[dionhouston]

Hi all,

(Apologies for anyone also on Cameraderie).

I recently purchased a negative scanner on Amazon that is rather underwhelming, so after some searching I found a system for scanning negatives with a DSLR. Printables

This appeals to me as it's pretty easy to print a tube, it looks relatively easy with good results. The question I have, though, is whether the lenses I have will work. These two lenses have a "macro" mode -- but it appears that the minimum focus distance is far enough that a negative doesn't fill the frame. Obviously, I can crop, but that seems to defeat the purpose.

Has anyone tried doing something like this? Any suggestions?

Thanks!

[AstroDave]

Well, the obvious suggestion is get a macro lens! The somewhat older Pentax-F 100mm 2.8 comes highly recommended: SMC Pentax-F 100mm F2.8 Macro Reviews - F Prime Lenses - Pentax Lens Reviews & Lens Database Looks like you might snag one for a couple hundred bucks. Maybe even better - check Ebay.

Cheaper by far would be extension tubes. You can get away for a few dollars if you are willing to go full manual.

[JohnMc]

I'd suggest shopping for a used manual focus true macro (1:1) in the 70 to 120mm range. You don't really need AF or AE for this application. Once you establish your set-up, changes shot to shot are minimal to none, depending.

[Not a Number]

Yes, as suggested before you should get a dedicated macro prime lens. Macro mode on a zoom lens usually means the lens can close focus under 1 meter and magnification can be around 1/4 to 1/10th. Not really macro.

[K2 to K50]

I have an old manual late 1970's Pentax 50mm Macro lens (manual focus - which is fine for this use). I suspect you could find second-hand versions of this lens for around $350.00 or less. It is a very sharp lens, and would be a cheaper option than buying the current model 50mm or 100mm Pentax Macros (I do also have the current model Pentax F2.8 100mm Macro - incredibly sharp).

I used to use it for exactly what you are talking about here - copying slides. But I had (in fact, still have) a Pentax Bellows with a film/slide holder. Sometimes used a flash for lighting, sometimes outdoors pointing the set-up at a white sheet in direct sunlight.

[dionhouston]

Thank you so much everyone already!

You've confirmed what I suspected that macro mode isn't truly macro. There is still a lot to macro photography I don't quite understand so wanted to confirm.

Unfortunately， I've recently spent quite a bit on lenses so I promised the CFO (my wife) no new lenses for a while. I think I'll see how the quality of the cropped image is - since the camera is 30 megapixels, it might still be better cropped than my Olympus. Or maybe see if there's an OM-K adapter (my true macro is OM).

Thanks for the quick response!

[calsan]

Can you still return the scanner to Amazon (Due to poor performance?)
If I were your CFO, I would permit cash return on the scanner to be used for an old macro lens. Also, you end up owning LESS stuff with a macro lens, so that's something you could defend at a board meeting with your management.

[dionhouston]

Can you still return the scanner to Amazon (Due to poor performance?)
If I were your CFO, I would permit cash return on the scanner to be used for an old macro lens. Also, you end up owning LESS stuff with a macro lens, so that's something you could defend at a board meeting with your management.

Thank you for making my day That is a _really_ good idea. I'll be honest I'm one of those guys that stores love because returning stuff is such a pain in the butt I generally don't do it - but it was 95 Euros... Hmmm... I did see some on eBay for less than $100...

[othar]

Old macro lenses sometimes only offer 1:2 magnifications (like the M 50mm f4 macro), but if you use it with an APS-C camera this will be enough for your purposes, because of the smaller sensor size.

As mentioned above can you also increase the magnification by using extension tubes, this might work for negative scanning with the F 35-70mm lens (I could try that this weekend and report back ), but I have doubts about the A 70-210mm lens, as zoom lenses tend to produce good sharpness in the centre of the frame for the whole zoom range, but edge sharpness usually decreases at the long end of the zoom range (where the macro option usually is offered).
This is often no problem when you photograph insects or flowers and so on, but when you fill the frame with a flat negative this (and possible field curvature in the focusing area) might become an issue.

[dionhouston]

Old macro lenses sometimes only offer 1:2 magnifications (like the M 50mm f4 macro), but if you use it with an APS-C camera this will be enough for your purposes, because of the smaller sensor size.

As mentioned above can you also increase the magnification by using extension tubes, this might work for negative scanning with the F 35-70mm lens (I could try that this weekend and report back ), but I have doubts about the A 70-210mm lens, as zoom lenses tend to produce good sharpness in the centre of the frame for the whole zoom range, but edge sharpness usually decreases at the long end of the zoom range (where the macro option usually is offered).
This is often no problem when you photograph insects or flowers and so on, but when you fill the frame with a flat negative this (and possible field curvature in the focusing area) might become an issue.

Good to know! I think in the short term I'm going to try high res mode with the 35-70mm. I'm not sure if I'll be able to get everything together, so definitely would appreciate your trying it out if you have time. Thanks for sharing about the 1:2 -- it would definitely have been bad if I had bought a lens and it worked similarly to the one I already had. And roger on the extension tubes -- I don't currently have any in K-mount, but I'll look into that too.

And sharpness is overall a thing with the 70-210mm - it isn't terrible, but it's clearly from a time where zooms were not as mature as they are today.

[Jonathan Mac]

1:1 macro can be reached with a normally 1:2 macro lens using an extension tube.

I'm awaiting delivery of a system for "scanning" negatives with a digital camera and will need to see which lenses it's compatible with to get the most out of it. It's essentially a JJC-branded copy of the Nikon product to do the same thing.

[dionhouston]

1:1 macro can be reached with a normally 1:2 macro lens using an extension tube.

I'm awaiting delivery of a system for "scanning" negatives with a digital camera and will need to see which lenses it's compatible with to get the most out of it. It's essentially a JJC-branded copy of the Nikon product to do the same thing.

That looks really interesting! It looks actually like a commercial version of the 3D printed project, but with a light source, which seems handy. Let me know how that goes!

I'm also looking for extension tubes -- only ones I've seen so far are manual only, which is OK in this case - but wouldn't mind autofocus in others...

[othar]

I'm also looking for extension tubes -- only ones I've seen so far are manual only, which is OK in this case - but wouldn't mind autofocus in others...

AF is in my opinion not awfully helpfull for macro work (from what I've already seen with my F 35-70mm lens with magnifications only around 1:4 on my K-3) and, as far as I know, not available in any extension tubes that are not custom made.
I usually choose the desired magnification and focus by moving the camera closer to (or away from) the subject when doing close-up or macro work.
Contacts to allow the use of lenses without an aperture ring, or using lenses when the aperture ring is set to "A", would be desirable, but those are expensive (deglassed teleconverters are a somewhat cheaper alternative).
Beware of some very cheap extension tubes that don't even have an aperture lever, they would be a pain to use.
Some older extension tubes also have black coating on the lens mount, which might prevent your camera from stopping down the lens; but this can easily be fixed with some sandpaper

[JohnMc]

This (or similar)


amazon.com : 58mm Macro Reverse Adapter Ring for Pentax K PK mount : Flash Adapter Rings : Electronics?tag=pentaxforums-20&


and a 50mm manual lens on APS-c would (possibly) likely perform well in a static copy set up and be quite affordable since you can use any brand glass with suitable filter size. While you don't have to have a dedicated light source/shooting stage having one or being able to maintain a set-up for large batches takes a lot of work out. It's mechanical copy work. Aperture is set for max DoF before lens diffraction kicks in, say f8 and exposure generally will vary on film bases only. Need to (re)focus is dependent on reliability/stability of your set-up and flatness of film.

[dionhouston]

Thanks everyone! I played around with it a little bit last night.

On the Pentax side, I tried @JohnMc 's suggestion -- a little bit of nostalgia because when I was a kid I remember how excited I was that I could reverse the lens and get super close. It does in fact fill the frame. I'm tempted to get the adapter regardless just because it's fun I think on the other end I'd need to print something that takes the camera mount and sends it out a tube. Doable, but probably would take some time to design.

I also tested my OM macro on my Olympus, and it worked pretty well. The aspect ratio is slightly off - not terribly so - and frankly shooting negatives with my Olympus is likely better than the scanner I currently have, but optimal definitely seems to use the K-1.

I ->am<- thinking it might be worth it to get an OM->K adapter. I'm a bit on the fence because I own all of one OM lens, and I don't use it very frequently (it's a bellow lens, so getting everything set up is an emotional event).

So... final thing to test is the 35-70mm, high res mode, with an extension tube...