Sharpness of negatives

[Jack the boatman]

Oh, and make sure you have a BRIGHT LIGHT aimed at the stick to get an acceptably fast shutter speed!

Hi again.

I have tried the tape measure idea using a 50mm Zuiko lens as loupe.

I also ensured the film was properly loaded and that the film holder was pushed in properly.

Exposure was at f5.6 and 1/50th sec.

I focussed on 15 inches which was about the middle of the tape.

Developed in Rodinal 1:50 for 15 mins.

Results:

15" was the sharpest area of the image and the image was also sharper than anything I have seen before. I reckon you have helped me to solve the problem.

Thanks very much.

Jack

[Steve Barber]

...I have checked the aerial image and it certainly looks very sharp, but I cannot be sure that I am in the same plane as the film would be.

No, but it does eliminate the lens as the problem and it is consistent with the negative image of the book not being the same as what you saw on the ground glass when you focused on it. In other words, what you are getting on your negatives is not the image you see when you have it focused on your ground glass. That proves the registration of the film plane with the film holder inserted into the camera is not the same as the registration of the ground glass when the image is in focus on it.

The question is, "How much is it off and in what direction?" Using a ruler to figure it out will work, but I like a ready-made target for this better. You can download the image with this link:

http://www.ragarecords.com/photo/ima...testtarget.tif

Print it out on an A4 or letter size sheet and use it as described in the post for using the ruler; with the lens looking down from about a 30 degree angle above it and focused on the line marked, “CM”. And, as was said, use the lens wide open with plenty of light on the target to shorten the shutter time. When developed, you can easily see any difference in film plane as opposed to the plane of the ground glass and which way and how much the ground glass needs to be shimmed to make both planes the same, if any.

And, regarding your comment about golf, if your negative image shows the lens focused on the line as it was on the ground glass, then, yes, the easy fix is not going to be the solution.

[Steve Barber]

As always, I need to check to see what has been posted while I have been composing.

With the lens and registration eliminated, you can, now, move on to all of the other possibilities that continue to frustrate all of us.

[Cletus]

Jack -

I'm sure glad that helped point you in the right direction. I'd like to take the credit for offering the suggestion, but I really think Leigh was the one who offered up this method early on in the thread.

The nice thing about that particular test is - aside from using a calibrated target, which is really the best for this - is that you can incrementally increase the 'angle' of the tape and thus, "zero in" on the issue. With the tape at an extreme angle and shooting with your lens wide open, the narrow DoF will only allow a very small portion of the tape graduations to be sharp, the rest will blur away - you can get a much better idea of where your exact focus point is. The closer your stick or tape is to the lens, the narrower the DoF and the more accurate the test.

Using this method I was able to accurately see the effect of adding a 1.5mm fresnel in front of my GG (I have a Shen Hao too) and it was a very small difference, negligible really. Certainly not enough for me to worry about shims, or focus compensation, as some have had to do when installing fresnels, or changing to a different GG.

Glad you're getting your problems solved though and hopefully keeping most of your hair in the process!

[Bill_1856]

I use a 5~ pound Tiltall. .

Hi, E. Von H.
You gave me a wake-up notice. I wondered if for years I'd been misquoting the weight of my Tiltall, but I just weighed it again and it was exactly 6# 1.5 oz. Still pretty damn light -- one would have to spend hundreds of $$$ to shave more than a pound off with equal capacity and tilt/pan head.
Dammie, they're hard to beat for up to 5x7!

[E. von Hoegh]

Hi, E. Von H.
You gave me a wake-up notice. I wondered if for years I'd been misquoting the weight of my Tiltall, but I just weighed it again and it was exactly 6# 1.5 oz. Still pretty damn light -- one would have to spend hundreds of $$$ to shave more than a pound off with equal capacity and tilt/pan head.
Dammie, they're hard to beat for up to 5x7!

To tell the truth, I've never weighed mine except in my hand. Now I'll have to! Mine's a Marchioni, I wonder if the Leitz versions were different.

Tiltalls are hard to beat, period. They're one of those things they got right the first time. I forget what I paid for mine, something like $35 or so used in the 80s. I'll never need another, that's for sure.

[E. von Hoegh]

Hi again.

I have tried the tape measure idea using a 50mm Zuiko lens as loupe.

I also ensured the film was properly loaded and that the film holder was pushed in properly.

Exposure was at f5.6 and 1/50th sec.

I focussed on 15 inches which was about the middle of the tape.

Developed in Rodinal 1:50 for 15 mins.

Results:

15" was the sharpest area of the image and the image was also sharper than anything I have seen before. I reckon you have helped me to solve the problem.

Thanks very much.

Jack

Well, that's good news! You can't focus if you can't see the ground glass..... Do get a proper focussing loupe, though. The convenience and reliability is worth it.

[Jack the boatman]

Hi,

Thanks again to all who contributed.

Jack

[Jim Jones]

To tell the truth, I've never weighed mine except in my hand. Now I'll have to! Mine's a Marchioni, I wonder if the Leitz versions were different.

Tiltalls are hard to beat, period. They're one of those things they got right the first time. I forget what I paid for mine, something like $35 or so used in the 80s. I'll never need another, that's for sure.

My Leica Tiltall weights 6# 4 oz. and my Marchioni weighs 6# 5+ oz., both with similar slings attached, on a cheap household scales. Perhaps the Srar D version I lost a few years ago weighed a bit less, with small plastic instead of larger aluminum knobs. That cheap Star D would have lasted a lifetime, too.

[E. von Hoegh]

My Leica Tiltall weights 6# 4 oz. and my Marchioni weighs 6# 5+ oz., both with similar slings attached, on a cheap household scales. Perhaps the Srar D version I lost a few years ago weighed a bit less, with small plastic instead of larger aluminum knobs. That cheap Star D would have lasted a lifetime, too.

I'll weigh mine tonight or tomorrow.