Minolta 50/1.7 AF Repair (updated)

Another post on a very common issue: sticky diaphgram blades.
From old Exakta lenses to Nikkor AF Zooms, apparently anyone gets there.

This time, the classic Minolta 50/1.7 has the issue, although in its AF version.

Dismounting AF lenses can be tricky, but in here everything seems fine, except the Iris. I want to avoid regreasing the helicoids because I haven't yet found a satisfactory Grease, even if I tried several! I will try unmounting as little as possible from the lens as possible to get to the Diaphgram Iris assembly.

We can work from the front, by unscrewing in sequence the cone with the name plate first, then removing 3 screws to remove the the front part with the retractable sun shade. Without these parts, the lens is still fully functional.

From the rear, we can remove the lens bayonet and put it aside and we see the picture like this:

AF Rokkor 50/1.7 from the back, mount removed (left)

The optical assembly is in the middle and has two guides, clearly seen top and bottom in this picture. Mark the helicoid for convenience and unscrew them
Now it is possible to unscrew the optical kernel to the back of the lens.
Getting it back will be a little tricky, since the infinite setting needs to remain. Even if I marked the helicoid, I needed a couple of attempts.

The hard part is done! The 50mm is a double-gauss type and it is easy to take it apart. Removing three screws enables to remove the front part and the same is for the back.

What remains is just the Aluminum barrel with the Iris mechanism inside. Now you can clean it by flushing or by opening it.

My first attempt of repair was done with a flush-clean: often this is enough if just a little oil is astray. However it worked for a couple of months, but then the blades stuck again. This means there was a lot of oil in the non-accessible mechanism (the ring that acts as governor for every pin), so a more drastic solution was needed: remove the blades with their governor ring.

The open diaphgram blades, the governor on top

Mounting everything back is relatively easily, except for getting the right screw thread and not damaging the delicate Aluminum thread when screwing it in.

Check the infinity focus.. and that the diaphgram is snappy again!

HP5 SuperGrain - Industrial heritage

Industrial Photography - inside Serimide Impianto Idroforo

Film: Ilford HP5+
Development: SuperGrain 1+15  7'

Camera: Minolta SRT303

Slightly thin at visual inspection, high range negatives.

Here some direct negative scans. Even in difficult indoor lightning situations, the tonal range is impressive.

Pump room - Minolta SRT303 - Rokkor 28/3.5

Here an image with just indirect window light, metal and bricks.
Not only the light Rokkor 28/3.5 defends itself quite well at full aperture, but this film and developer combination extacts good detail and contrast.

Boiler front - Minolta SRT303 - Rokkor 28/3.5

As a proof, here an extreme detail of the boiler plate. You can clearly read "Associazione Utenti di Caldaie a Vapore" ! Not bad for HP5+.

If you like it, the image is on sale, in different prints and on some objects.

OM1 + SFX200 in Supergrain - Aerial and not

I run an  Ilford SFX200 in my Olympus OM1

I developed it Supergrain 1+12 21°C 7'.

The results are slightly thin but quite pleasant and usable. Scanned very well, the grain is present, as I have experienced with this film before and the developer also, so somehow expected. Looks a bit like HP5.

Here some aerial images, with a standard Red filter (Olympus OM1 - 50/1.8):

Here an image without filter which shows the extreme dynamic range this film can handle with this developer combination (Always Olympus OM1 - 28/2.8).

Ferrania P30 Rodinal

Tests of the first 5 Ferrania P30 Alpha 35mm films. Development in Rodinal 1+50.
The film proved to have lower sensibility than advertised, development times completely off, difficult "foot" in the curve for shadow rendition.

First attempt

Nikon F90x, exp. 80/20° ISO, 7 minutes in 24 °C, one inversion every minute.
These should be roughly equivalent to 11 minutes to 20°C

The negatives are quite thin, although the highlights developed black. I'd say underexposed and overdeveloped.

Furthermore, even with using my standard process of washing and rinsing with wetting agent, I have lime specs (you can see the white dots, not retouched)

Second attempt

Leica M2, exp. 80/20° ISO,  22°C one inversion every second minute
12 minutes.

This is also very thin. I hoped in minimal compensation from slower agitation... and wanted to exclude errors in the first attempt.

Again evident lime specks!

A completely ruined image, due to insufficient shadows and lime specks and deposit! It gets very visible because the scanner tried to read the shadows, highlighting the dirt.

Third attempt

Nikon F90x, 20°C, 17 minutes, agitation every second minute.

Still too thin. The film leader is black, but the skies in the pictures barely are. Things are becoming usable, still the film proves a magnet for lime deposit and specks!

 

Here, where the dark shadows don't disturb too much, the result is quite pleasing: nice detail in the sky, differentiated tones in oopen-shadow brickwork.

Fourth attempt

EOS 3, exposed 50/18° ISO. 20°C, 20 minutes, agitation every second minute

Finally, density is high enough, almost too high. However shadows are very thin. Even attempting exposure at 50 ISO is not enough to get full shadow detail. Almost usable now, but highlights blow easily, given the long development.

 

Greyscale card shows that things are not too bad, shadows are blocked only at the last to levels. However, this is a print in sun. Real scenes have more dynamic range.

Fifth and last attempt

Canon FT, last roll. Exposed at 64 Stand 1h 1+100 about 19°CC 

 

 

 

 

The film is capable of excellent mid-hight tone rendition:

 

 

Here again, shadows bite us. The tree is too black. Actually, there is some detail that could be recovered, Stand development helped, but images here are quite straight examples.