Spotting on HP5 35mm

[technopoptart]

Has anyone seen spotting on 35mm Hp5 that appears with a rainbow pattern looking like motor oil on water? I just developed Hp5 in ddx 1:4 and two frames has a small rainbow ellipse. [examples attached]. I cleaned the negs with Pec-12 negative cleaner, transposed position in carrier, and re-scanned the next day and the result is the same. Film is dated for 2024.

 

[foc]

Without seeing the negatives, I would make a guess.
Could the negatives have touched, ever so slightly, on the developing spiral?

 

[albireo]

I think those have nothing to do with HP5 and all to do with your scanning technique. They are patterns of diffraction known as Newton Rings

https://support.polaroid.com/hc/en-...hat-are-Newton-rings-and-how-do-I-avoid-them-

You have, most likely, scanned your negative strip by placing it directly on the flatbed's glass. If not, and you have scanned itby placing it in the negative holder that came with your scanner, then the problem might be that the negative strip is so curved in the smaller dimension that the centre (longitudinal 36mm line running left to right) of the negatives touches the glass surface of the flatbed scanner.

 

[technopoptart]

I think those have nothing to do with HP5 and all to do with your scanning technique. They are patterns of diffraction known as Newton Rings

https://support.polaroid.com/hc/en-...hat-are-Newton-rings-and-how-do-I-avoid-them-

You have, most likely, scanned your film by placing it directly on the flatbed's glass. If not, and you have scanned them by placing them in the negative holders that came with your scanner, then the problem might be that these negatives are so curved that the centre of the negative touches the glass surface of the flatbed scanner.

Checking with a 10x loupe i didn't see any problems. I haven't encountered this persistent a problem before that didn't affect the whole set, I did use the carrier, and the frames are in the middle and end of the roll. I re-scanned them in different positions in the carrier and re-scanned on 2 different days. yes i do need to flatten them more, but those are the only 2 frames on the roll with this problem. I just wanted to see if anyone had this problem with HP5 on 35mm or using DDX as this was my first time using ddx. I will update in a few days when they are more flat, but now they arent more curved than other scans i have done with no problem, i would rate the curve as average.

 

[Don_ih]

If the film touches the glass of the scanner, you will get newton rings. In the instance where the film is bowed, scan it upside-down. The Epson V600 wants you to scan the film emulsion-side up - that results in frequent newton rings. I pretty much always scan it emulsion-side down - flip it in the software. You can put the emulsion side directly on the glass and not get newton rings (most of the time).

 

[snusmumriken]

I've found that some preparations for cleaning glass greatly increase the likelihood of getting Newton rings, so I now use isopropyl alcohol only

 

[technopoptart]

issue resolved, re-scanned with negs flattened in a book for a few days. rainbow spots on both frames did not show up this time.