The difference between a sample and a full print.

[adamlugi]

Welcome,

I have been struggling for some time with the final print being more yellow than the sample.
You can see it in the picture.
What could be the reasons for this?

Regards
Adam

 

[cramej]

Are your test prints from a different roll/box/batch of paper? The contrast and exposure also look vastly different.

 

[pentaxuser]

So nothing changed in the making of the final print in terms of filtration etc? Apart from what I think is a light shining on one of the prints which clearly affects its quality I am unsure where the extra yellow is or which is the sample and which the final print.

I feel we need more details

Thanks

pentaxuser

 

[adamlugi]

Sorry, I inverted the photo but it is vertical all the time.The one at the top is a test at the bottom a photo of the whole frame. The test is laid over the whole photo.

The paper is from the same roll. I'm preparing 15 sheets of paper (1 m square) and I use it for tests and finished photos. I divide the test sheet into 3 parts.

The settings remain the same - filter and time.

For the final photo I use RBB . I put the test in the middle and the top and bottom end of the paper is under the strip. Often the paper on the sides stands out slightly from the tabletop.

 

[cramej]

Sorry, I inverted the photo but it is vertical all the time.The one at the top is a test at the bottom a photo of the whole frame. The test is laid over the whole photo.

The paper is from the same roll. I'm preparing 15 sheets of paper (1 m square) and I use it for tests and finished photos. I divide the test sheet into 3 parts.

The settings remain the same - filter and time.

For the final photo I use RBB . I put the test in the middle and the top and bottom end of the paper is under the strip. Often the paper on the sides stands out slightly from the tabletop.

What is RBB?

 

[pentaxuser]

OK now I understand which is which. The test has a much deeper blue shirt but appears to lack the detail in the shirt that the "print " has. The face difference is marginal to the extent that if presented with one without the other until I had seen several other unrelated pics and had forgotten the first I doubt if either would have struck me as being a problem.

I am tempted to say that given a lack of detail in the shirt of the test that the sample received more exposure but if literally nothing changed and that includes everything connected with the process of developing the prints including the interval in time between then two prints such that the developer may have started to exhaust then nothing should have changed and I am at a loss to explain the difference in the shirt

pentaxuser

 

[Vaughn]

Same easel?

Just thinking that if you used a different one with a different color (white, black, or yellow) you would get different results.

 

[adamlugi]

Hey,

The paper is developed in an ICP 42 plus IWD processor.

What is surprising is the repeatability. Always in the same direction.
Maybe the problem is the reflected light from the easel white substrate affecting the first layer in the paper.

Regards
Adam

 

[Mick Fagan]

There certainly looks like a 1 stop density difference between the two, is it possible that when aligning the easel with an opened aperture, you may be adjusting the aperture incorrectly for the final print?

Certainly looks more yellow, however the way you have presented the two prints makes it difficult for us to reasonably judge the differences between the two. Can you make another copy of the two prints without the light flaring the image?

Colour changes will occur with density changes, in general. That said, a darker print will be more red and a lighter print will be more cyan. This is how automatic printing machines adjust for red/cyan balance, the other colours are obtained by filtration adjustment in the colour head.

Do you expose your paper in total darkness, or are you using a colour safelight?

I too am puzzled as to what RBB is, can you explain what this means?

Mick.

 

[koraks]

There certainly looks like a 1 stop density difference between the two

Far from it. A full stop would have a way more dramatic effect. The example shows a 10% or perhaps 20% difference in exposure.

Maybe the problem is the reflected light from the easel white substrate affecting the first layer in the paper.

That's indeed a reasonable guess. Another possibility is a low level light fogging acting as a pre-flash exposure that is more pronounced in the test strip because the test strip may have spent more time out of the light proof bag/container (because it needed to be cut one more time than the full print for instance, or another difference in handling time).
You don't use a safelight, do you? If so, try without.

 

[Vaughn]

This might be the reason why I was told not to use test strips for color work, but to use the same size paper to eliminate variables...along with using the same time for all tests (and change the f/stop, instead).

 

[koraks]

Yeah, but that may be a bit too crass, at least that's what I'd say. I've done oodles of test strips with color work with reproducible results. There's nothing inherent to test strips that make them unreliable for color work. Consistency is key, though.

 

[DREW WILEY]

Part of the name of the game is how to get consistency between test strip and full sized print, or print to print. There's more to it than one might initially suspect. You have to iron it all out one step at a time to eliminate each potential variable. Of course, that is what you are already attempting to do. But I don't know enough about you specific workflow or equipment to be of much help. Any number of things might be involved.

Is your work station surrounded by black, or involve reflective areas? You already described a white baseboard or easel. Put some flat black paper on it and see what happens.

But it might well be related to the much greater surface area of the final print versus the test one. Is all the stray light masked off in each case, or potential background reflection? Or it might be related to the processor chemistry itself (volume, potency) in relation to print surface area. Does you processor have tight temperature control?

 

[adamlugi]

Dear,
1.RBB and the eassel.
2.I work in total darkness.
3.I develop in a processor that holds temperature, and other variables like PH ect.
4.The sample is made from 1/3 of a 20x30cm size sheet of paper.
5.After taking out the sample I do not change anything on the enlarger just expose the 20x30cm sheet.
6.The situation is repeatable - meaning each sample has the same difference vs the final print.

I have to try to put black cardboard on easel.

I'm trying to calibrate a second AC 800 enlarger and if it works I'll compare.

Regards
Adam