Reciprocity failure and Development by inspection

I took a group of pictures last week at night. All were shot on 4x5 Tri-X 320. The exposures were determined with both a spot meter and a Horseman film plane meter. One such shot is in the gallery (there was a url link here which no longer exists)
The metering indicated about 1.5 sec at f16 I exposed this for 4 sec, base on data sheet for reciprocity. This particular shot was done because of the crowds of people. triyng to get a picture of the rare event of the mission being lit up at night.

I shot several full front on shots but relied on the long exposure to eliminate the passing people. In general the exposure indicated 2 sec at f16. But I shot f45, which would be 16 sec, but I made the exposure 90 sec. to accommodate for reciprocity. I developed two sheets, the one posted, f16 4 sec, and one shot f45, 90sec. in microdol-x 1:3 13min 24C. The one came out the other completely clear except for the point sources of light. I developed a third negative singularly exposed microdol-x FS 13min @24C where there is a bit more detail but not usable.

So my questions are;
What development technique and developer might be best suited to get an image?
Would development by Inspection be valuable? ( having not done so before, but do have a Kodak green filter for safe light )
If I do used dev by inspection any techniques I should know?

TIA

TR

I think you have to do more testing on reciprocity. If you exposed your sheet correctly, the shadows develop rather quickly. In a reasonable time of development, you should have shadow detail similar between the f/16 and the f/45 shot.

If anything you probably should reduce developing time after correcting for reciprocity so you don't blow your highlights.

Developing by inspection is neat, but it won't get your shadow details back.

- Thomas

at F45 make your exposure about 45mins.

scootermm said:

at F45 make your exposure about 45mins.

Click to expand...

WOW Maybe I did not think the exposure thru.

F Sec.
16 2
22 4
32 8
45 16


The data sheet has for 10 sec adjusted time 50sec. I picked 90 for the 16 that was indicated.

the reason I say that is that things get all kinda wonky when yo utake reciprocity into account AND night time.
Metering has always seemed rather pointless in a night time scene, anytime I've tried metering and then using a chart to calculate reciprocity I've gotten exactly what yo got, a blank neg with one specular highlight from lights.

If you are doing dev by inspection.... expose the heck out of the film - IE, figure out what you think is "way too long of an exposue" and then double that number - "Theres no way this could require 5mins" then expose for 10mins.
Then when you are developing by inspection you can "observe" the negs coming up.
I'm willing to bet money I don't have that the one negative that was double the time you thought was too much... that neg'll look great.

This all just comes from my experience shooting at night with everything from 35mm, to 120, to even 12x20. Take it with a grain of salt... as others have likely had the complete opposite experience.
Hope it helps some.

You may find an answer here: http://unblinkingeye.com/Articles/Inspection/inspection.html

and here:
http://www.michaelandpaula.com/mp/devinsp.html

Also in unblinkingeye.com look for LIRF is Lurking at Your F-stop. "LIRF" stands for "Low Intensity Reciprocity Failure."

My reciprocity chart for Tri-X 320 indicates that a metered exposure of 16 seconds needs 1'56" exposure. You were off by about 30 seconds. Sounds like you were farther off than that.

I'm curious about your metering methods, however. Where did you place the readings? If you wanted a highlight with detail for the brightest parts of the scene, you needed to overexpose two stops from the meter reading. In that case, your metered reading would have been 64 seconds, which requires about 18 minutes of exposure.

In the good old days, you could have done a test Polaroid and worked it out from there. Chalk it up to experience and try again!

Peter Gomena

And if you rated your Tri-X at 160, you're at Scootermm's time of 45 minutes given Tri-X's lousy reciprocity characteristics.

Peter Gomena

OMG it just dawned on me I had the reciprocity chart form the new tmax not tri-x
I meterd the balcony at 3, and I have a Horseman film plane meter, H69, that confirmed average about two stops off of that. I lookes at the, now fully dried, negative I developed 13m FS microdol-x and it does have printable image in the center. but light falloff is very sever. The Center is printable. I'll print in this weekend.

I printed a crop of the gallery photo on 11x14 Adox tonight and I am please with the result.

Thanks again for all your input. I'll do better the next time , 5 years hence, when the mission is lit up. Any tips on an active developer and development by inspection that can get the most out of what is on the remaining negatives I have that are yet to be developed.

Try microphen fs

Sounds like a job for Diafine. Increases film speed without blowing highlights. Designed for Tri-X.

Peter Gomena