Tri-X v HP5+ and Tri-X v Delta 400 - The Naked Photographer Comparison Tests

[Adrian Bacon]

Would the above then lead to HP5+ and Tri-X in the same developer, ID11, at the box speed and for the Ilford times for both films result in this let's say, apparent difference in shadow detail and box speed. I mention ID11 as Ilford gives times for both films at 400 so presumably ( but this is an assumption only) to the same contrast index.

It may make no difference but I could not find any Kodak publication listing both film for D76. Alaris give times only for Kodak films. I mention this only as an explanation why I have used ID11 in my question.

So can I ask that while this discussion proceeds along the specific lines of shadow details and contrast, will no-one else bother to make comment on the rights and wrongs of what KA apparently ignoring times for other than Kodak films. I wish to avoid any chance of it becoming
a KA v Ilford discussion

Thanks

pentaxuser

Ilford's times do not produce the same contrast between the two emulsions. I've not looked specifically at ID-11 and these two emulsions, however, my experience with other Ilford developers have shown that the times listed between Ilford and Kodak films does not produce the same contrast when using Ilford's listed times for each emulsion. Ilford seems to work out the minimum development time needed to make zone one 0.1 density above film base plus fog if shot at box speed and the contrast is whatever it is at that time.

For example, in replenished Ilfotec DD, HP5 is listed at 7:00, 400TX is listed at 7:30. HP5 at 7:00 produces a G-bar of ~0.50, whereas 400TX is significantly higher contrast at 0.60. If you shoot HP5 at 400 and run it at 7:00 minutes, zone one comes out at 0.1 above FB+F. If you were to work out what time produced the ISO 0.615 contrast, exposing at 400 would produce a significantly higher density zone 1, whereas, with 400TX, it's already pretty close to ISO contrast and barely eeking out a zone one at 0.1 at 400 speed. To get a matching zone one with HP5, you'd need to expose it at ISO 500 or 640 if developing to ISO contrast.

This has very much been the case with most all of Ilford's times I've seen. They either work out a time that produces 0.1 above FB+F at box speed and let the contrast fall where it will, or they use an extant common time that is well known, and that contrast is whatever it is. Their development times do not produce the same contrast between emulsions.

 

[DREW WILEY]

Adrain - as a hired gun trying to best juggle other peoples exposures on a variety of films as consistently as possible using the choice of just one developer, you have a logical reason for your own perspective. And yours is the kind of service many people should simply revert to and avoid headaches. But for those who do want to optimize the characteristic of either a specific film by any means possible, or find the best complement to their own subject matter and esthetic taste, then one has to somehow get a grasp of the actual nature of the problem. And that has to transpire beyond mere speed rating mentality. I don't really care if they doing using some kind of Zone System mentality or more directly sensitometric modeling like I do, or just sheer bumps and bruises long-term experience, but no sweat and effort, no real quality. That fact will never change.

I will state that Ilford films like FP4 and HP5 are much more forgiving than high-performance products like TMax. Pan-F, however, has a very narrow scene contrast range due to its blatant S-curve. I use all these films. Each has its own ideal set of usages. Tr-X is more like the last living dinosaur, but does render its own special look.

 

[DREW WILEY]

Well, just by selecting just one developer and alleged speed point, there is an automatic skewing toward a particular end. Like I said, that might make sense as a commercial service, but inherently excludes an awful lot of pertinent details, and therefore simply cannot be objective in a wider manner. It is itself a form of optimization towards their own choice of standardized development, which potentially differs from one lab to another. In other words, if someone wants Adrian to process their film, then take his advice about how to expose it. Another lab service, with different processing machinery using a different developer, might reasonably set the parameters differently.

A lot of people on apug seem to want very simple generic answers. But in this case, they've gotten bogged down in misleading web chatter. You yourself participate in another forum where probably everyone involved is highly interested in personal image optimization, and we all debate about the best way to achieve that. But there are certain underlying themes actually tied to standardized practical densitometry, such as the popular Zone System, which I don't use anymore, but is still at least a kind of common-denominator lingo. I also participate in yet another forum where I'm probably one of the least technically-minded people there, and where the topic of optimization becomes a lifetime commitment. Those guys don't just use densitometers and film recorders and advanced laser printers for pillows every night - they design them.

So I take no issue with helping people enter the swimming pool gently, but am certainly not amused by those who try to assume the role of web instructors when they don't even seem to have latched onto the basics yet. And that syndrome is indeed symptomatic of the web and Utube era, more so than previously. Someday I might just gravitate away from this forum completely, and then they can party. The forum does at times get annoyingly amateurish and artsy-craftsy in the "just whatever" sense. But worthwhile elements remain, and just like you, I do tend to bounce back and forth.

 

[pentaxuser]

Drew, was your response to me answering my questions in #79 or that plus my # 83 and 84? I read it but I have failed to work what the answers are. Would it be possible to say what the hard sensitometric science says and if possible put it in relatively simple terms the way a medical expert might have to explain a diagnosis to the man in the street or Joe Public as you say in the U.S.

So if for instance as you say HP5+ is more forgiving that a high performance film like Tmax, is it more forgiving than Tri-X and how might this manifest itself in the nub of what we are talking about, namely, apparent better shadow detail than Tri-X but with less contrast?

Thanks

Adrian, I think you may be saying that HP5+ and Tri-X do exhibit differently at box speed in those developers you mention but you cannot speak for D76 as it isn't one you have used to use the example of ID11 it might be that the identical times of 7:30 for both will result in different outcomes for both films.

So is there a way of developing and/or using a different box speed for HP5+ from Tri-X that would ensure that the negatives were identical and this the contrast and shadow detail. The differences we see in scans of the negs taken in the same light with identical cameras etc are down to inherent differences in the films which can be but are not corrected to the extent that both films then exhibit identical characteristics

As you may have discovered I am attempting but struggling in this attempt to narrow down why there appears to be differences, if there are any, and why in simple terms they are there and what if anything a user might, if he so chooses, be able to do about them if he wishes to eliminate them.

Finally I was unsure if what you are saying is that there is "no such thing as a free lunch" in the sense that if both sets of negs of the same scene, same light etc were made to behave identically then this would have to be at the expense of shadow detail or contrast. In other words I cannot have HP5+'s better shadow detail and the improvement in contrast that Tri-X brings

Thanks

pentaxuser

 

[Lachlan Young]

in my own experience, using the same developer and actually working out development times to produce the same amount of contrast between the various emulsions, HP5 is the faster film by a solid 1/3 to half a stop compared to Tri-X. If you take that into account and adjust your exposure so that each film is developed to ISO contrast and exposed at the speed it has at that contrast, the two emulsions are very difficult to tell apart.

I've observed what seem to be the same speed/ contrast behaviours with ID-11/ D-76 and these emulsions as well. The main differences are largely that 400TX shoulders off the highlights a bit earlier than HP5+, but up until that point, if speed/ gradient are corrected for, the curves track very closely indeed. There are some other differences in terms of MTF/ visual granularity & colour sensitivity, but it isn't terribly hard to make HP5+ look quite 'Tri-X-like' and vice versa. Delta 400 seems to have closer highlight behaviour to 400TX (and similar shadow behaviour/ toe shape) but they have some midtone divergence in D-76/ ID-11.

I do wonder if Kodak chose not to use epitaxial structures in TMY-II (for example) because of what they saw as potentially unfavourable sharpness/ granularity/ latitude trade-offs in the Delta structure emulsions when exposures didn't quite land correctly.

 

[DREW WILEY]

Pentaxuser - many of these issues are indeed more easily apprehended by learning how to read curves themselves. I sometimes get flack about that on forums like this one whenever people don't realize that seemingly small differences in toe shape on tiny published graphs, for example, are in fact relative to logarithmic increments and have quite significant consequences in actual image reproduction. But let me try an analogy I have used before. HP5 is like an airliner very gradually rising off the runway before it attempts to dramatically attempt to climb at a more rapid rate. The gradual liftoff is like the toe of the film. It covers a lot of ground, but without much elevation distinction. Similarly, a longer film toe will bag quite a range of shadow value if adequately exposed, but not differentiate it very well. But something is likely to be there, even if not ideally usable. That's what I refer to as "forgiving".

Now let's take a film like T-Max. It was engineered to replace several prior films, so is especially amenable to development tweaking. But in terms of its typical characteristic curve, it's more like a jet fighter launching off an aircraft carrier. It lifts off and gains height very quickly. So it's like a film with a shorter toe, launching right up onto the straight line section of the curve faster. But with that short runway, it's not so forgiving. The deep shades will be better differentiated than with longer toe films, but if you're exposure is off, you're more likely to crash. Sometimes I do that deliberately - underexpose and overdevelop TMax to get bold totally black shadows. But if I try the same trick with HP5, I just get gradual blaah muddiness down there. The value separations aren't crisp. Well, there are ways to improve that in printing; but I'm referring to characteristics of the film itself.

But per film speed examples, I should really be comparing TMax 100 to FP4. Both have a long straight line section. But even though TMX100 and FP4 have similar box speeds, in terms of crisp shadow separation, FP4 needs a full more stop of exposure to push the deepest shadows up onto the straight line section of the curve, so in effect it is the slower of the two films if push comes to shove, By this I mean high contrast scenes. Under low contrast lighting, we don't need to be so critical.

Now on to Tri-X 400. It's somewhere in between in terms of its characteristic curve.. Most people addicted to it seem to rate it at 320 or less in order to boost the deep values up the curve and get better shadow separation. In those rare instances I shoot TX400, I am deliberately after an overboard look, and tend to shoot it at full 400 speed and even overdevelop it. Of course, that risks blowing the highlights out. But that's where staining developers like pyro come into play. Of course, when Kodak decided to keep Tri-X alive, yet let Super-XX and Plus-X go extinct, they needed some kind of marketing ploy attached to nostalgia, so came up with ads touting a alleged traditional combination of Tri-X and D76, both obviously their own products. But there was a bit of mythology behind that. Most of the people whining to keep Tri-X alive were actually contact printers using the sheet film 320 speed version of Tri-X instead, and developed it in pyro all along. Why? They were of the old "thick negative" persuasion. Significantly overexpose the negative to get excellent shadow gradation, then give full development, and end up with a very dense or "thick" negative actually quite hard to print except with special low-contrast contact papers like Azo. I think some of that mentality was counterproductive; but it can be hard to break old habits.

Hope I haven't been too wordy, and that this at least gives a partial view of what is involved. And I suspect that for most serious printmakers, D76 itself has been in the rear-view mirror for a long time by now. But it is a safe middle of the road formula quite suitable for beginners.

 

[DREW WILEY]

Sure Michael, I wouldn't be a bit ashamed to do that if it made any difference. I'm not intimidated by those kind of guys. I can print in their league any day of the week (silver, not platinum - I don't do that). Tice is a good example of making great prints the hard way. A thick negative guy. Another one is Roman Loranc. He is a religiously pyro/ Tri-x exclusive practitioner and does enlargements, but otherwise is also of thick negative persuasion, and I can easily point out when that works, and why, and when it backfires. So can many others. I've heard em say so. It becomes obvious. If it works for him, fine.... but sometimes it conspicuously doesn't, and the highlights are all blown out. No crime. But why would I want to repeat the same mistake, or endorse it? Another is Barnbaum. Good printer, but addicted to Farmer's Reducer as a prosthetic leg to the one he chopped off during film development. It could be avoided if he was open to new ideas. But that will never happen.

And there are good reasons why D76 has fallen from favor not only with printmakers but replenishment labs. It's not consistent unless one understands its idiosyncrasies. Where the heck have you been the last thousand threads about all this? Hilarious?? Are you really that far out of the loop? These issues have been widely discussed for half a century. Even Sexton, who was tasked and paid by Kodak to promote the combination of early TMax and D76 sought a better developer for his personal usage. There's a thread about that on the other forum just today. I haven's spoken with him in a long time, but he certainly isn't confined in a Kodak straightjacket unless that's his specific commercial assignment at the time.

So you might "begin" by not turning up your nose to me. Photographers a lot more famous than those mentioned in this little chat have actually bought prints from me, and treated me like an equal. I'm not claiming I am equal, but do know about mutual respect among serious practitioners. And at a certain point, the kind of ploy you're making with trying to beat me down with your own notion of hero-worship just shows a kind of artistic immaturity. It doesn't work that way.

 

[pentaxuser]

Thaks Drew I liked the analogy with the jet fighter etc but what I am trying to nail down is why it appears that HP5+ and Tri-X differ in terms of shadow details and contrast based on what is known about them scientifically or are you saying that your knowledge of both leads you to believe that what I saw in the various tests was simply wrong and that the two films apart form the picture taking were somehow processed wrongly either accidentally or deliberately.

So to simplify matters can I pose this question: If I expose both films to the same scene within seconds of each other cameras that are identical in terms of shutter speed and aperture and take it to a lab in the U.K. where one developer, ID11 is used and each film is given the time Ilford recommend for each film, namely 7:30, then when handed back to me there should be no difference in the negatives?

I just want to find out if under the conditions I mention above I will see no difference in the two sets of negatives so other than price there nothing to distinguish the two films.

If there is something to distinguish under the conditions I describe then what is/are these features?

As I saId before, I like a lot of "man in the street" film users seek the truth about various films' features and if possible seek as simple as possible explanation of why these difference arise so you are right a H&D curve is important and an explanation of what it shows but beyond that I for one may not have the time left on this earth to devote more time to the kind of in-depth knowledge that you speak of but I do desire to know if what I see on these test videos and here I am not including Greg's but only the ones that did as I described and shot various street scenes under the same lighting etc reveal a true difference and if not why not

Thanks

pentaxuser

 

[DREW WILEY]

I really wasn't trying to get you to overthink all this. Most people would choose between HP5 and Tri-X mainly according to overall appearance in print. The grain structure difference is generally the deciding factor in that particular set of options. I really love what the previous generation of journalistic photographer did with the gritty bold look of Tri-X, but that look doesn't fit my own work. And I'm not a journalistic photographer, and in that speed range prefer TMax 400. But where all this comes into play in reference to what I was trying to explain is that a film like TMax400 can handle deep shadows in high contrast scenes quite well at box speed of 400, whereas longer toe films like either Tri-X or HP5 are either a better fit to somewhat less demanding situations, or else need to be shot a lower speeds for sake of better shadow rendition. If you look at the popular Massive Developer Chart, you'll see examples that, with people exposing these at 320 or even 250 instead of 400. With TMax, that's rarely the case; most people shoot it full 400 speed. Among medium-speed films instead, FP4 is an excellent choice for high quality and sheer cooperativeness.

Sorting out fact from fiction in web content can indeed be challenging unless one is themselves so in depth in a particular field that they instantly recognize when something is fishy. Back when I wrote equipment reviews for glossy magazines they always paid me double because I did my homework, even dissecting gear to inspect the parts and digging up long-term maintenance information. All the BS fakers barely looked at things. Consumer Reports was among the worst, but it all depended on the specific party they had contracted with. But I was no camera expert. I did have the advantage of my older brother having sold Linhof and Rollei gear, with a good understanding of the three primary sheet films of the day and how they differed, namely, Super-XX, Tri-X, and Plus-X pan. Color photography was more my niche back then. And a Hollywood pro cameraman used to hang around the shop, who knew an awful lot about film and lenses. But a great deal I learned was the hard way, making mistakes until I figured things out.

Don't be afraid of experimenting, especially where relatively affordable roll film is involved. In my case, goofing up exposures was not a welcome option if it involved days on end of strenuous hiking in the mountains with an 85 lb pack. Some of those early 4X5 negs came out less than ideal, and it took me a long time to learn how to print them well. Within a couple years my negs were way more consistent. But I recommend sticking with just one film for awhile until you really understand it and can identify what you do and don't like about it, before moving on.

 

[Lachlan Young]

I just want to find out if under the conditions I mention above I will see no difference in the two sets of negatives so other than price there nothing to distinguish the two films.

The point is that you can make either sort of look like the other to a fairly large extent in terms of much of the characteristic curve if you pay attention to the small speed differences and develop them to deliver matching average gradients (though you'll have a hard time of it with HC-110 - which can deliver all sorts of atypical curve shape results between materials that can be much more readily normalised with D-76/ Xtol types of developer - but HC-110 is/ was not the reference developer at the design stage of most of the materials used for regular photography - though for some graphic arts materials it probably was) but there are quite a few differences that are visually perceivable, if not specifically identifiable to your heavily culturally conditioned ideas of Tri-X or HP5+.

 

[Stephen Benskin]

When it comes to sensitometry (speed, shadow contrast, highlight contrast, exposure scale etc. - all of the things falling under the general "tonality" moniker), you characterize a film, and compare films using:

1. Characteristic ("H&D") curves
2. Spectral sensitivity

Anything else is unreliable at best, involving too many variables and subjective impressions.

Example: If two films have the same ISO speed and spectral sensitivity, if one of them has more shadow contrast than the other, this will be evident by comparing the characteristic curves (the film with lower shadow contrast will have a longer toe). I've attached an illustration of this - two hypothetical films with the same ISO speed, the "red" one having lower contrast in the shadows, but also a lower threshold exposure. In common parlance, the red film would be said to have more latitude against underexposure relative to the blue film. The price you pay for that increased latitude is lower shadow contrast. View attachment 281624

Sorry Michael, I'm going to nitpick by saying that a fix density speed point isn't an accurate method for determining film speed. But I know you know this.

That said, I can't understand why anyone would create a sensitometric test and not plot it, or in the very least read it? Now there are other concerns that can be addressed. For instance, it looks to me to have been exposed using one of those x-ray sensitometers, which introduces a questionable element in that they do not use daylight balance, but making sure the films were processed to the same average gradient would be the first step in "comparing" films. Also, using a flash to shoot the test subject introduces a possible short term reciprocity situation which may not be consistent between the two films. Testing should be based on the conditions of the general usage of the film.

Was the color chart hand held in the actual tests? Angle of incidence equals the angle of reflectance. The values will be different depending on how it's tilted.

I stopped watching there.

 

[Raghu Kuvempunagar]

Now there are other concerns that can be addressed. For instance, it looks to me to have been exposed using one of those x-ray sensitometers, which introduces a questionable element in that they do not use daylight balance, but making sure the films were processed to the same average gradient would be the first step in "comparing" films. Also, using a flash to shoot the test subject introduces a possible short term reciprocity situation which may not be consistent between the two films. Testing should be based on the conditions of the general usage of the film.

Was the color chart hand held in the actual tests? Angle of incidence equals the angle of reflectance. The values will be different depending on how it's tilted.

Very valid concerns. Thanks again Stephen, I've been reading this whole week several posts of yours on sensitometry and immensely benefitted by them. I hope you and Bill can make the selected papers on sensitometry available again.

 

[grat]

The point is that you can make either sort of look like the other to a fairly large extent in terms of much of the characteristic curve if you pay attention to the small speed differences and develop them to deliver matching average gradients (though you'll have a hard time of it with HC-110 - which can deliver all sorts of atypical curve shape results between materials that can be much more readily normalised with D-76/ Xtol types of developer - but HC-110 is/ was not the reference developer at the design stage of most of the materials used for regular photography - though for some graphic arts materials it probably was) but there are quite a few differences that are visually perceivable, if not specifically identifiable to your heavily culturally conditioned ideas of Tri-X or HP5+.

Ah. And here's the crux for me personally, something that you, Drew, and a few others are overlooking:

How, as an amateur just starting out developing film, do I know all that?

I grok that knowing the response curves and the characteristics allows you to make these determinations and adjustments-- but you have to have a fair level of knowledge to get there. Me smart guy with computers-- chemical reactions with silver halide make Ogg brain hurt.

The equivalent would be me expecting you to know the optimum block size, cache size and file system to use to get the maximum performance out of any given type of application before I'd admit you knew what you were doing with Lightroom (or equivalent application).

I'm not sure Greg's videos aren't targeted at you, Drew, or a few others-- they're targeted at the guy who knows how to spell two, maybe three developers, thinks pyro is something that sets your film on fire (possibly for carbon printing), and rodinal might be about sculpture.

 

[Stephen Benskin]

Stephen, if you’re referring to my graph, it’s not a fixed density criterion. The two hypothetical films would have the same ISO speed rating (they both satisfy the ISO criteria in the same way). It was meant to illustrate how two films of = speed can render shadows differently.

I was just having a little fun. Of course I know why you used them as an example. i was pointing out just because two films both had a fixed density of 0.10 at the same log-H doesn't mean they had the same speed. The two examples don't appear to have the same ΔD. Thus the nit-pick. There's probably only about three people who might think it was fun.

 

[Stephen Benskin]

Very valid concerns. Thanks again Stephen, I've been reading this whole week several posts of yours on sensitometry and immensely benefitted by them. I hope you and Bill can make the selected papers on sensitometry available again.

Glad to hear it. I can't believe the thread on the papers was six years ago.

I was thinking about ic-racer's suggestion about an overview of the papers and there is a really good one. It's the sensitometry and tone reproduction chapters in The Theory of the Photographic Process, 3rd edition. Once the papers are available again, there is also my Defining K which walks through the photographic process from Illuminance to print, basically combining all the papers and plugging in numbers. Strangely, something I have never seen elsewhere.

 

[removed account4]

Ah. And here's the crux for me personally, something that you, Drew, and a few others are overlooking:

How, as an amateur just starting out developing film, do I know all that?

I grok that knowing the response curves and the characteristics allows you to make these determinations and adjustments-- but you have to have a fair level of knowledge to get there. Me smart guy with computers-- chemical reactions with silver halide make Ogg brain hurt.

The equivalent would be me expecting you to know the optimum block size, cache size and file system to use to get the maximum performance out of any given type of application before I'd admit you knew what you were doing with Lightroom (or equivalent application).

I'm not sure Greg's videos aren't targeted at you, Drew, or a few others-- they're targeted at the guy who knows how to spell two, maybe three developers, thinks pyro is something that sets your film on fire (possibly for carbon printing), and rodinal might be about sculpture.

hi grat
im the amateur you are talking about LOL
don't forget to have fun!
John

 

[Alan Edward Klein]

While those with darkrooms who develop their own film can argue over the niceties of each developer, photographers like me without a darkroom have to depend on the labs we use. We're stuck.

I've used North Coast Photo in Carlsbad California who uses Clayton F76+ developer which is similar to D76 Kodak. I've also used LTI Lightside in NYC. They use XTOL but will use other developers but have a $50 set-up charge when you don't use XTOL. All the labs push and pull at a dollar or two more.

In any case, the fine points of this discussion is pretty much beside the point to me., I just hope for decent developing and film returned clean, no dust, and protected in plastic sheets.

 

[Stephen Benskin]

They have the same delta D. That was the whole point. Same delta D (0.8) over the 1.3 log H interval from the speed point m. Same ISO speed rating, but different curve shape.

Okay, they looked different to me. I take my nit-pick back. Interesting fact, long toed curves need a higher CI to fit the parameters than short toed files. So the CI 0.61 doesn't necessarily apply.

 

[Stephen Benskin]

Sorry for the confusion. It was an illustrative example in response to pentaxuser’s question about how two films of the same speed might potentially elicit user characterizations such as one film having either better or muddier shadow separations/contrast than another, all other things being equal.

And in that respect, it was a good example to accompany your response.

 

[pentaxuser]

The point is that you can make either sort of look like the other to a fairly large extent in terms of much of the characteristic curve if you pay attention to the small speed differences and develop them to deliver matching average gradients

your heavily culturally conditioned ideas of Tri-X or HP5+.

Lachlan I am not sure what having heavily culturally conditioned ideas of Tr-X and HP5+ consist of nor what it is I have said that indicates I have such ideas. All I can say is that I have no ideas about Tri-X at all as I have never used it so have no pre-conditioned views. At the risk of sounding like a stuck record It was simply that I had seen several Tri-X and HP5+ film comparison videos by various presenters on YouTube where they had taken the shots under the conditions I had described and wondered if there was a reason why the conclusions they reached from the scans was that HP5+ had better shadow detail and Tri-X better contrast. I saw in those scans what they saw and agreed that HP5+ did appear to have better shadow details but lower contrast. This was, as I said, true in the vast majority of scenes. Where the shadow detail and contrast differences diminished to the point of insignificance it appeared to be in scene where the light conditions rendered the range of shadow to highlight smaller

So to try and make a straightforward answer easier I then asked a specific question which I'll repeat:
I am using the two films in question and have take identical shots in identical light conditions at identical apertures and shutter speed based on an accurate light meter reading for each scene. I have then developed both in ID11 for the same time as recommended by Ilford.

1. Will it be impossible to tell which negatives are which i.e. for all intents and purposes they are identical? It sounds from what I have quoted from your reply that they will not be identical but if this is the case then in using the Ilford times which are identical for both films are we to conclude that Ilford has given a time that matches each film to its maker's "aimed for" contrast rather than a time for both that matches Ilford aimed for contrast? If its the latter and the times ensure both film match Ilford's contrast gradient then doesn't that rule out the difference being accountable by a difference in gradient?

2. If it will be possible to distinguish the negatives, what will be the differences in them with respect to shadow detail and contrast?

3. If there are these differences what is it specifically that needs to be done to render the negs the same ie. what changes in speed and gradients and how might this be achieved?

So using ID11 and the same Ilford times for both film what changes to film speed and development time do you believe you'd need to make to one of the films to get it to match the other?

Thanks

pentaxuser

pentaxuser

 

[Stephen Benskin]

Kodak has a few very simple primers on this (how to read and interpret curves, and the characteristics of films). In my opinion this sort of basic understanding is a pre-requisite to discussing any sort of test or comparison by Greg or anyone else.

It doesn’t require much beyond that.

I would also like to address one of your earlier remarks about objections to tests of graininess being largely matters of nit-picking for more decimal places of precision. None of this (besides Drew’s stuff) has anything to do with adding more decimal places. It’s about directionality. If you draw a subjective conclusion that is directionally at odds with proven photographic science/theory, and you know there are several places in the test where things can go wonky on you, the first thing to do is check your results, even if you have zero trust in the statements made by Kodak or Ilford.

Absolutely. That's been a basic tenet of most of my posts over the last few years. Good testing is about good methodology. Just because instructions are followed (ie Zone System) doesn't mean the testing is good or the results are accurate. All aspects need to be questioned and correctly understood. And that takes a solid understanding of theory. BTW, the other tenet is people conflating exposure with film speed.

An excellent book on testing for resolution and grain is Image Clarity. I don't remember the author.

 

[Tom Kershaw]

An excellent book on testing for resolution and grain is Image Clarity. I don't remember the author.

This book: https://tinyurl.com/y27v9asp ?

 

[faberryman]

So using ID11 and the same Ilford times for both film what changes to film speed and development time do you believe you'd need to make to one of the films to get it to match the other?

Why do you want to know what you need to do to get the two films to match each other? It seems to me the question should be what do I need to do to optimize the quality of each film, and after having done so, evaluate their individual characteristics.

 

[Stephen Benskin]

This book: https://tinyurl.com/y27v9asp ?

That's the one.

 

[DREW WILEY]

Michael - I already discussed somewhere else one of the reasons TMax and TMaxRS developers were developed into addition to the very many already extant options, and it was for sake of a specific set of technical applications of TMax film related to color separations rather than just general shooting, although they of course marketed these new developers for general use too. And the seemingly modest improvements possible with this new developer were important in that setting. But the big color labs involved seem to have just reverted to their ongoing more affordable brews. In the context of this particular thread, all that is pretty much irrelevant.

And if this thread is just going to boil down to how to get the best results using a lab developing roll film for a person, rather than doing it themselves, then I'd just revert back to what I earlier hinted, whether a lab is using D76 replenished, or Xtol, or whatever, then I'd just go with their advice about shooting speed and then do a test roll with them, see how it turns out, and go from there. Since all of this seems to be in a small format context, whether 35mm or 120mm, any competent lab should be able to reasonably develop both HP5 or Tri-X to a similar contrast index. No big deal.

But with respect to grain and general look, Tri-X is apt to have a more gritty look, and HP5 more a blended large grain. Delta 400 is not a film I've explored much because I was quite disappointed with it early on. So if someone wants dramatically finer grain and acutance in a 400 box speed roll film, they'd have to shoot TMax400.