Finding development time for ADOX HR-50 using Ornano Gradual ST-20 developer?

[Hozu]

Firstly, hello! This is my first post, and I was hoping to find a great place to gather information on film photography, as I've recently jumped down this vast rabbit hole with no way out. I've been doing film photography for a year and a half, and for half of that time, I've been developing and scanning my own film. I had no prior knowledge of photography, but since then, I've learned a lot.

I started off using Rodinal, which was a great introduction to developing my own film because, well... all the development times were available! Everything was handed to me on a silver platter. However, very recently, I moved away from Rodinal, as I started to dislike the way film looked when developed in it, just my personal preference. I bought Ornano Gradual ST-20 from Bellinifoto, and I absolutely love it! I especially love how Fomapan looks when developed with ST-20.

But there was a small caveat, and I knew I needed to get my feet wet here... That is, finding development times for films that haven't been developed with ST-20, and there are quite a lot.

As an example, right now, I have two rolls of Adox HR-50 that I would love to develop with ST-20 and find the right development times for. But the question is, how? What is the best way to do this?
For now, I thought I would research and try to look at possible developers that behave similarly to ST-20. I thought that Adox FX-39 seems to be a suitable candidate, as I was comparing development times currently published, e.g. (both films are hydroquinone but FX-39 is not phenidone-based I believe?)

Film	FX-39 (1+9)	ST-20 (1+9)
Ilford FP4+	6:00	6:30
Ilford HP5+	14:00	12:30
Kodak TMax 400	10:00	12:00
Adox HR-50	7:15	???

While similar, I feel like this logic is full of BS and flaws but I was thinking that a possible baseline time could be between 7:30, 8 minutes or 9 minutes?
But how can I be sure before I go off developing a roll and have it be absolutely useless?

Do bear with me as its all kind of new to me and I'm learning from any resources I can find so I would really appreciate any information possible!
Thank you!

 

[cliveh]

You are asking a question about 4 different films with 2 different developers. When you factor in different development times/temperatures/agitation, just work out the mathermatical computations and you will see this is an impossible question to awnser.

 

[Hozu]

You are asking a question about 4 different films with 2 different developers. When you factor in different development times/temperatures/agitation, just work out the mathermatical computations and you will see this is an impossible question to awnser.

Sorry, should’ve made it clear that my question is aimed only at Adox HR-50. the other ones were nothing but an example of times and they’re already times within the data sheet of the developer.

 

[MattKing]

First, welcome to Photrio.
Second, I'll see if I can assist by adding a reference to the developer and film combination you are using to your thread title. That might drive some attention to the thread.

 

[Hozu]

First, welcome to Photrio.
Second, I'll see if I can assist by adding a reference to the developer you are using to your thread title. That might drive some attention to the thread.

thank you! Apologies I’ve just added it! Should’ve thought about this earlier!

 

[MattKing]

For what it is worth, I've never heard of the developer, and my sense is that the film has a relatively small user base, so you may have picked a challenging combination!

 

[MattKing]

thank you! Apologies I’ve just added it! Should’ve thought about this earlier!

Actually, I may have beat you to it . As a Moderator, I'm able to do a couple of extra things to help.

 

[Hozu]

For what it is worth, I've never heard of the developer, and my sense is that the film has a relatively small user base, so you may have picked a challenging combination!

To be honest I thought of the same but I really wanted to challenge myself somehow if possible. Ive never shot any of Adox film or ISO below 100 before and I really wanted to try something “new” to me.

 

[djdister]

Normally I would suggest checking the Massive Dev web page, but it currently is not working for me..

Massive Dev chart

 

[Hozu]

Normally I would suggest checking the Massive Dev web page, but it currently is not working for me..

Massive Dev chart

I have the mobile app and I’ve been using it very often, but unfortunately there’s no time for it as well.
the only ones are the ones I’ve attached

 

[djdister]

I have the mobile app and I’ve been using it very often, but unfortunately there’s no time for it as well.
the only ones are the ones I’ve attached

Well then, this is your chance to take the lead, do some testing and publish a set of recommended times for that combination! You could also submit your suggestions to the Massive Dev folks...
Time to get famous, if not rich.

 

[MattKing]

You may want to reach out to the film manufacturer and the source for the developer.
And if you have more data points for the comparisons, someone here might be able to help improve the accuracy of any guess.

 

[John Wiegerink]

Normally I would suggest checking the Massive Dev web page, but it currently is not working for me..

Massive Dev chart

and I thought I was the only one or my Mac was playing tricks on me.

 

[Hozu]

did a bit of more sleepless research and will probably do a snip test before developing my film and pretty much pray/hope it will be close enough to my assumed 8 minutes?

I will definitely get back here with a developed negative and see if people think it’s overdeveloped or underdeveloped because I honestly always find it difficult to tell the difference

 

[Hozu]

So I've taken a guess on the development time and went with 8:30 which yielded some result (surprisingly! I was expecting it to fail)
The developer came out in a very peculiar colour that I haven't seen it go before, normally it's clear or ever so slightly yellowish but this time it came out almost brown/reddish? I guess it's the anti-halation layer perhaps?
Here are some photos of the negatives (and the dev for curiosity sake) ->

Here are some test shots, nothing amazing as I've bought two rolls of the film for testing purposes.


Personally I feel like the highlights are quite blown out, but these samples are not edited in post and are straight from the scanner.
Is it overdeveloped? Should I perhaps drop the development time to 7:30 or do you guys think it's good as it is?

 

[MattKing]

Is it overdeveloped?

Looks that way to me.
A reasonably useful reference I refer people to from time to time: https://www.ephotozine.com/article/assessing-negatives-4682
In my experience, people with less experience in these things often end up over-developing their negatives.

 

[Hozu]

Looks that way to me.
A reasonably useful reference I refer people to from time to time: https://www.ephotozine.com/article/assessing-negatives-4682
In my experience, people with less experience in these things often end up over-developing their negatives.

Aha, yeah that does look like it.
I will probably go down in development time by 7:30? Or just 7minutes, not too sure but the 8:30 dev time was a estimate after some research since there's no data for this dev + HR-50.

 

[MCB18]

FWIW, HR-50 is just Aviphot 80. Adox supposedly does something to it, but the H&D curves strongly suggest (to me at least) that they’re just telling you to pull it about 2/3 stop in dev compared with Rollei 80S (and about 1/3 pull from “box speed”). No idea if you have any times for Rollei 80S, but if you do it should be easy to get a time for HR-50

 

[Hozu]

FWIW, HR-50 is just Aviphot 80. Adox supposedly does something to it, but the H&D curves strongly suggest (to me at least) that they’re just telling you to pull it about 2/3 stop in dev compared with Rollei 80S (and about 1/3 pull from “box speed”). No idea if you have any times for Rollei 80S, but if you do it should be easy to get a time for HR-50

did look around and found that someone developed Rollei 80S in 9 minutes so if I do the calculation it would possibly be around 7-7:30? That sounds reasonable, will try this with my second roll!

 

[MCB18]

G

did look around and found that someone developed Rollei 80S in 9 minutes so if I do the calculation it would possibly be around 7-7:30? That sounds reasonable, will try this with my second roll!

Glad I could help!

 

[Hozu]

G

Glad I could help!

thank you, much appreciated!
I will definitely come back with an update once I finish the second roll so hopefully anyone using the same developer can find use the times too!

should probably think of uploading it to massive dev if it works out

 

[loccdor]

HR-50 and RPX 25 are also the same film... HR-50 gets pre-flashed which improves the speed. RPX 25 needs 10 minutes in HC-110 H to achieve 25 speed and HR needs 8-9 minutes in the same developer to achieve 50 speed.

I've done similar to what you did when I needed missing dev times, compared the percentage difference in times with known films on the two developers in order to extrapolate a time with the unknown film. It usually gets pretty close on the first try and on the second with an adjustment you're spot on. Massive dev chart will gladly accept your times, they're always updating it.