Looking for accurate focus

AlexBC · Jul 25, 2017

Hello,
I am using an RZ67 Pro to photograph flower still lifes and I'm getting just a little tired of racking the focus back and forth hundreds of times to focus on the very subtle petal edges. I've always used a Peak x8 loupe instead of the popup hood loupe, but that doesn't seem to help much for fine flower stems and soft petals.

I normally do urban landscapes where the camera is set to infinity, so focusing on a vase 6 feet from the camera is all fairly new to me. I recently made a number of images of plates of food, but I always focused on sharp plate edges or knife blades and used a deep depth of field. I love the camera, but focusing accurately on soft organic details (without hard lines) is tedious if I want to use a shallow depth of field. I bought a focusing screen with a microprism dot in the middle that will probably help some, but I'm wondering whether a different camera with a traditional viewfinder would be easier all together. That said, I've been told numerous times that the viewfinder hood for the RZ67 is dim and makes focusing harder, but I've never used one. Like I said, the camera is fantastic and I'll happily use it for most of my work, but stems and petals are giving me trouble.

Any advice on a different camera system or techniques would be much appreciated!

btaylor · Jul 25, 2017

I find that sometimes using a high powered loupe can actually make finding exact focus harder for me, that the image doesn't "snap in." Viewfinder hood makes the image more dim? That doesn't make sense to me, it doesn't put anything in the light path other than a magnifier. I don't think you are going to find any accurate viewfinder other than a reflex system, which is what your RZ has. It might help getting an aftermarket Brightscreen or similar if brightness is an issue for you. You might also try different magnification loupes and see what works best for you. My preferred macro focusing screen is a plain groundglass.

RalphLambrecht · Jul 25, 2017

AlexBC said:
Hello,
I am using an RZ67 Pro to photograph flower still lifes and I'm getting just a little tired of racking the focus back and forth hundreds of times to focus on the very subtle petal edges. I've always used a Peak x8 loupe instead of the popup hood loupe, but that doesn't seem to help much for fine flower stems and soft petals.

I normally do urban landscapes where the camera is set to infinity, so focusing on a vase 6 feet from the camera is all fairly new to me. I recently made a number of images of plates of food, but I always focused on sharp plate edges or knife blades and used a deep depth of field. I love the camera, but focusing accurately on soft organic details (without hard lines) is tedious if I want to use a shallow depth of field. I bought a focusing screen with a microprism dot in the middle that will probably help some, but I'm wondering whether a different camera with a traditional viewfinder would be easier all together. That said, I've been told numerous times that the viewfinder hood for the RZ67 is dim and makes focusing harder, but I've never used one. Like I said, the camera is fantastic and I'll happily use it for most of my work, but stems and petals are giving me trouble.

Any advice on a different camera system or techniques would be much appreciated!

I suggest to make yourself a focus target, which is any small object with sharp-edged lines.Lace it into the scene, focus on it and remove it before making the exposure.This makes focusing somewhat easier without spending a lot of $.

chassis · Jul 25, 2017

Good suggestion from Ralph.

There is an accessory magnifier loupe for the RZ/RB prism. I use it and it is good. Even with the loupe I do the in/out focusing procedure.

If you want shallow DOF then there will be some fiddling. It's a manual focus camera and takes more time to focus than an electronic camera.

AlexBC · Jul 25, 2017

By dim, I mean that the eye level finder (in some situations) is much harder to focus than with the waist level finder that I use. That's just what I've been told, I've never used it.

The focusing target is a pretty fine idea. That might be the easiest for the time being.

jeffreyg · Jul 25, 2017

I am under the impression that you are using a waist level finder. If so check out a prism finder such as a 90 or 45 degree finder. If dimness is the issue a strong flashlight to help when focusing. Depth of field might be related to the focal length of the lens so perhaps a longer lens from further away from the subject. Most flower petals have some texture so shining the flashlight from an angle might accentuate the texture. A piece of thick black thread lain over the petal you want in focus to focus and of course removed before making the exposure.

http://www.jeffreyglasser.com/

Sirius Glass · Jul 25, 2017

Use a prism finder.

voceumana · Jul 25, 2017

You might try finding a chimney finder--I like it for such types of shots.

MattKing · Jul 25, 2017

A chimney finder makes the biggest difference for me.
The AE Focusing Hood is designed for the RZ67 Pro.
I believe that you can also use the PD Magnifying Hood designed for the RB67.
The additional advantage is that both provide you with through the lens metering - no more bellows extension compensation calculations.

jim10219 · Jul 25, 2017

Use a dark cloth. Dark screens are the reason large format photographers use them, and are the best solution to that particular problem, especially if you have the camera mounted on a stationary tripod. Spend a minute under one to let your eyes adjust, and bring it around the screen if necessary, and the dim light shouldn't matter anymore.

Focusing screens are usually a lot rougher than film will be, so they won't show sharpness as well as the final shot will. Sometimes I find them hard to focus on, even with a loupe, if critical focus is necessary with wide open apertures. Especially if my eyes are tired or blinded by bright light. For those circumstances, I usually just swing the focus back and forth against the object I want, trying to find the points in front and behind the object where I can just barely notice it being out of focus, and then set the focus to exactly half way in between those two points. Sometimes it's easier to tell if something is out of focus than in focus. So I try to use that to my advantage.

AgX · Jul 25, 2017

A complete different approach from the above that all circles around the camera would be to introduce a focusing target:

Make a target appropriate to you, mount it on astand with flexible stem, put it on the table with the vase and shove it around until the target is in a plane you consider best. Focus on the target, then move out of sight. Be careful not touch any leaf and be aware that under strong lighting a blossom might move meanwhile.

Maris · Jul 25, 2017

I do botanical close-ups with a Mamiya RB67 and I find that racking the focus back and forth is not the easiest or best way of focussing in the macro range. Once I have set the repro ratio I move the entire camera back and forth to focus on the detail I want. Alternatively, if possible, I move the subject to bring in the detail.

The problem with all front focussing cameras, Mamiya RB67 and RZ67 included, when doing close-ups is that racking the lens back and forth changes the magnification ratio and also the distance to the subject. It is possible to rack through the entire focussing travel of a camera and not get focus at all, just different size blurry images.

Harry Stevens · Jul 25, 2017

I would have thought that flowers would look better slightly soft, sharpness is not everything honestly.....Well not to me anyway.

RichardJack · Jul 25, 2017

Hi,
Just my two cents. Buy one of those focus testers that are sold on the web for about $25. Focus the way you normally do or try different screens and finders. Use a fine grain film and a shallow f-stop and perfect exposure of course. The purpose here is to check your camera body focus. Sometimes with age the angle of the reflex mirror changes slightly and what you think your focused on is not. Once you confirm that there are no issues with body focus try other variables and through the process of elimination determine what works best for you. Your vision is even a factor
Rick

TheRook · Jul 26, 2017

AgX said:
A complete different approach from the above that all circles around the camera would be to introduce a focusing target:

Make a target appropriate to you, mount it on astand with flexible stem, put it on the table with the vase and shove it around until the target is in a plane you consider best. Focus on the target, then move out of sight. Be careful not touch any leaf and be aware that under strong lighting a blossom might move meanwhile.

A few times I've used a laser pointer to create a small, very bright target to focus onto. Works best in dim light conditions.

grahamp · Jul 26, 2017

It is probably worth checking that your own vision is properly corrected. If you have astigmatism in particular you may find fine detail or soft contrast subjects hard to pin down. High contrast items are easier. Screens with focus aids on them (even grid lines on LF) are useful because you can check that you can focus the boundary of the focus aid. If you cannot do that well, you will not be able to focus the camera.

btaylor · Jul 26, 2017

I like Ralph's focus target idea, it reminded me of another trick I used when shooting films. In those situations I would often be checking focus just before rolling with the lens stopped down, tough in low light. A Mini Mag Light with the lens removed provided a sharp point of light that was easy to see. I would have an assistant place it right at the plane of desired focus. Worked great.

Lots of great ideas here!

RichardJack · Jul 27, 2017

The advantage of a purchased target is they are built like a pyramid with a distance scale at an angle. This will show you where your actually focused. You can do this yourself using a meter/yard stick placed at a 30 degree angle and marking the mid point with a bright red marker. Focus on that red line and see if that is the sharpest point (when you examine your negative). If you have a problem your focus will be short or long of that mark. The next step will be figuring out why. I had a problem several months ago, focus was perfect in the viewfinder but my focus was off. I was because the rubber bumper under the return mirror was worn and it changed the angle of the mirror. It's very unlikely a lenses focus will change unless it is dropped, 95% of the time it's the body (focus screen or mirror).
best of luck

M Carter · Jul 27, 2017

This is interesting to me, because (at least with the RB) the popup hood with the magnifier popped in is focus heaven for me. I have a prism, but it's darker and not as magnified. When I use that on people, I throw up a 650 fresnel with a footswitch for checking focus with the prism, kind of a trick from the 4x5 product days.

YamanoteE235 · Jul 29, 2017

I actually just got lucky and purchased a vertical split focusing screen for my RZ. I have the standard focusing screen and was having the same problem you are with general focusing. I would constantly be overshooting then undershooting the focus just to make sure it was 100% sharp.

Hoping the split focus screen will cut that back drastically. It took a little bit for one to pop up on eBay but it eventually did when I wasn't looking! There's a Beattie intenscreen up there right now as well but it's about $129. You can set an alert for your searches so you always know if one pops up. I'll try to get some photos of mine once it comes in. Might be worth looking into if you want to stick with the RZ.

AlexBC · Jul 30, 2017

Thanks all for the suggestions. I decided to buy a gently used PD prism with a flip up magnifier so I can get the camera into a more comfortable angle and try focusing with that. I use a light meter for every shot so I didn't need any AE functionality. Luckily the camera body and my lenses appear to focus accurately as I've never had issues when inspecting my negatives/slides and making prints. Checking those variables is good advice though.

I am intrigued by the idea of a laser pointer and may try that, as the red dot turns very, uh, sharp when it is in focus for lack of a better descriptor. I find that for delicate flowers that my old flash light method just washes out the details of the petals (as I don't like to use modeling lights when I can avoid it and generally sit in the dark like a bearded bat), but a pointer might be a little smaller and easier to confirm through the ground glass.

That said, as several of you have pointed out, many of the problems would be eliminated by just spending a little more time allowing my eyes to adjust to the flowers through the finder before starting to fiddle with the focus. I also appreciate that the dof and distance to the subject will change, but my backdrop is a simple gray so those changes are not that obvious or concerning in my case.

Thanks everyone. Keep shooting film!

AgX · Jul 31, 2017

A correction lens added to a finder make work wonders too...

AlexBC · Aug 6, 2017

After receiving the prism and magnifier, I am pleased with the results. The microprism dot on the ground glass is nicely enlarged so I can quickly and accurately focus on the center subject. even when the subject is off center, the viewfinder with magnifier gets me closer than putting my loop onto the ground glass and with less eye strain, too. I must say that in my opinion the prism viewfinder is very poor without the magnifier and very difficult to verify accurate focus if a shallow depth of field is desired.

If I'm shooting outside, the waist level will be my go to so I can quickly focus and verify my framing. When I'm using artificial light in my basement studio, however, the prism finder and magnifier is more accurate. Modeling lights are definitely required as there is a noticable light loss, but I can do that without too much annoyance.

Thanks everyone!

mfagan · Aug 6, 2017

As I consider myself still a beginner (despite the grey hair), I ask this question of those having better knowledge of optics than me: if one uses the laser pointer method, would it be better to use a green rather than red laser pointer if there is focus distance difference that would matter? Thanks.

darkroommike · Aug 8, 2017

Something to consider: as your magnification nears 1:1 with any setup you should extend the lens to the desired magnification and then more the camera in and out until sharp focus is achieved. Many macro rigs have a focusing rail attached below the camera to smoothly move the camera in and out for sharp focus. RRS Really Right Stuff makes a very nice one.

Looking for accurate focus

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