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ICF data available


lost cat

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Saw today that Kolarivision has provided transmission the spectra for various ICFs that were mentioned as having been promised in the camera sticky.

 

http://kolarivision.com/articles/internal-cut-filter-transmission/

 

Looking at the charts my D40s are looking pretty good for UV but the Pentax *iST D and *iST DL really take the cake!

 

Also its my understanding both the D40 and the ist-DL use a sony 6.1MP APS-C CCD sensor. Both cameras were released at about the same time, do they use the same sensor?

 

https://en.wikipedia.org/wiki/Comparison_of_Nikon_DSLR_cameras

 

http://aflenses.net/id/cam/pentax-ist-dl

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Curves like these were indeed expected based upon practical use of the various models. D40x was known to be poor for UV compared to D40 or D70, for example.

 

However, the ICF curve alone is not enough to tell how the sensor itself responds to UV.

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Curves like these were indeed expected based upon practical use of the various models. D40x was known to be poor for UV compared to D40 or D70, for example.

 

However, the ICF curve alone is not enough to tell how the sensor itself responds to UV.

 

True. OTOH it does indicate which camera are NOT good candidates for unmodified UV imaging.

 

And that the Pentax *iST D and DL are promising candidates especially if they use the same Sony sensor as the D40/70.

 

Edit: The D40/50/70, Konica Monolta Maxxim 5/7D and the *ist DS/DL do indeed use the same 6.1MP Sony CCD sensor:

 

https://books.google...0dl&f=false

 

http://digital-photo...classic-review/

 

The Konica Minolta products were compared a few years ago by Alex H and found to be less sensitive to UV than the D70:

 

http://www.dyxum.com...9441_page3.html

 

Since the sensor is the same this lack of sensitivity is presumably due to a stronger ICF.

 

The Minolta cameras have the same CCD Sony sensor as the "good" Nikons as well as an in-body anti shake feature the others lack, as such Minoltas may be good candidates for ICF removal surgery for someone looking for a lower cost body with anti-shake for legacy lenses.

 

There is also the issue of the ease of achieving infinity focus using M42 lenses on Pentax bodies vs Nikon.

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The current asking prices for these Pentax bodies are very low, thus anyone so inclined can buy one or two and try them out for UV without ruining himself.
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And if you ever want to "go for it" with a really nice quality sensor for M42 lenses, I can highly recommend the Pentax K5 for conversion. I like it a lot. They can be found used at KEH.com. There is a very simple adapter insert for the newer Pentax digicams to convert them to M42.

 

On the unmodified thing --- I've used both un-modded and modded versions of some of the older digicams. Modded was/is always better. There is only a certain amount of savings possible in this UV photography game !!

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The current asking prices for these Pentax bodies are very low, thus anyone so inclined can buy one or two and try them out for UV without ruining himself.

 

Exactly.

 

Can M42 lenses yield infinity focus on Pentax K bodies?

 

And if you ever want to "go for it" with a really nice quality sensor for M42 lenses, I can highly recommend the Pentax K5 for conversion. I like it a lot. They can be found used at KEH.com. There is a very simple adapter insert for the newer Pentax digicams to convert them to M42.

 

On the unmodified thing --- I've used both un-modded and modded versions of some of the older digicams. Modded was/is always better. There is only a certain amount of savings possible in this UV photography game !!

 

Of course; however there is also a lot to be said for cheap, readily available entry level products that work right out of the box for those who aren't ready to "go for it" quite yet.

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Yes, both Pentax K-mount and M42x1 have a flange focal distance of 45.46 mm. The K-to-M42 adapter fits just inside the K-mount, so that the FFD is maintained. The adapter can be bought on Ebay or from Pentax. If you get an Ebay clone, just make sure it fits nicely with no gaps.

 

I have not tried in the past a Pentax *ist, but I did have either a K10 or 20 or 100 which worked well for UV. (Sorry, geez, don't remember which one as it was sold off some time back.) But it was converted. Point being -- Pentax has always made nice digicams. Easy to use, good menus, etc.

 

I recommend KEH.com for used camera bodies. They are reputable, friendly and their ratings are spot on.

 

BTW, the Kolari Vision folks are really nice - and responsive.

 

*******

 

Look further into old enlarging lenses for inexpensive UV-capability in the upper levels (approx 360/370 - 400 nm). I have an old Rodenstock Omegaron 50/3.5 and Omegar 75/4.5 which I picked up for a few dollars. And a Spiratone Flat Field Macro 75/3.5 which was $30 I think. They all shoot UV nicely because most typical UV shots are in the interval between, say, 365-400 nm.

  • Problem One with these enlarger lenses is that you cannot always predict the FFD from the mount.
    We have some FFD info in the Stickies.

  • Problem Two is that they do not always have a good way to fit a front filter.
    So fit rear filters to adapters or helicoids.

  • Problem Three is that some of them need a focusing helicoid.
    Go Ebay cheap from China which are Good Enough in almost all cases.

Now, even though you have to get creative with helicoid and adapters (or helicoid-adapters) and filter fittings for these old ELs, they are fun. I enjoy getting them kitted up and working in UV. Just call me Nerd-Girl !!! :D :D :D

 

And, even though you may have to purchase a helicoid-adapter for old ELs, such stuff is certainly re-usable as are step-rings and filter fittings.

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BTW, the Kolari Vision folks are really nice - and responsive.

 

 

Kudos for Kolarivision for providing these graphs! I wish more companies were so generous with their information.

 

The current asking prices for these Pentax bodies are very low, thus anyone so inclined can buy one or two and try them out for UV without ruining himself.

 

I ordered one tonight from Adorama for $81 shipped. :)

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Problem Three is that some of them need a focusing helicoid.

Go Ebay cheap from China which are Good Enough in almost all cases.

 

For use on tripod, good bellows are sometimes better option, especially with longer focal length lenses, as they will give a wider range of magnification.

Some bellows will also allow to adjust the camera position from horizontal to vertical without the need to "flip" the tripod head or use L-bracket.

Bellows that have integrated focusing rail are much easier to focus in close-up range.

 

They are bulkier indeed, but not always heavier than the big focusing helicoid.

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And if you ever want to "go for it" with a really nice quality sensor for M42 lenses, I can highly recommend the Pentax K5 for conversion. I like it a lot.

 

I should point out that the Pentax K-01 is essentially a stripped-down, mirrorless version of the Pentax K-5 ... and much more cost-effective. Thus, if one wants access to the same exact high-quality images that the K-5 produces (including the generous ISO range of up to ISO 25,400, with surprisingly low-noise and very usable images up to ISO 12,800), but at a significantly reduced price for the same exact sensor and image-processing algorithms as the K-5, they can opt for the K-01.

 

Not to mention, the K-01 body is somewhat more compact and much lighter than the K-5, too. So, in a nutshell, the K-01 is the result of the Ricoh engineers cramming the guts from a K-5 DSLR into a stripped-down, rangefinder-styled and more minimalist package, for all intents and purposes. No mirror also means more quieter operation, too, compared to its K-5 DSLR big brother.

 

At $200 a pop, as of current Ebay prices, these K-01 "boxes" (the body is shaped like a brick, haha) are really a steal, in my opinion.

 

I've been very happy with my full-spectrum-converted K-01.

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Thank you for those ICF curves, Lost Cat. I think I will actually consider taking a hit on one of those used Pentax *iST bodies on Ebay, considering that I am already heavily invested in the Pentax-mount system, given the fact that this has been my primary shooting platform for paid / professional work over many years ... LONG before I got into UV / IR work.

 

(I have around 40 auto-focusing lenses of various focal lengths for the Pentax KAF-mount, and about 80 more manual-focusing Pentax K-mount lenses.)

 

So, I have nothing to lose, anyway, even if the UV performance turns out to be lacking. I can always turn the Pentax *iST investment into a "backup" / "supplemental" body.

 

(Yeah, as if I do not have enough "backup" bodies, as it is. Three K-20's, two K-5's, two K-01's, and four classic film bodies such as the K1000's and the Spotmatics.)

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Thank you for those ICF curves, Lost Cat. I think I will actually consider taking a hit on one of those used Pentax *iST bodies on Ebay, considering that I am already heavily invested in the Pentax-mount system, given the fact that this has been my primary shooting platform for paid / professional work over many years ... LONG before I got into UV / IR work.

 

(I have around 40 auto-focusing lenses of various focal lengths for the Pentax KAF-mount, and about 80 more manual-focusing Pentax K-mount lenses.)

 

So, I have nothing to lose, anyway, even if the UV performance turns out to be lacking. I can always turn the Pentax *iST investment into a "backup" / "supplemental" body.

 

(Yeah, as if I do not have enough "backup" bodies, as it is. Three K-20's, two K-5's, two K-01's, and four classic film bodies such as the K1000's and the Spotmatics.)

 

Glad to be of service :)

 

As I mentioned earlier I put in an order myself for a gently used *ist DL. Assuming the order goes through I hope be posting some comparisons to my D40 in a couple of weeks. I'm not sure how much sensitivity will be gained as the CCD may not be able to take advantage of the extra photons. I have a recollection of someone once estimating a gain of maybe half a stop to convert a D40 to full spectrum. OTOH infinity focus with M42 lenses will be a nice feature.

 

I am currently on a search for a QE curve for that Sony CCD. That will shed some light (pun intended) on the topic.

 

Update: Discovered the sensor in the D40/70 is a Sony ICX-453-AQ

 

http://radojuva.com....r-nikon-matrix/

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Why the DL, over the D?

 

Online available specs seem to show that the D model (although the prior model to the DS and DL releases) is the slightly more superior camera, in spite of it being the first-ever digital DSLR released by Pentax.

 

For instance, the available specs demonstrate (strangely) that the DL model had some features removed, compared to the prior D model ... such as offering only 1 custom-user memory bank, instead of 3 custom-user memory banks of the D model. Additionally, the AF has been downgraded to an anemic 3-point system in the DL, as opposed to the 11-point AF in the prior D and DS models. JPEG processing also seems to be somewhat worse in the DS / DL releases, compared to the prior D model. Even the image-writing buffer had been downgraded! (According to dpreview.com and a few other sites). Finally, they replaced the spectacular penta-prism found within the prior D and DS models with a cheaper penta-mirror for the DL model. That can make a big difference when manually-focusing with a darker scene. (Pentaprisms tend to produce brighter images in the viewfinder, compared to pentamirrors).

 

To add insult to injury, they also removed the Flash-sync PC terminal that the D model had (which is known to be an otherwise unique feature among some other Pentax digital bodies, by the way).

 

How odd, indeed, that they went backwards, with the majority of the DL specs as opposed to the D specs.

 

Finally, the ICF curves above appear to demonstrate that the D transmits somewhat deeper than the DL.

 

So, unless you got the DL for a drastically lower price point, compared to the D model, I am puzzled over your choice? :huh:

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EDIT: Ahhhh, well, going back to the ICF curves, I noticed now that the transmission peaks on the DL model are significantly higher, whereas they are somewhat deeper on the D model.

 

So, depth versus height, seems to be the only valid battle (with regard to UV performance), between the two models.

 

But, if we average out the two variables ... higher transmission peaks of the DL model, versus deeper transmission of the D model ... perhaps they would perform almost identically in real-world UV tests?

 

Otherwise, as stated, the DL seemed to take a step backwards from the D, in terms of overall capabilities / features. But you know what??? Maybe since I am interested in getting the D, and you are already getting the DL, then we can at least compare notes (and photo results). Hmmmmm. So, perhaps in real-world testing, as I stated, they would perform much closer in the ways that matter the most (UV performance), additional feature-sets be damned.

 

(Besides ... they both lack live-view capability on their LCD screens, right? Live-view via mirror lock-up on DSLR cameras did not become more widely-available until around the latter half of the 2000's decade, with Olympus and Fuji being the earlier innovators before the rest of the DSLR crowd caught up. So, with no live-view available on either the D or DL models, it will be an equal royal-pain-in-the-a$$ to adjust the focus for any focus-shifting between a VIS and UV photo composition.)

 

I suppose for a mere Benjamin in cost, we can overlook these shortcomings ... all in the name of science? ;)

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I'm not sure what you mean by the D having "deeper" transmission than the DL. The DL ICF has a near 100% between 375-425nm, 90% @ 350, 50% @ 325 and 20% at ~305nm. The D ICF shows the same depth to ~305nm but with less light getting through at all UV wavelengths (15% @ 305, 40% @ 325, 65% @ 350, 72% @ 375, 78%@ 400).

 

If anything I'd say they both have similar depth but the DL has at least 20% more UV getting to the sensor.

 

As to why I went with the DL rather than D all my lenses are either Canon, Panasonic, Nikon or manual focus only. I have no Pentax autofocus lenses and (at the moment) don't plan on purchasing any unless I can find some that work well in the UV. In your case the D is the better choice since you have many autofocus lenses to pair it with. I look forward to comparing results with you.

 

I will point out the DLis a bit lighter, and has a bigger, higher resolution screen as well. No Liveview but can at least one can see the image after its taken.

 

...that and I saw this DL in "excellent" shape delivered to my door for four Jacksons, that was hard to pass up :rolleyes:; however, looking at the completed auctions on Ebay the prices range quite a bit so perhaps more patience would have been warranted. Still for working, hopefully UV capable camera for "less than a Benjamen" its not too bad.

 

I still have hopes that the Helios 44 I bought last week for a "Roosevelt" will display the same UV capabilities and minimal focus shift as the Biotar it's based on. If not, well there are always the El-Nikkors...or Ebay.

 

And yes the lack of liveview is a total PITA. But its the same on my Nikons. I'm getting used to it.

 

Someday I will get around to converting my G5 and enjoy the bliss of UV liveview and video :lol:

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I'm not sure what you mean by the D having "deeper" transmission than the DL. The DL ICF has a near 100% between 375-425nm, 90% @ 350, 50% @ 325 and 20% at ~305nm. The D ICF shows the same depth to ~305nm but with less light getting through at all UV wavelengths (15% @ 305, 40% @ 325, 65% @ 350, 72% @ 375, 78%@ 400).

 

If anything I'd say they both have similar depth but the DL has at least 20% more UV getting to the sensor.

 

I went back and checked the two charts, yet again. Yes, looks like you're right. I got thrown off, because of the fact that the ICF data for the DL model had the transmission line stop a bit shorter (it got cut off), whereas the transmission line of the ICF data on the D model continued on for a bit more. So, that caused me to misinterpret the chart, by just staring at the lines themselves.

 

Good that you prompted me to give it all a second look-over. Thanks!

 

Of course, still doesn't change the fact that there is only ONE custom-user memory bank on the DL model, versus THREE of them on the D model. That's a big deal for those who like to store more than one custom-white-balance (CWB) setting in their user presets, so that one does not have to keep re-setting the CWB between shots of different transmission. That saves additional steps and time, too, especially when doing comparison shots between UV and VIS (or even a triplet comparison between UV, VIS, and IR).

 

So, yes, I'd still prefer the D over the DL. I like to have a more seamless workflow, with less hassle. :) To have the ability to set all of your custom-white-balances for each type of shot ... UV, VIS, and IR, and never have to do it again ... THAT'S a big deal for me. From that point on, just rotate through your custom user settings, for each composition, and boom. Easy-peasy. No constant fumbling with white-balance cards and targets.

 

(Unless, that is, the *iST series do not have an ability to set a "through-the-lens" custom-white-balance to begin with. If that be the case, then even I would consider the DL over the D.)

 

And yes the lack of liveview is a total PITA. But its the same on my Nikons. I'm getting used to it.

 

Someday I will get around to converting my G5 and enjoy the bliss of UV liveview and video :lol:

 

 

 

And you just have no idea HOW blissful that is. Especially when you get live-view through the EVF viewfinder, too. And not just getting it through an LCD after a mandatory mirror lock-up. What a huge BOON it has been for us UV shooters, for mirrorless cameras to have come on the scene. They are definitely the way of the future ... whereas the ol' slapping and clunky mirrorbox is on its way out. It's already singing its final "swan song" ... evident by how many companies are increasingly moving into mirrorless territory - even their Full-Frame models.

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Of course, still doesn't change the fact that there is only ONE custom-user memory bank on the DL model, versus THREE of them on the D model. That's a big deal for those who like to store more than one custom-white-balance (CWB) setting in their user presets, so that one does not have to keep re-setting the CWB between shots of different transmission. That saves additional steps and time, too, especially when doing comparison shots between UV and VIS (or even a triplet comparison between UV, VIS, and IR).

 

So, yes, I'd still prefer the D over the DL. I like to have a more seamless workflow, with less hassle. :) To have the ability to set all of your custom-white-balances for each type of shot ... UV, VIS, and IR, and never have to do it again ... THAT'S a big deal for me. From that point on, just rotate through your custom user settings, for each composition, and boom. Easy-peasy. No constant fumbling with white-balance cards and targets.

 

(Unless, that is, the *iST series do not have an ability to set a "through-the-lens" custom-white-balance to begin with. If that be the case, then even I would consider the DL over the D.)

 

 

I haven't gotten into IR - yet. For now this is a UV and VIS only camera so one custom and the stock WB should be enough for me. For now anyway.

 

Still couldn't you do the same thing on your PC with editing software?

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If you shoot RAW, you can of course alter w/b later. However, it is practical to have a w/b in-camera not miles apart from the one you end up with, in order to derive better information from the histogram shown by the camera and thereby evaluate your exposure. The reliability of this histogram is heavily dependent on the set w/b.
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Bill De Jager

If you shoot RAW, you can of course alter w/b later. However, it is practical to have a w/b in-camera not miles apart from the one you end up with, in order to derive better information from the histogram shown by the camera and thereby evaluate your exposure. The reliability of this histogram is heavily dependent on the set w/b.

 

That's a big mistake I've commonly made, leaving the camera on auto white balance out of habit (thinking in snapshot mode or just not remembering, period) when shooting in IR,UV, or for any even semi-serious visible-light photography. This is basic digital photography stuff that I've just seemed to have a mental block over. IIRC I finally started setting white balance for UV use sometime earlier this year, just before I stopped entirely for a while with my UV training. Assuming you can fix it in post is not a good working assumption. My efforts to get better initial data capture should include white balance as well as the other techniques and equipment I already strive to use.

 

New Year's resolution for me: Always check and consider changing white balance before starting taking photos, if there's time to do so.

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I haven't gotten into IR - yet. For now this is a UV and VIS only camera so one custom and the stock WB should be enough for me. For now anyway.

 

Those are not the only CWB settings that a UV shooter is concerned with. There's also "dual-band" compositions (such as stacking UG-5 with an IR-block glass) to obtain a simulation of "bee" or "bug" vision, and those require their own CWB settings.

 

Granted, I am just mostly playing "devil's advocate", here, because I'm not really going to use the *iST D for formal-quality photographs (my best or most demanding work) ... since the truth of the matter is that it is a vastly outdated camera (when all is said and done), and there are likely going to be more limitations than it is worthwhile to use it as my "go-to" device.

 

Still, one has to anticipate how a camera might "grow" with them, should they aim to expand their compositional pursuits. And there isn't much "growing" room to be had with a limited device such as the *iST series (nor any DSLR from the early 2000's for that matter). If that weren't the case, then all of us would still be doing our most demanding work with Nikon D40's / D70's, and otherwise. But many of us no longer do that, and for good reason. (Reason being: More capable technology is no longer so prohibitively expensive, and now within reach of even the budget-minded individual.)

 

Especially if there is only one CWB user memory bank, no live-view, and very little use of images going over ISO 800. It would be like me trying to enter an athletic event with one hand tied behind my back, when I can otherwise easily untie it and regain the use of a very capable second arm. (That I already have more capable technology, amid my existing arsenal.)

 

So, in other words, my interest in the *iST series for UV transmission falls more within the territory of novelty, rather than serious use. I'm certainly not going to use this camera to deliberately make things harder on myself, when I have no logical reason to do so. :)

 

Thus, out of sheer curiosity for how its ICF stands up to converted full-spectrum cams - in terms of UV response - would be my primary interest, and little more. It will probably start collecting dust, beyond that point (if I were to be honest with myself).

 

EDIT: Well, ok ... I might also consider using the *iST body for spur-of-the-moment (unexpected) use, by always keeping it on me (in my workbag that I take to work every day, or even my car's glove compartment, so long as it's not an exceptionally hot day). Meaning, a "bang-around" body, for less intensive and/or spontaneous UV photos that arise from unplanned opportunities.

 

Still couldn't you do the same thing on your PC with editing software?

 

Post-photo editing is certainly a powerful tool, but it should be thought of as a support tool, and not a crutch to lean on. As Bjørn pointed out, it makes sense to try to come as close to the desired image, in-camera, even before moving to the software.

 

Not to mention, not all software has a lot of headroom in WB manipulation in areas that fall far outside of "stock" WB algorithms, and that would cause one to burden their workflow even further, still, by adding in yet a separate piece of software just to attain the desired CWB.

 

For instance, I do the bulk of my photo-editing with Adobe products. But many Adobe products (even Photoshop products) fail miserably in matters of custom-white-balance manipulation when it comes to UV image processing. This, then, requires one to bounce back and forth between yet another piece of software (such as Photo Ninja), just to perform the desired CWB step to one's satisfaction.

 

Thus, if one can come closer to their desired CWB, in-camera, such pitfalls can at least be softened (if not entirely circumvented) within the photo-editing workflow process.

 

I am in line with Bill De Jager's sentiments: "Assuming you can fix it [all] in post is not a good working assumption."

 

For me, therefore, it is about being more efficient with one's workflow (because my time is highly limited). This may not be as big of a deal for others, but it's a big deal for me. So I admit that my points stem largely from my own personal preferences, of course. :)

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Those are our member Shane Elen's measurements of ICF filters. "-)

 

As mentioned from time-to-time, even the cameras like Nikon D70 or Pentax *istD which can transmit some UV/IR through their ICF filters will perform much better after modification. Just sayin' - so that we keep the information available to newcomers. Def not trying to convince everyone to spend $$$ on conversion until such time as they wish to pursue UV photography more deeply. :D

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It should be mentioned that the modification by removing the ICF indeed improves UV sensitivity of the camera, but at the same time, allows far higher sensitivity to IR. Thus the whole picture as it were has to be taken into account. Thus if a modified camera increases response in UV by 1-2 EV, and in IR by 5-6 EV, the problem is just shifted from the camera per se to the IR-blocking property of the filter(s) used.
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