill It Up at a 45 degree angle, and rap on the table.