PDA

View Full Version : Efke PL 25 M resolution / datasheet?



dh003i
17-Sep-2009, 16:07
Does anyone have the datasheet for Efke PL 25 M film? I'm looking for a high-resolution B&W film to try out that tri-color/filter idea.

I found that Rollei Ortho 25 film is rated at 330 l/mm, but can't even find the data-sheet for Efke PL 25 M.

Also, any other suggestions for high resolution film? Anything that rivals the Ortho 25's 330 l/mm? (or if lower, is it better in other characteristics?)

Thanks.

Don Hutton
17-Sep-2009, 17:13
Depends what format you're looking to shoot. In 35mm, nothing surpasses Adox CMS IMO - apparently, it can do about 400lp/mm (800 l/mm) under perfect conditions. I've tested a bunch of the best Leica lenses and had number in excess of 150lp/mm (300l/mm) at optimum apertures. Almost all of the best MF optics top at at around 100lp/mm under real shooting conditions and in MF, the highest resolution film I've used is Rollei ATP 1.1. I've tested MF lenses with it at around 100lp/mm under medium/low contrast conditions. I'm not sure why you're looking for a highly specialized high rez film to do tricolor separations though - if you're shooting LF, you are very seldom going to be able to put more than 60lp/mm onto film and Tmax 100, Acros and a bunch of other emulsions with much more sensible spectral sensitivities can easily achieve that limitation - in fact new TMY can get there pretty easily too - a lot more easily than achieving that sort of on-film resolution in making real world photographs. Almost all of the ultra high rez films have limited spectral sensitivity or at least very skewed spectral sensitivity which would make using them for tricolor separations just about impossible. Also, have a thought about using ultra slow films for this purpose - every exposure is going to be at least 2 stops slower than a monochrome negative would be without the color correction - using ultra slow films, most of which have very average reciprocity charateristics, get's you into a whole different set of problems, especially when you consider that you'll need three ultra long exposures.

If you're intending to use small formats, you're looking at more choices, but will need the right optics to utilize some of these choices; for MF or LF, Tmax100 or Acros would seem to offer the most options, although I'd suspect that in real world shooting, new TMY, which is a really fast film with excellent reciprocity characteristics and exceptionally high resolving charateristics for a 400 speed film would satisfy most...

John Kasaian
17-Sep-2009, 17:15
No data, but interesting example of what Efke 25 is capable of
http://www.petergowland.com/camera/testimonial.htm

dh003i
17-Sep-2009, 18:19
Don,

Thanks for the response. Looking at the data-sheet for the Rollei Ortho 25 and Adox Ortho 25, I can see what you mean about he spectral sensitivity. They have no red sensitivity.

I do have a few very high-resolution lenses that resolve 133 l/mm in aerial resolution (I back-calculated this from the 90/8, & presumably 90/4.5's resolution measured on Tmax at Hevanet). That's 80 l/mm on Tmax, and it goes up to 95 l/mm on Ortho 25; again, from my calculation: R = 1/(1/133 + 1/330). (Ortho25 has 330 l/mm).

Assuming a final print-resolution of 10 l/mm (254 dpi), that's the difference between 9.5x and 8x enlargements, or a 38x48 print and a 32x40 print.

Ok, maybe that's a little bit nit-picky, but that's me.

In any event, any recommendations on films with a higher resolution than T-max but that still have reasonable performance in other areas? (like sensing the color red).

Don Hutton
17-Sep-2009, 18:43
Are talking lines per mm - l/mm or line pairs per mm - lp/mm (half the l/mm)? FWIW, I've tested about 40 different large format lenses under "real world conditions" of contrast rather than extremely high and never had a number exceeding 75 lp/mm, which Tmax100 can resolve... In real world conditions where you would typically be shooting at f16 (if things are perfect) or f22, you will be lucky to exceed 50lp/mm on the film over most of the area. For 4x5 film, you're looking at a high-end scanner to get over 60 lp/mm back off the film. Dedicated smaller format film scanners can do this, but with LF, choices are very limited. I believe that Acros is slightly better than Tmax100, but I have not bothered to test it myself as I don't have of the targets required.

dh003i
17-Sep-2009, 18:48
Are talking lines per mm - l/mm or line pairs per mm - lp/mm (half the l/mm)? FWIW, I've tested about 40 different large format lenses under "real world conditions" of contrast rather than extremely high and never had a number exceeding 75 lp/mm, which Tmax100 can resolve... For 4x5 film, you're looking at a high-end scanner to get over 60 lp/mm back off the film. Dedicated smaller format film scanners can do this, but with LF, choices are very limited. I believe that Acros is slightly better than Tmax100, but I have not bothered to test it myself as I don't have of the targets required.

Thanks, I'm talking about lines/mm (l/mm). Those are the numbers that I believe C. Perez' tests on hevanet are in.

Drew Wiley
17-Sep-2009, 20:23
Efke 25 is very fine grained and has a very long relatively straight line, BUT it is
quite slow and is orthopan, not panchromatic, so would be a very poor choice for
attempting tricolor separation work. The easiest film to use is TM100 because it is
perhaps the only one currently available where all three separations can be developed together for the same time to obtain equal contrast. But expect a lot of
work, using a lot of film, and access to a densitometer.

Drew Wiley
17-Sep-2009, 20:54
I should add that balancing a set of negatives requires a very high level of skill with
development. If all three negatives (or a single roll) can be developed together it
greatly simplifies the problem because minor contrast corrections can be done
afterwards, either conventionally or in Photoshop following a scan. If the negatives
are dissimilar in contrast, curve, toe, heel, etc you are going to have a very hard time. However, your final resolution is determined by the print media. I don't know
why you want an extremely fine-grained film. If you're talking 4x5 or larger, either
of the T-Max films is sufficiently fine-grained. What is also very important is that
the film have a very long straight line right down into the toe and still be capable of
being developed to a relatively high gamma without developing a premature shoulder. With the correct developer you can do this with TMax films.

Tim Povlick
17-Sep-2009, 21:18
In any event, any recommendations on films with a higher resolution than T-max but that still have reasonable performance in other areas? (like sensing the color red).

On another thread Noah recommended some Adox Pan 25. I just tried some and I believe it's sharper than Efke 25.

It's almost as sharp as Kodak PanatomicX-II / 2412. 2412 has 500 l/mm (1000:1 - TOC). If you search you will find a fairly recent thread on this film. It should be available from HAS Imaging in Dayton OH.

upside - good red, no exposure compensation for exposures up to 1,000 seconds.

downside - is it's sold in spools of 9.5" x 200ft.

If I may ask, what format will you shoot?

Regards,

Tim

dh003i
17-Sep-2009, 22:02
On another thread Noah recommended some Adox Pan 25. I just tried some and I believe it's sharper than Efke 25.

It's almost as sharp as Kodak PanatomicX-II / 2412. 2412 has 500 l/mm (1000:1 - TOC). If you search you will find a fairly recent thread on this film. It should be available from HAS Imaging in Dayton OH.

upside - good red, no exposure compensation for exposures up to 1,000 seconds.

downside - is it's sold in spools of 9.5" x 200ft.

If I may ask, what format will you shoot?

Regards,

Tim

Thanks....I use a 4x5. It does seem like th Adox Pan 25 is available on Freestyle Photo (http://www.freestylephoto.biz/12945-Adox-Pan-25-iso-25-4x5-25-sheets?sc=24100), although I haven't heard of them before.

The red spectrum goes to 700 nm, but from looking at a color-table, it looks like what I'd consider a normal red (as in the R in RGB or the "red" in HTML or most computers) is around 650. Are the red's past that in near-IR?

I presume that by 400-650, that means it has absolutely no sensitivity beyond 650, as that's the way the Ortho 25 was from looking at it's datasheet (for Agfa Ortho 25, not Rollei).

Tim Povlick
18-Sep-2009, 06:59
Thanks....I use a 4x5. It does seem like th Adox Pan 25 is available on Freestyle Photo (http://www.freestylephoto.biz/12945-Adox-Pan-25-iso-25-4x5-25-sheets?sc=24100), although I haven't heard of them before.

I had not heard of this film either but so far it seems very good, although I may stick with the PanX-II (will decide after I see how the Adox scans).


The red spectrum goes to 700 nm, but from looking at a color-table, it looks like what I'd consider a normal red (as in the R in RGB or the "red" in HTML or most computers) is around 650. Are the red's past that in near-IR?

From experience with film based astrophotography work, it seemed Kodak would always reformulate a color film once they found out it worked well in astrophotography. The H-alpha at ~650nm is very important for nebula images. It seemed ability to image at 650 hurt the portrait ability of the film (image did not look like what the eye was seeing). I recall at ~650n, eye sensitivity is down around 10% so I could see their point. It does seem this starts the near IR region.

[QUOTE=dh003i;509042]I presume that by 400-650, that means it has absolutely no sensitivity beyond 650, as that's the way the Ortho 25 was from looking at it's datasheet (for Agfa Ortho 25, not Rollei).

That's the way I read the datasheet too. Once a film was reformulated to remove the 650nm and longer wavelength sensitivity it became useless for astrophotography. You could expose for an hour and get practically nothing of the nebula.

Good luck with the RGB, it's interesting. I tried it with 6x7 and was able to stack the images with an astro program that made it easy to align and gave a lot of control over the final image color. There is also L-R-G-B where the L is a luminance image (a full spectrum B&W).

Best Regards,
Tim

dh003i
19-Sep-2009, 23:23
I had not heard of this film either but so far it seems very good, although I may stick with the PanX-II (will decide after I see how the Adox scans).

Are you using 4x5 PanX-II negatives? Where do you buy them from, if so? Also, why'd you recommend the Adox over PanX-II for the tri-color exposure process? It seems like PanX-II gets the entire spectrum, with extended red-sensitivity (from the datasheet). It also seems like it has no reciprocity compensation required for exposures up to 1,000s (but are required for 1/10,000 sec):

"No exposure or development time adjustments are required
for exposure times from 1,000 second to 1/10 second. At 1/
10,000 second, increase the development time by 20 percent."

That's copy & pasted from the datasheet. Unless there's a typo.




The red spectrum goes to 700 nm, but from looking at a color-table, it looks like what I'd consider a normal red (as in the R in RGB or the "red" in HTML or most computers) is around 650. Are the red's past that in near-IR?

From experience with film based astrophotography work, it seemed Kodak would always reformulate a color film once they found out it worked well in astrophotography. The H-alpha at ~650nm is very important for nebula images. It seemed ability to image at 650 hurt the portrait ability of the film (image did not look like what the eye was seeing). I recall at ~650n, eye sensitivity is down around 10% so I could see their point. It does seem this starts the near IR region.



That's the way I read the datasheet too. Once a film was reformulated to remove the 650nm and longer wavelength sensitivity it became useless for astrophotography. You could expose for an hour and get practically nothing of the nebula.

Good luck with the RGB, it's interesting. I tried it with 6x7 and was able to stack the images with an astro program that made it easy to align and gave a lot of control over the final image color. There is also L-R-G-B where the L is a luminance image (a full spectrum B&W).

Best Regards,
Tim

Tim Povlick
20-Sep-2009, 08:47
Are you using 4x5 PanX-II negatives? Where do you buy them from, if so? Also, why'd you recommend the Adox over PanX-II for the tri-color exposure process? It seems like PanX-II gets the entire spectrum, with extended red-sensitivity (from the datasheet). It also seems like it has no reciprocity compensation required for exposures up to 1,000s (but are required for 1/10,000 sec):

"No exposure or development time adjustments are required
for exposure times from 1,000 second to 1/10 second. At 1/
10,000 second, increase the development time by 20 percent."

That's copy & pasted from the datasheet. Unless there's a typo.

I am using the PanX-II in 8x10. I purchased a 200 foot spool from HAS Imaging in Dayton, OH-USA earlier this year. So happens I cut 20 sheets last night from the spool and it looks like I finally have the technique down as the scrap pieces are all the same size (except one). I 100% agree with your points about PanX-II but mentioned the Adox Pan 25 because of availability in sheet format whereas the PanX-II is not. FYI this is a discontinued film now, so once it's gone --it's gone.

I have read on this forum that Adox Pan 25 is really Rollei Pan 25. From the Freestyle product description the Adox Pan 25 has spectral sensitivity: 400 650nm. Personally, I believe this should be enough of the deep red spectrum for RGB (based on film data sheets, such as Fuji 160C / 160S where sensitivity drops by 650nm).

Best Regards,

Tim

mcfactor
22-Sep-2009, 07:45
Hi, I can't really comment on the spectral sensitivity of Adox 25, since I have only used it for my own personal work, not for scientific test. However, I agree with Tim in that it does seem sharper than Efke 25 and seems to have "normal" spectral sensitivity. It is also incredibly fine grained. I had also wondered about how this compares to Rollei Ortho. I would be highly surprised if the resolution of Ortho was that much higher than Adox 25.

dh003i
24-Sep-2009, 07:29
mcfactor,

Do you have any information about the reciprocity failure specs on Adox or Rollei Pan 25 film?

The datasheet I have is very thin (just one page).

mcfactor
25-Sep-2009, 07:33
I don't. I do not usually do very long exposures. sorry.

77seriesiii
26-Sep-2009, 05:33
I think for the differences between Efke and Adox see this thread:

http://www.largeformatphotography.info/forum/showthread.php?t=53190&highlight=adox

I have shot with both Adox and Efke in 4x5 (25 iso version) and have been very happy with both. As far as differences, have not noticed any other than the notch is cut differently. I have not printed any yet...missing that side of my 'dark room' AKA bathroom :D so that is where the differences may shine.

./e

EDIT: For reciprocity Efke is out there. Its fun to shoot and people freak out when they notice I am taking a shot, talking with anyone, walk in front of the camera, etc. Occasionally, I get the "when are you going to take the shot?" "Doing it now and I am 5 minutes into a 15 minute shot" With a big smile on my face. They usually walk away shaking their head and their expression kinda says "How sad, I wonder when he goes back to the special home."

EdWorkman
26-Sep-2009, 12:14
Tim
My google search for HAS Imaging was fruitless. Do They have a website please?

Tim Povlick
29-Sep-2009, 06:38
Tim
My google search for HAS Imaging was fruitless. Do They have a website please?

Hi Ed,

Sorry for delayed response, just caught this.

The correct name is HAS Images

http://www.hasimages.com/

I talked with Ed at HAS and they have about 75 spools (PanX-II) left.

Best Regards,

Tim

Pere Casals
18-Jul-2016, 06:44
There is an option yet mentioned (Don Hutton) in this thread I support: ADOX CMS 20 film.

http://www.adox.de/Photo/adox-films-2/cms-20-ii-adotech-ii/

Not like Efke... but perhaps it would like you as a HiRes film it is.


In case you don't know this film, I would say:

It has 800 lppmm (line pairs per mm, so 1600 lines). http://www.adox.de/Technical_Informations/CMS20_ADOTECHII_instructions.pdf

Special developer has to be used, Adotech II to go straight, or POTA, etc. Common developing would render extreme contrast.

There is no need for a very high ressolution film if your lens do not has it, as in practice real 60 lppmm (high contrast) it's a lot, you would need something like this glass to go beyond after high lppmm:

http://www.ebay.com/itm/Huge-Carl-Zeiss-Biogon-for-8x10-large-format-Pleogon-A2-4-153mm-/221938551851

It weights 30kg for a 150mm focal, and not cheap.


But CMS 20 is virtually grainless, and records every drop of optical performance from your lens... and has a nice particular mood!!!

See:

https://www.flickr.com/photos/55873497@N04/albums/72157631623052598
https://www.flickr.com/photos/55873497@N04/16957759580/in/faves-125592977@N05/

Shot it al ISO 20 for dull illumination, but ISO 12, as much, if not.

For the spectral sensitivity you can use filters to make it work like you want, but it reaches just 650nm, see above pdf link


In my case, I've shot some rolls to learn this stuff, now I've just started shooting 4x5 sheets. It's a difficult film...


Regards

Pere Casals
18-Jul-2016, 07:00
[QUOTE=Don Hutton;[/QUOTE]

Sorry, the CMS 20 suggestion was pointed earlier by Mr Hutton...

JMO
19-Jul-2016, 13:52
There is another "extremely fine grain" option available in roll film, which is ILFORD's PAN F Plus at ISO 50. I have shot a couple of rolls with it in landscape situations over the last few months, and it seems to develop well in the D-76 I use. When I look at the images from this film under my enlarger, using a PEAK grain focuser, it is quite hard to see any grain in it at all. The description at Adorama's website (http://www.adorama.com/ilpfp120.html) mentions that it is commonly used in photographing documents, but also in landscape photography and other applications. However, all the preceding discussion of resolutions in lines per mm is beyond my experience (and, frankly, tends to leave a bit of a headache). ...

Drew Wiley
19-Jul-2016, 15:33
This is a Pleistocene thread by now; but most of these films looks suitable for tricolor work anyway, either due to lack of true pan qualities or due to the very
restricted nature of the characteristic curve. I just shot my last two rolls of Rolleipan 25. It might work so-so. But until somebody attempts color separation negs
with something like this, they rarely realize the headache involved. Use something reasonably fine-grained instead, with a proven track record, named TMX 100,
or perhaps FP4. Going ultra-fine just opens a can of worms.

Drew Wiley
19-Jul-2016, 15:33
typo once again... most look UNSUITABLE for tricolor work.