• Welcome to Photrio!
    Registration is fast and free. Join today to unlock search, see fewer ads, and access all forum features.
    Click here to sign up

Acutance - is there something real behind the hype?


Alan

I think your note was at the tale end of a string of notes, highlighting the importance of the final product, which is, of course, true but doesn't add much to this technical discussion.

No harm intended. I have one of those wonderful Yorkshire ales please!
 

Alan,

I will have a Jack Daniels on the rocks, if that can be had in an English pub.

Sandy
 
http://www.pbase.com/dpurdy/image/66316727
http://www.pbase.com/dpurdy/image/66316065
http://www.pbase.com/dpurdy/image/66317330
http://www.pbase.com/dpurdy/image/66315879

I do use acutance developer quite a lot and really think the unpleasant side affect is untrue. I get beautiful tonality and the edge affect is really hard to see on the fine grained film I use. I do add the Potassium Iodide and using the Beutlers Developer as it was designed is a good compensating developer.
My print scans don't do the sharpness justice but I will post a few.
Dennis
 
Having had a pint of Yorkshire beer with Alan (in Goathland) I think I can say that we are all talking along the same lines, however the perspective on the degree of acutance changes as the film format changes, so that what is aesthetically good for a large format contact printer is potentially detrimental to a 35mm or 120 worker.

As Ralph mentioned earlier no-one has really looked at how varying degrees of acutance affect the final image from different formats. My own work on acutance developers was around 30 years ago and primarily with 35mm films, while Steve Sherman has evolved his technique for LF contact printing as has Sandy King (with some 120 overlap)

The danger is that while we all understand and can control what we want from a developer other photographers with far less experience may think that a form of stand or semi stand development that's suitable for LF Contact work is equally applicable to smaller formats.

As it happens developers like Pyrocat HD give very good acutance, far better than Paterson Acutol, with smaller formats, and as a bonus also better tonality. It's really a case of getting a balance view of roughly how much acutance is beneficial aesthetically for each format, before the degree of acutance becomes detrimental, which is something I've discussed with Ralph.

I'd ask a question of Sandy, or anyone else as to howmuch film choice can effect the level acutance. My gut feeling printing off RFKE PL25 is quite significantly with this emulsiom (and most likey PL50 & PL100).

Ian
 

Dennis

Very nice compositions. I love the last one!
 
Results definitely vary with film choice. I used TFX-2 (Photographer's Formulary version of FX-2) with Acros, APX 100, Delta 100 and PanF+, all in 120 format, all with reduced agitation of 2 inversions every 3 minutes. I enlarged all to 10x10". I obtained beautiful results from all except PanF+, which formed very distracting, heavy edge effects. While the other films exhibited crisp, very sharply delineated detail, PanF+ obviously needed either a different developer or more frequent agitation to tone down the edge effects. That's why they make so many different films and developers for us to play with.

Peter Gomena
 
Ralph,
Sorry, I missed your last post until now.
I've just ordered you a pint of Black Sheep.

Alan
 
Ralph and Sandy,
I really am not one of those people who sits around criticising and doing nothing. I would really like to contribute.Today I have just finished modifying my 5 x 4 camera so it is now useable again. I have Adox 25 and 100, tomorrow I will mix up a fresh batch of Pyrocat HD, then I can start developing for edge effects, and will report my results. But I would appreciate some guidlines for dilutions strategies and times just to get me started. My target print size is 20" x 16" and 16" x 12

Alan Clark
 
Ian Grant said:
I'd ask a question of Sandy, or anyone else as to howmuch film choice can effect the level acutance. My gut feeling printing off RFKE PL25 is quite significantly with this emulsiom (and most likey PL50 & PL100).

Ian
Click to expand...


My experience in general is that older thicker emulsion films give wider and more dense edge effects than modern T grain films and thinner slow speed emulsions. I get much more pronounced edge effects with Ilford HP5+ than with Rollei Pan 25, at the extremes. However, even with films of the same type and ASA results can be quite different, for example I get much greater edge effects with Tmax-100 than with Acros, all other things being equal.

Sandy King
 
Thanks Sandy, I suspect that with EFKE PL25 although it's a very thin emulsion that the reason Pyrocat HD works extremely well with it because of it's relative lack of hardening compared to virtually all other modern emulsions and so a greater degree of tanning takes place. My 10x8 negatives using the combination have a good high degree of acutance which suprised me the first time I used the combination.

Ian
 

Alan,

Wish I could help but I have no expereince at all with Adox 25 and Pyrocat-HD. Is Adox 100 same as Efke PL-100? If so I can give you some development guidelines for it.

Sandy
 
Thank you Sandy,
Yes I believe Adox 100 is the same as EfkePL-100, but Ian will know for certain.

Alan Clark
 
It is, I've been using Adox/EFKE 5 film on & off since they started importing them again in the mid 70's. Adox 100 was sold re-badged in the UK as Jessops 200 ISO film for some time, the speed ratings are very conservative & based on the pre 60's version of the ASA/BS/DIN system, they should not be over-exposed.

I was shooting PL25 at 50 EI & my niece (Jenny) shot Tmax100 @ 50 EI when we met up with you Alan, excepting the slightly different spectral differences the negatives were very similar in tonal quality, shadow detail ect, both in Pyrocat HD. In 5x4 I process my PL25 for 15mins 1+1+100 @ 20°C in a Jobo tank, about 15 seconds agitation followed by 2 inversions every minute, (my tanks are pre-Rotaray)

But I'd suggest going with any times Sandy can give you for the PL100, as I've never used it.

Ian
 
Last edited by a moderator:
AlanC said:
Thank you Sandy,
Yes I believe Adox 100 is the same as EfkePL-100, but Ian will know for certain.

Alan Clark
Click to expand...

How are you printing? Silver gelatin graded papers or VC, or both? Or perhaps some alternative process? I need to know this information to get in the ball park for development recommendation.

Sandy
 
Sandy,
VC paper. Ilford warmtone fibre glossy to be precise.

Alan


Ian,
Thanks for the backup .
Alan
 

Pat on the back Alan, "above post" refers to the first one which got everyone excited.

If your serious about a round of ales, then the pat on the back would turn into a big hug!
 
AlanC said:
Sandy,
VC paper. Ilford warmtone fibre glossy to be precise.

Alan


Ian,
Thanks for the backup .
Alan
Click to expand...

Alan,

BTW, how do you propose to develop 4X5 film to allow it to test between agitation cycles?

Sandy King
 
Steve,
I have ordered a pint for you. Black Sheep Brewery's "Riggwelter". It's strong. Hope you like it!

Alan
 
Sandy,
My normal method of developing 5 x 4 film is in an open dish divided into four sections by little plastic tubes glued to the bottom to stop the sheets from overlapping. From what I have read about semi-stand or minimal agitation this won't work, as it seems the film needs to be vertical.

I thought of doing a first trial with one sheet of film placed vertically in a Paterson 3 reel tank. Steve Sherman reccomends agitating by raising and lowering the film in the developer. Having developed quite a few sheets of Adox 100 I know how soft and easily damaged its emulsion is, so I am reluctant to hold the film to move it up and down. So I plan instead to put the film in a tin that once held Jack Daniel's Old No. 7 brand Tennessee Whiskey Fudge. Honest! That's what it says on the tin. I thought you would like that. The tin is 6" high and a thin oval in shape, and just over 4" wide so the sheet of film goes in easily and only really touches the inside of the tin at the film corners.
If I cut a big hole in the bottom of the tin then it can be lowered, with the film inside, into a larger container of pre soak water, then transferred to another container , of develper. Agitation can then be done by raising and lowering the fudge tin. After development the fudge tin can be transferred first to a container of stop bath (or water) and then to a container of fixer. I have just bought some suitable plastic containers.

I am slightly concerned that the chemicals could react unfavourably with the metal tin, but if the trial works I could make some plastic containers, or utilise plastic tubes to replace the fudge tin.

Alan Clark
 
 
You must log in or register to reply here.
Menu
Log in
Register