Peak Model 2 Focuser - How to properly use?

[Marco S.]

Good Evening, Hope everyone is well.

I recently picked up a Peak model 2 grain focuser used and sorry to say I have no idea as to how to properly use it to attain maximum print sharpness. I've looked for a manual online but have found none.

I print 6x7 negs onto 5x7 paper using a Nikon 80mm lens on a 23C condenser enlarger. I understand that you should not stop down the lens more that a couple of stops, but have really short printing times of around 6 to 8 sec. at f16!

The prints just don't seem as sharp as they could be. I open up the lens all the way, focus, then stop down wait 5 sec. for the enlarger to stabilize, then expose the paper and develop as usual. The enlarger has been calibrated so all that seems okay.

Marco

 

[Rolleijoe]

I recently picked up a Peak model 2 grain focuser used and sorry to say I have no idea as to how to properly use it to attain maximum print sharpness. I've looked for a manual online but have found none.

I print 6x7 negs onto 5x7 paper using a Nikon 80mm lens on a 23C condenser enlarger. I understand that you should not stop down the lens more that a couple of stops, but have really short printing times of around 6 to 8 sec. at f16!

The prints just don't seem as sharp as they could be. I open up the lens all the way, focus, then stop down wait 5 sec. for the enlarger to stabilize, then expose the paper and develop as usual. The enlarger has been calibrated so all that seems okay.

Marco

Hi Marco, I've got a Model 1 Peak focuser, and find it quite easy to use.

First, you align your eyepiece (rangefinder type double image) by turning it until the image is 1 as you look at it.

Second, raise the little door and expose the mirror so that when you are focusing your negative the image is projected onto the mirror.

Third, look through your eyepiece, and focus your enlarger using the image you see. You may have to move it around to find a section of your image with enough detail for you to focus by.

That's it! That's all there is to it. Just be sure to keep the little door closed when you're not using it, so the mirror doesn't get scratched.

I don't understand what you were told about stopping down your lens. You can do whatver you like with it, to get the print as you want it. Of course, you open it wide to focus, then adjust for density to print. My times usually run around f/11 - f/16 for up to 30sec. I've done as wide as f/5.6 before, but that's not the norm.

Unless there's a problem with the lens you are using. Do you have any other lens to use? In my 30+ years of doing this, I've found (IMO) Nikkor lenses to be rather soft when it comes to detail. I stick with the German lenses (Zeiss, Schneider, etc) and find that combined with the Zeiss glass my cameras use, the prints are so sharp, they could cut steel.

If your film shooting/processing has been standardized, printing becomes a breeze. But if your exposures vary too much in the camera, then printing can take a while.

What paper are you printing on? That can make a difference to the trained eye as well. I used to use Agfa papers, but since they're gone, I tried the Forte, Foma, and finally settled on Fotokemika paper (fiber). The same Plus-X negative printed on Fotokemika looked much sharper than when printed on Forte.

I'd like to help you with this, if you're interested. PM me if you've got any more questions about it.

Rolleijoe

 

[Marco S.]

Rolleijoe,

I'm using Ilford MGIV in fiber and RC coated varieties. I also have some AGFA papers that I use as well.

The only adjustment on the Peak Model 2 is the eyepiece rotates until the grid in focus. Should this be done on the easel? I have always put a piece of paper on the easel the same thickness before focusing.

As far as the Nikkor lens, they were highly recommended here so that's what I have. I'm not sure how to check if the lens is defective.

Thanks for the reply,

Marco

 

[jstraw]

Marco, focusing the eyepiece can be done anywhere, it needn't be on the easel.

Two other things for sharp prints besides grain focusing:

Make sure your enlarger is in alignment and check grain focus in the middle and corners of your easel.

Use a focusing sheet. That is to say, put a piece of the same paper that you're printing on in the easel when you're focusing. The thickness of paper raises the focuser and without it, your focal point would be below the surface of the paper. It's also easier to position your easel when your negative is projected onto white than onto most easel surfaces.

 

[bdial]

For my eyes when using a grain focuser the image is usually too bright when the lens is wide open, stopping it down a stop or two may help. If you are using a thick paper, then you should have a scrap sheet under the focuser so that it is at the same height as the paper emulsion. Nikor lenses are respectable, and dare I say it, any difference in sharpness between them and similar German lenses is probably more a matter of taste than actuality. It's not too likely that your lens is defective, though it's possible. Another important factor in print sharpness not mentioned yet is negative sharpness. Unless you are cropping heavily, a 5x7 from a medium format neg at F16 should be sharp almost regardless of the focus. Do your learning with the focuser with a known tack sharp negative, or double check the negative you are using with a magnifier.

 

[Mick Fagan]

If you are using multigrade filters, and/or a colour head, make sure you focus with no filters in the light path.

With filters in place, it is extremely easy to get the focus, ever so slightly out of focus.

The human eye has difficulty in low light and also towards the red part of the visible spectrum. I found out about this after getting eye problems and studying some of the possible problems I may encounter with some reference material supplied by my Opthamologist.

I then focused the enlarger with magenta filters in place and made a print, compared it to one focused with no filters in place. The difference is that the white light focusing was more accurate.

Now, I have an eye problem, that makes red/magenta light a problem, your eyes shouldn't have a problem as mine, the problem generally, is overcome by young healthy eyes quite easily.

However the problem does exist for human eyes in general, according to the Opthalmic charts I looked at in books in the surgery.

Mick.

 

[Marco S.]

If you are using multigrade filters, and/or a colour head, make sure you focus with no filters in the light path.

With filters in place, it is extremely easy to get the focus, ever so slightly out of focus.

The human eye has difficulty in low light and also towards the red part of the visible spectrum. I found out about this after getting eye problems and studying some of the possible problems I may encounter with some reference material supplied by my Opthamologist.

Mick.

I've always focused with the filters above the condenser in place. I will try taking out the filter next time I print.

I almost never crop, except for the slight loss of print area that gets left out when printing a 6x7 neg. onto a 5x7 sheet. Perhaps I should just start printing more 8x10's instead.

I do use a tripod and monopod whenever I shoot MF, so my negatives are relatively sharp.

I will double check the alignment on the 23C, and try out all the suggestions given. Thanks for replying.

Marco

 

[Claire Senft]

Making 5x7 prints from 6x7 negatives is not demamding at all. If you are using anything but the coarsest grained emulsions and developers you will only be able to focus on projected details instead of grain.

The eyepiece adjustments are to suit YOUR vision. The filters should be out of the light path. The lens should be wise open for focus, stopped down 2 stops for exposure. Any modern enlarging quality lens that is not defective will do fine in this application. Glass crriers can aid your sharpness. You could be experiencing negative pop that occurs with open frame carriers due to heat but it does not sound likely.

If your prints are not suffieintly sharp then it may be necessary to look at you camera technique because the prints should be so sharp that there is more detail visisble in the print with using a loupe than can be seen by the unaided eye.

 

[Marco S.]

Making 5x7 prints from 6x7 negatives is not demamding at all. If you are using anything but the coarsest grained emulsions and developers you will only be able to focus on projected details instead of grain.

If your prints are not suffieintly sharp then it may be necessary to look at you camera technique because the prints should be so sharp that there is more detail visisble in the print with using a loupe than can be seen by the unaided eye.

No doubt that my technique may be a bit off as I have no formal photographic training, having learned everything from books and the internet. But I do try the best I can and enjoy the hobby immensely and it gives me great satisfaction sharing my prints with family and friends (or anyone that will, have them!).

Thanks to everyone who took the time to kindly reply and offer help and suggestions. Your time is valuable and using it for learning, teaching and sharing will never be in vain.

Marco

 

[pentaxuser]

We don't seem to have covered your second point about short exposures of 6-8 secs at f16. Maybe this isn't a problem now but as I understand it and based on my 80mm Rodagon there is likely to be a f22 setting on the Nikkor, I would have thought, which will double exposure.

6-8 secs at f16 does seem to be very short. Dodging and burning becomes difficult at 6-8 secs so if you need to do any then longer exposures will help. Is it possible to lower the bulb rating to reduce power and lengthen exposures?

pentaxuser

 

[Les McLean]

Another factor to consider is that when you stop down the lens after focussing there could be focus shift on the lens. I have had that experience with a Nikor 80mm lens so I always check the focus at the exposing aperture.

 

[fschifano]

Les mentions focus shift at f/16 and that may very well be true. I rarely if ever stop my enlarging lens down that much, usually using them at two or three stops down from their maximum aperture where they seem to be at their best. If you are finding that your exposure times are too short, you can always cut down the amount of light reaching the negative stage. If you have a filter drawer in the light path, simply adding one or two sheets of neutral density cine gels can increase your exposure times by 1 or more stops. See here for an example: Dead Link Removed. These gels are cheap and you can cut them to size. With a color head, simply dialing in equal parts of cyan, magenta, and yellow filtration can accomplish the same thing.

 

[Les McLean]

Les mentions focus shift at f/16 and that may very well be true.

My post
Another factor to consider is that when you stop down the lens after focussing there could be focus shift on the lens. I have had that experience with a Nikor 80mm lens so I always check the focus at the exposing aperture.

Not guilty your honour

Like you, I rarely if ever stop down to f16 usually it's f8

 

[Marco S.]

My post
Another factor to consider is that when you stop down the lens after focussing there could be focus shift on the lens. I have had that experience with a Nikor 80mm lens so I always check the focus at the exposing aperture.

Not guilty your honour

Like you, I rarely if ever stop down to f16 usually it's f8

I've been using Prescysol EF on all my films as of late. I have noticed that my negatives have less density than before, although much easier printing. Along with the small paper size I use and condenser enlarger might be causing the shorter printing times.

I'll check out the ND filter, that may do the trick, or start printing 16x20's!

I'll do some more research as I really don't understand why the more you stop down an enlarging lens, image quality seems to suffer. Which confuses me greatly. The greater the DOF the greater the overall sharpness? Not the case when enlarging? I feel very dumb...

Marco

 

[Dave Miller]

I have yet to be convinced that stopping down an enlarger lens past its midpoint either causes a focus shift or a degradation in actual picture quality. I think this is another example of theory being touted as fact, without practical tests to first prove the calculated result.
I have about 10 enlarging lens of various makes in focal lengths from 50mm to 150mm, and any one of them would find a place in the trash can if they exhibited either of these characteristics. I am unable to say, when viewing a finished print, whether it was printed at f8 or f32, and that must be the acid test of this matter.
When producing 5” x 7” prints I generally find I need an aperture of f22 in order to obtain an exposure time of around 10 seconds.

 

[Claire Senft]

Dave I certainly agree that diffraction stopping down an elarging lens to a small stop when enlarging a 6x7 negative to 5x7 inches will be damn near invisible. Enlarging a extremely detailed 35mm to 16x20 may possibly be a different story.

 

[Dave Miller]

Dave I certainly agree that diffraction stopping down an elarging lens to a small stop when enlarging a 6x7 negative to 5x7 inches will be damn near invisible. Enlarging a extremely detailed 35mm to 16x20 may possibly be a different story.

It may Claire, but what I'm asking is that it is tried; before any adverse pronouncement, or statements of "fact" are made.

 

[Les McLean]

I have yet to be convinced that stopping down an enlarger lens past its midpoint either causes a focus shift or a degradation in actual picture quality. I think this is another example of theory being touted as fact, without practical tests to first prove the calculated result.


Dave, whilst I have not carried out scientific tests on the lens in question there is no doubt in my mind that when stopped down by 2 stops the focus did shift. I checked it a number of times just to ensure that I had not moved the enlarger due to the imbibing of falling down water or some such inexplicable reason. When closed down I re-focused and the printed image was absolutely razor sharp.

 

[resummerfield]

Concerning resolution, I’ve tested my El Nikkor and Rodenstock enlarging lenses ranging from 50mm through 300mm, with a glass USAF resolution target, at both the center and each corner. This was just something I did informally, to be sure I was getting the maximum resolution my lenses could provide. All lenses increased resolution when stopping down, to reach maximum resolution at about 2 stops from open. As they were stopped down further, resolution started to decrease due to diffraction. The resolution loss on my lenses due to diffraction averaged about 20% from their maximum resolution values. I do not have any APO lenses, which may give the best resolution wide open.

In theory, and with my lenses, any degrading of the final print image would not become apparent until enlargement exceeded about 10x. In actual practice up to about a 12x enlargement (the largest I’ve used so far), I have not seen any difference in the final print image when using any f-stop ranging from the midpoint (2 stops from open) to the smallest. My eyes, my judgement, etc.

Concerning focus shift, I always focus again when stopping down, and I never considered testing this.

 

[Dave Miller]

Les,I'm not doubting your word regarding focus shift when stopping down; what I suggested was that the only place for such a lens is the trash can. It shouldn't happen.
Eric, as you say, it is that actual result that is important, that's the point I want to get across. It doen't matter how wonderful the equipment is, it's the film, and paper that sets the resolution limit; and that's not very high.

 

[Claire Senft]

Not to be agrumenative but a 2.5x enlargement at f16 gives, if I am not befuddled, an effective apertue of approx f55. A 16x enlargement by the same calculation would give an effective aperture of f270...this is pinhole territory.

If my calculations are all wet then it is because I am in pinhead territory.