Is the base tint of Kentmere very dark?

[Craig]

I developed some film this week and I noticed that the base tint of Kentmere 400 seems very dark.

I bought the Kentmere and some Delta 400 at the same shop, they commented how they were having trouble keeping film in stock; they get a brick in from Ilford and it's sold in 3 days, so the film was fresh and in date. I developed the film in a Jobo with Ilford ID-11 used one shot. Fixer was Ilford multigrade, mixed fresh for this film.

After the film was dried and I was sleeving the negs tonight, I noticed how much darker the Kentmere leader was compared to the Delta. Is this normal for Kentmere? I have not used much of it before. The only reason I bought it this time was the shop had 2 rolls of Delta left, and the Kentmere was the other 400 speed film they had.

Delta 400 on the left, Kentmere 400 on the right.

 

[MsLing]

My K400 looks like yours, but I only shot one roll to test my Moscow5 camera.

 

[koraks]

Kentmere 400 on the right.

That doesn't look right to me. I've only shot this in 35mm and I don't recall the base was significantly darker than other comparable films.

@retina_restoration has compared Delta 400 to Kentmere 400 specifically in 120 format some years ago; perhaps he can (if he's willing to spend time digging up the negatives) show an example of how the base density of these films compare.

 

[250swb]

I can't say I've used the Kentmere film but if you made a similar comparison between Delta and HP5 the film base would be much darker on the HP5.

 

[koraks]

But not that dark! It doesn't look right to me.

 

[Saganich]

Yea, that's too dense for normal bd+f. I've measured the base density of Kent400 in 35mm as 0.34 consistently which is same as my HP5 measurements but a bit more than TriX or XX at 0.26...all in D23. In old TriX (2 years out) I get an additional 0.15 bd+f.

 

[albireo]

I developed some film this week and I noticed that the base tint of Kentmere 400 seems very dark.

I bought the Kentmere and some Delta 400 at the same shop, they commented how they were having trouble keeping film in stock; they get a brick in from Ilford and it's sold in 3 days, so the film was fresh and in date. I developed the film in a Jobo with Ilford ID-11 used one shot. Fixer was Ilford multigrade, mixed fresh for this film.

After the film was dried and I was sleeving the negs tonight, I noticed how much darker the Kentmere leader was compared to the Delta. Is this normal for Kentmere? I have not used much of it before. The only reason I bought it this time was the shop had 2 rolls of Delta left, and the Kentmere was the other 400 speed film they had.

Delta 400 on the left, Kentmere 400 on the right.

View attachment 399180

Left: Hp5+, right Kentmere 400 - both fresh, no Xray, both in HC110 1:31, fixed in Fomafix fresh 5 minutes

Kentmere 400 is IME much darker than HP5+ in both 120 and 35mm.

 

[DWThomas]

Personally haven't done much with Kentmere, but can't help wondering ... Is this a developed base fog, or perhaps a different base substrate with some internal anti-halation/light-piping tint? Be interesting to just fix some unexposed, undeveloped pieces -- or strip the emulsion with chlorine bleach and compare.

OK, I'll just let myself out ...

 

[koraks]

I dug up some 135 HP5+ and Rollei RPX400 = Kentmere 400. It's possible that my RPX400 (2019?) is a different version of the product that now retails; IDK for sure; maybe @Lachlan Young can clarify. The HP5+ happens to be developed in Pyrocat HD and the Rollei/Kentmere in Instant Mytol, which will make a small difference to the advantage of the latter, but this will not be a dramatic one. The HP5+ measures 0.31logD b+f and the Rollei/Kentmere 0.33logD. Visually, the Rollei/Kentmere doesn't look much darker at all.

There can be variation w.r.t. the wash-out of the magenta dye in both films, which can be quite stubborn. In combination with the natural base color, this can appear as significant density. Maybe this plays a role, too.

 

[retina_restoration]

That doesn't look right to me. I've only shot this in 35mm and I don't recall the base was significantly darker than other comparable films.

@retina_restoration has compared Delta 400 to Kentmere 400 specifically in 120 format some years ago; perhaps he can (if he's willing to spend time digging up the negatives) show an example of how the base density of these films compare.

Craig's examples posted above look exactly how those two films look for me as well.

 

[retina_restoration]

Personally haven't done much with Kentmere, but can't help wondering ... Is this a developed base fog, or perhaps a different base substrate with some internal anti-halation/light-piping tint? Be interesting to just fix some unexposed, undeveloped pieces

I've done this, and the base tint is still there: it's not film base/fog that is generated through development. It's the color of the substrate.

 

[koraks]

Here's the sample I referred to earlier:

Rollei RPX 400 on top, HP5+ bottom.

Same pair, backlit:

As said, density measures pretty much the same as what @Saganich reports above.

I've not shot Kentmere in 120, so IDK what base they use on that, and again, the Rollei RPX I used was purchased in 2019 or so (could have been 2018).

Edit: I also came across a HP5+ sample that I processed in Instant Mytol and might have washed longer; this measures 0.27logD base density.

 

[pentaxuser]

Should I take it, Craig, that the exposed negatives are fine?

pentaxuser

 

[Craig]

Should I take it, Craig, that the exposed negatives are fine?

pentaxuser

They appear to be. I have not tried printing any of them yet.

 

[retina_restoration]

Here's the sample I referred to earlier:
View attachment 399200
Rollei RPX 400 on top, HP5+ bottom.

Same pair, backlit:
View attachment 399201

As said, density measures pretty much the same as what @Saganich reports above.

I've not shot Kentmere in 120, so IDK what base they use on that, and again, the Rollei RPX I used was purchased in 2019 or so (could have been 2018).

Edit: I also came across a HP5+ sample that I processed in Instant Mytol and might have washed longer; this measures 0.27logD base density.

Kentmere 100 and 400 in 120 format have a very dark grey base material the emulsion is coated on. It's not unusual for someone using the film for the first time to assume something is wrong when they pull negs out of the fixer.

 

[mshchem]

Is the grey color the color of the base plastic? Base fog? Or dye?

Inquiring minds want to know.

 

[Lachlan Young]

120 and 135 Kentmere 400 are coated on the same (dyed) base. 135 HP5+ is coated on a dyed base, but 120 HP5+ is on a (thinner) clear base. The reasoning for the dyed base in 135 is well known, and because Ilford managed to make the 135 base work within the packaging systems for 120 (initially for Delta 3200) it has meant that some materials that might not have a sufficient ROI to make it feasible to invest in building/ coating a 120 clear-base variant (or technical limitations that prevent usage of a thinner base) are now available in 120. The bases in use for each format are in the first few paragraphs of their tech docs for each film.

 

[koraks]

Thanks Lachlan, that makes sense. So the phenomenon isn't so much the dark base of Kentmere 400, but the clear base of HP5+ 120!

 

[Saganich]

The purple hue looks like anti-halation layer that isn't being softened in development, and/or fixed long enough and/or washed away. When I have this issue I add a minute or two to the fix and about 10 min extra to the wash. For the Kent400 35 I'm fixing 5 minutes in TF5 rapid fix and washing at least 30min and haven't had this issue. Often I'll know when the fix is petering out because the purple starts to increase.

 

[Prest_400]

I actually had the same realisation. Don't have them at hand but I shot D400, HP5 and K400 in the same trip.
Kentmere appears slightly darker and with a more persistent purple dye.
Granted that it was developed and fixed last in that batch. Recently I had 3 Kentmeres developed after Delta 100 and while the Delta id quite transparent, the K400 has a grayer base with some purple dye left.
I was using the Ilford method.

Kentmere 100 and 400 in 120 format have a very dark grey base material the emulsion is coated on. It's not unusual for someone using the film for the first time to assume something is wrong when they pull negs out of the fixer.

 

[MsLing]

Is the grey color the color of the base plastic? Base fog? Or dye?

Inquiring minds want to know.

It is mentioned that manufacturer add dye into base to decrease reflection in a 2000s book.

 

[mshchem]

It is mentioned that manufacturer add dye into base to decrease reflection in a 2000s book.

IIRC Plus-X had a grey tinted base.

 

[Craig]

I recently developed a roll of Kentmere 200 in 35mm and the base, while tinted, is noticeably lighter than the Kentmere 400 in 120.