Kentmere 120 at box speed in D76/ID11 at 1+3

[pentaxuser]

Has anyone found that the above film's development time of 21 mins has resulted in over exposed negatives? I ask this because while browsing Youtube I discovered a video comparing Arista 100 with TMax 100 and Kentmere 100. When the results were shown the Kentmere negs appeared to be consistently over developed compared to those of the Arista or TMax

The times, based on what each maker recommended, were 17 mins for Arista and T Max so 4 mins shorter than for Kentmere. As far as I can tell from the presenter's narrative all other things were equal so I had difficulty working out why the Kentmere negs were that much darker and the subsequent "prints" ( in fact negative reversals) were much lighter

In terms of all other things being equal, he used the same camera with 3 backs, took the same picture within in seconds of each other based on the same aperture and shutter speed which is why we can eliminate differences in the camera, its shutter speed and aperture settings or so it would appear

If anyone wants to check the video I have linked to it below. The part about all other things being equal occurs after about 15:30

11:50 pm Sorry about this I forgot to provide the link I had to go somewhere tonight so was trying to do too much at once I have now returned here's the link He talks about how he set up the test of the 3 films from about 15:30 mins



Thanks

pentaxuser

 

[MattKing]

Has anyone found that the above film's development time of 21 mins has resulted in over exposed negatives?

Did you mean "over-developed" negatives?

 

[Saganich]

I guess to answer that question you would have to know the manufacturers process for determining the respective development times.

 

[Steven Lee]

I guess to answer that question you would have to know the manufacturers process for determining the respective development times.

I doubt they have a process.

A couple of years ago I developed a bunch of films in ID-11 using the Ilford's datasheet. I followed their temperature and agitation instructions to the t. The resulting contrast was all over the map, so I don't buy their claim that their suggested times aim to achieve the same contrast index. Maybe this was true 20+ years ago, but I am starting to suspect that present day datasheets are either obsolete or/and are a result of some kind of model/simulation, similar to computer-generated MTF charts.

 

[Andrew O'Neill]

Where's the video link?

 

[pentaxuser]

Did you mean "over-developed" negatives?

Sorry yes Matt . See my addendum

pentaxuser

 

[pentaxuser]

Where's the video link?

Andy see my addendum to my original and excuse why I didn't attach it Apologies to all who have replied previously

pentaxuser

 

[Kino]

21 minutes for Kentmere 100 in D76 @ 1:3 seems suspect to me when the other two were at 17 minutes, but that's just a hunch.

Maybe he should have developed them all at 17 minutes and then evaluated the results.

Hate me if you like, but IMO if he got his processing information from the Massive Development Chart, he just as well throw darts at a Bingo card for the time...

 

[Andrew O'Neill]

Very subjective, but I preferred the Kentmere exposures. Pretty good for box speed.

 

[pentaxuser]

21 minutes for Kentmere 100 in D76 @ 1:3 seems suspect to me when the other two were at 17 minutes, but that's just a hunch.

Maybe he should have developed them all at 17 minutes and then evaluated the results.

Hate me if you like, but IMO if he got his processing information from the Massive Development Chart, he just as well throw darts at a Bingo card for the time...

Well I am overwhelmed at the amount of replies since I amended my incomplete original post. So thanks to all three of you All I was seeking was a reason or reasons why his Kentmere negs seemed to be over-developed compared to his Tmax and Arista one when his test seemed on the surface to be well constructed in terms of ceteris paribus ( all other things being equal ) as they should be in such a test?

In answer to your question he does say he obtained his times from the manufacturers and certainly in terms of the Kentmere time of 21 mins Ilford mentions that time for ID 11 which I think we may take as being identical to D76

It's still a puzzle to me. I was hoping for more replies to help the discussion

pentaxuser

Very subjective, but I preferred the Kentmere exposures. Pretty good for box speed.

Yes it can be subjective Andrew but it still seems strange that Kentmere at the time for ID11( D76 equivalent) gives such an over-developed look( almost washed out highlights compared to the other two film makers times for their film.

Is this the look of all Kentmere negs shot at box speed using Ilford times? I admit I don't know

It would be helpful if there are any Kentmere 100 "shooters" here who use either D76 or ID11 as the developer and the given times who may be able to shed light on this

pentaxuser


pentaxuser