View Full Version : Off Topic: clear details enlarging 13-fold?

19-May-2005, 09:21
What is the conventional wisdom on the maximum enlargement factor which will retain reasonably sharp details? Yeah, I know opinions will vary, but I wonder if there is a generally accepted answer or range, and if not, what you folks personally think.

The issue arises for me over a 35mm color negative that looks great enlarged 6x, and I'm deciding how much larger to go. Twice as long should satisfy me. I'm using a lab which makes experimentation pricey.

Image was shot in bright sunlight with a Widelux, and is in sharp focus with lots of small details. Due to an unavoidable emergency, it was shot on Kodak's consumer 200 film, I believe it is named Gold.


David A. Goldfarb
19-May-2005, 10:02
How pricey is a 5x7" test print at 13x from a critical area?

jose angel
19-May-2005, 10:42
I usually enlarge 35mm Velvia 100F to 1 meter wide, it is around 27x magnification. I like it scanned and (Lambda 130?) printed on photographic paper. Grain is noticeable but not disturbing thanks to that process (and to the divine hands of my lab tecnician, thought). Detail is absolutely fuzzy at 2ft., but the prints looks colourful and very nice as soon as you can see the whole image.

Iīm afraid Gold 200 could have a very huge grain; as David says, you can ask for a test print on a small paper to see the results.

Obviously, high enlargements from 35mm format are not a detail issue. Content, mesagge, colour, harmony and other subjects must be the reason of the print. Donīt worry about little details. I never hear anybody mentioning sharpness looking at this kind of prints: usually, comments are related to colour saturation, composition, even about the meaning of the image (usually so funny things in this topic!).

19-May-2005, 10:45
No duh! as my teen-age daughter would say, if I had one. That's the correct and blindlingly obvious answer. I'll do it. Though I'm still curious how big others enlarge...

Leonard Evens
19-May-2005, 10:56
The degree of tolerable enlargement depends on the resolution in the source and the distance from which the final print or other image will be viewed.

It is generally agreed that anything less than 5-6 lp/mm viewed at about 10-12 inches will not appear sharp. Some poeple would put it even higher, perhaps 8-10 lp/mm. But if you get back further, then less resolution in the print would be acceptable, propotionate to the viewing distance. Thus, at 20-24 inches, you might get away with half what you would need for closer viewing.

Few 35 mm film images, not made under special circumstances, are going to do better than about 60 lp/mm, and probably not that well. That would seem to put a limit of about 10 x enlargement for 35 mm or proportionately more if you can be sure viewers won't be getting really close to the print.

Bruce Watson
19-May-2005, 12:35
As Leonard says, the rule of thumb is about 10x. This will vary according to the film and processing; some slow small grained films may do well at 12 x or higher, some fast films that are push processed may do worse, for example. More depends on the image, your intent for it, how viewers will be viewing it, etc.

I've seen some 35mm Tri-X enlarged to 40x60 inches that looked pretty good. I've also seen some 35mm Tri-X enlarged to 8x10 inches that looked pretty bad. Basically, the only real answer is "try it and see" because clearly YMMV.

Richard Littlewood
19-May-2005, 12:57
I've enlarged some 35mm half-frame negs on HP5 and TRI-X to 40 inches wide. The grain is staggering! There is though, a lovely quality to the image from this. The biggest problem is the neg popping in exposure and making 'zones' of soft grain. Image detail seems to reveal more also, - wait a mo, this isn't anything like large format, better move along now.

Gene Crumpler
19-May-2005, 14:51
The film stock is the limitation. I've made some 16x20 prints from 35mm Tech Pan that shows little grain and good sharpness. I used a 55mm micro-nikkor which is blazingly sharp.

Gold 200 is too grainey for much of a blow up. I used Kodak Supra in 35mm for several years and could get a low grain digital print at 8.5x11. At 11x14, the image pretty much fell apart.

This is reason that I abondoned 35mm and now work in MF and LF!

Neal Shields
19-May-2005, 15:13
I totally agree with Leonard.

Everything I have read and tests that I have run, lead me to the same conclusions.

The best research that I have seen on this is published in Ctien's book "Post Exposure".

Also the book "Image Clarity" deals with this in more detail than most people would want.

Alan Davenport
19-May-2005, 15:46
Though I'm still curious how big others enlarge...

I usually make quick inkjet prints at 2x. If I really like a picture I go to 16x20, that's a 4x enlargment. Maximum I will go to is 8x for a 30x40 print.

Obviously not using 35mm here, I've become a believer in the axiom, "There's no substitute for square inches."

19-May-2005, 15:54
2' x 3'. About $15 at Wolf/Ritz Camera centers (such a deal). Beyond that it gets a little pretentious.

19-May-2005, 19:43
When I had a shop the enlargement was (apart from the price limitation) governed as much by the size of the faces in the composition. the 5x7 'proofs' were fine for what they were but for portraits enlarged to 8x12 (full frame) *looked* a lot better due as much to the ?bloom? if you will, given by the softening due to enlargement. 11x14 were ok also but 16x20's were best only when the size of the faces in the image required it, to see those peary whites. Full face shots were taken to 20x24's only to be viewed from the street. All this with mid range equipment using supra and PJ100. All ordinary stuff. Finer equipment and film of course would offer improvement.
For what it's worth an increase in format size sort of equalled one size enlargement. ie. 16x20 in 35mm equalled 20x24 in 6x7 format.

John D Gerndt
19-May-2005, 20:02
I believe one can see (I know I can consistantly) the difference in a print with 30lp/mm and one with 10 lp/mm. Depending on circumstances I enlarge between 2x and 6x. I prefer to stay under 3.5x, thus the large format camera...

I agree with Jose Angel's last paragraph. For me though, 35mm cameras are for capturing news or making postcards. Big prints from 35mm look like bad paintings.


19-May-2005, 20:31
Here's another thought: I have a 6x print and a 7x loupe. If I look at the print with the loupe, shouldn't that give me a hint of what it will look like at 13x? Well, I just tried it, and boy does it look mushy. Assuming this technique has any validity at all, it confirms for me that 10x is a good ballpark limit, since the 6x to the eye looks impeccable, but louped to 13x it is bad.

Pete Caluori
19-May-2005, 20:36
About 10 years ago I had a cheap 20x30 print (cost $10) made from a 35mm consumer film neg and the resulting print was awesome. I gave it away to a good friend that helped me move thinking I could have another one made, unfortunately I have not been able to reproduce it; this includes trying myself and having a very capable printer try it. The conclusion I came to is one of two possibilities: it was done digitaly or multi-stage enlarging.

I would think that a carefully made digital scan, skilfully manipulated might be able to produce what you're looking for, or a larger format interneg then a large print.

If done traditionally, I think a well make 4x5 interneg of the 35 mm neg then enlarge the 4x5 neg to the desired final output might do the trick. Finding someone with the skill to do such a feat might be a more difficult challenge these days.

If conventional means fail, then I would seek someone with sufficient digital skills, but either way you're looking at eeking the maximum quality out of your source and that won't come easily or cheaply. Good luck!

Regards, Pete

Mark Erickson
19-May-2005, 21:02
Based on some wall-sized Franz Lanting enlargements that I saw at Calypso Inc in Santa Clara, I have to agree with what Bruce said above: it really depends on the image. Images that rely on a crisp feel for their punch are going to fail if you try to enlarge them and look up close. On the other hand, some images have strong graphic content that withstands fairly close inspection even if they are large.

Frank Bagbey
19-May-2005, 22:31
It was routine for me to make 16x20 enlargements from Kodak TriX 35mm negatives and then sepia tone the prints. Some of the best prints I have ever made. From around 3 feet away you could not even see the grain. Several shots, however, were done over in 8X10 negative size just to be doing it, not really because the grain from the 35 bothered me. I also routinely made 35mm copy negs from 16X20 originals onto PlusX film and then made 16X20 prints. This process was a little more grainy but still great at three feet. I think the most important factor is the viewing distance and most importantly, I realize these are all relative terms.
In other words, what is grainy to one may not be very grainy to another. Ideally, I make 4x5 copy negs with Ilford FP4 if the original is large enough to make it worthwhile.

Some of the best portrait photogs around make 20x30s are so from even Fuji 800 Pro, and the quality is fantastic. If you cannot do that, I would worry about who is processing your film!

Terence McDonagh
20-May-2005, 07:59
I'm going to have to pull out my math books. Wouldn't a 7x view of a 6x enlargement give you a 42x view of the image?

20-May-2005, 09:07
Terence, I suspect the loupe is designated in square size, and I was talking about linear size. I don't know if it is the math or coincidence, but the square root of 7 is in fact the factor needed: 14" x 2.646 = 29.1", in the ballpark of the target size, 30", if the number means anything.

Its gotten to the point where I crave some closure on this issue, so I will do the 5x7 test print, hopefully teach myself something.

Image contains a junkyard, where steel is recycled, from car-sized on down, next to some railroad tracks and swooping freeway overpasses, so nice sharp edges are crucial.

Thanks to all.

Bruce Watson
23-May-2005, 11:11

IIRC, magnifications add. So a 6x on top of a 7x is a 13x, not a 42x.