On this page you will find pricing information and answers to Frequently Asked Questions about our CPU conversion services. For convenience, we have put the pricing information near the top of this page.
For information about our Clean, Lube, Adjust (CLA), repair, and “declicking” services, please see our Lens Services menu.
Please scroll down this page for details on the following topics:
- Cost of CPU conversion
- Advantages of CPU conversion
- Standard vs. Pro CPU
- How CPU-equipped lenses function on Nikon DSLRs and film cameras
- Modifying pre-AI lenses for safe mounting
- Limitations or issues with CPU converted lenses / body combinations
- Using converted lenses on both consumer and pro bodies
- Choosing a manual focus lens
- CPU focal length identifiers with zoom lenses
- Third party lens conversions
- CPU kits
- International customers
- Lead times
We have also created a User’s Guide for our customers who wish to change the programming parameters of their lenses. The User’s Guide covers some of the topics in our FAQ, below, and conveys information and recommendations about configuring the CPU.
Frequently Asked Questions
What is the cost of Digital Matrix CPU conversion, and how do you determine the cost of converting my lens?
From our research on Nikon lens design we have compiled an extensive manual focus lens database that we use to determine which variables apply when installing a CPU on a Nikon manual focus lens. The degree of modification required to install a CPU in your Nikkor lens will depend on the type of lens, series, era in which it was manufacturers, and sometimes the specific sample.
Generally, we can provide you an reliable quote based on a lens description and serial number. In some cases a photo of the lens mount is need for us to give you an accurate quotation.
We base CPU installation pricing complexity and time involved for the conversion, as follows:
LEVEL 1: requires minimum lens mount modification to accommodate CPU.
♦ Conversion pricing starts at $79.00
LEVEL 2: requires moderate modification to accommodate CPU.
♦ Conversion pricing starts at $139.00
LEVEL 3: requires significant modification to accommodate CPU.
♦ Conversion pricing starts at $199.00
LEVEL 4: may require extensive modification to accommodate CPU along with some customization or parts fabrication.
♦ Conversion pricing starts at $279.00
CUSTOM LEVEL: may require extensive fabrication of custom parts, including a custom CPU.
♦ Conversion pricing starts at $399.00
Basically, what are the advantages of the Legacy2digital Digital Matrix Chip conversion?
You can now take advantage of the millions of excellent quality manual focus Nikon F Mount lenses produced since 1959, and of which are still made today. Once CPU converted, these lenses can work with ALL digital Nikon SLR camera bodies with ALL exposure and metering modes (A, S, P, and M). Note: you may have to modify non-AI lenses to mount safely on cameras such as D40-90, and D7xxx, D6xx-8xx, and D2/3/4 pro level bodies.
Our CPU converted lenses are fully compatible with Digital SLR Nikon bodies. There is also full backward compatibility with manual focus Nikon film cameras (mechanical and electronic—though pre-1977 cameras require “ears” on the lenses for metering), and wide compatibility with autofocus Nikon film bodies from 90s and ’00 (note: we have not tested every AF film Nikon and a few models have limitations—see our Limitations section, below).
The Digital Matrix CPU allows very precise calibration of focus focus indication, similar to the setting adjustment for autofocus “fine tune” in prosumer and pro level Nikon cameras’ configuration menus. Our fine tuning is done entirely in the CPU.
CPU Choice: Standard or Pro
We offer both a Standard and Pro CPU. The main difference is that Standard requires you set the F-stop on the lens to minimum aperture (just as you would on an AF/AF-D lens) and use the Command Dial to set shooting aperture (or let the camera do so if you choose S or P modes); the Pro allows “classic mode” shooting: direct setting of aperture using the F-stop ring on the lens (in M or A modes). The Standard turns your manual focus lens into essentially a “G” Nikkor, in terms of setting aperture—which is always done using the Command Dial or by the camera.
The Pro CPU allows aperture setting using either the Command Dial or, when enabled in the camera menu, using the lens F-stop ring—but only on prosumer level Nikon cameras (D7xxx or higher) and only when aperture setting is enabled in the camera set up menu (under “f5 Customize command dials>Aperture settings>Aperture ring” – select “ok”).
Note that with all Nikon DSLRs that permit aperture setting using the lens, aperture setting using the F-stop ring is turned off by default and must be enabled in the camera settings menu to shoot in “classic mode” (using the lens F-stop ring). If the pro level camera is set to default (uses Command Dial), then the Pro CPU will operate with Command Dial for aperture setting, just as with the Standard CPU.
On Nikon DSLR Pro bodies with the Pro CPU two methods of aperture input are available: a) Command Dial or b) lens F-stop ring. This permits classic mode shooting using the Command Dial to set shutter speed, while the F-stop ring is used to select aperture. When the Pro CPU is used on consumer level Nikons (D3xxx – D5xxx), the only advantage is convenience: if the F-stop ring is accidentally moved from the minimum aperture, as can sometimes happen accidentally, the camera’s LCD displays a “FEE” warning. With the standard CPU there is no indication, but the camera’s metering system will not operate until the F-stop setting is again at minimum aperture.
Before deciding which CPU to choose, you should consider future Nikon body upgrades, your interest in shooting in classic mode, and whether you want to optimize pre-AIS lenses for exposure consistency (which requires a pro body as well).
For pro bodies with pre-AIS lenses there are some important advantages to the Pro CPU: the Pro CPU with pre-AIS lenses—such as non-AI, converted AI, and Nikon factory AI— provides exposure consistency across the full aperture range. See Limitations and Known Issues, below.
The Pro is a $35 upgrade over the Standard CPU.
In addition, we offer custom CPUs for some lenses, such as the 50 and 55mm 1.2 Nikkors, which require special or custom modification, micro-cabling, and other custom-fabricated parts. For these lenses, only the Pro CPU is offered and there is no upgrade charge.
If you have a consumer level Nikon and AIS lenses, the Pro CPU provides the convenience of a FEE warning, only. You should consider the Pro CPU if this convenience is important to you and /or you plan to upgrade to a pro-level Nikon, which is capable of using classic mode and the Pro CPU capability.
How does lens operation change from using a manual focus lens on my camera now?
WITHOUT CPU on consumer level Nikon DSLRs: If you own a consumer level Nikon digital SLR camera (e.g., D40-90, D3xxx, D5xxx), when you mount a manual focus lens your camera will not recognize the lens. The metering system will not operate at all, and no lens information is transmitted to the image file EXIF data. The camera and lens do not communicate whatsoever.
WITH CPU on consumer level Nikon DSLRs: After conversion, all metering modes operate (Spot, Center-weighted, and Matrix), the lens communicates EXIF data to the camera, and precise focus confirmation is indicated. AIS lenses operate fully with no issues. Non-AI, AI’d, and AI lenses function fully but have some minor limitations (see below) when used with Command Dial exposure input (mandatory on consumer level Nikons). Focus confirmation (light in finder) is achieved without changing any camera settings.
WITHOUT CPU on prosumer/pro level Nikon DSLRs: If you own a pro level Nikon camera (D200/300, D2/3/4, D6xx-8xx, D7xxx), your camera will meter with AI and AIS manual focus lenses, allowing use of Aperture Priority and Manual modes, and record EXIF data. However, proper operation requires that you first a) enter lens focal length and maximum aperture into the camera’s lens database and then b) invoke the correct setting when you use that specific lens. Shutter Priority and Program modes are non-operational. Lens aperture is controlled only by the lens aperture ring, not the camera’s Command Dial. Correct EXIF data depends entirely on both correct entry of lens information in the camera dbase and invocation of the correct lens when that lens is used. No information is transmitted electronically from lens to camera body.
WITH CPU on prosumer/pro level Nikon DSLRs: After conversion, all metering modes operate, lens EXIF data is stored in the CPU and transmitted to the camera when the lens is used. Precise focus confirmation is indicated and customizable. It is no longer necessary to use the camera’s lens database when changing manual focus lenses.
WITH CPU on all Nikon DSLRs: Default behavior for Standard and Pro CPU on all Nikon bodies, the lens aperture ring is set to and left on minimum aperture (e.g., f-16 or f-22/32). Manual F-stop is selected using the Command Dial on the camera or automatically by the camera itself at time of exposure (in S, or P modes).
WITH PRO CPU: Classic mode on Pro Nikon cameras (D7xxx or higher), and L2D Pro CPU, an lens aperture may be input directly from the lens aperture ring. Pre-AIS lenses with Pro CPU and camera set for aperture input provide linear F-stop control (requires camera configuration setting change).
Focus confirmation (green light) is achieved without changing setting on camera. Optional: for pro cameras, users may (or have us) program the CPU to trigger focus indication on camera focus switch “M” setting. All CPUs are set to indicate focus on “A” or default focus settings other than M on all cameras. This provides the greatest out-of-the-box compatibility. However, our user guide explains how to program the lens to change how this parameter functions.
Optional “focus trapping” configuration for Pro CPU: allows the autofocus system to determine point of focus for the lens before shutter will release.
There are many wonderful non-AI Nikon lenses available. But these will not mount on all Nikon DSLRs. How much is the cost of modifying a non-Ai lens for use on pro level Nikon?
Nikon’s lens compatibility is remarkable in that any F-mount lens can “mount” on any F-mount camera body. However, there are a number of interoperability issues, including potential damage to AF drive shaft and aperture tab on D7xxx bodies and higher.
Pre-AI lenses (mostly lenses built before 1977) have an aperture ring ridge that extends slightly below the bottom edge of the Nikon lens mount. This ridge can interfere with and potentially damage the aperture tracking ring and / or autofocus engagement drive shaft of DSLRs D7xxxx level and higher (and any Nikon DSLR that autofocuses with traditional AF lenses, such as D40-90, or meters with any manual focus Nikon AI or AIS lens, such as D200/300, D7xxx, D6xx-8xx, D2/3/4).
Nevertheless, pre-AI lenses may be used on all Nikon cameras without an internal autofocus motor and drive shaft (D40 through D3xxx, D5xxx). With minor modification to the aperture ring, pre-AI lenses may be used safely on all Nikon DSLRs (see below). Full aperture metering using all exposure modes is possible with non-AI lenses on all Nikon digital cameras only with a Digital Matrix CPU.
L2D Auto Indexing (AI) Conversion service: this is similar to the traditional aperture ring modification once offered by Nikon and other third parties for using non-AI lenses on cameras with auto-indexing (~1978 and newer)—except that ours does not have the second, small aperture scale required to show aperture setting in 70s and 80s era film bodies. Because ours lack this second F-stop scale, we refer to ours AI conversion as “eAI.” Our eAI modified lenses will convey F-stop information to all auto-focus and digital era Nikon bodies—but not to manual focus film cameras from the ’70s, 80s, and ’90s (note: our AI converted lenses will also safely mount on all film cameras from ’77 onward, but they will not convey F-stop setting information through the optical pickups on the underside of the camera’s prism. It is possible to add a scale to our eAI modified lenses to provide this feature).
Details of our eAI conversion: We machine part of the aperture ring to clear the AF drive shaft, and provide a notch in the aperture ring that allows it to couple to the aperture tracking ring on professional Nikon bodies and many older film cameras. But (as mentioned), we do NOT include a second aperture scale for use with old film camera metering systems though our conversion is backward compatible (you can mount the converted lens safely on ANY Nikon F mount camera).
♦ eAI Conversion for Nikon F mount lenses: $69 at time of CPU service; $89 when done separately.
♦ eAI Conversion for Third Part F mount lenses: Most are $69 (at time of CPU service) / $89 (when done separately). Some third party lens conversions are more complex than those on pre-AI Nikkors and can range up to $199 or higher.
Note: Our eAI Conversion does NOT include an F-stop scale, as with the classic AI conversion once offered by Nikon in the late 1970s. Our eAI conversion aims for compatibility with auto focus and digital era Nikon cameras. These bodies display f-stop information electronically in the finder, which makes a second F-stop scale, for optical read out, unnecessary. Let us know if you require a printed F-stop scale, as we may be able to provide one.
What limitations or known issues exist with the Legacy2digital CPU conversion?
Generally, L2D CPU converted lenses on Nikon DSLR cameras function essentially like an AF Nikkor, with the exception that they do not autofocus.
Some lenses, pre-AIS (1959-1977, and ’77-’80) have minor limitations (see # 3 below) on consumer cameras. The limitation is solved entirely with the Pro CPU and pro-level Nikon body (D7xxx and higher). AIS series lenses have no limitations and offer the widest compatibility with the greatest variety of Nikon DSLR bodies. All of the Nikon F Mount lenses, and most third part F mount lenses, from 1959 through present can modified to mount safely and to meter with ANY Nikon Digital F mount body, and all may be fitted with either our Standard or Pro CPU.
Film camera compatibility: Our CPU is 100% backward compatible with Nikon mechanical film cameras and any Nikon body (mechanical or electronic) designed for use with manual focus lenses (including Nikon F3). We have tested our CPU with a limited number of autofocus film cameras and find 100% compatibility with most bodies, including D80 and F100, but we have not tested every model; instead, we have relied on customer reports and feedback. Our customers report no issues with the F6, and we have users with the F4 who also report good success. Electronic focus indication (arrows in the viewfinder) may not function correct with the F5 (though it is otherwise fully compatible).We understand there may be some issues with correct F-stop display in the finder of the N/F90. Note: The feature set we’ve incorporated into our CPU has prioritized DSLR interoperability; our features include “focus trimming,” similar to the in-body, per-lens focus compensation adjustment of pro level DSLR bodies, and “focus trapping,” which allows the camera’s AF sensors to trigger the shutter at point of focus. These features have resulted in the few AF film incompatibilities noted here).
This section describes specific limitations or issues with some of these lenses and / or lens body combinations.
- Auto Focus—Our conversions do NOT add auto focus capability to manual focus lenses. However, we do offer a “trap focus” option, which may be especially useful with telephoto or macro lenses (the camera will not fire until the AF sensors detect correct focus).
- Pre-AIS lenses in Command Dial mode —Digital Matrix conversion pre-AI (~1977 and earlier) and AI (~1977-1980) lenses exhibit slight to moderate exposure inconsistency through the F-stop range (greater than 3 F-stops) when used with the Command Dial. Only the Pro CPU on a prosumer/pro level Nikon body (D7xxx or higher) offers optional direct aperture input and eliminates exposure inconsistency (requires Pro CPU).
- Non-linearity with non-AI / AI lenses and solutions—Exposure inconsistency with pre-AIS lenses (manufactured before 1981) is usually relatively minor issue, especially for RAW shooters. Nevertheless, the limitations are important to understand. The exposure issue does not stem from your camera’s metering system or from our CPU, but rather from the design of the lens aperture stop down lever (a stubby lever protruding through the lens mount, which the camera throws at moment of exposure to move the aperture from wide open — for bright viewing — to shooting aperture, for correct exposure). The mechanical interaction between the stop down lever and the camera body may result in non-linear F-stop increments, but usually not noticeable under less than a 3 F-stop range. For instance, identical exposures using a specific F-stop / shutter speed combination (e.g., F-2.0 / 500, F-2.8 / 250, F-4.0 / 125) may produce slightly different exposure results and histograms. Over a range of 3 F-stops or more, the total variation (cumulative) may be +/- ¾ to 1 stop or more variation. Through some initial trial-and-error and checking the histogram, our customers quickly learn the degree of variation. This is then compensates for either using the camera compensation control, Manual mode, or in post-processing. After you receive your lens and work with it for little while, you may note any exposure inconsistencies. AI-S lenses have linear F-stops and do not have the issue exposure issues described here with pre-AI, AI’d, and factory AI lenses.
- The simple solution (consumer and prosumer/pro level cameras using Command Dial)—Set your camera to Aperture Priority mode (A), select the F-stop you wish to use, and take a shot. Check your histogram. Dial in +/- compensation, if needed. You’re all set to work with your non-AI / AI Digital Matrix Nikkor. It is important that you first spend some time with your converted lens and determine how much, if any, compensation is needed at a given F-stop. In our experience this is not a lengthy process, and this issue one of the idiosyncrasies of working with this older lenses and our CPU conversion method. It is also important to note that many photographers use their lenses over a limited F-stop range, in which case the non-linearity issue may be irrelevant.
- Other methods—You can use converted non-AI /AI lenses with ALL metering and exposure modes. However, we advise against using it in P or S mode, as both these modes allow the camera to set aperture automatically. Hence, the possibility of engaging F-stops across a wide range is more likely in these shooting modes. Once you have gained some experience with your lens, M mode can be very useful because you will know exactly how much to compensate for exposure variance when you set the F-stop relative to indicated exposure on the camera’s metering scale.
- Shoot RAW and correct in post—If you shoot in RAW mode, you can often correct the variance in exposure during post-processing as variation usually falls comfortably within the exposure latitude of RAW file headroom. This method is best if you use your lens within a 3-4 stop range. Beyond that, some compensation may be needed — but that is lens-specific. (We will be adding some images here to show exposure variance and post-processing correction). Pro CPU and Pro Nikon body with aperture input enabled If you have a D7xxx or above Nikon, you can specify our Pro CPU and set your camera to aperture input in the camera set up menu. This will “linearize” exposure for lenses older than AIS and produce consistent exposures across the entire F-stop range.To put exposure issues with pre-AIS lenses in perspective: we at Legacy2digital shoot with all of the manual focus Nikkor lenses, going back to the earliest versions, and do not find the exposure inconsistencies with pre-AIS lenses to be a problem. This limitations are easily and quickly worked-around, and then mostly ignore in daily use, especially with RAW format. With the Pro CPU on a pro body, this is a non-issue and most of us prefer shooting with aperture ring input enabled.
- F-stop control uses Command Dial—On cameras without an aperture tracking tab (all consumer level cameras, e.g., D3xxx / D5xxx) the aperture ring cannot physically communicate aperture setting to the metering system. After installation of the Digital Matrix CPU, lenses must be set at minimum aperture in order to operate. F-stop selection is made using the Command Dial, unless a pro level body with Pro CPU is used. Even though pro level Nikons have additional options for lens-body communication, our standard CPU conversion requires use of the Command Dial to set aperture; with Pro CPU and the camera’s set up menu configured to allow aperture input directly from the lens, class mode shooting is possible.
- Potential underexposure bias using aperture ring on lens—This is a known issue (some might say a “feature”) with any digital Nikon body, whether the lens is manual focus using the camera’s non-CPU lens database, a Digital Matrix CPU converted lens from us, or even a current autofocus Nikkor such as AF / AF-D (but not G series lenses): setting the aperture from the lens may result in some degree of underexposure. We have reason to believe that Nikon designed an under-exposure bias into its DSLR metering systems. The bias is invoked when the camera “talks” to an aperture equipped lens (again, pre-G). The purpose of the bias is to avoid blown highlights (film cameras, for which all pre-G lenses were designed) are not nearly as sensitive to over-exposure, especially with color negative film). Further, we believe that Nikon chose an under exposure bias with film-era lenses on DSLRs because mechanical exposure control is less precise (compared with G lenses), and hence more vulnerable to the inexactness that could lead to over-exposure. In our testing with numerous Nikkors — manual, AF, and AI-P — we find a range of exposure set points from normal (no bias) to -2 stops. This is easily detected and eliminated through +/- compensation, deactivating Active D Lighting, and or switching from Matrix to Center-Weighted metering. We have also found that using the Command Dial may reduce under-exposure bias with some AIS lenses (but pre-AIS lenses using the Pro CPU on pro level cameras are better served by class mode / aperture input from the lens).
How do I choose a lens and where can I learn more about Nikon manual focus lenses?
You will find many sources on the Internet, and a wide variety of opinion. Some sites have taken a special interest in manual focus Nikkor lenses. You can also ask us: we have used most of the Nikon manual focus (and AF) lenses. We also offer a wide range of Nikon lenses for sale (ours have the advantage of careful inspection, refurbishing if needed, and a Pro CPU, included—see our store for details
It is important to note that several factors go into choosing a manual focus Nikkor lens:
- Does the lens compliment your current system? There are many fine single focal length (prime) lenses that offer distinct advantages over standard, especially the consumer level, zoom lenses. Advantages include, smaller size, much better build and tactile feel in the hand, and faster speed (larger maximum aperture). Often the optical results are better, but not always.
- Cost savings for ‘high end’ zoom and telephoto lenses: There is a good number of fine zoom lenses from the legacy line-up, and some of these cannot be easily replicated in an auto focus model for a reasonable cost. Super telephotos are another category where cost savings are possible.
- Whether you are purchasing for DX or FX format. Most lenses have better optical performance in the central 1/2 to 2/3 of the image field than they do out to the corners. This limitation with edge resolution is much more evident with FX format. The best Nikkors perform well out to the edges, but usually they must be stopped down 2-3 stops for optimal performance. Lenses that do not have great corner performance may still be an excellent choice for DX and still be usable on FX.
- Target lens / body size factors. Manual focus lenses offer the possibility of creating a compact “kit” for travel, hiking / backpacking, and street photography (esp. useful for zone and focusing, where auto focus will attempt to refocus after each shot).
- There are a variety of sources on manual focus Nikkor lenses. A Google search on “nikon lens review” brings up these sources, among others.
- As with all mass produced lenses, keep in mind that sample variation may affect the optical performance of a given lens; some times reviewers do not take this into account and pick or pan a lens based on a single sample.
What about zoom lenses — can they be converted to Digital Matrix?
YES. But zoom focal length setting is NOT communicated to the camera body or to EXIF data. You must select a fixed focal length for your zoom lens EXIF data. This could be an intermediate focal length between each end of the range. This will be programmed into the Digital Matrix Chip and appear in the EXIF focal length data field.
Examples: 70-210/4 Ai-S Series E Nikkor may be programmed, for instance, as a 135/4 lens. This is just an example: you may choose for us to set the focal length at some other point in the range (but this setting is not user-changeable once we have installed and programmed the Digital Matrix chip).
What if my zoom is variable aperture, can it still work?
These lenses will work perfectly well with our Digital Matrix Chip. However, we must specify a specific aperture. Matrix conversion does NOT include tracking of zoom focal length change OR change to maximum aperture. The best zoom lens candidates are either constant aperture or those whose aperture changes 1 F-stop or less.
Nevertheless, most of these lenses do not change more than one F-stop throughout the zoom range. Therefore, choosing an intermediate maximum aperture provides a good solution to variable aperture lenses. This means that the correct exposure at either extreme the zoom range will only vary by about 1/2 an F-stop either side of the F-stop we set. We consider this an acceptable trade off for the benefit of working with manual focus Nikkor zoom lenses.
A manual Nikkor zoom lens will meter and confirm focus in the same way as a contemporary AF Nikkor, but only a single focal length will be communicated to the camera body and written to EXIF data. You may choose the focal length that is programmed to the lens at time of conversion (we recommend a mid-point of the zoom range and mid-point in maximum aperture, if the lens is a variable aperture zoom).
Note: the Nikon database on pro level cameras does NOT provide for variations in maximum aperture either. There is no way for a Nikon DSLR to “know” more than one maximum aperture of a Nikon manual focus zoom lens. Practically speaking, this is a minor issue for the user, who may simply dial in compensation when zooming to the longest or shortest end of the range.
What about third-party manual focus lenses, such as Rokinon, Samyang, Voigtlander, Zeiss, Tokina, Tamron, Vivitar, and others?
There are many fine quality third-party Nikon F mount lenses that produce stunning results on Nikon digital SLR camera bodies. Legacy2digital offers conversions for a good many of these as well. Just let us know which lenses you would like to convert, and we can inform you of feasibility and pricing.
Can I purchase a CPU kit from you and convert my own lens?
While some lenses may be relatively straightforward to convert, the majority have a variety of issues. These include the need to modify the lens mount using special jigs and machining tools to ensure a precise fit of the CPU, reconstruction of light baffles, and accurate radial location of the CPU to avoid wear on the camera-side contacts.
We considered offering our chip as a do-it-yourself kit. However, when we reviewed our lens mount database and the variety of installation challenges that we have encountered, we saw a significant potential for being overrun with user-support issues. Plus, inexperienced users could permanently damage their valuable if not irreplaceable Nikon lenses, have difficulty reassembling lenses after conversion, or achieve less than desired results. We do not want to assume responsibility — or liability — for these kinds of difficulties.
For customers intent on “chipping” their own lenses, there are companies offering chips. However, we strongly advise that you carefully review the experience of others who have attempted to convert their lenses and determine the process and modifications that may be involved in converting your lens.
Do you work with international customers?
YES, if we can communicate with you in English or Spanish, or use a translator, we will accept an order from anywhere in the world. We have made special shipping rates available from our international customers to make our services affordable.
When you ship us multiple lenses for conversion at one time, you can save money on return shipping and insurance. Ask us about our volume discounts.
What are your lead times?
We have experienced a strong demand for our services, which is sometime seasonal. The conversion process requires time and close attention to detail. Our average lead time is 2-4 weeks. However, if you have a special need for a quick turn-around, please let us know and we will try to accommodate you. We do offer an expedite service—but we generally prefer to accommodate customers who need conversion quickly, without additional charge.