4x5 Newbie. Out of focus pictures, am I doing something wrong?

[apugnumpty]

Hi,

I'm used to Medium format and thought I'd take a look at Large format so got myself a graflocked back 4x5 field camera.

The first shots I put through it where to see if the bellows were ok so I was not bothered about sharpness so I played with the tilt and shift to see what it would do, this was with out of date Ilford FP4. The detail was ok not great. I was using f11 which I thought would be reasonable.
The developed film came out OK and quite contrasty so assumed that the bellows were ok but as I tilted and shifted the focus was a bit iffy any way.

I then ran through some new Kodak Ektar, I kept the camera straight put it on f16 did some straight on DOF tests and tilted slightly and did some more.

Now I've used a whole box of Ektar and the first two I've developed are very soft, compared to what I would get from MF.

I would focus with either the knobs or by pulling the rack until the foreground was what I would think was sharp, then I would check the rest of ground glass to check the focus in the rest of it. Assuming that this was the correct procedure I then put in the holder and take the shot with the desired f stop and shutter speed being care not to jog the tripod or camera with a remote shutter trigger.

Is there something I'm missing to get critical sharpness or are there tricks and tips to nail focus?
Or is there something I should check or test to help nailing the focus issue?

Cheers in advance.

 

[Dan Fromm]

What lens and camera are you using? If the camera is an early Chamonix 4x5, there's a design error that makes getting good focus impossible.

What focusing aid are you using? The unaided naked eye doesn't always get things right?

Are you scanning the negatives or did you examine them directly? If you examined the negatives, what did you use?

Is the ground glass oriented correctly in the camera's back? The ground (matte) side should face the lens, the smooth (shiny) side should face you.

If there is a fresnel lens, is it in front of the GG or behind it?

There's a simple test for finding out whether the problem is poor focus or poor lens. Set the camera on a tripod in front of a brick wall with the lens' axis at 45 degrees (or so) to the wall. Zero all movements. Put a mark on the wall where it will be in the center of the frame. Focus on the mark. Shoot, develop the film and examine the negative with a decent magnifier. If everything is soft, the lens or camera motion (typically caused by the head being loose on the tripod) is the problem. If the vertical line of best sharpness contains the mark, focus is not the problem. If the vertical line of best sharpness does not contain the mark, focus is the problem.

 

[mdarnton]

There should be something in focus, somewhere. Is it consistently either behind or in front of where you intended? If you can't find any spot at any distance, then it's the lens not the camera.

If focus is consistently in front of where you intend, check and see if someone has switched the ground glass with the fresnel. Usually the ground glass should face you, shiny side out, and the fresnel should be inside, facing the back of the lens, with the cut rings against the ground glass. That's unusual for a camera with both, and yes, Graflex did it that way, so maybe the last owner put things back the "right" way, wrong for Graflex.

To confound things, there was a short period where Graflex apparently did it the "right" way, fresnel on the outside. If you have one of those, and it's together backwards, the usual Graflex way, focus will be on the far side.

Then there's the possibility that the positions are right, but the ground glass is simply flipped in for out.

To figure any of this out, you need to know where the actual focus point is in your photos. If it's inconsistently in front or back, it's you; if never, it's the lens; consistently on one side, it's something about ground glass placement, probably.

 

[palewin]

It was a little unclear from your description whether your soft shots were with all controls zeroed, or with some degree of back or front tilt. When you use tilt, you actually refocus slightly after tilting, i.e. you focus on the subject, then tilt to bring the foreground into focus, and then have to refocus slightly because the tilting impacts the focus on your primary subject. (This is why Sinar and some others developed sophisticated asymmetrical focus systems, to avoid the focus shift caused by tilting or swinging.) If you were using the camera zeroed, the tests posted earlier should find the problem.

Here is a very nice summary of view camera focusing: http://www.largeformatphotography.info/how-to-focus.html

 

[ic-racer]

The film and the front of the ground glass have to be motionless and in the same place to achieve critical focus.

 

[RobC]

welcome to the frustrating world of large format.

As others have said, film plane must go into the plane that ground side of glass was. The ground side should be on lens side, i.e. facing the lens.

There are lots of possible causes of problems with focus, the main ones already mentioned above.

Also different makes of film holder, especially older ones do not conform to the standard depth of film from film holder edge.

And many film backs have shims to adjust the depth and often they have been fiddled with or removed.

Also lens front and rear elements have shims to make them the correct distance apart when mounted. On Symmar type lens designs this NOT very critical but other non symmar type designs it is.


Good luck !!!


p.s. lens front and back elements should be designed to work together. Sometimes people sell odd front and back elements as such and such a lens when they are from different lenses. All these things have to be verified if you are having problems with focus.

 

[gone]

It's a little unclear from your description of what you're focusing on. You mentioned that you focused until the foreground was in focus....but if you're shooting something far away (at infinity), then this obviously won't do. Assuming that your GG is installed correctly (matte side towards the lens), and your film holders are good, you focus it just like any other camera. If you have a fresnel screen as well, make sure it is pointed the right way. Bring the part that you want to be in sharp focus into sharpness using a good loupe on the gg, lock the focus down, carefully slide the film holder into position, carefully slide the dark slide out, and fire the shutter. F16 is good for LF, and you want a high enough shutter speed so that wind isn't causing leaves/trees to blur. This all also assumes that your lens is collimated correctly and actually capable of making sharp images. People sometimes take these things apart to clean and flip an element backwards.

I would take some close up shots inside to avoid wind and such w/o making any movements of the lens board, then a medium to long shot, then two at infinity in still conditions. Maybe of a building. No movements w/ any of these. At all times, what you see on the GG should be tack sharp and clear when properly focused. Please keep in mind that LF lenses are more about coverage than sharpness, and you're never going to get a shot as crisp as a good MF camera. But nothing should be obviously soft or out of focus either.

 

[Dan Fromm]

OP, sorry for not noticing your sig.

Look at http://photo.net/large-format-photography-forum/00OUgT

Unfortunately the MPP Users' Club seems to have gone away, so I can't check my recollection that although earlier MPPs had non-standard film position so that focusing with normal ordinary film holders (dark slides in UK photographers' English) is impossible, the MPP VII was fitted with a standard Graflok/international back.

 

[apugnumpty]

What lens and camera are you using? If the camera is an early Chamonix 4x5, there's a design error that makes getting good focus impossible.
I've got an MPP VIII with a Schneider 150 lens

What focusing aid are you using? The unaided naked eye doesn't always get things right?
Naked eye and Hasselblad Viewfinder used as a loupe.

Are you scanning the negatives or did you examine them directly? If you examined the negatives, what did you use?
I am scanning the negs and have gone through the mill getting the exact sharpness from my Epson v750 from my Medium format film and various other holders so assume I've not cocked that up, thought LF film is much much thicker than MF film so I wonder if the orientation of the film is a factor to, like emulsion side up or down?

Is the ground glass oriented correctly in the camera's back? The ground (matte) side should face the lens, the smooth (shiny) side should face you.
The shiny side appears to be facing me.

If there is a fresnel lens, is it in front of the GG or behind it?
No fresnel as far as I can see.

There's a simple test for finding out whether the problem is poor focus or poor lens. Set the camera on a tripod in front of a brick wall with the lens' axis at 45 degrees (or so) to the wall. Zero all movements. Put a mark on the wall where it will be in the center of the frame. Focus on the mark. Shoot, develop the film and examine the negative with a decent magnifier. If everything is soft, the lens or camera motion (typically caused by the head being loose on the tripod) is the problem. If the vertical line of best sharpness contains the mark, focus is not the problem. If the vertical line of best sharpness does not contain the mark, focus is the problem.

I will try that next.

 

[apugnumpty]

I have Toyo Holders, which I thought were supposed to be the best?

As a quick down a dirty test I took off the shade and the GG mount and put my digital camera (without lens) in the hole and took a picture the picture was sharp with a lack of contrast which to me is indicative of a lens without a coating, which I have no problem with. I'm assuming is the either the position of the holders, the GG position or the scanning position of the film which is incorrect.

Under a my makeshift Hasselblad viewfinder/loupe the film actually looks sharper than from my scans.

Somethings afoot here.

Another thing. I bought some extra Toyo holders which arrived yesterday afternoon. These ones have some paper put in the backing where the film would go and I am concerned that this may present another issue when I come to attempt to use them - which I have not as yet.

Has anyone heard of putting black paper in the holder underneath where the film would go?

 

[grahamp]

As an MPP VII user, I am not entirely convinced about the focus screen hood. It is hard to get close enough to use a magnifier. Since you have problems, I would switch to a dark cloth (anything reasonably dark and large enough), and remove the focus screen hood. Then you can use a loupe and be confident that you are focusing to the best of your ability. Then look at the film to see if the sharpness and focus point is what you expect. Definitely leave scanners out of it - that's another focus issue entirely.

I can think of two reasons for paper inside film holders, a) unusually thin film was being used, or b) the film did not have an anti-halation backing and the paper was there to reduce reflections from the back of the holder. Both of those are unusual cases.

I am not sure why the MPP Users web site is still down - I would have expected the new committee to have a handle on that by now.

 

[palewin]

I use (and prefer) Toyo holders, but have not bought any new ones in a long time. My guess is that the paper is just there as part of the packaging, you definitely do not want it in the holder when you load film.

 

[Steve Smith]

If focus is consistently in front of where you intend, check and see if someone has switched the ground glass with the fresnel. Usually the ground glass should face you, shiny side out, and the fresnel should be inside, facing the back of the lens, with the cut rings against the ground glass.

That's not normal. The ground glass matt surface should face the back of the lens and if there is a fresnel lens, it should be on the outside.

The matt side of the ground glass (with no film holder fitted) should be the same distance away from the lens as the film emulsion when a film holder is in place.
As a test. remove the lens and without a film holder in place, measure as accurately as you can the distance from the ground glass to a fixed position on the front - such as the surface the lens board fits up to. Then put a film holder in place with a scrap piece of film in it. Remove the dark slide and take the same measurement. They should be the same.


Steve.

 

[shutterfinger]

http://www.butkus.org/chinon/mk_viii/mk_viii.htm

 

[apugnumpty]

That's not normal. The ground glass matt surface should face the back of the lens and if there is a fresnel lens, it should be on the outside.

The matt side of the ground glass (with no film holder fitted) should be the same distance away from the lens as the film emulsion when a film holder is in place.
As a test. remove the lens and without a film holder in place, measure as accurately as you can the distance from the ground glass to a fixed position on the front - such as the surface the lens board fits up to. Then put a film holder in place with a scrap piece of film in it. Remove the dark slide and take the same measurement. They should be the same.


Steve.

Funny you should suggest that I was just measuring the ground glass position and depth of the holder to film emulsion position from the camera frame as reference and there is a 1mm difference.
I.E. The ground glass (which is the correct way around) is 3mm depth to the edge of the frame to the frosted side (the side that faces the lens) of the glass.
If I measure the holder the holder depth is 2.7mm and then add the film that takes it to 2mm. Meaning the film emulsion is closer than the GG has focussed.

That can't be right.

I assume that the focus point is based on the frosted part of the GG?

If that's so my focussing is off by 1mm. Which would explain the slight softness.
Now all of my Ektar shots were taken with the Toyo holders.

I have what looks like a Fidelity holder which I originally used for my Ilford Fp4 which seemed sharper.
I've just shot a flat surface and will develop that tomorrow as a base point.

This is all very frustrating, not loving LF so far.

 

[RobC]

I tested brand new toyo holders quite a few years ago and found them to be non standard depth. I don't remember the full details now.

However, that doesn't mean they aren't any good. It means that providing all your film holders are the same depth and your GG is adjusted to the correct depth, then everything will be fine. But if you are swapping makes of holder from one shot to the next you could have problems.

But be warned, before you start adjusting anything be 100% sure that you are correct about your assessment of what is causing the problem. i.e. double check and treble check and then check again.

And note that film is never 100% flat against the back of the film holder. It can flop forward a bit, especially if the camera is pointing down.

 

[shutterfinger]

The ANSI standard for 4x5 film holders is the image plane shall be .197 inch ± .007 inch from the edge of the film holder. TriX 320 TPX is .007 inch thick.
Being the back of your camera will be difficult to remove, remove the lens board and lay a rigid straight edge across the front standard lens board opening. Measure from the straight edge to the ground glass in several places, all measurements should be the same. Insert a film holder with a sheet of film in it and remove the darkslide. Measure to the film surface as you did with the ground glass. If the measurements differ make sure the film holder is seating flush into the camera then if that is good shim the ground glass to match the film plane of a loaded film holder. If you have a film holder out of spec toss it or make a shim for its film back plate to put the film at the correct depth.
The ground glass only has to match the film holder when they are on camera.

 

[palewin]

I tested brand new toyo holders quite a few years ago and found them to be non standard depth. I don't remember the full details now.

However, that doesn't mean they aren't any good. It means that providing all your film holders are the same depth and your GG is adjusted to the correct depth, then everything will be fine. But if you are swapping makes of holder from one shot to the next you could have problems.

But be warned, before you start adjusting anything be 100% sure that you are correct about your assessment of what is causing the problem. i.e. double check and treble check and then check again.

And note that film is never 100% flat against the back of the film holder. It can flop forward a bit, especially if the camera is pointing down.

RobC: I'm certainly not looking for an argument (I've never measured any of my holders) but I have used Toyo holders for a long time (2 decades?) and never had a problem; I have also shot with a combination of Fidelity and Toyo holders, and never seen a difference in the negatives between the two. I know that over on the Large Format Photography Forum where I spend more of my time than on APUG, lots of us consider the Toyos to be the best holders out there.

 

[paul_c5x4]

I was just measuring the ground glass position and depth of the holder to film emulsion position from the camera frame as reference and there is a 1mm difference.
I.E. The ground glass (which is the correct way around) is 3mm depth to the edge of the frame to the frosted side (the side that faces the lens) of the glass.
If I measure the holder the holder depth is 2.7mm and then add the film that takes it to 2mm. Meaning the film emulsion is closer than the GG has focussed.

I suspect you are measuring from the wrong reference point (or you have set you calliper zero incorrectly). If you pop the back off the MPP, you should see four square(ish) pads (see attached image). Measure from one of these to the glass, and it should be 4.85mm to 4.90mm[1] - The glass will move if you apply too much pressure, so care is needed.
Note: In this orientation, the ground surface of the glass will be facing you.

The film holders should measure ~5.00mm (+/- 0.178mm) to the septum plate. See this page for specs: http://home.earthlink.net/~eahoo/page8/filmhold.html

Note for others: The older MPP cameras with the spring backs did have a non-standard film plane distance. The later models (including the OPs Mk VIII) used international (Graflok) backs, so film plane distances shouldn't be an issue.

[1] Archived page from the MPP user club: http://web.archive.org/web/20070814060433/http://www.mppusers.freeuk.com/registers.htm

 

[apugnumpty]

Thank you all for your replies.

I have taken a few pictures to hopefully illustrate what I mean.

http://www.bright.vg/MPP_VIII_and_Film_Holder/

These include pictures of the FP4 film (Fielity Holder) and Kodak Ektar (Toyo Holder)

I don't have measuring callipers but a mm ruler so I might be +/- .05mm

I still think I am 1mm out somewhere. Though I could be wrong.

Below is what I have. See the link for more detailed pictures.

 

[Steve Smith]

It looks like you need to shim the ground glass so it is the same distance away from the highest point of the frame as the film is from the top surface of the holder (if I am reading the notes on your pictures correctly).


Steve.

 

[paul_c5x4]

I don't have measuring callipers but a mm ruler so I might be +/- .05mm

I still think I am 1mm out somewhere. Though I could be wrong.

With a good quality steel rule, the best you can hope for is +/- 0.25mm. Any parallax errors will also throw your readings right off.

I do think your measurements are off - The film holder you measure to the septum as 5mm - Close enough. Then you say film thickness 0.3-0.52mm. Nope. FP4+ is coated on to an acetate base of 0.11mm thickness.

It may ne possible that your ground glass is off, but it really needs checking with a decent depth gauge. If it needs shimming (which I have my doubts), you will need accurate tools.

If you find yourself in my neck of the woods (Norfolk), drop me a note and we can sit down with some tools and check things out.

 

[RobC]

+1

you need a micrometer to measure depth and be able to use it properly.

your loupe must be focusssed on the etched side of the GG. For that it must be a focussable type loupe and not the fixed focus type which is focussed only on the surface its resting on.

As I said, you must be 100% sure of what is causing the problem before trying to fix it. It could be GG depth but then again it might not be. You must exhaust all other possibilities before altering GG depth because if you've got it wrong it'll won't work and be a real bugger to put it back where it was before you changed it.

 

[RobC]

You have a rangefinder on that camera. have you tried focussing with that?

Also, with a decent GG you should be able to focus on the GG by eye. It should pop into focus. Some replacement GG which claims to be brighter actually makes focussing more difficult because it doesn't pop into focus.

And do your focus tests on something a reasonable distance from the camera (more than 3 meters), doing them on something close up requires you to extend the bellows and that increases the depth of focus making it more difficult to determine whether the focus is to the front or back.

 

[Gimenosaiz]

+1

...
your loupe must be focusssed on the etched side of the GG. For that it must be a focussable type loupe and not the fixed focus type which is focussed only on the surface its resting on.
...

Hello!
Please, can you explain this? I've got one of this:
http://www.magnicenter.com/media/ca...5d08d6e5fb8d27136e95/c/u/cuentahilo10x4_2.jpg

Thank you!
Regards