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Thread: ERA 100, field test

  1. #1

    ERA 100, field test

    I got some ERA 100 4X5 film, bought through Ebay, and put a few sheets through my usual test procedure. I use the front of my garage which is white and open one of the doors to give me deep shadows. I shoot at mid day on a “Key” day (bright sun, no clouds, as bright as I will ever get In Iowa). The metering (Pentax Digital Spotmeter) was:

    VIII (16.)-Brightest white on front of garage door.
    VII (15.)-Cement in sun
    VI (14.)-High values on wood fence in sun
    V (13.)-Black trash can in sun
    IV (12.)-Medium blue garage in shade
    III (11)-Inside garage in sun
    II (10.)- Inside garage in shade

    Nice 7 stop range with detail in all of the areas.

    Development was in HC-110(b), 1 minute pre soak, 10:00 minutes, continuous agitation in a roller drum, fixed tin T-4 for 4 minutes. I estimated the development according to the Iford times for HP4 as recommended by the manufacturer.

    I think the exposure times are pretty close but I need to retest for development times. I am going to guess they will need to be 20-30 % lower than I initially anticipated, I appears the film is at or above it’s 100 asa rating which is a bit of a surprise.


    Here is a scan of the 3 second exposure, auto adjust off.
    Attached files

  2. #2

    ERA 100, field test

    This time I guessed the proper exposure to be 7 seconds for the 100 asa film, 1 stop less than my Tmax 400 at asa 200.

    I made a 3, 7 13 and 29 second exposure (N-1, N, N+1 and N+2). I ended up with an N, N+1, N+2, and N+3 judging by the scans (Epson 4990) made with auto adjust off.

    The 3 second exposure is nearly identical with auto exposure on or off which is how I judge my negatives for this process. Here is a composite of the 4 negatives with out auto adjust. Attached files

  3. #3

    ERA 100, field test

    Here is a composite of the 4 negatives with auto adjust on.

    Attached files

  4. #4

    ERA 100, field test

    Here is a composite of the shadow area.

    Attached files

  5. #5

    ERA 100, field test

    This is an adjusted file from the 3 second exposure, scanned with auto exposure on. The shadow area was lassoed and the file inverted so the shadows received no adjustment, just the rest of the image. I adjusted levels (Input levels 0/.72/255) in the mid range to bring the low values down a bit.

    Attached files

  6. #6

    ERA 100, field test

    This is an adjusted file from the 29 second exposure, scanned with auto exposure on. The shadow area was lassoed and the file inverted so the shadows received no adjustment, just the rest of the image. I adjusted levels (Input levels 27/.60/255) in the low range and mid range to bring the low values down a bit. I tried to “match” the 3 second exposure for values.

    Tends to get grainier with over exposure which is not unexpected. Attached files

  7. #7

    ERA 100, field test

    This is a crop from the 3 second negative scanned at 800 resolution with no auto adjustment. The final output was 100 resolution saved at medium. This is representative of the grain from a negative that is a bit over developed but pretty close on initial exposure. Not bad and I think adjusting the exposure and processing will result in a bit finer grain.

    Attached files

  8. #8

    ERA 100, field test

    Conclusions? Well, the first 6 negatives have a stripe across them which can be seen in the first photo with the Zone placements. It is about ¼ of the way down and is visible on the negative before processing. I pulled the last sheet out of the box and looked at it and the stripe is not visible so maybe it’s just a few sheet of this box. I’ll test with a few more sheets so it’s not big deal unless it shows up in the other boxes I got. For now I can clone out but if quality control is poor the film savings in price will not offset the extra work.
    Not a deal breaker yet.

    It does have a bit of a curl (see photo) which should not pose a problem. The surfaces seem pretty hard and I have not shuffled the negatives around enough to see any tell tale scratches.

    It has a good range of tones and doesn’t block up as bad in the highlights with overexposure as I expected it would. Shadow area should be easy to hold while getting the Zone VIII whites that I like. I’ll have to see how it does in an underexposure situation to make a final call on it’s full potential. Not that I make a lot of under exposures or anything…..

    At $75.00 including shipping for 125 sheets it seems like a good deal, barring anymore defects and I printed an 8X10 of the 3 second negative that looks pretty good, considering I am not done with the development tests.

    I’ll update as I go, for now it’s a little iffy on whether we will pursue it as an alternative to the name brands.






    Attached files

  9. #9
    500+ Posts earlj's Avatar
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    ERA 100, field test

    Wow, Marv, nicely done. I need to come up with a similar shot. You were able to learn a lot with a few sheets of film. My shots with this film came out thin, but I am pretty sure that I did not give enough reciprocity correction. However, I am pleased with the first results.

    I think that it is time for me to learn how to do some systematic testing and calibration.

  10. #10
    500+ Posts DaCh's Avatar
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    ERA 100, field test

    Cor, blimey mate (an old English phrase).
    I am really impressed with your thoroughness Marv.
    Very interesting comparisons.
    I had no idea that taking photographs was so involved. :-/
    You seem to be suggesting that knowing the true film speed and using a light meter can be good things.
    I must look into this
    My picture taking is usually sunny 16 plus one stop (‘cause UK is a bit dull) plus a bit for reciprocity when I think it needs it. I do own a couple of light meters and I even bought a spot meter many years ago but I never got on with it. Maybe I need to write 100 times “must try harder”.
    Thanks for the info.
    Now, about scanning:
    I have an Epson 4990 and I never let it do any image processing because PS can do it better, I always check the histogram to make sure it is capturing the entire detail range (it usually wants to cut a bit off), also I find it is better if the light and dark sliders are pulled to the ends.
    I normally scan at 2400 and retain the original size (100%). In PS I normally only adjust levels and curves, very occasionally I may use “highlights & shadows”. Hate filters.
    The stuff I post is often given a slight warm tone ‘cause to my eye it looks nicer on the screen.

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