35mm negative scanner with best depth of field

[elek_ludvigh]

Hi All,

 

I have a Minolta scan elete 5400 which I love in every respect except for

depth of field issues. If a negative has the least bit of curve, the film

holder will not hold it dead flat and as a result the top and bottom of a

landscape oriented picture or the sides of a portrait oriented picure will be

noticeably less sharp (in big enlargements) than the center. The issue is not

camera lens edge sharpness, since if I manually focus the scanner on the edges

of the negative the edges will be razor sharp in the print with the center

significantly less sharp.

 

In a previous post regarding this issue it was suggested I modify my negative

holder with anti-Newton ring glass but I am very reluctant to do that as it

may just produce a new set of problems and would probably not work unless the

negatives were actually sandwiched between two layers of glass.

 

Anyway, what I am wondering is if anyone has found a solution for the Minolta

5400 or, what seems more likely, knows from personal experience if there is

any scanner out there for under $1000 that does not have this depth of field

problem and can render razor sharp scans from edge to edge with curved

negatives.

 

Thanks in Advance,

 

 

Jay Ludvigh

[john_brewton]

Jay, I also have a 5400, but have not had the problems you relate. You must be working with some very curly film! Even the curliest film I shoot, Efke 25, still does ok with the negative holder provided by Minolta. The glass layer approach is available for the Nikon scanners. Good luck.

[ronald_moravec1]

Reverse wind the 36 exp film strip for 24 hours or put the strips in a plastic nega files page under a book for two days. They will flatten. Scan immediately.

 

My leica enlarging lenses are not totally flat field. Best results are focus 1/3 to 1/2 the way from the center to the corner. I do the same with my 5400 and can see sharp grain corner to corner if I flatten the negs.

 

The only solution is a drum scanner and you do not want that investment.

[robert_k1]

I only scan mounded slides with my 5400. After messing with glass mounts, I found them too troublesome and settled with a full frame Wess mount AHX500A. It has pegs to keep the film *flatter*, and by focusing somewhere between center and edge, the scans are sufficiently in focus for my needs. Auto or manual focusing do not seem to make much observable or consistent differences.

[mike_r.1]

I've struggled with my 5400 too. The 'reverse wind, cut, sleeve, book on top' thing is my method too. Also, try not to leave the holder in the scanner any longer than necessary...I've found the heat tends to cause a bit of curl on the individual frames.

[JohnMWright]

I don't know if this will help, but I use Vuescan, and with it you can set the point of focus in the slide/negative. I usually set it about halfway between a corner and the center (and always over the details of interest), in the hopes that is the middle of any curvature.

 

I like Mike's suggestion for flattening your negatives too.

[mendel_leisk]

I'd concur with just about everything Robert K said, though the Wess Mounts won't be of help for strip film. Re his last sentence, I *have* found manual focus to be more spot on.

 

Commenting on John Wright: you can do off-center focus with Minolta Scan Utility, just not with the fully automated focus. That said, Vuescan is a great program, and it's manual focus will help you understand your film's topography.

 

One tip: if you are using the manual focus knob (best control imo) to do the manual focus, and have the emulsion face down when you load the holder, start with the knob at the counter clockwise extreme of it's travel and turn slowly clockwise. you will get *two* peaks of the indicator bars. As far as I can tell, the second one is at the emulsion, and will yield sharpest focus. The first is (I think) at the film back surface.

 

As to your orig question, I think the depth of focus on the Coolscan's is better than the Elite 5400, perhaps 50% greater. But I would explore all avenue to improve focus. Switching may help, but introduce new issues. Anyways:

 

* Off-center focus at compromise position: work at it, map the topo with Vuescan's manual focus, try different points and compare, panning around the images.

 

* Tension slide mounts like the Wess AHX500K: not only do they flatten the film (somewhat), but they also stabilize it, reducing flexing for duration of scan.

 

* Full manual focus at the "second peak": the actual emulsion, as far as I can tell.

[jtk]

Nikon V doesn't have Minolta's corner-to-corner focus problem with its standard motorized SR-21 carrier ... with the exception of curls at ends of strips.

 

FH-3 optional carrier handles that perfectly, but it's a hassle to use and nearly impossible to buy anywhere (listed on various European sites however).

 

The problem isn't depth of focus, it's film holders that were engineered by nitwits.

[robert_k1]

"I think the depth of focus on the Coolscan's is better than the Elite 5400, perhaps 50% greater."

 

Confused by this claim. Is this what you "think", or can you (or a reference) substantiate that the Coolscan's dof is "50% greater"?

 

Few (if any) posters here own both a Coolscan and a 5400. And I bet that among those who do, even fewer have done objective testing and comparison on both. I don't own both, but have tested both *only* for flares in the scans.

 

Let's stick with what we know from our own hands-on experience (or from references), and not spread any urban legend.

[mendel_leisk]

Robert, I exchanged a couple of slides with another Photo.net member who had a Coolscan 5000. As you probably recall, I have the the Elite 5400. His corner to corner sharpness with these slides was significantly better than my results.

 

This was before I commenced remounting with Wess AHX500K. With remounting, I'm happy with my results, but from this first-hand experience, I think the Coolscan has superior depth of focus.

[robert_k1]

Thanks. With that context, readers can decide for themselves how to interpret your test results.

 

BTW, are the scans raw and not sharpened? For this kind of comparison, every little thing counts.

[mendel_leisk]

My scans were not sharpened. I'm not sure but I think the coolscan 5000 scans were not sharpened either. I have both still. Also, I don't think the guy doing the Coolscan scans was doing anything special, just autofocus at center. On the other hand, I was compromise position focusing, very carefully.

[jtk]

Mendel and I have kicked this back and forth quite a bit. The issue is bad film holder design. Both Nikon and Minolta would be a lots better with hardened aluminum carriers, as standard with decent enlargers. I think Mendel accomplished flatness by mounting each negative frame in a Wess slide mount...fine for fanatics but maybe not for the majority.

 

Owning 5400II initially, Nikon V now, I did compare the two with the same film and found them equally sharp, though Minolta had center-vs-edge problems with normally curled film, and Nikon didn't (I don't remember either having problems with cardboard slide mounts).

 

Nikon's standard SA21 motorized carrier is focus-perfect across every frame, even with very curvy film...except for frames at ends of strips. Then the FH3 accessory holder is mandatory, and those are becoming extinct: one sold for $135 recently (list price was under $25), you-know-where.

 

"Depth of field" isn't right btw, it's "depth of focus."