harpofreely
Well-known
Jan,
Thanks again for your help on this. From what I've seen, I love the look of the this film and am excited to try it - I'll just go on and save a few pennies by getting the 80s packaging.
Best,
-Paul
Roger Hicks
Veteran
Dear Jan,
Indeed: I am not arguing. I do not know enough to be sure that you are right, but it seems extremely likely.
All I meant was that some people have fetishes for more or less speed, and that ISO speeds are somewhat manipulable.
Also, straightening/emphasizing the S-curve is an interesting and semi-magical art. The late Geoffrey Crawley was a great believer in trying to straighten curves, even to the extent of using three developing agents together. Grant Haist, on the other hand, maintained that there was often little or no point in using even two. I had the privilege of discussing the subject with them both -- which is why I say I don't know enough to be sure that you are right.
Like many people, I don't have the equipment to do ISO testing, but I can do pretty convincing comparisons and plot characteristic curves with a densitometer. As I get older, though, I find that increasingly I can't be arsed. I have no reason to imagine* that either you or Moersch are lying (and Frances knows Moersch much better than I) but there are others whose assertions I do not accept quite so lightheartedly, hence my observations on "cooking" ISO speeds, quite independently of ISO standards for general-purpose and aerial films.
I hadn't even realized that Equivalent Aerial Film Speed had been incorporated into an ISO standard, but then, I suppose I never needed to!
*Aaaargh! I originally wrote "doubt" which is of course the exact opposite of what I meant.
Cheers,
R.
HHPhoto
Well-known
Hi Roger,
just have a look at the following sensitometric values (just two of my several tests of this film), the characteristic curve and it is immediately obvious:
1. Example: Retro 80S at ISO 20/14° in Rodinal 1+50:
I: 0.01 logD
II: 0.09
III: 0.23
IV: 0.46
V: 0.7
VI: 0.89
VII: 1.05
VIII: 1.15
IX: 1.21
X: 1.24
2. Example: Retro 80S in DD-X 1+4 at ISO 40/17°:
I: 0.03
II: 0.13
III: 0.30
IV: 0.55
V: 0.78
VI: 1.00
VII: 1.14
VIII: 1.22
IX: 1.28
X: 1.32
The density in Zone I to III is too low: Lack of shadow detail.
The density in Zone IX and X is also too low: Bad highlight separation; somewhat "muddy", not brillant highlights.
Cheers, Jan
just have a look at the following sensitometric values (just two of my several tests of this film), the characteristic curve and it is immediately obvious:
1. Example: Retro 80S at ISO 20/14° in Rodinal 1+50:
I: 0.01 logD
II: 0.09
III: 0.23
IV: 0.46
V: 0.7
VI: 0.89
VII: 1.05
VIII: 1.15
IX: 1.21
X: 1.24
2. Example: Retro 80S in DD-X 1+4 at ISO 40/17°:
I: 0.03
II: 0.13
III: 0.30
IV: 0.55
V: 0.78
VI: 1.00
VII: 1.14
VIII: 1.22
IX: 1.28
X: 1.32
The density in Zone I to III is too low: Lack of shadow detail.
The density in Zone IX and X is also too low: Bad highlight separation; somewhat "muddy", not brillant highlights.
Cheers, Jan
Roger Hicks
Veteran
Dear Jan,
Until you posted that, I wouldn't have said I could visualize a characteristic curve just from the numbers, without plotting it. Fascinating! Thanks.
Cheers,
R.
retinax
Well-known
Interesting, I'll keep this film in mind for low contrast subjects like tele shots in misty weather or crushed-shadows-street-photography-look, it should deliver in these situations with much less pronounced grain than pushing a normal contrast film, right?
HHPhoto
Well-known
You're welcome, Roger.
I think when you are doing these sensitometric measurements quite regularly as I do (for every film-developer combination I am using), it is very easy to visualize the characteristic curve just by the numbers.
Cheers, Jan
HHPhoto
Well-known
Roger Hicks
Veteran
HHPhoto
Well-known
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Freakscene
Obscure member
The spectral sensitivity strongly suggests that RPX 25 is Aviphot 40, not 80, but irrespective, you can get it a lot cheaper another way.
Marty
Marty
HHPhoto
Well-known
Hi Marty,
RPX 25 cannot be Aviphot Pan 40. Because Aviphot 40 is only produced as PE0 film with a 0.06mm PET base.
But RPX 25 has the standard 0.1 PET base.
Aviphot Pan 80 is produced both as PE0 and PE1 film. PE1 has the 0.1 PET base.
Just have a look at the original Agfa tech-sheets:
http://www.agfa.com/specialty-products/solutions/aerial-photography/aviphot/
Another evidence: Detail rendition of Retro 80S and RPX 25 is identical.
If RPX 25 would be Aviphot Pan 40 it must be finer grained and higher resolving. But that is not the case.
The Rollei RPX 25 data sheet is wrong in many aspects to hide the real source of the film.
Cheers, Jan
Freakscene
Obscure member
I measured the spectral response, I didn’t rely on the data sheet. The Aviphot 80 data sheet must be inaccurate. Strange. I have plenty of RPX, and both Aviphots, so I might do some more testing. Either way, there is plenty of Aviphot still around, and is the cheapest way to buy it, although finding it cut to 135 size is hard unless you buy Rollei branded film.
Marty
HHPhoto
Well-known
Well as said already above, I've tested the films in direct comparison. And concerning several technical parameters: characteristic curve, fineness of grain, sharpness and resolution.
Result: Both RPX 25 and Retro 80S are Aviphot Pan 80.
Aviphot Pan 40 is finer grained and has higher resolution. And of course has less speed.
And I've talked to several others who also did detailed tests and they got the same results.
And photo chemistry producers Wehner and Spur have had also the same results after their intensive tests.
Cheers, Jan
Result: Both RPX 25 and Retro 80S are Aviphot Pan 80.
Aviphot Pan 40 is finer grained and has higher resolution. And of course has less speed.
And I've talked to several others who also did detailed tests and they got the same results.
And photo chemistry producers Wehner and Spur have had also the same results after their intensive tests.
Cheers, Jan
Ko.Fe.
Lenses 35/21 Gears 46/20
Here we have one company selling food by two store chains. One is for sissy people, with more fancy store and another is for working folks, with shelves and nothing else stores.
Trucks of both store names bringing food to both stores. And nobody calls tomatos as pomidoros la grande in sissy people store. They just sell tomatoes for more, because it is fancy store.
This is value added re-selling.
So, the only value Maco added is correct ISO for made by Ilford film.
I could call it as act of "value added re-seller".
But then Ilford makes same emulsion, same speed film and tossing it around under another name through some speculant, who is using using long gone none existing original manufacturer name or just some name... It is shame. Basically, they are in the agreement to fool people to buy same film while been unknown what they are buying same film, not trying different one. This is what Ilford'O'maco does with Kentmere 400 film.
Trucks of both store names bringing food to both stores. And nobody calls tomatos as pomidoros la grande in sissy people store. They just sell tomatoes for more, because it is fancy store.
This is value added re-selling.
So, the only value Maco added is correct ISO for made by Ilford film.
I could call it as act of "value added re-seller".
But then Ilford makes same emulsion, same speed film and tossing it around under another name through some speculant, who is using using long gone none existing original manufacturer name or just some name... It is shame. Basically, they are in the agreement to fool people to buy same film while been unknown what they are buying same film, not trying different one. This is what Ilford'O'maco does with Kentmere 400 film.
Roger Hicks
Veteran
Maco will buy pretty much anything from anyone, and according to someone who knows more than I, they have even been known in the more or less distant past to sell different films as the same kind. The film described here is NOT an Ilford product: they make nothing like it.
Ilford doesn't like to admit it but they do make "own brand" products, because there are far more resellers than coating lines. Twenty or more years ago, an ex-Ilford employee told me of a head-to-head competition between their own label and a "premium" brand (the same thing, re-branded) "and we were delighted to be narrowly beaten by our own product."
Kentmere is a "second line" for Ilford so it would certainly make sense for it to be re-branded as an economy film, just as their top-of-the-line stuff is often re-branded as "premium"; but you won't find better materials than Ilford's own, unless you have a particular weakness for e.g. Tri-X.
Cheers,
R.
andrewnelles
Established
Really interesting, I never would have guessed that RPX25 and 80S were the same emulsion. I am a big fan of both films, so I guess that makes sense....
Guess I will save a few cents and just buy 80S from now on.
Guess I will save a few cents and just buy 80S from now on.
DKimg
Established
Likewise! would have never known either! And to love both...
Here's one shot with RPX25...
css9450
Veteran
I would try the Aviphot Pan 80 that Skiff is referencing here but I do not see a source for it this side of the pond. Does it go by another name here in the U.S.? If not, that's not the end of the world since I can get other favorites like Delta 100 locally (and of course RPX 25 at B&H).
HHPhoto
Well-known
Hi Roger,
Correct.
RPX 25 and Retro 80S are Agfa Aviphot Pan 80. The film itself.
But the the converting (cutting , spooling into cassetttes, packaging) of 135 format RPX 25 and Retro 80S, and 120 format RPX 25 is done by Harman technology (Ilford Photo).
120 format Retro 80S is done by Foma.
As each manufacturer has his own specific converting techniques and materials, everyone can directly see which company is doing the converting. And the Maco staff has also told customers at their Photokina booth about the converting.
Maco (license taker of the brand name Rollei-Film) is a pure distribution company. They cannot produce anything by themselves. They don't have any own production capacities.
Correct.
Their Kentmere 100 and 400 are sold to lots of other distributors for being sold as their housebrands:
- Rollei RPX 100 and 400
- Agfaphoto 100 and 400
- Fotoimpex CHM 100 and 400
- Oriental 100 and 400
are all repacked Kentmere 100 and 400.
Cheers, Jan
Correct.
RPX 25 and Retro 80S are Agfa Aviphot Pan 80. The film itself.
But the the converting (cutting , spooling into cassetttes, packaging) of 135 format RPX 25 and Retro 80S, and 120 format RPX 25 is done by Harman technology (Ilford Photo).
120 format Retro 80S is done by Foma.
As each manufacturer has his own specific converting techniques and materials, everyone can directly see which company is doing the converting. And the Maco staff has also told customers at their Photokina booth about the converting.
Maco (license taker of the brand name Rollei-Film) is a pure distribution company. They cannot produce anything by themselves. They don't have any own production capacities.
Correct.
Their Kentmere 100 and 400 are sold to lots of other distributors for being sold as their housebrands:
- Rollei RPX 100 and 400
- Agfaphoto 100 and 400
- Fotoimpex CHM 100 and 400
- Oriental 100 and 400
are all repacked Kentmere 100 and 400.
Cheers, Jan
fs999
Member
And also Ilford Pan 100 and 400 ?