Duration and temperature

[Whateverist]

I understand that a higher temperature of the chemicals requires a shorter development time and vice versa. Are there any other effects of temperature? Is there going to be a difference between two rolls of film if both are developed according to the spec sheet, but one has a warmer, shorter dev time and the other a colder, longer one?

 

[Gareth Rees]

If temperature is high then development time maybe short and uneven development may occur.

 

[Roger Hicks]

I understand that a higher temperature of the chemicals requires a shorter development time and vice versa. Are there any other effects of temperature? Is there going to be a difference between two rolls of film if both are developed according to the spec sheet, but one has a warmer, shorter dev time and the other a colder, longer one?

Possibly. Grain and sharpness may be affected but across the normal temperature range (65-75F, 18-24C) you'd be hard put to demonstrate the variations.

Cheers,

R.

 

[Dwig]

Possibly. Grain and sharpness may be affected but across the normal temperature range (65-75F, 18-24C) you'd be hard put to demonstrate the variations.

Cheers,

R.

+1

Carried to extremes, there will be some differences, but withing in the normal 68-75F range you won't likely be able to tell the difference.

That said, development times need to be long enough so that the uneven exposure to the chemicals that is inherent in filling and emptying the tank isn't significant. Too short of a time will result in uneven processing. Also, overly short time are less easy to time accurately.

It is also very important that all of the processing chemicals, including the wash water, at least the initial wash, are the same temperature. Any sudden temperature change during processing, especially where there is a pH change as well (e.g. developer to stop bath), can aggravate grain.

Back in the day... I would never use a temperature that required less than 5-6 minutes when processing film in 8-16oz tanks. With my larger 32oz tank (4-35mm or 2-120) I would fill the tank with developer first and then in total darkness lower the loaded reels into the tank and then cover. Filling through the lid was too slow unless the development time was in the 12-15 minute range.