Lack of Sharpness; need Help!

[gmfotografie]

hi my friends,

i recently started with large format.
after my first pictures i notice lack of sharpness.
watching my negatives with a 4x rodenstock loupe gives me also the assumption that my system is out of focus (acros100 in pyrocat hd manually-rotating development in jobo 3010).

i use a new chamonix 4x5f1 with fresnel lens.
when i look on the groundglas with my magnifier loupe, i always focusing the object.
i think this way should be correct?! or should I focusing the fresnel lens?

can you give me some tipps how can i find out step by step the source of error?

- should it be okay starting checking the groundglas focusing on a newspaper or something like that?
 does it frequently occur that groundglasses are out of plane?

- is it possible that a wrong pyrocat development cause lack of sharpness?

- is it possible that my lens is not exactly screwed on the lens-plate?

you see, a lot of questions for a rookie… maybe you can help me finding the error :-)

thx for help,
best michael

[TXFZ1]

Are you seeing the focus shift for all your lens?

Have you seen this? http://www.chamonixviewcamera.com/Fresnel_lens_problem_of_45N.pdf

David

[dave_whatever]

Are you seeing the focus shift for all your lens?

Have you seen this? http://www.chamonixviewcamera.com/Fresnel_lens_problem_of_45N.pdf

David

That applies to the old model, not applicable to the newer 045N2 or F1 cameras.

[gmfotografie]

yes both lenses... 150 apo sironar s and nikkor 300mm f9

[TXFZ1]

That applies to the old model, not applicable to the newer 045N2 or F1 cameras.

You are correct, I misread the OP.

David

[Tobias Key]

There are lots of possible sources. Are you experiencing a general lack of sharpness - in which case you have an issue with camera vibration, or are you getting front or back focusing which could be a number of things. First thing I would check is that you have the camera locked down adequately so that the rear standard doesn't move when you insert a dark slide. This is simple to do just set up the camera, focus, insert a dark slide, and pull it out to check focus again, if the image has shifted focus there is your problem.

An out of alignment ground glass is possible but you would have a consistent back or front focussing error. If you are new to large format I would look to rule out operator error first..

[Jac@stafford.net]

Did you install the Fresnel? Upon what side of the ground glass is it?

[gmfotografie]

thx!

i have a problem with general lack of sharpness!

first of all i check the right level.
i focus the subject, fxing the ball head and put in the filmholder. Then setting the aperture and use my cable release after pulling out the darkslide of the holder.


First thing I would check is that you have the camera locked down adequately so that the rear standard doesn't move when you insert a dark slide. This is simple to do just set up the camera, focus, insert a dark slide, and pull it out to check focus again, if the image has shifted focus there is your problem.

i will give it a try.


Did you install the Fresnel? Upon what side of the ground glass is it?
the camera shipped with a mounted outside fresnel lens

ps
i will post a picture later...

[Bob Salomon]

Are you at the optimal aperture of f22? Are you focusing with the lens wide open or stopped down?
Vibration at the tripod. Did you wait a few seconds for any handling vibrations to settle out before firing the shutter?
Vibration from handling the shutter. Do you have a long enough cable release so it isn't pulled tight when you trigger it?
Is your tripod and head substantial enough for a view camera?
Are you focusing your loupe on the grain of your ground glass? You do that by taking the lens off and placing the loupe on the top of the gg/Fresnel and adjusting the eyepiece until the grain of the gg is in sharp focus. Then replace the lens.
Lastly, is the gg properly installed? The grain of the gg must face the lens. And it is also possible that the camera was misadjusted at the factory if everything is equally soft with all lenses.

[Leigh]

i have a problem with general lack of sharpness!
That problem is not caused by your focusing technique.

Take a picture of a tree perhaps 20 feet away, with grass all around, from the camera position into the distance.
At some point the grass should be in sharp focus. If that's not at the tree, where you focused, then there's an error.

It sounds more like you have some kind of vibration, which will blur everything in the photograph.

I too have the 150mm Apo-Sironar-S, and it's sharp as a razor blade.

- Leigh

[Woodturner-fran]

1. Check your loupe is focussed correctly for your eyesight (if it has diopter adjustment) - check using newsprint or the etch marks on the ground glass. You really always need to check the focus on the ground glass with a loupe. This checks your own eyesight/focussing ability.
2. You could measure the distance from the lensboard to the inside of the ground glass. Then insert a DDS with a darkslide pulled and measure the distance again. The 2 measurements should be within 0.5mm of each (I think!). This checks whether the ground glass is in the correct plane.
3. Look at overall stability of your setup - shutter times are long for LF compared to medium format or 35mm. Lots of scope for shake due to wind etc etc.

[Mark Sawyer]

A misadjusted loupe won't make an out-of-focus image on the ground glass come into focus, it just makes it hard to focus your eye on the ground glass. As it's happening with two lenses, I'd guess either out-of registration ground glass (although something should be in perfect focus, in the foreground or back ground); a Fresnel screen mounted in the wrong place could also put the registration out of focus. It could also be an unsteady tripod, or something you're doing at the time of exposure that moves the camera slightly, like tugging the cable release when you press it, not using a cable release, using too stiff a cable release, holding the darkslide as a lens shade and letting it touch the camera...

I'd also hold your lenses up to a light and look through them backlit for haze, but it's not likely on two modern lenses.

You've got some elimination to do...

[gmfotografie]

Hi my friends,

i did a test shoot today without wind and try to do my best (following your advices).
I scanned with an Epson V750 without sharpening.

100% Crop
http://diefenwald.com/fotos/Test__001-413.jpg

http://diefenwald.com/fotos/Test__001-413o.jpg

I think the best way to show you the negative is doing a "normal" scan without sharpening.
Most of you are experienced looking at a V750 scanned picture... to less sharpness?!

[gevalia]

Ken Lee (poster here) has info on his web site about pulling in just the green channel when scanning. http://www.kenleegallery.com/html/tech/scanningGreen.php It may be your scanner setup. Oops, sorry, I just re-read your original post and you said you viewed your negatives using a loupe so the scanner platen height is not an issue.

[Andrew Tymon]

What aperture and shutter speed did you use when you made the image?

[pasiasty]

"Sharpness" is a subjective impression depending mostly on resolution (how minute details are recognisable in the picture) and local contract. I am afraid that using a standard film, standard developer and - last but not least - typical lens, you won't achieve much higher resolution than you did; and that there is no much purpose, unless you aim in printing huge enlargements to be seen from very short distance.

As for apparent (subjective) sharpness - you may consider either analogue or digital sharpening; the former using unsharp mask, the latter - using one of available algorithms, including digital unsharp mask.

[gmfotografie]

thank you for your help.

it seams to be that my very short cable release is the bottleneck :-)

i put my iphone on the camera and used the app -set my camera- with a movement control.
my 25cm iron cable release transfers every small movement. si i have ordered a 50cm in plastic design.. hope it will be better:)

best michael

[E. von Hoegh]

thank you for your help.

it seams to be that my very short cable release is the bottleneck :-)

i put my iphone on the camera and used the app -set my camera- with a movement control.
my 25cm iron cable release transfers every small movement. si i have ordered a 50cm in plastic design.. hope it will be better:)

best michael

I use a pneumatic release, it has a 1~meter long tube connecting the bulb to the slave cylinder which screws into the shutter. On some lenses I need to use an angled extension on the slave, to keep the cylinder clear of the lensboard/front standard, but it's worth it because the pneumatic arrangement transfers no motion to the camera.

[Lachlan 717]

I have 1m long cables on each of my lenses and tend to make sure they're hanging slack when shooting. However, I was watching Clyde Butcher shooting, and it looked like he was using a 30cm/12" release. So, maybe the release's length doesn't matter, as there's nothing wrong with the sharpness of his photos!!

[Leigh]

So, maybe the release's length doesn't matter...
The only factor that affects release length is the distance from your hand to the shutter when releasing it.

The release should hang slack. If it's pulled at all, there will be camera motion and problems.

- Leigh

[tigger_six]

Hi my friends,

i did a test shoot today without wind and try to do my best (following your advices).
I scanned with an Epson V750 without sharpening.

100% Crop
http://diefenwald.com/fotos/Test__001-413.jpg

http://diefenwald.com/fotos/Test__001-413o.jpg

I think the best way to show you the negative is doing a "normal" scan without sharpening.
Most of you are experienced looking at a V750 scanned picture... to less sharpness?!

That looks perfectly alright. You cannot expect significantly sharper scans from a V750 in my opinion.

[Lachlan 717]

The only factor that affects release length is the distance from your hand to the shutter when releasing it.

The release should hang slack. If it's pulled at all, there will be camera motion and problems.

- Leigh

My thought was that the movement/shake/vibration generated by pressing the release would be absorbed by a longer cable in the same way that a long rope or hose will absorb the wave of a flick at one end (http://www.youtube.com/watch?v=YPMbStWCjC4).

I still stand by this in principle; however, I'm just not sure of its relevance to reducing vibration in shooting IF other good shooting techniques are followed...

[Ken Lee]

That looks perfectly alright. You cannot expect significantly sharper scans from a V750 in my opinion.

Exactly !

Your detail section appears to be a 15-20x enlargement from 4x5. Some subjects appear sharper and will give more impressive results, but in general anything more than 5X with that scanner is likely to disappoint - and that's only if we use adequate sharpening.

You might find Scanning Tips (with EPSON and VueScan Software) (http://www.kenleegallery.com/html/tech/scanning.php) helpful.

[RandyB]

A few other things to consider: When you took the picture did you focus on the building or on the mountains in the distance? Was this shot with your 300mm lens? Longer FL lenses have less apparent DOF than shorter lenses at the same f/stop. How's your eyesight? If you have even a little eyesight problem a focusing loupe can hide incorrect camera focus by making adjustments for your eyesight variance. This happened to me when I got older and my eyesight started to go downhill. Eyeglasses may not correct the camera focus problem. In my case I have to use the bifocal part with the loupe to get correct camera focus, both LF and 35mm. The only exception is my Nikon F-100 which has the eyepiece diopter adjusted fully negative.

[Jac@stafford.net]

The issue is likely the scanning.

Look at the negative with a good loupe.

[rdenney]

thank you for your help.

it seams to be that my very short cable release is the bottleneck :-)

i put my iphone on the camera and used the app -set my camera- with a movement control.
my 25cm iron cable release transfers every small movement. si i have ordered a 50cm in plastic design.. hope it will be better:)

best michael

Even a short cable release can work, but there is a technique involved. Hole the cable release so that it make a complete U shape. With a short release, that may be uncomfortable, but that's what prevents hand motion from transferring through the release.

Rick "still working through the thread" Denney

[rdenney]

My thought was that the movement/shake/vibration generated by pressing the release would be absorbed by a longer cable in the same way that a long rope or hose will absorb the wave of a flick at one end (http://www.youtube.com/watch?v=YPMbStWCjC4).

I still stand by this in principle; however, I'm just not sure of its relevance to reducing vibration in shooting IF other good shooting techniques are followed...

Longer cables can transmit vibration quite as effectively as short cables, if the cable is pulled tight. The inner cable is in enough compression to take up all slack. Steel is quite elastic and does not absorb or attenuate vibration at useful frequencies.

The trick is to hold it in a U shape, which turns this column (when held straight) into what amounts to a string.

Rick "who learned this the hard way" Denney

[rdenney]

You can't tell about ultimate sharpness with a scan. You really do need a loupe and a light table. I use a 10x loupe on a light table, and my negatives are as sharp as my eyes can detect. If the detail you are looking at is significantly sharper on the negative than on the scan, you don't have a camera problem.

But I do think this is sub-par sharpness even for a V750. I'm seeing a hint of fuzziness even in the full image, which is a 2x enlargement on my monitor. My own results are much better, and I also use a V750 scanner. Compare that to this image:

http://www.rickdenney.com/Island/pump_lores.jpg

I don't have the enlarged details to show you that are at full scanner resolution, but I scanned this at 2400 spi. Even at "actual pixels" in Photoshop (a 24x enlargement), it appears just about as sharp as the monitor is able to display it. And this is color film, which is not as sharp as black and white. I can tell the difference between the focus plane and the portion of the pump that is well within the depth of field but not quite all the way in the focus plane. I used swing to bring the mouth of the pump and the handle directly into the focus plane, and the bolt head at the base is just about an inch outside that plane and I can see a hint of fuzziness at 24x there. I can see more detail than I could see with a 6x loupe on my Sinar ground glass (with Maxwell screen).

Some general points to consider if the negative looks no sharper than the scan you showed here with a 10x loupe:

- Check that you can focus the image very sharply using a 10x loupe on the ground glass. You have to see past the fresnel pattern (and not focus on it), and see the image itself right on the grain of the ground glass. If you can't find a focus point that is as sharp as you can see with a 10x loupe, then there is an issue with the lens or alignment, not with the position of the ground glass or any downstream process.
- If there is a focus point where you can see everything to maximum detectable sharpness using a 10x loupe, but the negative is not as sharp, then there are several possible causes: Ground glass in the wrong place, misalignment of the back when loading film, film loaded incorrectly in the holder, focus shift on the lens when stopping down (should not affect a modern plasmat, but I don't remember what lens you said you were using), camera movement during the exposure, or grossly suboptimal selection of the aperture. This thread has so far pointed out the first two of these plus camera movement.
- Camera movement is easy to see. The fuzziness will create a directional pattern--it will be fuzzier along one line that at right angles to that line. If the fuzziness is even in all directions (as seems to be the case here), then it probably is not camera shake.
- Focus shift is only a problem for convertible lenses with the front cell removed (such as using an old Schneider Convertible Symmar), or with some other archaic lenses where the aperture is not in the correct plane. If the lens is modern, it shouldn't be a problem.
- If you stopped down to f/45 or f/64, you will see a loss of sharpness at high magnifications caused by diffraction. This is a trade-off for when you need extreme depth of field, and the result is that you won't be able to print as large.
- If you made the image at f/8 (you said you stopped down, but you didn't say how far), then understand that even the best large-format lenses don't hit their sweet spot until f/22 (f/16-f/32 is the best range). That means long shutter speeds, which means camera shake is again a potential problem. You described how every jiggle of your hand transmitted through the short cable release--that tells me your tripod may be a bit floppy. You may need to be using a heavier tripod. Also, there are ball heads that are sturdy, but most are not that sturdy. Which one are you using?
- Make sure the film is loaded in the correct slot of the holder. We've all made the mistake at one time or another of sliding it into the darkslide slot instead of the film slot on the holder. The film should be in contact with the holder itself--if there is a gap it's in the wrong slot. Practice with waste film in the light so that you can see what I'm talking about.
- If the ground glass is in the wrong place, then try Leigh's experiment of photographing a target in the middle distance with a range of foreground and background information. A tree at 50 feet with good ground detail in front of and behind the tree is a good target. Focus carefully on the tree trunk with a high-power loupe. Use f/5.6 or f/8--that will limit maximum sharpness but it will tell you more precisely where the focus plane is--and it will let you use a faster shutter speed to prevent camera movement issues. If the sharpest part of the image is the tree trunk, then the ground glass is correctly installed and you didn't make any mistakes in loading film, moving the back when inserting the film holder, and so on. If the sharpest part is on the ground in front of or behind the tree, then the ground glass is not correctly installed (frosted side towards the lens), the ground glass holder is not seating fully in the back, or the film wasn't in the right slot. If the sharpness varies across the image, where subject at the same distance from the camera is sharp on the left but not the right, the camera is not correctly aligned.

If the negative is sharp but the scan is not, then understand that the stock Epson holder is not adjustible and may not be at the exactly correct height for the focus of the sensor. This takes some experimentation. Also, make sure you are scanning emulsion side down in the holder. Study Ken's advice on the use of that scanner. Use the holder for 4x5; don't scan directly on the glass. I was lucky--my V750 is right on the button with the stock holder, but that has not been the case for everyone.

I do not print my V750 scans larger than 4x, because prints are much sharper than computer monitors. But to get a print at 4x that is really sharp, it will need to be as sharp as my 100 pixel/inch monitor can display at 12-15x, just as you have displayed it here.

Rick "good luck" Denney

[Larry Gebhardt]

I use Gepe 8" cloth covered releases on my lens. No problems as long as you leave a bit of slack in it as you press the plunger. I don't like the plastic covered releases since they don't seem to allow the same amount of slack. The Gepe cloth ones are the best ones I've tested, and they are pretty durable.

[Kevin Crisp]

I've given up on any plastic covered cable release -- they are too stiff. A cloth covered one, that flops around, is fine for me even if only 12" long.

[gmfotografie]

hi guys, i few points from my experience...

for good sharpness i know using a aperture between 16 and 32 (depending on the lenses)

i also checked the film- to groundglass plane, see attachment; seams to be okay
105817 (from way beyond monochrome)

yes i had used a very light tripod in the past 3 months. now i switched to a manfrotto 190xprob.
cable release is very short. tested it with an iphone vibration check (set my camera app)
holding it in an u shape gives much better results; great tipp!

one thing that i want to mention:
i'm wearing glasses because of my nearsighted (~ -6 diopter)
i uses only a 4x lupe
i don't have a light table

best michael

would be great to have a very sharp negative for comparing.
is it possible to get some test negatives?

[rdenney]

In my experience, 4x is not enough for focusing 4x5 accurately, and though my eyesight problem is astigmatism rather than being near-sighted, I still need more like 6 or 7x to focus accurately. For this testing, I'd use 10x, though you'll have to fight the Fresnel pattern and ground-glass grain a bit with a 10x loupe.

Rick "who fights his glasses when using a LF camera" Denney

[Jac@stafford.net]

In my experience, 4x is not enough for focusing 4x5 accurately, and though my eyesight problem is astigmatism

Rick I appreciate that you mentioned astigmatism. Our collective experiences probably cannot help to find the correct loupe magnification. Individuals must try and find for themselves. I have profound astigmatism and my eyes cannot be corrected to 20/20. A high power loupe is useless to mr. 5X is just right.

It is a strange experience we all live.

[gmfotografie]

so i don't have an astigmatism, just nearsighted ... i will give 10x loupe a try. can send it back.
got a lighttable for free...

[Harley Goldman]

Do you know anyone who can give your gear an independent test and see if it is the gear or something you are doing? It would only take a sheet or two to see if comes out soft.

I use a 4x loupe and don't have any sharpness issues, unless I forget to check a corner or some other oversight (which happens semi-regularly).